Pasture establishment

Sowing is a significant investment. Without proper preparation:

• seedling emergence can be patchy
• weed competition can dominate
• fertiliser inputs may be wasted.  

When sowing a paddock, consider:

• Is the pasture short or long term?
• Are there specific paddock issues, such as being prone to waterlogging, soil acidity, etc?
• What species are suited to my climate and rainfall?
• If irrigating, is the intent to fully or partially irrigate?
• What role will pastures play in grazing (and whether sheep or cattle), hay production etc?
• Do you want a single species, or a range and diversity (including, grasses, legumes, herbs, annuals and perennials etc)?
• Can you manage your pasture over the long term?

Understanding the reasoning behind sowing a pasture and taking steps tailored to individual conditions based on the answers to those questions will allow newly-sown pastures every chance of returning a good investment. 

Every property will have differences in the soil profiles of their pastures. To have the best chance of success, it’s important to make sure your paddock improvement plan considers the following steps. 

Planning for and preparing pastures

Establishing a productive pasture starts well before sowing. The condition of the paddock will determine whether new seedlings thrive or fail. These influential conditions include:  

• weed pressure
• soil fertility
• surface structure.

Reduce weed seedbanks and control pest animals

Weed control is the first step of a paddock improvement plan. As the first step, there should be a minimum three-year clean-up program prior to sowing a paddock down to a new pasture.

Use a combination of controls to get the best results.  

Control options include:

• spraytopping to prevent seed set in annual grasses like ryegrass and silver grass
• silage or hay cutting in early November to remove seed heads before maturity
• strategic grazing to reduce seed set and open the canopy for desirable species
• using cereals or forage crops to suppress weeds and improve soil structure
• applying pre-sowing knockdown herbicides or residual herbicide based on species, timing and herbicide label directions.

For paddocks with excess biomass, consider Slashing and Mulching to improve light access and reduce competition before sowing.

Pest animals like goats, deer and feral pigs can damage existing pasture and interfere with pasture establishment, so proactive pest control is key to pasture preparation.

Assess soil fertility and structure

You can assess soil fertility and structure by sending a sample of your pasture’s soil for testing. Soil testing helps:

• identify the nutrients present and deficient
• guide fertiliser decisions
• ensure that pH levels are suitable for pasture species.

Important things to remember are that:

• phosphorus and sulphur are critical for legume establishment
• nitrogen may be needed in low-fertility soils or for grass-dominant mixes
• pH should be above 5.5 (CaCl) for effective rhizobia activity in legumes
• soil structure should allow for good seed-soil contact and water infiltration.

Choose species and seeding rate

Species selection depends on climate, soil type, grazing system and seasonal goals.

Choosing seed

Significant differences exist within and between pasture varieties with respect to their growth, maturity time and persistence. Things to consider include:

• using certified seed with known germination rates and disease resistance
• optimising the variety of seed used as unoptimised seed varieties can reduce pasture production and persistence
• making sure you are choosing the type of seed that suits your rainfall and climate, be aware of the impact of dormancy on survival
• if using pre-inoculated seed, ensure it is sown within six weeks of the inoculation date.
• using other seed treatments and/or primers to minimise problems caused by pests and diseases..

Seeding rate

A lower seeding rate will result in lower production, whilst providing greater opportunity for weeds to germinate and establish. Always take note of the recommended seeding rate and if conditions are less than ideal, consider increasing the rate.

Seedbed preparation

Seeding methods are a personal choice. Common seeding options include:

• a prepared seedbed
• direct drilling
• broadcasting.

Whatever the seeding method, important things to remember are:

• sow seed shallow as sowing too deep will reduce germination and establishment
• do not drop seed on the surface as it can often lead to ‘harvesting’ by ants, or the seed drying out before the root enters the soil
• aim to sow to a depth of 1-2 cm, cover lightly with soil and get good seed-soil contact (use a rubber tyred roller or similar).
• for sowing in wet conditions or flood-prone areas, see Pastures in Wet Conditions.

Select the right sowing window

• Monitor forecasts and soil moisture to time sowing effectively.
• Sow when conditions are favourable for at least a couple of weeks after sowing and aim to sow when the soil has a good moisture profile.
• Sowing into the late autumn-winter will reduce pasture establishment, growth and production.
• High soil temperatures will inhibit the germination of many annual pasture species.
• The ideal soil temperature (at sowing depth) for ryegrass is 15-25°C. The most practical indicator is to use average daily air temperature over a period of 7-10 days.
• You can use Farming forecaster to use free data to inform your decisions. Autumn rainfall is the key trigger for germination.

Monitor and maintain pastures

Proper establishment and maintenance of the new pasture are essential for its growth and persistence. Ensure good seedset by minimising grazing during the flowering and seed production period.

This video shows how to calculate plants and pasture cover using a pasture square and counting plants in sown rows.

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Video transcript

Sown rows and the pasture square

I’m Wendy Gill with the Central West Local Land Services, Mixed Farming Officer based at Forbes.

Today we’re going to look at calculating plant establishment in sown row crops. We use this calculation to help make sure we are making some critical decisions about your enterprise.

One of these decisions is to objectively monitor and adjust your seeding rates to hit your targeted yields. It will also assist you on-farm for your fertiliser budget decisions and management going forward with all your sown row crops.

Using the LLS Pasture Square, walk into your sown row crop paddock and choose a random row using the one-meter rule.

Lay it on the ground between the rows and count along the length of the one-meter rule how many plants have actually germinated in the establishment along the furrows.

Record this number on the recording sheet or in a notebook. Ideally, repeat this process at least 10 times.

Using the conversion table on the Local Land Services Pasture Square, align your row spacings in either centimetres or inches to your sowing implement.

Use this conversion table to convert your row spacing measurements for your own equipment to rows per meter squared. Record this figure on the recording sheet.

Now use those combined figures of your average plants per meter and multiply by the number of rows per meter squared to calculate the plants per meter squared within your sown crop.

This formula can also be found on the Local Land Services Pasture Square for easy reference.

If you need to convert your plants per meter squared figure to plants per hectare, multiply this figure by 10,000.

Use your workings from all your sown crops to calculate plants per hectare as your establishment figure.

You can also refer to industry plant-based population guides for different sown crops, whether that be a cereal, a pulse, or canola.

Use your establishment figures to compare them against industry standards to ensure your plant population and establishment of your sown row crops are at adequate levels to achieve your desired goals for your enterprise and end use, whether that’s for livestock fodder or for grain

You can help maintain your pastures by:

• using appropriate grazing management, not grazing too early but grazing lightly to encourage tillering and good root development
• continuing to control weeds and pests
• using improvements like fertilisers including gibberellic acid
• reducing biomass by slashing and mulching.