[Music] Michael Gooden regional a glare care
facilitator for River area or the loan services and we recently held a workshop with job Williams he's a psychologist
based in North America in Canada the presenter today talking about his
benefits in the science behind multi-species cover cropping hope you enjoy this presentation
you
pleasure to be here and thank you Michael for the invitation to come and speak so I am based in Canada at the
moment I much of my I'm originally from Brisbane but I and worked here for a few
years and then I've actually lived abroad ever since so it's been a lot of time in the UK and working predominately
throughout Europe and a couple years ago I moved to Canada I still do lots and lots of work back in Europe I'm back
there three or four five times a year and and do quite a bit working in there
throughout Canada as well so that's probably where I'm most active and so I do bring a bit of a northern hemisphere
perspective in a sense and so consequently some of the information that we're going to start with through
the lecture side of things will be of a general nature but we're going to prophecy the gear to focus today on
cover crops so I'm and I have a bit of a big passion around soil so really we're going to talk and link a lot of the
discussion around cover crops back to soils and soil health so that's going to be really the core of the focus but the
intent then will with the panel discussion this afternoon is then we will or afterwards we will then we
obviously will get a little more applied we'll talk about some of the practical application but also bring in some of
the regional and local context here you know things are obviously very specific and very different here to how it
operates in Canada and Europe and so this is that will be the point of the panel there will try and take some of
the broader learning and the principles perhaps so to speak and will and then
apply that through through a local discussion so that's roughly how we're all kind set out the day for today that's my
website and Twitter if anyone's on Twitter feel free to have a look at that
so I guess in the format for today what we're going to do topics that we'll cover we're going to start with really
just a pretty broad overview and introduction on cover crops you know what they are why would we use them some
of the benefits and then we'll kind of we'll really do the how through the panel this afternoon so we'll kind of
discuss well it's up to you to kind of steer the panel I've got some kind of thoughts there and we'll talk about some
seeding rates and species selection the seeding dates some of these kinds of things timings bits and bobs there but really
let's make a discussion based you know let's so have a listen to the lectures and then really it'll be great if you
can steer the discussion I'll facilitate and we'll steer the discussion in the panel but I've got a few things in mind
that I'd like to touch on but very very keen to hear from you guys as well so that's really that'll cover the house is
around the panel discussion and then we're going to do another lecture also just around the benefits of plant
species diversity so specifically looking at this transition away from monocultures and what happens to sort
chemistry's or physics or biology what happens to insects to disease to weed pressures what happens to solar ganic
matter when we begin to transition away from monocultures towards more plant
species diverse production systems now and I'll throw in some examples there around even companion cropping
intercropping you know even that little transition from one to two species indeed even that
small step actually starts to have big impacts on some of the so properties disease pressures and these kinds of
things and I'll share some some studies around that with you all so that's going to be that second lecture so Basics
around cover crops specifics into diversity and then we'll have a bit of an overall kind of panel discussion
there could I just get a quick show of hands perhaps in terms of who's in the room here is just John Titor who's got
livestock and things are not so anyone who's exclusively cropping just a
picture of hands and no livestock just cropping okay there's a small number so who you would be mixed cropping and
livestock okay be nice and so any of you just livestock okay also quite through
to okay so that's that's a pretty good mix you've probably got about 50 mix a half or so mixed up or so livestock and
a handful of pure properties actually that's quite interesting usually it's the other way around
usually a dominance of crop that said ok I wasn't man anybody here organic is
anybody organic in the room ok brave
soldier in the front here ok awesome good well yeah that's a topic for
another day but some of how with our traditional definitions I think of things like that the classical divide of
organic and conventional seems to be breaking down these days there's so much fascinating stuff happening in the middle ground you know whatever we want
to call it regenerative agriculture or what but there's a lot of really fruitful collaboration and interaction I
see happening in the middle we're kind of both sides are moving into the middle it's quite interesting what's happening in the world of kind of soil
health these days but anyway that's a topic for another discussion okay so as
Michael said we're happy to share the video so and I can also share a PDF of
the slide so if anybody wants the slides and things in a note format also happy to circulate that around with so don't
feel like you have to write down everything on the slides but you do have to write down everything I say okay all
right okay let's dive in to cover crops so really I thought I'd start by saying
a few quick slides around photosynthesis let's just talk a little generally around photosynthesis this is obviously
how plants grow and this is going to be understanding that it's going to help us then steer and lead into the discussion
around how we're going to use specifically cover crops and their photosynthetic potential to help kind of
drive fundamental kind of changes in in soil health etc so it starts with this
very simple little equation photosynthesis and it's this idea of course the plants are breathing in that
carbon dioxide and taking up water and they are stitching back together to
build carbohydrates chrno they've got those three key ingredients that they need to then bind those together to form
sugar the very first glucose the very first product of photosynthesis get from
that building block that little that little sugar molecule and they can build their plant biomass they can grow and
build their roots building more complex carbon compounds from that building block growing shoots growing roots using that for energy
producing flowers producing seed fruits etc etc so really it all comes down
everything stems back to the core of this simple little equation here stitching together taking in carbon
dioxide and stitching back together into into chemical energy in which the plant
can use now as much as the plants are growing and this photosynthetic process
is driving what's happening there's also another key ingredient that the plants need in order to drive this process and
that is minerals it is the nutrients that essential macro and micro minerals is so yes it's energy air water and
nutrition and it is those role of those macro and micro minerals the essential
plant nutrients which also then help to catalyze that process of photosynthesis we can't do it without minerals they
have also helped to drive plant growth drive from biomass production by
catalyzing that little photosynthetic equation that we see here so we also need the minerals now if we take that
nice kind of simple concept here as you can see here an emoji speak here and let's put a little more detail into it
I'm saying the exact same thing but just a little touch more detail there again really again it's it's the key role of
carbon dioxide and water and then those in the gold rear the minerals and it's those minerals that act as as I say
catalyst or they're part of these enzyme systems simply just means a catalyst that they will then help to stitch
together and build that sugar molecule and of course produce oxygen as a byproduct for us and then it's the plant
again requiring nutrition to then take that building block and then bill
whole lot more complex and diverse carbon compounds inside its body so it
starts to stitch together that little simple sugar it starts to stitch it together to build more complex sugars
more complex carbohydrates it'll start to link in some nitrogen and sulfur forming little amino acids linking those
together building some of our protein that we're also generally trying to chase in terms of improving quality but
a whole host of other plant-based compounds are also synthesized from that building block fats the cuticle oils
waxes lipids hormones vitamins pigments ena colors smells aromatic compounds
these volatile are going to come out all sorts of smells and sense these are also again byproducts of photosynthesis other
protective nutrients defense compounds protective compounds defense chemicals
and also root exudates so point is to say that all of these various diverse kind of plant compounds
that that the plant builds as part of its biomass but although these other various covers and tastes and flavors
sense all these other things always other plant compounds they're all products of photosynthesis and again
none of these can be produced without the minerals the essential plant
nutrients that catalyze this process so if we have a mineral deficiency in the
soil this process will be held back will be limited and so we've got to address
nutrition now that's actually funnily enough part of the reason why we use cover crops in the first place is to try
and free up nutrition for access minerals from the soil unlock them make them available bring them up into the
biomass of the cover crop and then return it so that for the benefit of the following cash
crop yes so funnily enough what we're trying to achieve is enhanced nutritional availability through using
for growing plants for the next cash problem okay so that's the core of the
idea now when plants grow and produce this various biomass there's three core
elements as three core components that then get integrated back into the soil the three core pieces that we need to
manage components that we need to manage for the cash crop benefit and that's your shoots roots and exudates and we're
going to do I'm gonna tease out more of this concept as we move through the rest of the lectures so we've got shoot
biomass Oh above-ground litter is one part of the fraction we've got the roots the actual root biomass and then as
those plants are growing they photosynthesizing they are excreting also carbon compounds they're excreting
these root exudates sugars and carbohydrates and all sorts of other compounds out into the soil and so it is
these three pieces of the puzzle that bring the benefit of cover crops is reshoots and exhibits and they're all a
little different and we will talk a little more on each of those so it's not
that plants only breathe in carbon when they photosynthesize they also release carbon and they do that through these
root exudates now the traditional view of reaching root exudates focused on
things like organic acids so various kind of there's all sorts of different
organic acids hydrogen and acidic compounds that the plant will leak and excrete out
of the root system and the kind of classic soil chemistry dominated view of
soils looked at that and said okay all the plant is releasing these acids it does this to acidify the soil to
solubilize to scavenge nutrients from the soil so we see this direct solubilization where those acidic
compounds those assets will soluble eyes minerals release them and make those nutrients available for the plant to
take up and of course when the plant takes up those minerals well then we use those minerals as catalysts for
photosynthesis to grow biomass as we were just looking at so again nothing
wrong with that that's that's exactly what happens however it's just so that's kind of half the story plants don't just
scavenge minerals from the soil through these organic acids they also release a
whole suite of other root exudates sugars carbohydrates amino acids food
sources raw food sources to feed microorganisms and it is those organisms
the biology of the soil it is those organisms that also can play a role in
solubilizing nutrients and releasing nutrients and delivering those essential minerals back to the plant so the plant
does directly soluble I it's from the soil but it also feeds biology and let's
then do the work and and this is an important nuance because the again fact the classic kind of meal was very
focused in this one side I've just said had this very chemistry cut narrow kind
of view now we see the big a bigger picture that there's this whole living world of so biology that that also play
a very important role in accessing and scavenging nutrients now yes the plant
can scavenge nutrients from the soil itself through those organic acids
however the microorganisms in the soil if they can do it much much better much
much more efficiently they have many more tools in the toolbox the plants have a certain set of tools that's its
various root exudates that's the tools that it has in which you can scavenge nutrients because the soil microbiology
particularly exists in such vast diversity tens of thousands of different species of bacteria and fungi so
particularly some of these microorganisms well with such diversity of organisms brings such diversity of
tools or strategies to scavenge and solubilize minerals so the point is
microbes are much more efficient much more effective I have a broader array of strategies modes of action to access and
unlock the soil nutrients so that's why the plant will invest in them and that's really the strategy but we're also
trying to employ it through cover crops it really becomes a question how do we manage plants and how do we manage those
cover crops to help them help the biology actually cycle and scavenge
nutrients in improve that saw health so it's that's the way we kind of so consequently when
we're going to talk her about cover crops I'm going to talk a lot around about soil biology because it's it's we're using cover crops to prime biology
to do the work for us so they will they will overlap so then it turns out the
amount of these root exudates that the plants release as they're grows they photosynthesize is really quite
significant there's a lot of carbon that the plants breathe in and then release as these various exudates
now it depends on a whole range of different factors and different plant species it's there's a lot of variables
here but here's some kind of ballpark guideline numbers for you just to illustrate that certainly what we do
know is that annual plants will release less than perennial plants so annual plants 20 30 odd percent of the total
carbon that they breathe in will be pumped out as these exudates whereas perennials it can be 30 up to 50 odd
percent across that lifecycle the amount of carbon being released now that's not
a static figure each and every day it's a dynamic process plants mean release
most of their root exudates in the earliest stages in the vegetative stages so in that first four to six to eight
weeks in that kind of window that's your bulk period of reject sedation in the
vegetative stage when the plant transitions into reproductive mode and
begins to focus on flowering on grain fill on size and fruit etc that's where
it will prioritize sending carbon sugars etc into that developing branch so that's
where the root exudates get turned off okay the tap gets turned off their andhra tech station slows down so across
that whole life cycle these are the kinds of numbers in its in the early stages it can be as much as 80% of the
carbon that they're breathing in will be released but then as declines over time so cross that life cycle is what these
numbers are are kind of quoting so anyway either way the point is to say that the numbers are quite significant
whichever way we look at them I mean why wouldn't the plant just keep some of that carbon well I wouldn't have to hold
on to it and grow more root system produce more tillers it fillmore grain
size more see well I wouldn't keep that carbon for itself my nose would have been excreted and just give it away
because it might look like a bit of a waste at the face value but indeed it's a very valuable investment it's the
plant investing in those microorganisms investing in the soil biology to derive
that nutrient cycling because the plant knows that the biology can do it much more effectively with a broader set of
tools and then the plant can directly itself so that's indeed why the plant
will invest so heavily in it so these root exudates these carbon kind of compounds are an
important aspect in the dynamic between plants and soils and plant the twin
plants and microbes it is the root exudates that is the link between the world of plants and the world of the
microbiology it's the root exudates in which how they communicate how the plant communicates to microbes ever written
it's not just about sugars it releases all sorts of other chemicals in their musical kind of communication chemicals
signaling molecules the plant will also send various messages out into the soil microbiome telling the biology to bring
certain things back I need some zinc bring me some zinc I need some copper you know whatever it might be so the
root exudates they are raw food for the biology but they are also tools these
signaling molecules communication chemicals so there is important link
between what plants do above ground and what microbes do below ground and that link is through these taxa dates okay so
that's in a nutshell a super quick tour of photosynthesis and just basic plant
growth okay so it's about growing plant biomass but it's also background root exudates and the key thing is we need
the minerals the essential macro and micro minerals to catalyze that photosynthetic process to make that
whole kind of thing work so let's then move on to talk about then managing
specifics stands of plants I cover crops in order to help improve soil health and
drive some of those various kind of interactions so what is a cover crop well I guess the key def part of the
definition is is it's generally a plan that isn't harvested now you can harvest
them and we'll come to this in in various ways but generally the definition would be it's a plant grown
with the specific intention of protecting or improving some kind of
element of your production system of that Agri ecosystem how many we might say well it's there to protect him feed
and the soil is often one of our core focuses and rightly so but actually
cover crops bring all sorts of other benefits as well in terms of the wider water the hydrological cycles and the
water systems order infiltration or recharge these kinds of things they can also have agronomic benefits we can also
do it with the intention of improving yield improving quality improving nutrient use efficiency there are some
economic reasons while we might specifically grow a cover crop and there are also some other reasons for the
wider ecosystem for the ecology growing cover crops to support wildlife
pollinators predators these kinds of things so we'll tease out some more of these examples as we as we go forward
but the core is the idea says ok it's not something that we're harvesting is on a cash crop per se but it is
something that we are growing in order to improve the system so what kind of
plants can we use as a cover crop well the list is endless actually and by no means is this an exhaustive exhaustive
list this is just a few examples there's all sorts of different plants that can
be used and indeed there's all sorts of different plants that should be used part of the benefit of cover crops when
we start talking about cocktail cover crops or the diverse cover crops is that all of these very different plant
species well they all have different growth habits they all have different root biomass productions they're all
different species they release different types of root exudates so what we're trying to do with a
diverse cover crop is actually trying to get a selection of all of these so that we are hedging our bets so to speak
we're stimulating different and various aspects of the sort function through the
is selected and targeted music different species so you know for example ok legumes they're going to help to bring
nitrogen into the system ok and obvious benefits so if that's the goal let's design
heavy cover crop mix I will say our monocots since they are grasses in
particular of course they produce a lot of root biomass that the fibrous root biomass and that's really a great source
of material to build soil organic matter if that's the strategy so we might lean a little towards some of those grasses
some of the cereals of course good quick to establish quick soil protection if that might be able so the goal and then
we have arranged different kind of broad leaves as well I mean a lot of the brassicas of course they can bring the
various kind of biofuel again time benefits that they can bring but we have all sorts of other examples here that
also functions for that for example you
know phacelia a buckwheat is great for phosphorous scavenging for Celia the bees love it you know so you've got all
these various different particular functions of the plants and therefore the goal of the cover crop is okay you
could do a monoculture cover crop it is a perfectly fine scenario if you're looking for a very specific function
there's nothing wrong with that let's say you do want to access phosphorus well let's go for a cup a cup of
buckwheat okay that's perfectly fine it's just a destined benefits in it and and by the end of the lecture parts this
morning when we talk more around plant species diversity it's just that there are some benefits when we start to bring
more diverse root systems together there's a synergy there there's a 1 plus 1 that equals 3 they can start to
interact with each other in different ways in which a monoculture root systems interact with each other and there are
some some synergies some benefits too in doing that so you can have a simple
mix could be one species could be two or three or four that's fine some people like to go right out and go
up to ten and fifteen and onwards and 20 I don't have any it's hard strict
opinions about this I think generally do what works for you and within the budget what seed you can access affordably etc
and try and be as diverse as you can I think is my kind of general interpretation of that so so anyway this
is just a bit of a selection there's are many other plants that you could use but perhaps these some emerge as some of the
kind of the key key species that might
be of choice now this is a also an equally image here looking at kind of
breaking down some of the different cover crops into some of their functions it's I should stress it's not about
having diversity per se diversity for the sake of diversity you really want
functional diversity is the key so you know you wouldn't say well I've got ten
different varieties of votes and that's diversity okay they're all loads but again a little bit of rifle diversity
can be a good asset to but you might say well I've boats and I've got triticale and I've got some Bolly well you know
they're all quite similar all cereals they're all you've got some different species but they're all having a similar
growth habit bringing similar benefits you want some cereals you want some grow
later you want makings one functional diversity is it's not obviously for the person per se
for the sake of it so we can look here and then as you can see from the slide here we've got a selection of again some
grasses broad leaves and some legumes and we can also divide that into cool season or warm season kind of species so
this is really again a nice use of a chart to help select so you know
obviously are you going to be growing cover crops in the summertime you're gonna be doing it in the wintertime then you're going to be leaning towards
choosing from the warm species for the summer sub covers and you might be
leaning toward some of the cooler species for winter covers or other companions so you know it depends on
your time of year and what you're trying to do but equally you know here in
Australia say where we are very we doing most of our cash cropping during the winter time so you know that leans us
towards a lot of c3 type plant species where a very weak dominating kind of system there are benefits to kind of
breaking out of those temperate species and intentionally including some more tropical some kind of more warm species
plants because they're different see Falls are different from C threes and so what you're trying to do is again
increase the diversity we have a lot of temperate dominated production systems so those benefits of trying to bring
some of these wall species they have a different type of growth habit different types of root
exudates that they release uniquely and so there's benefits to bringing some of those into a kind of a very temperate
kind of dominated production system or vice versa if we were the other way around so okay that's just again you'll
have this on your slide but that's just a nice selection of opportunities there of species to to choose from and again
you want some grasses want some cereals we want some other legumes and some of these other broad leaves and we again
perhaps want a mixture of warm or cool species again more and more diversity that you can design into the picture of
the better it's just it's a really important tool but it kind of hedges your bets so okay well which species
well where do I start you know which ones and it really depends on what's the goal you know what are you trying to
achieve that's going to help them narrow down the list of species is to who you
might choose which ones you might choose so are we trying to get some free nitrogen and now we're trying to
increase the nitrogen fertility of the soil are we are we aiming for phosphorus scavenging phosphorus release so we're
trying to free up some of our phosphorus reserves are we trying to capture nutrients are we trying to suck them up
there did we over apply fertility with their basement fertility stool in the
soil can we suck that up in a closer to cash crop Club crop total
harvest cover crop to capture some of the nutrients that may not have been used by our cash crop so similarly
nutrient cycling are we trying I guess that's a bit a little bit like a phosphor peer Elise are we trying to release or unlock or access some
nutrients are we trying to depress disease are we looking for pests and disease kind of benefits there to that
cover crop I would try and encourage support the ecosystem so encouraging pollinators predators these kinds of
things we may be looking for goals around weed suppression and we're trying to smother weeds we might do some very
aggressive competitive species consequently is our strategy to is our goal to increase all organic matter and
then that might stood in which species we choose or are we also looking for maybe some other so functional benefits
compaction alleviation for example so we might want to choose some deeper rooted species particularly there to help get
down and it's maybe some subsoil or subsurface compaction again so you know what is it
you're trying to achieve because that is think about that question to start with that's what's going to help you think
and design will select the species that may be best for for that particular
cover crop okay so then that that's why then well often we're looking for multi
functions army we're not necessarily looking for just one of those things the record might be many of those things on
that list I guess so that's why then by default we start feeling a little towards this idea of
these diverse cover crops using these mixtures versus a monoculture and yeah I
mean a picture of says a thousand words you know and you can see very clearly why here we have different species
different plant growth habits some more upright some more prostrate some deeper
rooted some a little more shallow rooted we've actually got a lot of synergy going on here within this diverse
mixture and actually that can be actually a lot less competitive you know
often we might look at that and think whoa look at all those different competition look at all those different species aren't they competing with each
other surely this nice monoculture here over on the left surely this is this is efficient means
the most efficient opportunity here everything's the same we can manage that we can get the timings right you know
this has been kind of the mentality of production agriculture this this kind of dominance around the idea of we want any
working uniform everything to be the same and undoubtedly there are some
benefits in that there are some very practical benefits that make managing that crop easier but
I also kind of look at that and I see a lot of competition there too you know
there's a lot of competition in that monoculture yeah traditionally we look at that as a cropper to look of course Brad any of the weeds they're gonna
compete for moisture compete for nutrients get rid of everything else let's just keep everything the same but
when we do that I mean look at those root systems let's start here you know those various root systems of this
monoculture because it's a monoculture it's all the same species it's all the same variety usually - I really really
narrowing down that I look at all of those root systems well they're all exploring the same volume of soil
actually see I I see have some competition there they're all competing for the same volume of soil because
they're all the same I mean here we have some deeper to see we have some shallower areas well those roots are
scavenging up there and these are it's a scavenging down there actually I see less competition in that sense well what
about the timing of that farm they're over on the left I mean it's all flowering all at the same time as well
it wasn't flowering few weeks ago won't be flowing in a few weeks but right now it's flowering well that means every
plant is needing the same nutrients and required for flowering all at the same
time as well one small example let's say boron in bonds are important for pollen pollination and etc so now you've got
all those plants flowering at the same time so they're all scavenging boron at the same time same nutria at the same
time all from the same volume of soil I can't look at that I do see a lot of
competition over there on the left there are definitely some synergies to be had when we go more diverse different crop
stages different species different growth habits different space for competition different root structures
different species also means different root exudates in different plant species
is releasing a different fingerprint a different cocktail of those chemicals that are in those root exudates and
that's what's really important about these diverse mixtures is that with more
plant species diversity we have a wider range of tools a wide range of root
exudates in which we can communicate to the soil biology which we can actively
engage with recruit turn on you know access send various commands to them and
get the biology to do what the plants need I guess so you're simply increasing your array of tools when you transition
from monoculture to more diverse mixtures because now we have a whole new
set of tools a whole new set of a more diverse set of exudates that can do more to the soil
biology than just one set of root exudates one set of communication tools
okay so there's this obvious repeat reasons why we might transition
now you might again it might depend on your goal if your goal was nitrogen fixation we couldn't make the argument
that would say well if your goal was I need more energy in the system well sure maybe you'd be better off doing a
monoculture overlay kit shortly you might get more nitrogen into the system through that way but like I said before
I think a practical level well we usually are looking for many of those benefits many
of those functions we're not often looking for just one of them so I think you just you know again not opposed to a
monoculture cover crop they have their place but hedging your bets not knowing if what this is a season gonna be a bit
moister than maybe dryers and maybe a bit hotter than we cooler which of the switch of the single species do I go for
is it going to love those conditions that are coming well I don't know what's coming so a hedge my bets get more
diverse and you encourage at least something will will grow through that season so again it's a risk management
side of things I invested is not a right or wrong answer to that it just how you approach it so of course plants can be competitive
as well and they can be collaborative and again that's that point you know we
look at that monoculture and weird thing on any other plant is that it's going to be a problem let's get rid of it the
reality is it can go either away maquette plants can be competitive or they can be collaborative and it really
just depends on what the plant species are some work well together some don't so we have to design for that synergy if
it is designed for the collaboration over the competition of course these can
compete it's not to say that always more diverse will always be better it needs to be carefully kind of thought out and
designed but here's an example here illustrating this is from the US this was in a this is from 2006 this was in a
drought year that they had and this was a cover crop trial of looking in some single species and we're looking at biomass production here you can see each
of the various kind of single species there versus kind of a cocktail mixtures and you can see that as soon as we add
more diversity into the mix we got a much more greater biomass production now
what we're looking at here is this of that kind diverse mix is a full rate full seeding
rate of that cocktail mix and here's half a ceiling rent so indeed you can
see as we cut the ceiling right down as we use less of the of the various
cocktail seeds you can see now I have a pointer but um you can see at the top
there we've got a little bit more biomass production with a little bit increased biomass production by using a
lower seed rate okay so that is highlighting right there that little difference that inch or so at the top
there I can't point to it but that little inch or so at the top that's your
competition when we lowered the density when we lowered the seeding rate so we
can used off the competition we've got an increase in biomass so indeed there was too much competition there as we
lowered that cigarette we did indeed get a little increase environment that's the effective competition however that
little increase that we got you can see there all that little decrease we got from into the more heavier seeding rate
is a fraction of the game that we got the collaboration that we got from let's
say on average somewhere around about here is to get up to that you know that was your that was your collaboration
effect that was your competition effect so again again it can go either way but
again if it's designed for accordingly there are synergies to be had your
cocktail makes easy to smile it's it is a mixture of those and some
others yeah it wasn't exactly those same ones but it was it was a general mix that they used that includes some of
those but also some others yeah okay so it is both competition is a factor yes
but so it's called sales collaboration okay that it can work either away and I think tradition that we've had a very
competition you know blinkered view of things it being so focused on that
competition we've missed being a little blinker there we've missed the opportunities for collaboration and now
we're looking at plant species mixtures with fresh eyes you know actually there are innate opportunities for for
improvements okay and here's another example here we're looking at monocultures on the left-hand side and
then we're transitioning to some mixtures some public cultures over on the right-hand side so over there on the
left there you can see this is a this is a tillage radish this is a daikon radish
type thing that is in a monoculture and then we've added a few extra browsers and legumes here on the right-hand side
and you can see that there's a distinct color change I mean it looks greener on this side it looks a little more paler
on the side where there's the monoculture what about down here is we have some oats down the bottom here of a
monoculture as soon as we add a few more legumes into the mixture there well you can see again well well not only is the
color changed from being paler to a little greener but look at the growth stage of the oats you know that the oats
are more advanced we've also changed that dynamic there you know again
shouldn't these be looking worse on the right-hand side there's more competition I shouldn't things be looking a little
worse shouldn't these be looking a little better you know nice perfect either then well again just a little
example highlighting that with more diversity there can be a synergy at play
there okay so why have to then use some
cover crops why might we do a water some of the benefits in which we we might see
and as I touched on there earlier we might think about this in a soil context in a water context agronomy and and
ecology so from a soil point of view things like so protection emerges as a big an obvious one you know we're
protecting that soil from B that the Sun you know trying to conserve some moisture but particularly from erosion
you know we're gonna see it as we already see now you know heavier rainfall events when windier conditions
wind storms these kinds of things so wind erosion soil erosion you know the first the first manager has to be do no
harm you know keep your resource where it is so that the soil protection is a big and major first benefit of of cover
crops so function and we might be intentionally with the goal of trying to
increase the soil function or the sole quality in some way so what is the function of the soil the function of
ability to provide nutrients to provide moisture to the Croft provider a growing medium what cover crops can help make
nutrients available how to access water etc in which we can therefore improve
that sort of function so health would be another one again a bit of a hot topic these days however we
might define soil health but you know things like the chemical properties the physical properties some of the
biological properties all of those things can improve and what that's what we've been exploring in the lecture -
and maybe Saul organic matter definitely as cover crops can help us build sort of
anak Matta and we'll talk more to that now - so water things like water infiltration and drainage now that's
that overlaps a little bit with agronomy there you might want to improve your water infiltration from a cropping point
of view but we also want to do it from a landscape point of view from an from an ecology point of view helping to hydrate
the landscape prevent you know obviously water runoff and erosion etc equally we want to keep
nutrients in the soil rather than leaching through or keep the soil keep the sediments there in the field as well
rather than sedimenting and increasing turbidity of out of our water streams
etc so you know there's various water related reasons water use deficiencies for the crop would be another one there
is kind of water related reasons or benefits to using some cover crops okay
from a cropping or an agronomy point of view or let's let's think about it in
that context okay we might want to increase our fertility and that's good for a pasture production that's good for
our cropping production of course we need nutrients we need fertility to grow
that plant biomass that can also cover crops can help us improve nutrient use
efficiency so when we start to access and unlock minerals from the soil make
them available well that means we're going to need less fertilizer need less inputs
yes that's going to be strategy to improve your nutrient use efficiency okay if we have Anna grace cover crops
we'll talk about this briefly at the end of the session there's some obvious benefits there from a forage point of
view for the livestock and we can also grow cover crops to help suppress pests
and disease particularly you know smother out weeds but also those more
diverse mixtures are and I'll share a very interesting study on this in the second lecture these more diverse
mixtures are less attractive to insects less attractive to disease you know when
we have a monoculture there if the disease comes through if that monoculture is susceptible well of course it's just too easy for that to be
spread for that disease to spread through that monoculture as soon as we have a more diverse mixture well it's
so rapid for that pest or that disease to spread through it's just an obvious
there are certain benefits to monocultures undoubtedly but there's some serious Achilles heels to it as
well that being one of them it is the design fault of the monoculture that makes it more prone to disease makes it
more prone to pass that's simply a consequence of that genetic uniformity if that plan is susceptible then they're
all susceptible and that means you see your rapid spread throughout so you know
there's there's economic benefits in terms of our dependency on helping us to
kind of another integrated tool helping us reduce our dependency on say herbicides and and other pesticides then
benefits for the while or ecology for the wider landscape are we creating habitats for beneficials pollinators etc
helping them to give them habitat to her then also help fulfill an agronomic
function they can be part of an integrated pest management strategy but also just generally improving the
natural capital of the land or helping the ecology provide some of
those gives us some services okay so let's have a look then at some of these kinds of things some of the benefits of
cover crops we're going to do this primarily just through some kind of a lot of imagery here just to give some nice kind of clear and visual examples
of what we're talking about okay and again salt protection really big and obvious important one as soon as that
soil is covered it is protected from the elements be that rain be that for the
Sun you know be that wind etc etc and there's a very nice clear example
they're just some simply some dry grass understanding under some maize you know it's just such a simple easy strategy
and yet you know okay this is a particularly problem in many parts of the northern hemisphere where you're
going to be harvesting the maize in the autumn and of course that means autumn is coping winter has come that's your
wet season you know and this is a huge problem why the row spacings we combine on we take off that corn and we're just
left with bare soil and we're left with this or in the autumn time we're yeah in the northern industry some of those heavier rainfall events are more likely
so you know under so seeing some rye grass or any other companion bank any
problem solved I mean just total protection in that and it's so easy and yet so obvious
interestingly enough in the Netherlands as they've just passed them and you law there it's actually been
effect not just for the first year now cannot grow maize without underside
every farmer who grows maize has to underserve and of course most problems will use rye grass because it's a bit
cheaper see if they can buy but you know that kind of legislation there is I have to give an example of a good one it's
just some obvious benefits there so ok protecting the soil now when we protect the soil when we grow plants in soil as
those roots grow down into the soil those roots help to pull soil particles together and they help to aggregate the
soil so they're helping to improve the sort of physical kind of condition so and we want good aggregated soil because
that's what's going to help with infiltration that's what's going to prevent water from running across the landscape but actually getting that
water down into the soil it's directly linked to how well our sort of aggregated how well they are stuck
together forming structure forming pore space in which then water can also move
through ok so the thing is to say that one of the easiest ways to aggregate
soil take soil particles and kind of bind them together stick them together when we when we aggregate soil and stick
the particles together what we're creating is the important thing in between the AB again it's the pore space
it's the pore space in between those aggregates that's so critical to helping that water and moisture move down
through the soil now yes that's important from a landscape point of view preventing erosion but it's also
important from because that's what is going to recharge your subsoil moisture that's what's
going to help the agronomy of what you're trying to achieve is by getting more water into the soil and getting it
down where it can be stored rather than most of that running off so you know as
soon as we grow roots we start to pull sort of particles together we help to
aggregate the soil we start to clump salt together forming better structure again there's a really nice example of
some Rhino she's some some like juicy looking riser sheets there where you know soil is now clumping together and
it's that biological action of roots root exudates and microorganisms and
interacting and sticking salt particles together and get a really nice example of clumping on some riser she's there
but what they're also doing is this aggregation kind of process that you kind of see there in in those images so
we're helping with structure aggregation and when we do that well then that helps to improve the water quality that then
leaves the farm the water quality of the wider ecosystem you know so when water
runs it should be running clear we shouldn't actually be seeing sediment-laden water it should actually
be running clear when we have a proper infiltration I'm shooting for us and there's a nice
example of that and this is you know from a nice image from Tasmania this is exactly what we should not be seen you
know it's when we have those rainfall events and our soil is literally being washed off washed out into the ocean
this most precious resource that of course we need directly for production just literally going down the drain so
one of the easiest ways to prevent this is just keep the soil covered and that's that sort of protection benefit that we
saw in the beginning as well so one of them well okay it's a biological
interaction that helps with this aggregation it's the role of roots exudates and biology and that's been one
of the big benefits of cover crops is we feed sort biology all of those various microorganisms the various micro
critters and all the way up to some of our larger insects and earthworms very simply they need to be fed the life in
the soil like all living organisms needs to be fed and one of the easiest ways in which we can feed those organisms is to
keep living plants the living roots in the soil because then they've got food to grow and they feed on that root
biomass they can feed on those root exudates so it's one of the easiest ways
to increase soil bottom to collectively they simply keep the so covered with living plants and diverse cover crops
have a role there here's here's a study that was just literally recently published this year already a big review
on do soil do cover crops benefit the soil microbiome and big meta-analysis so
we're kind of reviewing lots and lots of studies taking a kind of global picture so we conduct a meta-analysis compiling
results of sixty relevant studies reporting cover crop effects on the soil microbial properties to estimate the
global effects and explore the current landscape of this topic overall cover
cropping significantly increased parameters of sort microbial abundance activity and diversity by twenty seven
twenty two and two and a half percent respectively compared to those of their fellow again so across those all of
those diverse climatic regions taking a global view of the benefits of couples
across all that variation so types etc etc across all of that we see these
consistent benefits to install biological activity as evidenced by this
reason reduced data here so ok that they helped indeed they do help greatly with
soar biological properties and that's just kind of one study I'm going to share some other example
in the next lecture so we might also use cover crops to access mineral reserves
we want to unlock nutrients from the soil there are lots of nutrients in
soils it's not just about what's soluble and what's available when we talk to sort s and look at kind of extractable
nutrients what we're looking at is a picture of the more available forms say maybe what's soluble perhaps what's
exchangeable or medium-term supply well there is another pool of nutrients that exist in your source that's the total
pool it's there but it's locked up it's not actually soluble it's not available but it is there but it's locked up it's
bound to other minerals and it's there as a potential bank account it's there
as a resource you just need to unlock it and the key to unlocking that is some of
these biological interactions that's what's going to help take that large pool of nutrients and break them down
unlock them and make them available and again it's that point that microorganisms have many many more tools
in the toolbox to do that than plants do microbes are specialists at accessing
this big total pool of nutrients and this pool of nutrients can be tenfold or
more greater than what you're used to looking at on your soil test when you look at it so test into Ola on low and zinc and I'm low in Falls
whatever it might be you're looking at the more available forms of those nutrients you do need have much more of
those nutrients present in your soil they're there but they're locked up and they're not coming through in the extract
the lousy reason so the point of cover crops is that you encourage roots and
root exudates and biology to work on those soluble nutrients sorry
work on those total nutrients and make them soluble and make them more available okay so that's that's your
kind of overall overall strategy and so you know there's also just using one
example of say phosphorus here there are many ways in which we can do that we can use biofertilizers using the
microorganisms directly themselves to kind of access and unlock foes in this
example and we could use other management practices so you know supporting the organic matter growth for
example or using other various amendments that overall help with pea cycling or we can use plants in a plant
specifically they release these various root exudates that can access phosphorus these various kind of enzymes and things
so we can use plants do this these are our tools in which we can use to access
and unlock unlock those reserves of nutrients that that are there in the
soil and what about general nutrient cycling I mean unlocking saw reserves and nutrient cycling are a little bit
interlinked but we could also think of it this way is that you know when we're growing that cover crop what we're trying to do suck up any other leftover
nutrients in the soil get them up into the biomass of that plant so that then later on when that plant dies and decays
it will release those nutrients and we will time that release with another cash crop so that cash crop can benefit so we
see this kind of catch and release kind of concept where we're going to catch all of the nutrients first with the
cover crop and then we're gonna release them later on for the cash crop and we're just aligning the timings of those
rather than straight after harvest where we might have a lot of excess nutrients
well then they can be lost if they left in the soil let's suck them up into the plants and store them in the plants before being
released later on yeah so that if you next cash crop is time by feeling soon
after your cover crop is it common to see deficit geocache property later mmm
so question for the camera there but question was if your if your timing of
that into the into the after the cash box straight into another one is quite
close can we see a tie-up of nutrients if we're using a cover crops which might
then have a negative benefit for the next cash crop and and yes you're right so cover crops and that
catch-and-release needs to be managed within the appropriate time scale so so
yes in the short term what you're seeing is a nutrient loss and in turn tie down when those covers are taking it up but
then they will release it later on now the question is what and wonder which conditions in which will they release
that and is a timed for the following cash crop and so certainly we know that
if your plant is a little if your cover crop is younger a little more tender
little more juicy of course it has a lower carbon to nitrogen ratio that means it will break down quicker if the
cover crop is more mature err it has more malignant or cellulose then a wider carbon to nitrogen ratio then the
release is going to be a lot slower so it does depend on your termination of
the cover crop as - at what point it is an in scrapping cycle and its growth cycle as to how quickly the nutrients
will be released so the basic message is is that a younger more tender plant is
going to release quicker and all of the more mature plant is going to release slower so you might want to adjust your
turn turn accordingly okay
[Music] so we're going to be cycling kind of
nutrients and part of that is also preventing those nutrient losses and this was just just a quick chart from
some work done in the UK where we can see that just immediately as soon as we have plant cover you know living cover
we're looking at nitrate leaching here and as soon as we have actual living plants living cover you can see we have
a dramatic decline in overall nitrate leaching or nitrate loss so the more
cover that we get the more plant living cover of course the more nutrients they're sucking up versus say for
example a stubble kind of thing you can see over here with bear cover as soon as
we have a living plants the amount of nitrates that are lost from the system declines have a very obvious reason that
living plants will suck it up and take it up so again it's that point that the more cover that we have the better we
will see that nutrient scavenging and to then prevent some of those losses then some of the things
around ecosystem benefits of course it's about habitat it's about mixed species having some flowers and you know various
kind of plant heights so flowers are good for pollinators of course taller plants just anything that generally has
taller biomass is also good at creates more habitat for predators and
beneficials so there we can see there's all sorts of benefits to the wider ecology as well as
what's going below ground you know all of those root and root interactions helping to improve the soil soft
function they're also it's the obvious kind of benefits there's again a nice
little example there of a nice little strip through a field providing some habitat for beneficial to them do bring
in integrated pest management bringing a group economic benefit into the into the cash crop yet so some obvious kind of
benefits there improving soil organic matter might be another reason that we
would try to grow a cover crop and that's for the very obvious reason but as we all know so organic matter is very
important it's very important for the chemistry for the physics for the biology of the soil the overall kind of
soil health is that the magic bull's eye perhaps in the middle and all I'll say is just quickly on this one is that we
have this growing body of evidence that highlights that it is roots that are the more important factor in building soil
organic matter than shoots again it is root biomass its roots that make sort of roots that build soil organic matter
shoots they're more important for protecting the soil shoots go on the surface they provide that stubble
retention of course all very important for moisture conservation for protecting the soil worm food and habitat for
insects all their important functions of your shoots and your stubbles absolutely but if the goal is to build some organic
matter it is roots that are much more important than shoots in doing that so
if your goal is to build so we're going to matter you must start thinking below ground think about how can I grow more
roots that's going to be your ticket to build and sell organic matter shoots above ground biomass it makes a
small contribution tribution to building so organic matter
Roots make a much more efficient contribution there much more better half way to do it okay so I'm not saying
don't don't not new stubbles but their function is different they protect the
soil they bring all of those other benefits its roots that build organic matter so you might want to start
thinking then about varieties that have better routing systems cache cover crop
species that are deeper rodents that are bigger hunters okay if the goal is building humans design when you're
choosing your cover crop mixes choose plants with bigger root systems because it's alright and don't be lured to
looking about looking at cover don't assess your cover crops from how they look above ground you know you have to
be taking your Spade and the real benefit of cover crop is the roots it's what's happening below the ground what's
happening above the shoots is part of it and linked but the real direct benefit
is those roots so make sure you think the low ground here's a perfect example okay again it's just an example from
Scotland here but again this is an autumn sown cover crop winters closing in it's a narrow growing window they
don't have a very big growing we know so many would say well cover crops are a waste of time you know that the winter
closes in too quick everything shuts down I only had such a short window look at this piddly little biomass this was
hardly worth it you know it's a few inches tall this cover crop what a waste of time and space why would you bother
well again don't be lured into looking and focusing
on the above ground okay yes it might only be a few inches tall yes it looks a little sparse but what's happening
below-ground is what's important and yet we still have very this's same feel same day or three photos the same field same
day and yeah we have excellent route by mass going on down below there is a lots
of benefit happening here to this cover crop even if it is only a few inches tall yes so don't don't be young don't
don't focus too much of an aboveground take that thinking below ground again so it's roots and not shoot so things there
if these strategy is to build soil organic matter but ultimately it is linked to how well you are managing
plant growth how well you are managing photosynthesis driving that cycle up the top you know the more photosynthetic
potential the more biomass you can grow particularly root biomass particularly with these root exudates that we've
mentioned it's the roots and the exudates that then feed into the microorganisms and the soil as they
digest and break down the roots and the exudates they grow their bodies and their dead bodies as we now know dead
microbial bodies make a significant contribution to building soil organic matter so this is called microbial necro
mass dead microbial bodies they make up as much as half of what we consider soil organic matter is made up of dead
microbial bodies and so the question the focus becomes on well how do we most efficiently grow a microbial by bodies
and we eat most easily grow in microbial biomass and the answer to that is that it's from roots and root exudates
of better food sources to grow microbial biomass and then the shoots up so again
it's this focus on the below ground component it's the roots and the exits that then drive this microbial growth
and their death and their decay which is what then makes a significant
contribution to building so organic matter so if your goal with your cover crop is build organic matter
start thinking about roots and build around okay and then just lastly a
little bit on covers on grazing covers sorry well you know I think as I've just
emphasized if the key benefit of the cover crop is the roots and the exudates
I kind of I don't mind what you do with the shoots now if you want to keep them on the surface for salt protection
that's absolutely fine and moisture conservation absolutely fine and you should in a very dry environment like
Australia but equally if you want to break those shoes I think that's also very good use of them as well
shoots are designed to go through an animal be that livestock like this or
through an earth one both homes will come up they will feed on the shoots they will take the stubbles and residues
and drag that down shoots are designed to go through an animal digestion cow
she earth went whichever roots are designed to go through the microbial
digestion roots or the soil shoots for L so if you want to put that through an animal that's absolutely fine
by me I think that's a good use of the chute material because you're putting a an economic gain into that so humanity
I'll turn that chute biomass into so make it on economic advantage
you know sure does yeah so the question was does animals speed up the nutrient cycling and absolutely you know when
they take you so that's you know link to your question to earlier man when an animal takes that cover crop
which we might be worried about well how long is that going to take to decay is that going to start to tie up nutrients
from my cash crop well take that sheet material put that through an animal
digestion through that room and through that fermentation well of course that speeds up the digestion massively so
that then when the manure comes out those nutrients are far far more available so indeed you are very much so
speeding up that process of nutrients okay so that's that really cattle
they're providing that manure and that manure horse feeds back into growing more violent and that biomass feeds back
into producing more forage for those animals so you have to admit I notice I'm sure some of you there's a lot of
discussion about there's a whole livestock reintegration part of the soil health kind of principles and many
farmers just really are not interested and don't want to go down the pathway of livestock and that's fine I I think you can do without them you don't have to
have animals there are lots of really good soil health the other parts of the puzzles pieces of the soil health kind of principles that all help and all work
I think it's all good but I think it's rather obvious there are some very clear benefits to bringing a livestock back
from a again in a landscape and ecosystem point of view from a microbiome diversity from a speeding up
the nutrient cycling there's lots of obvious benefits to bringing them back if people can do so
that's not for everybody told you they let it go to reproductive stage harvesting no indeed so from a root
exudates point of view as I touched on before as those plants become more and more mature they're turning the root
exudates off that turned the tap off there and and it is those it is and
we're not going to have a good time for elaborate on this but it is particularly those eggsy dates that play a more
important role in feeding this cycle and growing microbial bodies and producing dead biomass to build humors that are
even more important than the roots themselves so from that point of view yes you're turning off the tap a little
when the plants become more mature then you're not getting that benefit so that's certainly if you were to if you
had livestock graze at that point in time that's a perfect opportunity to reset the clock take that biomass put it
through an animal digestion make good use of it that way but also bring the plant back to a vegetative stage where
it will keep those exudates turned on and you then this is why animals and grazing animals of course
helped to build sort of getting matter much quicker than without them this is one of the key reasons now it's not to
say that if you didn't do that or if you let those plants get more mature that's somehow that's less beneficial I think
there's still benefits to them in the root decay and there's still benefits to the to the shoot decay yes I think
you're what really what you're doing though with the livestock is just kind of speeding up the process and it is a better way to do it you're you're
keeping that plant back turning those root exudates on and it's those that were now beginning to understand are
particularly important in driving a lot of these cycles so so I wouldn't say it's a central I would say it's a waste if your plants got to mature but I think
there's there's still being benefits to the biomass decay but because there's games to be had by you
know yes a lot of people say from farm if you ask a farmer that question there
seems to be a lot of farmers that say that they really do feel that the cattle are more effective than she many you
know many of this I hear this often out of Mills out of North America and these kinds of things I haven't seen any clear
couldn't distinct evidence it says one or the other or either way I think they're they're both couldn't be so beneficial anecdotally many might say
that cattle maybe have the nones you know of course the big benefit of what cattle can do over sheep is that cattle
are happy digesting you know more complex stuff you know in so when we're talking the more mature not this example
is a good in pictures again example but when we've got more higher lignin higher carbon to nitrogen racial material
cattle are going to eat that more happily than a sheep is so I think from that point of view you're getting you're
opening up the door to better nutrient cycling of crop residues with cattle than you are with sheep you'd have to
give them that at least okay well that's my last slide anyway so that's good timing attention and then we
can have a quick discussion so really in summary all I really want to say here and I'll return to this image is to say
that as much as we like to think about this idea of soil health and concepts around soil and we're going to expand on
this now and part two around this idea of chemistry physics and biology our soil is a balance of chemistry physics
and biology we've got to bring an integrate all of that kind of thinking bring biology into the picture
absolutely rightly so a good model a good way to think a good framework to think about soils but I'd argue that
perhaps a better way is a 4-part framework that brings plants into that picture you know it is the role of
plants plant growth root growth root exudates that as plants grow in soils indeed the
presence of those plants will change the chemistry change the physics change the biology that's what we're going to
explore now in this next lecture I'll talk about the effects of plants on these aspects of a very sort function
and soil quality so I'd argue that how you manage plot how you are managing your plant communities above ground is
also having a direct relationship with how you are managing your soil below ground and that's where cover crops can
be so beneficial is that we're having a very intentional focus potential
management focus on growing plant biomass diverse biomass usually for the
benefit of building sort help so it's it's just a little bit the opposite way you know often we might say well I need
to make my soil healthy in order to make my plants healthy to make my crops
healthy and nothing wrong with that line of thinking it's just that it also goes the other way if you make your plants
healthy your plant communities above ground well indeed they will also help to make your soil healthy so it does feed back indeed both
ways there was a question that's what we're gonna get all now in imparted this is
really fascinating do you ready playin and it's so inviting a lot of the
information I've seen about it the stuff you presented that does come from an old enemy and you know they're countries
that will call twice a year in some lessons I've got Hickson moisture moisture
and in my mind what we do know if we cover crops for the summer fallow but
then we've utilized the moisture that we're trying to store what the Sun and
can you take this through and you maybe you're going to do this through some assessments that we could actually apply this so that I think you came in a
little late but um yeah no that's okay so what that's part of where the panel discussion this afternoon is is really
we're gonna do exactly that I'm intentionally trying to lay down some of the principles and the ideas here so
that we will then take a very specific and local regional view through the
panel and interpret some of this information through some case studies of what some local farmers here are doing
so so yes we will do that but yes of course your point is absolutely valid
you have to it's all good and well learning from elsewhere but we have to
apply we have to translate that information into the conditions here and
of course the obvious one is of course soil moisture um I would argue that I
would say that you're already doing that you know you've already managed cropping in that context you know well you know
just say in UK we can grow 10 to 13 tonnes per hectare of wheat know just
because you can't do that here does that mean you shouldn't bother growing wheat just because you can't do what they can do well no you interpret it differently
under your moisture constraints and you manage accordingly and you do what you do the same principle applies with cover
crops yes it's all good well to what they can do we're not going to do the same thing but we're going to apply that
in a different way I think it doesn't detract from the underlying principles of it it's just it yes of course that
all-important practical application she said so well hopefully we'll get some of your answers through the panel discussion
all right so this next session we're going to really drill down specifically on this topic of more plant species
diversity this stepping away from the monocultures and we're going to explore so a little bit on various things so
chemistry physics biology how more diverse systems impact those and then also some things around insects weeds
and disease and then briefly comment at the end this lecture is going to be a
little more technical and I'm going to be sharing just a lot of kind of scientific papers with you I kind of
flashed one up there earlier you're going to see a lot of this kind of style I just I guess it's a bit of an
intentional thing to intersperse it with some nice images and things as well but it's an intentional thing just to show
you that there is this there is a real growing body of evidence highlighting
the benefits of more diversity you're gonna hear a good selection of that so it's just so highlight that
there's a there's a lot of academic research out there I'm going to share a little taster of that so some of it'll
be a little technical nature but I'll summarize it down kind of nicely for everybody but again just to highlight to
you that there is a really good foundation there is a good body of work around some of these ideas and it's it's
I guess I say this to highlight there's some fairly decent robust evidence there it's just and again it cooked to the
question in the front here it's how do we then best apply this how do we translate this in in the field kind of
condition than the next focus but let's lay down the foundation to start with and then
then we'll kind of see how we go in our panel discussion so this is kind of what we're going to explore I'm going to help
transition your thinking from the idea of the soils are just this chemical physical biological interaction to
highlighting that indeed plants should sit within that framework plants are an expression of that soil health yes but
your soil health is also an expression of your plant health and your plant
health is a tool that you can design for a tool that you can manage explain what
I mean by that and again it all comes down to this central to this discussion
is the role of root exudates there's a lot of work going on in the world of root exudates a lot of research
and studies at the moment and looking specifically at these activates they're
a very difficult thing to study they're just extracting them even once they're
excreted they're rapidly digested by the microbes there's a lot of challenges technical practical challenges to
studying root exudates but from the studies that we've done so far we're already realizing that they are much
more important than when perhaps we once gave them credit for that is for sure they do play a central role in driving a
lot of these interactions also drivers organic matter synthesis and we're just
really beginning to tap into it and they are but but I just put that up to tell Harlan we are going to come back
and talk a lot about these exudates that they are central in this discussion and really this is the core the argument
we're going to lay out what happens when we transition from a monoculture or kind of system to these more diverse systems
what happens with all of these various route interactions where it's route biomass there and particularly some of
those very different root exudates how does that impact the various sort of functions and soil properties which we
might be interested in from from an economic view a point of view and so I showed this one I'm going to go through
this quickly but I share this one just this isn't looking at a diversity study this is simply studying the difference
between wheat root exudates and Farmer being reached exudates and it's just I share it as an example to highlight that
we can study these things and look at how different look at the different species and what different types of
exudates they produce and this is exactly what this study was doing looking at studying these enzyme
activities so enzymes are some of those activates and how that impacts the soil microbial activity so what they found is
the activity of these various enzymes here they found that these were much more active in the farmer being and the
wheat so simply to say that the legume released much more of these enzymes than the wheat did and then they measured the
microbial activity around those roots the corresponding microbial activity around each of those root systems and
they found that the metabolic diversity again was much greater in the father being than wheat
I guess so I'm just highlighting this to highlight that they are indeed very different they trigger different
microbial activities and different functionalities are around their rises fears around their right root systems
and so it's just and what we often see is that again as true to this example
legumes particularly emerges an interesting candidate here its legumes that have very strong exudates very
unique exudates they're very good some accessing cycling nutrients solubilizing nutrients from
the soil because of that higher root x divot II and correspondingly there can
be good microbial benefits or biological benefits that come from them again so I put that up there just to set the scene
to say that okay we can study these are attacks aids from different species we can see that there are differences and
that's just kind of setting the scene took to where we're going to go so how can we increase plant species diversity
what are some of the practical strategies that we can employ well it could be as simple as you know more
novel cash crops or wider rotations you know that's that's diversity through time you know that's a good starting
point if you've got a very narrow orientation three crop or crop rotation can we get that a little bit wider
that's a good first step but even better if we could bring that diversity in at the same time at the same space and
times where we then begin to see those synergies of the one plus one kind of equaling three then so okay it might be
annuals and perennials I talked about the difference in root exudates in there and you'll release less exudates
perennials release more so as soon as we transition to perennial based plants they allocate more carbon down below
ground so there's an immediate benefit to perennial based systems or bringing
perennials into the system because they allocate more carbon down to the roots down as root exudates
and that's those obvious benefits that we touched on already we talked about coal season warm season so can we
broaden the diversity of there if you're a cool season dominant can you bring more or vice versa okay we're here today
to talk about cover crops definitely they're an opportunity for a burst of maximum kind of diversity all of the one
space of time so more more diverse pastures of course would be a another similar example even things
like companion crops and intercropping their emerging is a really interesting strategy where we can bring diversity a
little bit more practically into the cropping phase you know I know it's I know it's it's all very well and easy to
put this nice image up and say well yeah there's all these benefits to greater diversity of course that's easy with a
cover crop that's easy with a pasture how do we do that in a cropping situation and of course it becomes much
more of a challenge but as I'll share a few examples with you even that step from one too you know into an integral
being or a companion type scenario 2 to 3 you know there are quite significant
changes that happen to the soil functionality in that situation so I'll
share a couple of examples from that biodiversity strips we saw a few of those examples the the use of field
margins leaving tall grass areas maybe flowers pollinators these kinds of things for for some of our beneficials
and then maybe the role of trees there's a lot of interest in Agri forestry and silver pastures you know animals grass
and trees as an integrated system as I see there's a lot of interest particularly in there in these kind of
systems at the moment which is good to see trees can bring lots of benefits assistant of course in terms of the
overall productivity as well so you know these are just some examples any of
these we could begin to apply there would all help to increase the plant species richness of of our production
kind of systems anything or some of off this list okay so let's have a look now
start with a little bit on biology what happens to biology I shared that big review study already with you and of
cover crops and effects on biology and here's another one which was also a big very recent study a big meta-analysis so
again reviewing lots and lots of other studies here and here we conduct a global meta-analysis with paired
observations of plant mixtures and monoculture so we're comparing the monoculture and mixtures from 106
studies we show that the microbial biomass the bacterial by massive fungal biomass the fungal to bacterial ratio
and overall the microbial breathing the microbial respiration they all increase the effects of the increase plant
mixtures on all of those microbial attributes were consistent across the ecosystem types including natural
forests planted forest grass planted grasslands crop lands and even planted
containers our study underlines the strong relationship between plant diversity and saw microorganisms across
those global terrestrial ecosystems and suggests the importance of plant diversity in maintain of our ground
ecosystem function okay so that's again big review in many many studies many
observations that they're looking at within those studies that it is a consistent effect as we increase plant
species diversity we overall stimulate and increase the microbial functionality
of of the of the soil this was another specific study looking at the effects of
part in a grassland situation going from one to two to four to eight to sixteen
species and after seven years in these experimental diversity plots they found
that the microbial community biomass and microbial respiration again the fungal abundance all significantly increased
with plant species diversity and they also showed that the nitrogen cycling or nitrogen mineralization also increased
so again a specific example highlighting the links with the nutritional siphon
the nutrient cycling happening there as well here's another one looking at root
biomass and exudates again it's the roots and those activates that play a central role in this plant diversity
significantly increased the shoot biomass the root biomass and the amount of root exudates the bacterial biomass
the fungal biomass particularly it was that fungal biomass that increases the most shifting this fungal to bacterial
ratio so again another example highlighting the benefits to the soil microbial activity as we increase plant
species diversity and one last example looking at mycorrhizal fungi specifically you'd all be familiar with
mycorrhizal fungi onshore how do they respond to more species richness here we're looking at the effects of one two
eight and sixteen species the mycorrhizal fungi and those 16 species plots they produced 30 to 150 percent
more spores and forty to seventy spent the greater spore volume in the 16
species plots versus the monocultures okay and so more spores at greatest sport volume the spore volume is an
indicator of the health or the viability of those sports again so mycorrhizae fungi also respond very positively
plant species richness okay so that's just a little selection of examples going to show that there's a good body
of evidence plenty of benefits to the biology when we increase species diversity let's have a look at some
nutrients and some nutrient cycling aspects here this is quite a neat picture again just illustrating that
dynamic that different plant species release different root exudates and here we're just looking at one variable here
the pH looking at how different species change the pH are in that rhizosphere
around that root zone and so you can see that here we're looking at beam this is a farmer being again and you can see
that the exudates of that farmer being are making the root zone quite acidic
they're driving the pH down this middle ground here is this is soybean you can see it's a bit of a weird kind of
mixture there and over here we have maize and you can see that the exudates from the maize more to the neutral
they're kind of making the plant rhizosphere around that maze more neutral now what's going on in the
rhizosphere pH is often very unrelated to the bulk soil pH we love to focus on
the box or pH in agricultural production and of course it's important it has it has an impact but actually plants change
their micro environment to suit their agenda they have the ability to regulate their own rhizosphere pH as you can see
here and so the point is to say that what would happen if we brought that
beam and that maize together under an inter cropping situation put those two different root systems together and
planted them in a mixture well now those two root systems of course of growing into twining into tangling well this is
very acidic certain minerals become highly available under those acidic conditions some of the trace minerals
for example so now the may is growing into that root zone can get some of those trace minerals that are highly available but
equally things like calcium magnesium molybdenum another trace mineral is more available under neutral HTP agents so
now the beam as its roots grows into the rhizosphere of the corn well it can also
scavenge some of those other important minerals that it requires for its growth molybdenum being one example there
molybdenum is really important for nodulation and nitrogen fixation so again it's that
point just to say that when the two root systems come together and here we're just looking at pH you know we could
look at a hundred and one other types of exudates and functionalities but this is just kind of one little example when we
bring the two together there's a indeed there is a synergy there to be had and
so here's a study looking at again an example of phosphorus limitation so it will be a common problem here where
we're looking at species interactions of again just a step from one to two here we're looking at weight and okay soybean
in this example but many other legumes would bring a very kind of similar benefit so we're looking at below-ground
interactions in this legume cereal integral and we're looking at the interactions under P phosphorus adequate
and P phosphorus limiting conditions so they intentionally designed the study to
say let's give us the the crop sample phosphorus and that's imposed at phosphorus the limitation on them and
see what effects that species diversity just one to two has under phosphorus
adequate or phosphorus limiting conditions so they grew the soybean and the wheat as a mono crop and an
intercrop under this P deficient and insufficient condition and they found that the
root dry-weight the root length is the root surface area they all significantly
increase in P deficient into crop situations so even when there was a P
deficiency imposed as soon as we transition from one to two under low P situations we saw a dynamic between the
roots of this both crops where we saw overall greater root length weight and
the root surface area so the plants triggered greater root production root
by mass production even under phosphorus limitations and it was the synergy of the two that helps them do that
of course phosphorus is a really important mineral for root development phosphorus is a key driver for it
develops a keen mineral for that and what we're highlighting here is that even under phosphorus limiting conditions it's the benefit of that
Lagoon there's more acidic exudates that synergy between the two that frees up and makes phosphorus available so that
they both benefit even the cereal then begins to benefit from that even under phosphorus limiting conditions okay so
there can be this is at this point that using plant species diversity to access and unlock the minerals that are there
in the soil and make them available what about the obvious example of bringing a
legume into the mix as well well even under an integral situation say of two plants we can increase the nitrogen
fertility of the soil through the use of negatives and indeed legumes don't just
share that nitrogen when they die and decompose for the next crop legumes can
indeed share nitrogen in real time to the current crop to the current compact to the current cereal for example or
canola through other pathways now in order to get that benefit it has to be
designed for there's a lot don't go into all the details there's a lot of nuance in this discussion you have to choose
the right varieties some are better suited to this than others so the varieties have different kind of more
lateral root systems that's very important the two companions need to have better lateral kind of interweaving
root systems that will also help facilitate the nitrogen transfer if they're both deep roots boosting species
you don't see as good nitrogen sharing so it has if the goal is nitrogen sharing it has to be designed for it is
all I will kind of intentionally say but it's not just the decay of the plant tissues that as the ligand breaks down
and decays that it feeds that crop it's also this direct transfer one of those is through those root exudates
legumes release root exudates as we talked about some of those are amino acids that's organic forms of nitrogen
so when the Legian excretes these amino acids as root exudates if we have a
grass or a cereal or a canola or another companion here growing near to that root system it will scavenge it will absorb
those amino acids directly from the rhizosphere of the of the lady so that's
another pathway through these root exudates in which the other cereal for example will
they get more scavenge but if also the third pathway if the both plants are micro rising we also see direct transfer
of again amino acids organic forms of nitrogen from the legging through the micro riser into the clock again so
indeed plant species diversity even just one to two we can also see enhanced and
nitrogen of dynamics at play when we bring em into the system and you know
there are many ways in which we can do that there's a lot of discussion around should that be kind of alternate rows as we can see in the top here we're looking
at peas and beans etc or more of a hodgepodge and mixed and if the goal is
nitrogen sharing well it's clear that actually if they're all in the one row closer route intermingling that there's
better nitrogen transfer if the goal was disease suppression for example all the
evidence suggests that actually alternate rows are better for disease protection disease lowering disease
pressure of course as a disease spores blow through this field at the top here you know then 50% of the time the
disease spores are handing a non host you know so actually breaking up the rows is better to slow the disease
spread and if we're looking for new nitrogen sharing it really depends on
the goal or your outcome now that said it also really depends on what your row
spacings are and if even on the interrelations like above if the roots are close enough and intermingling
indeed you will nitrogen transfer okay so that's just
there's a few examples there around phosphorus and nitrogen it's increasing the fertility through more species
diversity okay let's have a look at soft physics and here again another example
of intercropping here just moving from one to two so studies verify that
intercropping increases the presence synthesis of these aggregates but the
mechanisms are still poorly understood here we show that the macro aggregates in intercropping systems increased from
50 up to 58 percent across three sites in two years that's just from one to two
species we are increasing the presence of those aggregates those important
aggregates that improve the structure and the porosity that let water infiltrate that we talked about this morning we're increasing the presence of
those aggregates anywhere from 15 up to 58 percent just from shifting from a
monoculture to beginnings of the pollen culture that will buy a culture net so
how do we what is the effect here well they they determined that intercropping alters the sort microbial communities
and it is those who then further facilitate this aggregation process that's why we saw that image before it's
it's the roots the exudates and the microbes that glue the soil particles together to form those aggregates it's a
biological process and when we simply shift from one to two plant species we are driving both those biological
interact that will also impact salt physics impact presents synthesis of those
aggregates okay so then again as we discussed it's all about that precious pore space in
between we want pore space so that not just water will infiltrate but also for gaseous exchange we want oxygen to come
into the soil many of the microbes in the soil are aerobic they need to breathe like we need to breathe a bring
it in that oxygen and they release carbon dioxide and so when they release that carbon dioxide we want that carbon
dioxide to come out of the soil we want oxygen to come in we want carbon dioxide
to come out and when that carbon dioxide comes out of course plant where's the
stomata on a plant it's on the underside of the leaf as not by chance we go to
the plants are then sucking up that carbon dioxide that microbial respiration they suck that up through
that stomata on the underside of their leaves so when we have compact soil tight and compact soil it's not just
about oh we've capped off the surface where it's stopping moisture coming in we're also stopping oxygen coming in
we're also stopping carbon dioxide coming out and that carbon dioxide coming out is an important nutrient for
the plant plants want that carbon dioxide so part of the growth suppression we see in compact soil is
the fact that we're not letting carbon dioxide out of the soil to help think apply
photosynthesizing as we talked about at the beginning okay
so let's then that's a little snapshot there chemistry physics and biology let's have a little look at some of the
discussions around some of these agronomic considerations effects on disease insects and weeds as we shift to
more diverse systems so again here's another example of integral P just
shifting from one to two okay here we conduct our meta analysis to quantify the disease suppressive effects of
intercropping cereals with legumes at different rates of nitrogen fertilizer intercropping reduced disease incidents
by forty five percent on average so this is in a wheat and bean so we saw a
yellow rust and mildewed and lower in the wheat and chocolate spot and Kazarian will mow it in the fava bean
gets a forty five percent reduction in disease pressure simply from going from
one to two now the result therefore show that intercropping has a substantial and consistent effect on disease incidents
and these cereal farmer mixtures across those various studies again it's a meta-analysis that's reviewing all sorts
of studies all different context environmental conditions but the effect is not sufficient to provide complete
disease control therefore integral being is best used as a component as an integrated disease management strategy
okay so sure it didn't give a hundred percent control but i still think of forty five percent lowering in disease suppression that's a
disease susceptibility is a fantastic win we should be using integrated strategies anyway so if that's giving me
forty five percent well ok then i can use other strategies integrated into better can i management nutrition better
calcium silicon boron for example they're really important in increasing the cell wall strength of the plants
manganese and silicon also really important for driving plant immunity so we can use nutrition to - plant immunity
to get a little more percentage control we could use biologies and biologicals inoculants some of these
other beneficial microbes to also antagonize or suppress disease you know again all of these things begin to come
together as an integrative approach and I think a forty-five percent reduction sure might not be complete control but I
think it's an excellent first step in a very easy one we're just I'm just asking
one to two it's not a big big answer okay still what about insects here's a
really interesting one I talked about plants releasing carbon they don't just breathe carbon and they also release it
through exudates they also release it through the air they also release
volatile organic compounds smells and sense that's also carbon that is released from these little glands and
through these trichomes you can see in these various senses and smells that are
released in the gaseous form these are volatile organic compounds carbon compounds now some of those volatile
organic compounds can actually make the plant invisible to invading insects it
can also attract in beneficials and what we can kind of see is that some pets here actually getting actually attracted
in and then caught and stuck so this is part of the plants defense mechanism there's also a class of these compounds
that get released that are called semi-volatile organic um so a volatile are gonna come it's just a gas it's
something that walks up into the air that's why it smells so we have this class called semi volatile organic compounds and these are compounds that
are small enough they're light enough that they get released they get off gassed but they're a little bigger so
they're not so small they're a little bigger so they don't just drift off into the wind they get off gas and then they
fall back down again so they fall back down to the earth to the surface and it turns out that these compounds these
semi volatile compounds can also have an influence over how well companions work together or not
so as you would know some certain species are good companions so good team together and often we talk about its
effects of Amelia pathway and easily leo chemicals that they release from their roots that are very untag inist ik to
another well it turns out that there's also these gaseous compounds that can also be antagonistic or complimentary
that can enhance and this is part of the reason why certain plants go well together is that they actually will off
gas particularly in the in the dusk of time yeah well and if we go walking we
often see and get a lot of smells and sense from the mmm we go walk in nature the plants will off gas these things and
there will fall onto each other and so those chemicals that get land on the plant can either be suppressive or
supportive so it's a whole nother dimension to intercropping that we're
only just beginning to kind of tap into and so many of these chemicals can also
have effects on insects making the plant as I said invisible or attracting in
beneficials these kinds of things it turns out some of them can also some of these chemicals can also stimulate an
immune response in the plant so helping the plants turn on their immune system so to fight off insect passes or even to
fight off diseases as well okay so it's very interesting you know if you some of you might have seen some of those pictures and things online where they
will often take two different plants that are growing just one plant in one pot and simply by putting them together
next to each other they're not sharing soil they're not there's no competition to roots at play but simply
putting them next to each other you can see one enhance and one suppress whereas put them away from each other
they grow both grow fine bring them next to each other one is suppressed in one growth and that's due to some of these
volatile compounds that can then be suppressive but as I say they can also be in
they can prime the immune system make the plant more immune to stimulate plant
growth or make the plant more immune to dependence again just a little example there Oh perhaps next generation where
some of this is also going as we understand more and more the benefits of these client diverse systems okay so
what about weeds well it's the obvious benefit here that under a monoculture system if we just let's let's in our
minds I just remove all of those beans there we can just see some nice rows of wheat well I'm then I can see all this bare
soil exposed so as soon as we see bare soil exposed well of course weeds going to fill that gap so we're going to need
some selective herbicides to manage those weeds well what if I go and put a companion into the inter row let's fill
up that interro area with okay have been in this example well now those beans or any other companion now they're going to
be filling that niche filling that space and suppressing some of the weed activity there now then you could take
those two crops all the way through to harvest if you want it as a intercrop or if we treated them as a companion crop
and we had a temporary companion that there are many ways in which we could then take out that bean now okay but if
cultivation would be one way something they might not be too keen on soil disturbance so that might not be
relevant for everybody but for some systems obviously say an organic system that's something that might be relevant
and what we've done is at least at least we've suppressed the weeds through that species diversity during that stage and
then we kind of mulch them down and didn't provide a protective multi-layer okay so if you didn't want
to interrupt all debate what about inter Oh mowing okay so now lots of really
cool innovative ideas happening here I see could we could we intercede companion into the cash crop and then
could we go through with some kind of some kind of an interim mower to then suppress that complaint so at least it's
there it's stopping the weeds it's growing as it starts to get a little too tall and maybe begin to cut start
competing on the cash crop mow it back slash it back of course it'll leave all
that nice residue to decay and feed the main cash crop it also will just trigger a lot of root X addition and root decay
which will also help to feed the main cash crop so some neat ideas you know this is kind of novel stuff that people
are playing around with not what not mainstream adoption yet but the early innovators are playing around with these
kinds of fairly good ideas now we're not tilling the soil no sore disturbance just keeping that companion load back
and control that way and okay then of course you can also still use herbicides
to also take it you selective herbicides to take out good companions as well so here we have an example of canola and
beans it's a bit not the best photo store a little shaded but you can see the canola plants down here so this is
from the UK where we're going to be sowing in the autumn time so they will drill these together in the autumn
they'll both establish in the autumn then they'll go totally dormant or winter long and then come spring they
will break that in the that dormancy and off they grow together so this is what you can see here we're in springtime
here late spring where then now on the plants of emerge out of that dormancy of course the beans they emerge a bit
quicker than the canola they don't mind the cooler temperatures still and off their rocket and as right as you can see
right as these beans are probably getting definitely a little competitive they're really beginning to tower over
the canola here right at that point in time come through with a selective herbicide
and take out those beets okay then they decay then those roots decay then they
are helping to feed the main cash crop so okay we're still using a herbicide in the situation of course however if we
just think back to this point I'm afraid to think back to this image here you know at this point in time where we're
helping to lower that dependency on pre-emergence we're helping to lower that effectiveness that herbicides maybe
touching having more contact with the soil potentially having some negative effects there so we're smothering out
the weeds earlier on okay we're still using herbicide selective herbicide a bit later on but at least it's just on
top of the canopy there's less perhaps potentially less negative effects down into the soil and definitely some
benefits during that autumn during that winter of more species diversity before
we remove their companion at least we've got the benefits of that route to route interaction all autumn long or winter
long before we take out the companion and then the primary cash crop carries on through ok so here's a few studies
looking at will can more species diversity affect we in step 2
that never such thing it's plenty companion or to take out leads and you
know
what's what's the problem with the weights the woods we provide a similar
role and the expense and cost
you know that what is the role of weeds in Plant City
mmm yeah it's a good question I'm not opposed to the benefits of weeds I think
they bring lots of lots of benefits and I agree with you that they're really the key point there is simply just it's it's
something that's a bit more manageable so with that you're filling the gap with
just one other plant that you know you can control it at a later point in time leaving the weeds you're going to get a
more diverse selection of weeds whilst they're there that's going to be a beneficial thing I would totally agree
with you for sure but then you may be limited with the practical tools in which you can use to then take them out
now so your herbicide may take some of them out but not others okay so it's really purely a practical management
point of view but I think your question speaks to a good point that I agree with you I'm not all that anti weeds I think
they do bring lots and lots of benefits really what we're trying to do is just replace the weed with maybe another
plant that has a specific function as well so if we wanted the nitrogen which if our strategy was to try and lower
nitrogen inputs well the beans going to do a better job at fulfilling helping us with energy
versus the way it says it it depends but I think your question is a good one actually yeah it does the weeds can
bring lots of benefits okay so here's the one I study looking at weeds and companions and weeds can de
legumes control weeds without decreasing crop yield again we're looking at a big
meta-analysis or review of lots of studies so we report data from 34
scientific articles corresponding to 476 experimental units considering all of
these put together the companion plants had no significant effect on cash crop
yield but significantly decreased the weed biomass by 56% relative to a non
winning control or 42% relative to a weed control okay so overall we see less weed biomass
pressure yet no negative effects on the main cash crop yield thus the use of
legged companions generally seems to enhance weed control without reducing crop yield but the conditions giving
rise to these win-wins should be explored further to encourage the full adoption of the technique okay
again it's that point that you know it's not to say that these things always work perfectly there are nuances it has to be
designed for you know so again there's there's definitely knowledge gaps that we have in all of this there's evidence
highlights the potential potential is very clear what we need to do is take that evidence and say okay how do we
apply this under our local conditions let's do some local studies with your on your cell types where's your varieties
available to you let's find the good combinations that work under this context but
is clear that the potential is that this
was a really interesting on looking at weak dynamics comparing conservation agriculture versus just a pure kind of
note strictly no-till approach so here I'm saying defining conservation agriculture as no-till plus keeping soil
covered stubbles or living plants plus plant species diversity that's your three principles of conservation Act and
here we're reviewing the effects of weed management under conservation and bringing the three principles in versus
just a pure kind of no-till approach so as they highlight here crop rotation and surface residue there's other parts of
conservation agriculture they can be effective weed control methods combining no-till property and surface residue
offers superior weed control no-till used with monocultures can result in
severe weed infestations get no-till on its own is not the answer it's a piece
of a puzzle it's a piece of a system and that system needs the diversity and that's all cover that's what
conservation agricultural system is no-till on its own use you're using
exclusively herbicides as your weed management tool of course when you're using one tool that's going to stimulate
and speed up the development of resistance it's a no-till and mono cultures and herbicides will lead to further weed
pressure conservation agriculture will lead to lower pressure okay what about
some quickly effects on soil organic matter so we're gonna carbon here we're looking at plant diversity on carbon so
by analyzing a thousand and one observations survey a meeting where containment plant mixtures to the
corresponding monocultures from 100 to 121 publications we show that both soil
organic carbon content and the carbon stocks are on average 5 and 8 percent higher in the species mixtures of 10
those monocultures these positive mixture effects increase over time and are more pronounced in deeper soils
species species species rich mixtures effects are consistent across forests
grassland and crop land systems and are independent of background climates ok so again more plant species diversity can
also stimulate what about the effects of
grazing let's just throw animals into the I'm talking let's jump off plant
species diversity let's talk diversity for a second what about the role of bringing animal diversity back into the
cropping situation and here we're looking at grazing inclusion inclusion and grazing exclusion so taking a
grassland splitting in half on 1/2 they slashed and mowed on the other half they put the animals in to graze so they're
both process but the capacitors got cut or utilized but one through cutting one
through the animal so grazing exclusion where the animals were excluded this was
associated with less below ground carbon allocation less route biomass as a result less root exudates less microbial
biomass and all of that led to lower Sol organic carbon because animals the
presence of animals versus just cutting it does trigger benefits to the below-ground interaction it does build
sort of an ignitor
well I'm not too sure I I don't know but
I will say this that as I touched on earlier as we now understand it is roots not chutes that build soil organic
matter so even if the if the grass was left on top most of that carbon would
have been oxidized off very little would have been gained for building soil organic matter very okay so that's a
little bit on on some livestock I'll share this one last study with you just
as closing one as any just purely for interest sake this is looking now to stepping out a little bit into the
ecology the wider ecosystem you know we we love this idea that the environment
and production and farming these two things must always clash you know it's it's one or the other and ok in many
examples of course that is true but I want to show an example here with you where indeed farming and environmental
benefits or ecosystem gains can indeed be synergistic they can work together and again it's just a matter of finding
the right variables there are twin winds that in order to make that work so here's a study again just from the UK
it's just illustrating a principle here though principle can be the same anywhere they took the field and what
they did is cut into that field so we're basically reclaiming the field margins and they cut into the area of
production and they planted up the field margins predominantly with four grasses so some quite tall species grasses a few
little flowers and things that we made the bulk of it was simply grasses tall species grasses and so they ate into the
production area by cutting into the fill module eating into the area under production by three percent so a
lowering the three percent area of production and then they cut deeper and lower the year of production by eight
percent okay so obviously we're reducing the the area in production of course yield
is going to go down isn't it because we're growing on less land and they're
cutting into that area under production of course our yields going to go down when we start to give land away into the ecosystem when we plant up the margins
with these biodiversity strips and Tamas pieces grasses well as you might guess
that wasn't the case so here we're looking at these three scenarios so here's our business as usual on the left the middle colon is when we were lowered
the land under production by the 3% and the column on the right is where we lowered the land by 8% so giving more to
the ecosystem so let's look at yield first so here we're looking at a couple of year of indices and as you can see
versus the control the business-as-usual when we ate when we gave a little bit of land over to the wildlife 3% of the land
we can see a bit of an increase in the yield there when we gave even more land over to the wildlife reduced in area
under production we can see actually an even greater increase in the yield so this is simply Shore land went out of
production but what we did is we gained an ecosystem service that habitat that we created in the field margin created
space for beneficials which we've measured over here here we're looking at the crop pollinators and the Predators
so and as you can see as we cut into more land or as we gave more land to the
wildlife it was this 8 percent reduction or a person game for the wildlife you
can see where we saw biggest impacts much more so than the 3% of pollinators
and beneficials so of course what we did was simple create environment for the insects and then those insects provided
an agronomic benefit okay they proved they were part of an integrated pest management tool they helped to lower the
pest insect or the insect pest pressure which then we thence therefore we saw the yield increases again so I show this
one purely is interest to highlight that indeed we can support the ecosystem who
can support ecology and we can still produce food we can do these two things together we can improve you and improve
the ecosystem out there can be those wing winds but indeed we have to design
for those okay so in summary more species diversity any one of these
strategies could be employed more cash crops wider rotations annual someone's
annuals perennials winter summons cover crops as we'll discuss today companions we get a few examples of intercropping
there and companion cropping some of those biodiversity strips field margins that one we just talked about there and
we didn't talk too much about trees but around livestock integration agroforestry and maybe some sweet
pastures okay one minute I've time
[Applause]
just a question a job give any info or whatever on what chemicals or things are
softer again there's a bit of work been
done on this there's no simple answer as you might have guessed all I'll say is
that doing two things I guess one it is clear that generally that a lot of the
older chemistry is a lot harsher some of the newer stuff has become more more selective so therefore having a less
broad-spectrum negative effects but really at the end of the day the answer
to your question is that each and every different chemical be that you know whatever it might be insecticide herbicide a fungicide each chemical has
a specific mode of action and there will be some groups of organisms who are sensitive to that mode of action and
others who are not and so there isn't a clear answer to your question it says you just would say that yes every
chemical would have some impact on some species that will be sensitive to it there will be others that will be not
sensitive they're the ones then typically will be playing a role in the detoxification and breaking down of that over time so they're the ones that are
resilient to it so they will help to break it down so it's not to say that you know a chemical will kill all of the
biology and we have a dead soil or anything like this it's what it's doing is affecting some species now that's
still a concern because what that's doing is creating a narrowing of the
diversity of the biological activity and when we when we narrow the diversity of
that biological activity that's still a concern because what we do know is that in terms of things like disease suppressive soils we know that disease
suppressive cells have wider diversity than disease susceptible off is still
important when narrowing the diversity often called dampening the diversity so you've still got plenty of organisms
there offer often they will still be functioning at a same or equal biological activity but you've just lost
some of the diversity and pointers to say that you may have lost some of the key species that perform us very
specific key benefit you might have lost those so there is cause for concern I
think they are tools use them judiciously use them try to integrate as many other strategies where
possible and keep them up your sleeve for only when absolutely necessary and the truth is we don't really know the
full effects of some of them we we haven't even classified or categorized all of those particularly the microorganisms that live in soil so how
can we say either way when we don't even know who's there yet we've only identified a handful a handful a percent
of species in the soil microbiome so to make kind of strong claims either way I think is a little loose but but yet from
the evidence we have already it's clear that some species will always be affected and that's enough I think to be
concerned from that lowering of diversity point of view so let's have a
quick introduction just a little bit about where you're from and maybe just a little bit on your main crops and/or
production systems and then we'll we'll explore your questions in mind but let's
do you have quick round of introductions my name is Luke Harrington now I run a little business called region farming
and I basically try and help farmers transition into these sorts of things
and just on probably a breach between someone like Joel and the farmer because then they come to these days and gets a
bit overwhelming there's a huge amount of information and then you go home and go what do I do about it and that's
where you can contact me and I can help you out with that that's what that's what I try and do one other thing I'd
like to say thank you my putting this on it's got a good turnout so support these days know where I come from we we don't
get a lot of support for these days so you support what Michael does all those things yet and
good job
Brendan Patterson grain farmer at Mara growing wheat barley oats canola beans
running a zero till full double retention system no livestock just
running out mixed with pinions most of it hi everyone I'm Brian Collins we've
got a farm at Big Springs about thirty five K's southeast of Walker we
multi-species crop summer and winter and we harvest harvest with our animals so
we do a rotational grazing system so lots of animals in small areas and we
try and keep them out all year try and have a living root in the soil all year round that's probably our main goal and
we just try and use the animals to do that ok guys
Matt McKinley will be with my father Dave who's a really really keen student
of soil health and better systems we're north of Coleman so 1325 Watkins knew of
the corn predominantly grain growers in recent times some reintroduction of livestock
on how on a small scale with which cover
crops Epona played a big role in that reintroduction of lifestyle for us I
guess a key a key feature of our thought process is a few years ago we come to a
realization that a reliance on or or a system that we had relied on synthetic
inputs fertilizers wasn't gonna be what to us forward and sort of pursued
avenues and come to a realization that a system that relies on biology and
natural ecosystem function probably was what was going to take us forward so and I come across some plant
diversity or played a big role in that and I guess we'll talk more detail best of the details here so again I'm very
happy to facilitate some questions if anybody I'm sure you'll have some so
very happy to hear from you I don't want to steer all of the conversation I'd really be better if it would come from you but I I think one that I just would
maybe like to kick this off two particular questions was it was really start up with maybe around species selection where did some of you
start in terms I mean I put a big big big old list of species options up on the screen there where did some of you
start around narrowing that list of things down where do you get your information from how did you decide what
species to put again and then if you could link in a little bit around that around seeding rates so again how you
determine that that that'd be a nice compliment but maybe that would be a good kind of first question to kind of get us going I know that's probably a
big one idea around species selection and everything that while you you've got
the microscope see yeah okay turned off isn't the other stone well first I guess
I've got a bit of a love love hate love hate relationship with with cow crops so
initially we that's right initially as a
as a way of introducing diversity into our system we pursued the Avenue of Tron
incorporated cover crop between two cash crops over summer as per a sort of a
North American or northern hemisphere type system that turned out not so
successful for us so we've we've moved away for various reasons which if we get
to our mic and I can go into it sort of ties into this gentleman's question here about moisture availability in Australia so species selection in
different forms of cover crops that we use now mainly during the winter I actually prefer to call them photo
crops because we grow them primarily for diversity and stop fee but I guess growing a multi species or cover crop
it's really really bloody simple so there's no reason to make it difficult
by trying to choose too many species by trying to overthink it
so I think if you've got like like Joel that up there a basic basic selection
from a lot what you might call the food groups or the plant groups you're feeding the diversity feeding the
biology different flavors of exudates so just try and have a good selection from each of the each of the plant groups I
guess cereals brassicas legumes so it's
not about the number it's just about they're about the diversity I think yeah also the the outcome you're trying to
achieve trying to imagine what you want the cover crop to look like at the end obviously if you know if it's if it's
not it probably should be the desired outcome to have a lot of ground cover so a high carbon loading to provide soil
Armour at the end so they're making sure a good amount of cereal species are
included in there sort of always Cerrito a good amount of ground cover at the end
yeah Brett put some questions so England
timing yeah it's really just like a cash crop the phonology of the plants that you're sowing need to be matched to the
to the sowing time I found you as job explained you your best benefit from
your root exudate is coming from when the plants in that before the
reproductive stage that vegetative stage so yeah we've sort of noticed that choosing varieties or selecting
varieties with longer growing season that will stay in that vegetative stage for longer will give you give you more
bang for your buck a more time where plants you know in a vegetative stage yeah but it is important like everything to
match the sowing time with the phonology of the plants you're choosing if you have two shorter season plants growing
you'll get certain species in the mix go ahead become become reproductive going to seed and then they're not they're not
giving anymore they're taking once they're going to seed and that's that's not the desired outcome so what kind of
species W say that a long little bit longer growing some of those longer vegetation once what was it you play
around so with cereal cereal selection you vernalization type winter winter
cereals wits and weights and oats and that type of thing we have made some tragic mistakes with that by choosing
short season oats in one particular instance and we say very early and that
yeah I went ahead in winter and basically shut the shut the show down for the year yeah so you learn by your
mistakes and that was one of choosing a short season cereal and song it too early and that vegetative phasing
that's gross just didn't last long enough to get the benefit for grazing warfare or for unix units all right so
when we started doing our multi-species cover cropping we were coming from a very degraded system we've been doing
production agriculture for years with high influence lots of spray lots of fur and we ended up with a system that was
basically dead and if we wanted something to grow we had to put it in the ground we had to win our country off
it's synthetic so I think the first year we cut our foot back half then the second year we cut it back half again and and now we don't use any fertilizer
at all on our system we don't use any sprayed or we don't have any weeds we
don't call them weeds everyone else does but what we're doing is a minimum
species for me would be eight species there wouldn't go any less than that the
goal is always to maximize how many different varieties a plant I can get in the ground at any given time for
instance at the moment I'm sowing and we're showing winter and summer species
together so I've got millet and corn and sorghum and all that sort of thing mixed
in with my my winter species I'm owning to get a couple of months out of it that's okay
but they're doing something for the soil while they're there we're always trying
to maximize how much root system we can
get in our soils and the more more root system we can get the more leaf section
we can get as well we try and keep our plants in that phase two all the time so
we do that boy out our celebrating so will if a plant gets too close to a
reproductive stage then we'll come in and we'll smash it back down to sort of the top of face to bottom of Phase two
again and just let it go again and we find we can keep that plant going
and growing for a lot and the animals we predominantly use sheep sometimes if we need cattle will
bring adjustment cattle in which we've got happening this week so we use
different stock types for different purposes sometimes we'll get stock in to smash down undesirables and sometimes
we'll give long rest periods to let the beneficial species that we're targeting get away we're just using a little twin
disk machine I think it's only 3.6 meters wide some of you guys I'd be thinking of God to be there all the time
but it suits our purposes we as I said
we don't use any any spray unless we really have to have use roundup once in five years I think and I felt guilty so
look it is all about maximizing our cover and maximizing that living root in
the soil all the time we noticed that we don't get runoff really at all even in
really heavy downpours that water is hitting the soil and it's going into the
soil we've still got dry dams at home after 150 mils which is good and bad but it is
good because all that moisture is still there it hasn't run off which we're loving get more stock
just make sure nothing ever comes see oh look there's a time when you need things
to go to a reproductive stage I think so I think that you know for your soil for
your soil that it's even when it goes reproductive it's still going to be doing something down that's also those
those dead roots of those plants they're going to open up the pathway for all
your other stuff like your water infiltration and all those other services to take place so there is a
time when you need to let country rest and go reproductive and then you can come in later and smash it down once
it's done that I'm also back into it it's going to leave you with some pretty cool cover
so you find the no you summer grasses like the middle like you're sowing them
now so I persevere oh they germinate
another story at the moment it's only pretty low
probably two kilos so the reason I'm putting a bit of millet out is I had a
bit of seed left over something I had about half a ton of seed so I've just put my half ton of my summer mix it we
we mix up which has got about I think it's about 17 different species of
things in there so I'm just blending that in with what we would normally do with our yeah winter mix and once the
four-ton that I mixed up yesterday's all that will go back to our traditional winter mix yep right springs it's sort
of it's mostly moisture to pin it so if we if we get a rain and it's it's
warming up enough for those species do to go I'll get into it as quick as I can
but on the flip side in autumn I will dry so I'll start dry say in February
regardless of what the outlook is because it's all about the in crop rainfall it'll just sit there and when
it's ready it'll go so you mentioned millet what are some of the others
people do your favorite ready then that are like central to all
okay so my summer mixes we ready for the
crazy talk so we go down to Southwest stockfeeds and we buy pigeon mix and
that pigeon mix is cheap as and it's got about six different species that we want
in there including safflower it's got cow peas it's got sorghum
it's got pearl millet it's got corn and some radish in it so we use that as a
bit of a base but then I'll also add five kilos of Shaarawy millet per
hectare we'll add a couple of different types of sunflowers sunhemp turnip
plantain chicory radish loosen I'll also have some wheat oat week notes in there
and it'll just sit there till we get a good rain when it cools off a bit but
really that that summer mix has got about 17 species get in and we treat it all with a firm adduce like worm goose
before it goes as it goes up the auger and that's pretty much all it gets we
aim for a really good selection of herbs forbs and grasses so we want to have all
three of them in our mix some of what we plant is not palatable to the animals
they won't like it they'll leave it that's okay because it's actually doing a really good environmental service for
us whether it's got a beautiful tap root like like a safflower or you know
sometimes it's a might be a great pollinator but the stock won't eat it that's okay it's not there for the stuff
we just use the stock to transfer those nutrients back into the ground we try
and make a bit of money along the way so you totally annual no no no so
there's we've got we've got some perennial tea in our system so because
we're not spraying we've got phalaris in our pastures we've got a lot of the
natives have come back in we've got some fescues we've got so they're already there I'm just trying to add to it so if
we're adding 10 to 20 species they might already be eight to ten species out in
the paddock I suppose their end goal would we would love to have about 80 species fine get
80 species by time I'd all be pleased so you're just over sowing notes you're
going into this drilling straight into what's there sometimes germination is an
issue if there's already something established and it doesn't happen the
way you want it to but I find if we can come in then and hit it hard with it with some stock that'll activate what's
sitting there and it'll kick along may not be as quick as you want it to be but it happens that's because it frankly yep
yeah the herd effect
so 650 mils I think we got 320 last year
if it 650s out our average we've never hit it before the been overrun once your
driver then I understand yeah so here we
are making money which is terrific I think when we were doing production AG
we weren't making money we do a budget every year and I never once hit it every
time they'd be more urea more spray some sort of outbreak you have to deal with get to the end of the year and you're
thinking well we just scraped through so what we're doing now is we're
deliberately trying to work with nature not against nature so that's why we're
actually not an organic system in the true sense of a certified organic but we
are an organic system in that we don't use any synthetics we'll use targeted chemical if we feel we have to the end
game for us I think long term is that we want to leave something for our kids
that's worthwhile that's a lot better than what we got and we just I suppose
we're taking a very long view that we want to leave something behind for the future that is going to be terrific
I don't need to make much money to get by got pretty simple means I don't have
a high-maintenance wife so it's pretty easy to get by on what we
make we don't need to be rich this is not a driver for me so if we can make
enough to get by I'm pretty happy with that but for me it
can't constantly keeps coming back to the soil if I've got functioning happy
soil and I can tell what it's doing because it smells different it feels different you walk on it and it's nice
and soft it infiltrates moisture the plants all look pretty happy growing
there we've got we've actually got so many ladybugs at home at the moment it's
absolutely crazy that everywhere I've got no idea what they're eating but they're eating something so those
beneficial species to see them working and you can see when you sow a crop when you got a tree line the insects that are
coming in off that tree line for 20 or 30 meters you can just see the impact they're me on those those paddocks so
yeah the end game for me is to have a low maintenance system we are increasing
Kearney ality all the time so in 8 to 10 years I actually hope I'm not doing this
anymore I'm hoping that I've got so many species in there that you know I'll just manage it with the herd I won't need to
do any more of this multi-species cover cropping for me this is a recovery process to get our soil functionality
back to where it should be so it becomes economically viable because you got such low in food cost
the synthetics but you sort of measure it didn't have any kilograms of lamb or
beef or whatever you turn off for yeah we measure everything yeah yeah we
measure our economic profit but we also try to measure our environmental profit
like our and that's in our our soil health our plant diversity our animal health like forgot healthy soils what
healthy plants we've got healthy animals healthy people so from a holistic context we that's that's the I once I
would get it every time but that's what we're aiming for that's the intent can I
can I say something on that economic side were just some numbers the farmer that I work with he he started at five
years ago so his fertilizer bill is down two hundred and sixty or thousands his
vet bill does not exist anymore he's a dairy farmer he's the happiest dairy
farmer I know anyway so and he has no herbicide bill anymore and but he's milk
productions pretty much the same so that's a huge driver or an ease his
minerals that he was giving his cattle in the bile every day when our milky is down 100,000 that's not bad that's not a
bad holiday money I just AM like a call me home you said there's a positive
comment happiest dairy farm you know yep what easily costs
that they are happiness that's something that we often look at purely the numbers
of what is the overall happiness and I think that's something that we often miss in those conversations that's
really important absolutely that can go but that can go to ways that give me a real two-edged
sword when you acknowledging the change is needed and you feel somewhat
unsupported by the general community and you're really striving to implement change hope you farm
it doesn't always bloody work the first time so happiness doesn't come instantly with change it's a real bloody leg fire
and I can promise you there's a real leg face there with with with happiness in
change so you know that it really tests you your conviction August's and yeah
and you spin you and your inner strength and your resilience because you know
when you're making a change that it's not gonna work the first time probably so you've gotta have that resilience to
get to get through that yeah that transition yes then the community - a
big thing yep acknowledge that it's delightful actually it can be very
romantic to think that the lady birds and everything make you happy instantly
for some it might but not for all so
yeah look we're still on the species selection seeding right I mean happy turn for it to diverge that was very
good so listen let's keep that going but we'd come back to that point around species selection
it's definitely lead well for animals but I don't know I just feel I'm just
trying to make a work without them like as for the selections well we just went
in with moved away from him what a culture a few years ago with our cereals and went into just adding one just added
some radish just purely just as an accumulator and bring up some nutrients from depth till feed the crop just tried
to cut down on our synthetic input just purely takes them across here if we could and then how to edit a leg here
just give a bit of nitrogen as well just a system there promoting more biological
aspects of it all just it feed at all so I get all the stubble to size and that
way instead of putting it through an animal at the moment we're finding is working well in the low rainfall years
the last couple years here we still pulled fair bit of grain off it's not a
lot of input got into it while growing several different things at once we are
terminating the Companions early spring so they're just taking what a culture through the harvest so
it was finding that early termination in the springs assisting with the cycling feeding the net feeding that cash crop
that year so not relying on a lot of nitrogen a lot of other fertilizers at
the start it's a fast way you've mentioned that radish and legumes purely
companions how are you determining kind of what seeding rate supposed to use not
putting a real lot out like radishes are sort of that half kilo to akela the
legumes playing around that 8 to 12 kilos somewhere in there
it's just tweaking from year to year
I've got fetches lentils mixed in the cereals in the canola you'll get a
random favourite behen obviously still come up from the residual seed but you
haven't really found a negative impact from having too many of something yet I
know that might be only around the corner but we don't know yet just keep
adding a few more or taking a few more out putting more together just trying to be more diverse yeah putting two legumes
together all the way have a bit rate or just a bolide rate of both
staying with the same group at the moment so the inoculations they're from year to year so if I don't knock you
laid them real well well the pressures not they have you done any of the
diverse covers you still have just moved the more companion cropping stage have you gone to kind of cocktail mixtures of
anything yeah probably back in 16 we put a couple of weedy paddocks out with a cocktail mix
and then just adjusted some stock in from next door but that was back then never having gone back to that yet
just felt us trying to do it through the cropping system mainly with the livestock as don't have enough
infrastructure there to run the livestock properly yeah they say enough
merit with enough people doing it that what I have to do one day but hoping not to small steps small steps Roseman where
you did that cover in grazing any any observation on the cash crops that followed that no not really
subsequent crops were quite healthy but
and I just noticed the black the braudy stock Avery did comment that he's lost like he's a lot better on that crop as
opposed to the straight oats he had back when he's farm over the road so his
lambs were scaring he did put a bit more weight on and he didn't have any deaths so to me the cocktail mix him to work
well for the livestock good question around soil constraints so
for example if you've got a high pH alive eh or if you've got compaction how
does how does it and if it does how does that impact what makes you for the
interview to you it might be a question for Joel anybody
soil pH just just reiterate the story I say you saw constraints so for example
if you've got a live pH does that affect what you put into your mix in your
compaction or like this year the chemical physical song it's coming I
would make there is to have a healthy impact might when you saw the new
ecosystem you need the plant to be healthy so you need it to be to be exerting its maximum potential
photosynthesizing at its maximum potential so putting selecting a plan that's not going to perform you know the
environment with his constraints he's not gonna provide it we had come yep so
and the same could be said for fertilizing cover crops you know on it I
don't know if that's jumping ahead too far but you need those plans to be healthy to provide that that service or
to provide that with an exudate if you have confidence that the plants will be healthy without fertilizer well maybe
not and by fertilizer I don't mean you know synthetic imports either you know just
some it's a mineral support or whatever else you would do to try and support any plant but the overriding thing I think
is that the plants need to be healthy to provide the service and you've gotta provide an environment to be healthy
yeah well with your soil constraints that's why you put in a cup crop to fix
our salt constraints so a compaction from for example you would pick a plant that's going to help you with compaction
if you pH I don't sort of take as much noticing because I find the plants as
we're looking on the slide before they'll actually make their own pH they'll make themselves that's that's
their that's what they do in nature yeah so you design your whatever you're going
to put in for the constraint for your end goal so if your end goal is to break up compassion where you're putting more
radish or more tap rooted type stuff if you're in goal is is and you're putting more things it'll fix in so that's
that's what that's what you're using them before any selection and things
that you've played around look we've we've mainly done for dairy guys at the
moment so they've just been quite diverse like with 1015 different things in them plus whatever is in the paddock
so and once again it's it's bringing it up you've got to have your grasses your broad leaves yeah and there's a chatter
point to that people talk about that they say really starts to get the get
the system going as well so that's things like sugar B spinach and quinoa R
and things like that and they say you put all all five together and it really kicks in but in Australia we've
struggled you to get that chain apart in England so we're working on that at the moment but the time yeah it's yeah
mainly for compaction around us it's a lot of radish and and those two deep tap
rooted things and yeah and nitrogen seems to be the things but we just clear as diverse as we can and cereals as well
and so that's most men a dairy situation yeah dairy shape the livestock mainly
and Westar and we've now got some sort of mixed varmints that are getting much more involved which is which is good and
so how are they integrating some of those covers with pastures is that a rotational thing was it
yeah we're just drilling straight into whatever is there because we're starting at a really low base like our soils are pretty trashed out our average organic
carbon would be 1.5 - well actually point five to one point five with an
average soil test so we're starting from a pretty low base so we're just trying
to put as much as much species in there to get as many of those egg today it's going so to build as much soil carbon as
we can get so that's that's our starting goal yeah so we yeah we have no trouble
just over sell it and then terminate it if we have to livestock if we have to
whatever whatever is there for the farmer whatever you've got make use of it so you're using cattle for
termination cattle cattle sheep sprays whatever that whatever works for
the farmer don't let don't let what you don't have be a constraint to your soil
health program just get in and get it done one of the things that we do is if
we're looking to so we'll smash it pretty hard with a stock before we tell it so well we're not spraying we're
taking as much of the as far as competition out as we can so that we can
get the other species established as quick as we can as well so you yeah if
you can we still we don't really refer to it as competition their companion plants but
if we can reduce the established plants to get the new new plants in going that's what we use stop to do it yeah
and just a bit lazy so yeah just do it when I can do it and when it starts to
round I can sit inside and enjoy it any
other questions just done two people think this world
organic management 8% 6 to 8% yep anything under - it's not
functional it's more I understand your soils just not functioning if you've got
under 2% your source it's not functioning so it should be at least over there Christine Jones done a fair
bit of work on that anywhere from sort of three or four percent through over 20 here we have how
many despite an irregular
results at an average for a sort of area the sole carbon was the Twain in zero
and to grade it
yeah maybe yeah sure yep so if we're
talking soul organic carbon that's always gonna be a lower number and that's the one that you would often say
would be you'd like to see that at least above your 2% that's that's measuring the carbon as it says when we talk about
soul organic matter that's going to include carbon but also some hydrogen some oxygen some other nutrients there
it's more of a diverse mixture so your minimum kind of organic matter would generally be around that four percent
say is a minimum that number is always going to be a bit higher because it includes some of the extra components so
if you're talking about soil organic carbon we'd say yeah you would like to see a minimum of 2% if it was so long
ago Nick motto you'd probably say minimum of kind of 4% but but higher on both of those ideally but that's that's
a little nuance yeah don't get those two confused they are different things yeah and it's important to have that carbon
there because that's where your soil life lives that's where your minerals are he'll that's where your moistures help so the more of that you've got the
more of all the other things that you've got so that's it's a really important thing to measure
just on that whole issue getting better intro okay
you know in form of this part of the world other examples of way that through the
doping in some of those practices like my traumatic increases in that is levels
and I thought wrong you guys I mean I've got a few thoughts
in my head but you'd probably would have better local examples than I I mean the one that jumps to my mind is Colin sighs I mean you know him doing pasture
cropping no disturbance and repeating that and having those perennials they're deeper rooters he saw some big increases
at depth I think he's the one that jumps out to me but I don't know if you guys have got some others but I need about
0.5 and here we're probably up over to now that's taken us about four years to
get to that level so it's a it's I don't know the first first summer crop we put
in or I can maybe one plant in a hundred terminated like one one said no it was atrocious now we get a much better
result but it just takes time to yeah to improve the soil health to get it back
to functionality where we've got a long way to go we really do but we're on the
right track yeah yeah one of the things
when people come and visit the farm we actually ask them how does it feel as a farm feel and nearly everyone will say
yeah it feels good because the soil is soft even in summer even when it's been
dry there's a softness to the soil you walk it there's not hard it's it you can feel the sponginess in it so there's a
there's a visual change the soil is always covered so we never have uncovered soil as far as if we had a
paddock that had only ninety percent saw cover we'd be we'd be thinking ah this is no good
the other thing is that check the smell of the soil changes like you've got to carry a shovel with you everywhere but
the smell of the soil scientist yeah you can smell the soil with it it just smells I thought I had to describe it
but you give me a compacted soil and a will functioning soil a night that I
have a very different smell of Adam so that the soil does take on a very
different smell and the other thing we noticed too is particularly reading rain
we don't get the runoff into the dams anymore at all so that's a real head to
say something's going on and then you know it's good because you know that the
rains going where it needs to be in the soil which is your biggest sponge the biggest water storage on your place but
not into the dam where you might need to the livestock yeah yeah but we use
rotational cell grazing so we're putting fences up and taking them down all the time we use hot wires there's the odd
place where you can't tread it in but Michael was out there putting electric
fence stays in there a little while ago what how was it it's good even in the
middle of summer before we had rain those trainings are just treat straight in there's a few paddocks that probably
were the last paddocks we farmed they're still pretty hard so you know you're looking around for a grass to put your
treating in like a perennial grass and I'll go straight in but yeah so yeah it
is different there is a difference in the soil and you can see it and you can smell it you can feel it what you'll
find pretty quickly when you go down this path and you don't even have to use cover crops to do what you can use bio
stimulants or whatever you hit down the soil health path the aggregation changes within a couple of years it's not it's
not something that happens really fast but it doesn't take that long once you get that to happen and you're in
filtration the air goes in at that speed to process up so it's something that
you'll see pretty quick I'd agree I think the early indicators have changed happened quickly the longer-term things
that sure of course building soil again matter takes time but some of the early indicators do happen quickly I would
agree with that to say that the effect of having carbon flowing in your system is recognizable before the sort s eaten
up before the numbers change the visual challenges you coming back to your
species sort of expand on ya so your
question you asked while joel speaking to me is that elephant in the room all
the time when you're talking about cover crops more time yeah so different
environments different strategies it's just so it's so relevant you're the only
person that's really qualified to make a judgement what works on your farm what's
giving you a service on your farm so just yeah there's gonna be a lot of in
size sorry but just in relation to that question you know the the notion of the
Christine Jones carbon cycle the green plants all year round it's it's really
sound science so I guess there's nothing small about that but trying to overlay
it you know in a cropping system where your productivities will align on how
has become relied on stored sort moisture proof really challenging for us
okay so we went into it with an attitude that we're not sure if this is gonna
work that we're gonna give it every opportunity to work growing summer cover crops so outside of our cash there cash
crop top and you know in hindsight it's not surprising that the moisture bet the
moisture deficit from those summer cash cover crops really had a devastating
effect on my cash crops here winter cash crops so the net result was over a
number of years is that over a 12-month period we feel we actually had less photosynthesis and less rude exudate
because our cash crop was severely compromised okay and of course the
flow-on effect is less less year on this profit and you know a system that's less profitable the
damages here your business health doesn't doesn't interest me personally so it leads in our case and I know
others in our situation that's led to a situation where we had to look to
incorporate diversity within the cash crop growing season so what where it
sort of led to to cut a long story short we look upon our cash crops now in a way as cover crops okay so cover crops with
a harvest so we overlay the the principles of cover crops onto our cash crops because
we found it detrimental to our system to try and incorporate a cover crop and a
cash crop in one year in one season so getting your question about the the
site-specific in the region specific variables that's just an example of I guess I guess an attempt to introduce a
system that we sort of saw working in North America really well and I believe I believe Europe really well been europe
lately and I can see why it works so well there during their during their non cash crop period their biggest problem
is trying to manage excess water on on their fields it's a very very different set of scenario different different
resource concern to farming north of corn so yeah I just think that that
question was such an important question I just wanted to share that anecdote there about being making your own
decisions on your own farm is so important but about the species selection so so so
you know you know cash crops like I said we just try and have a plant from one of the three food groups of cereal Brassica
and legume a really sweet little mix that seems to be working really good is
one killer of tillage radish and ten kilos of veg so we'll try different
variations of that we've actually seen I wouldn't say consistent but we have a
measured yield increases when comparing it to nil diversity strips I don't think
that's trying to mean that we're not addressing the maximum yield not trying to maximize yield but it's having a
massive effect on reducing yield minimizing factors like like a biotic stress frost disease and so forth
yep so rashly finding a big biggest benefit to productivity and profitability is taking a focus off
trying to maximize yield which what mono crops are designed for to try to minimize yield deficiencies because it's
very rare that our maximum your potential is met because of because of other factors abiotic stresses so that's
you know you know cash crops are growing crops are cereal crops that's one good little mix but with the the grazing
crops so the cover crops yeah we just don't really have have rules it's sort
of we just try different stuff all the time but but we do have that intent to try and at the end try and have a good
amount of carbon a good amount a good amount of lignin above gram so just to provide that armor
after the cover crop services started to display that our little son yeah
I know still spry / this summer
when you draw a news softer chemicals or it's just yes a
summer fellow it's probably the thing I hate most about our whole a whole system it's what I hate most about the whole
no-till cropping system for us in our environment you know that the moisture
limitation is real we summer fellow we use glyphosate we we
think hard before we do we don't use it really nearly and like there is some things we've developed you know some new
techniques in recent times just trying to cheat like that that molecule and buffer that molecule with some organic
compounds formic acid and so forth yeah yeah which which are thinks yeah it
doesn't make it it doesn't make it a good thing but it makes it not such a bad thing it does help break the
molecule down in the soil and for the fulvic acid just as a organic compound
yeah yeah and you should also try and get your pH down - with the citric acid in as well so your glass if it works best
at three three and a half pH so you want
to try and get around that mind since we started the four big acid thing we have
noticed with some testing we've done saw residues and to a greater extent crop
residues you know that the ampere I like the roundup molecules really really
getting broken down faster
they they're the random molecule I think in in a traditional system a synthetic
fed system I think they'll last a long long time but we've actually proven and demonstrated that you know in a
healthier system it can be broken down very rapidly minimizing the impact the much more the
concern is the breakdown product it's the AMPA glyphosate itself break downs breaks down fairly quickly within a
couple of weeks or so it's the ampere that's the byproduct that then has the much longer resistance lingering
residual thank you time and it's the one that's also more concerning from its
toxicity point of view it's the one that's been shown to be photo toxic to the plant and and then we'll link around
for a number of years glyphosate itself less so ampere more concerning it's a biological process
breaking down the molecule the glyphosate molecule so if you're acting to promote biological processes you're
acting to promote the breakdown of the molecule
plus you might have formic acid drop a ice bath right now so citric acids is
used for the four acidifying yeah and that look that that just depends on so
many things you're starting your starting pH and you your additives and mixture and so forth you really got a
test and trial but for for big acid just a seventy five percent solution we're
using that ten hundred mil spec tea
for begin the techniques hundred mils per hectare so however that however that calculation works with you with you with
your application rate of 75 percent solution so fulvic acid is just the
carbon source it's the citric that you aren't further acidifying and you if you want to work that acidifying just take a say a liter
of water and of your spray water and scale it back to a liter and just add small amounts of citric acid and measure
that to get down to that pH of three and then go back and scale that back up to three hundred liters or per thousand
liters kind of thing so just scale it back and then do your weights and then scale it back up to work that out it
won't be much I think doing that Mike's using glyphosate a good thing but it
certainly makes it less of a bad thing you can you can drop your rights of glossy faith considerably good thing for
you back to farmers around the world consistently it's this 30 odd percent
reduction in your herbicide rate seems to be a very safe and consistent number that I hear 25 to 30 percent lowered
herbicide rate when the pH is dropped to 3 and then at a carbon source I know even in farmer in UK's uses molasses
even a molasses carbon source can do the job fulvic works particularly good it's very good at the job but even molasses
can work it's just the carbon source and then get that pH down to 3 that's your
key presentation
based on that house selling right do you know what those rights
through the cocktail mix no I don't I
don't think I've got a note on that and my slide I don't know I mean it was in
the US it was it was on if you're familiar with J Fuhrer anokhin farm it
was on it was on his far on their trial farm in which they were playing around
with that that's where that came from let me just see I've got some notes on
here no I don't I don't know what the seeding rate was no sorry yeah firstly
thanks so much for a Joel and these guys I think it's really important to get this local context no I know for my own
personal experience you know it's probably a journey rather than destination so to speak and I think one
of the things I really want to try and help support people is if you do want to you know talk to each other as much as
you can share information because that's the type of conditions where I think the practice change will happen so we
certainly want to you know look at getting involved with you know big knowledge Hill or farm link or whoever
it is some of the local organizations and create a support network around you especially when you're making big
changes in your business on Tom's Akins you know exactly you know in terms of
you really doubt what you're doing and you're thinking everyone's telling me to do something else but yeah I think
you need to have clear goals and at the end of the day you can really only make a decision that's you know you're the
one who's making that you gonna make it in the best interest of your business and of your family not just say one
other thing yeah with that when you going down this path and this is a saying that was told to me a long time
ago of something else but you got to take the time it takes because it'll take less time so don't get in and just
go hard and then have a fire and go it's not gonna work you've got a you got a cheaper way out
of it because it does take a bit of time and it will take waste time if you just systematically work the way through it
so anyway thank you guys and also thanks a lot to Joel I think I don't know you
probably underestimate we're really lucky to get through a day like these well half a day and so you know I appreciate and we wouldn't have happen
if we knew or didn't know people were going to turn up so thank you I hope you
enjoyed the presentation at the end of the day we end up with 43 landholders in the room and 15 type students I think
the highlight of the day was the panel discussion getting those local examples of what farmers have been doing on their
own properties in the Riverina it's always great to bring those principles from around the world back to our area
and see them being adapted into our local production system if there's any further information that you require
from this please feel free to contact me appreciate your time listen to this
workshop thank you [Music]
