Perennial Ryegrass Plots Rokewood V3

Selecting your perfect pasture match!

Thinking about sowing a new pasture? There are four main considerations in choosing your perfect pasture mix. I like to think of them as drafting gates, which screen out unsuitable species or varieties.

They are:

  1. Intended purpose
  2. Rainfall and distribution
  3. Soil conditions and
  4. Management needs

Intended purpose

Look at your whole farm and consider what purpose you need your pasture species to fulfill.

Is it to fill a feed gap? For example, do you need to fill a feed gap over summer and need a small percentage of the farm sown to summer actives species to put weaners onto or finish lambs?

Or are looking for a winter active species to fill a winter feed gap?

Other purposes might be to cut hay/silage or for diversity, such as providing somewhere to put stock in case of a ryegrass staggers outbreak.

Rainfall and seasonal conditions

Pasture species guides will specify annual or growing season rainfall. When you get your rainfall is equally important. Areas with reliable summer rainfall can grow summer active species like lucerne.

In summer hot and dry areas, choose winter active varieties with some level of summer dormancy or drought tolerance for their survival.

An exception is in summer dry areas that experience milder summer temperatures. Those areas can support species with little drought tolerance like perennial ryegrass.

Within perennial ryegrass choose heading or maturity dates to occur before the growing season finishes. Earlier maturing varieties are suited to low rainfall areas with 550 to 600mm rainfall, so they can achieve peak production while there is still rainfall and soil moisture.

Likewise, if you have high rainfall, greater than 700mm, then match it with a longer growing ryegrass variety to capture its full growth potential.

Soil type/Conditions:

After rainfall, consider what the soil is like. The soil conditions will often rule out some species.

If the soil becomes waterlogged, then lucerne or cocksfoot will not be suitable.

While topsoil soil acidity can be easily corrected with liming, subsoil acidity that can limit root growth of aluminium sensitive species. In this case you will need to select species with good aluminium tolerance, such as cocksfoot or Advance AT phalaris.

Management or sowing needs

Consider management needs of the pasture variety and if can you meet them.

For example, spring slashing may be required to manage quality of tall fescue which would rule out its use in rocky paddocks.

For winter active phalaris , can you rest it to allow it to reach its full production capacity?

Or are you planning to over-sow into an existing pasture? If so, this method is only suited to species with good seedling vigour, like perennial ryegrass, cocksfoot, or sub-clover.

Narrowing down your choice

Once you have narrowed down your list of species suited to your rainfall, soil, management and intended purpose, you can use the MLA Pasture Trial Network online tool to compare cultivars.

I like to use this tool to check seasonal pasture production of different species and if the top performers consistently perform across different locations.

Don’t just select the cultivars showing the highest total production. They may have the longest growing seasons but might not complete important reproductive stages which helps their summer survival before the season cuts out.

Watch the video for How do I use the Pasture Trial Network (PTN) tool? – YouTube.

Final sowing mix

Your final sowing mix should contain one or two perennial grasses and a companion legume such as sub-clover.

Do not use a shot gun mix with a bit of everything, because inevitably only a few species will survive and those plants that die leave you open to weed invasion and waste money.

Also don’t compromise the establishment of species that are slow to establish, like phalaris and tall fescue by sowing them with highly competitive species like perennial ryegrass as they will fail to compete.

If you do want to add ryegrass to a phalaris mix then add only a small amount, no more than 2 kg/ha.

Final words of advice

If you are still unsure about suitability for your farm, then discuss your needs with your local adviser and find out what grows well in your district.


Image: Perennial ryegrass variety trial at the Rokewood pasture site in winter 2022

Source: L Miller, SFS

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