As seen in Farm Weekly, 13/02/2025

Effective pasture management relies on selecting the right components to enhance productivity, soil health and livestock nutrition.

Among the most valuable additions to any pasture system are legumes.

These nitrogen-fixing plants naturally enrich the soil, reducing the need for synthetic fertilisers while providing high-quality forage that supports livestock growth and farm sustainability.

Choosing the right legume species is essential for developing resilient, high-performing pastures and ensures long-term benefits for both livestock and land.

They provide high-protein forage that enhances animal nutrition and improve soil structure, increasing resilience to variable climatic conditions whilst enhancing biodiversity and extending seasonal growth for grazing rotations.

The success of legumes in pastures depends on several key factors, including suitability to soil and climate, persistence and regeneration, compatibility with other pasture species, and grazing management and utilisation.

Different legumes thrive in varying soil types, rainfall levels, and climatic conditions, with an optimal soil pH of around 5.5 (CaCl2).

Hard-seeded varieties ensure long-term productivity, particularly in regions prone to false breaks.

Balancing legumes with grasses optimises pasture nutrition and sustainability, while the ratio of legumes to grasses varies depending on livestock type, with sheep requiring a higher proportion of legumes compared to cattle.

Aerial-seeded clovers such as Balansa, Persian and Strawberry clover are ideal for wetter, waterlogged, or saline-prone areas, while deep-rooted legumes like Serradella, Arrowleaf, and Biserrula access moisture up to two metres deep, making them resilient in dry conditions.

Hard-seeded legumes establish persistent seed banks, ensuring long-term pasture regeneration.

The agronomic advantages of legumes include nitrogen fixation, improved soil health, and nematode cycle disruption.

Properly inoculated forage legumes can fix between 20–140kg of residual nitrogen per hectare, reducing the need for nitrogen fertiliser.

Supporting rhizobia populations enhances nutrient absorption and benefits subsequent crops, while species like Serradella and Biserrula help break nematode-breeding cycles, improving future crop yields.

Irwin Hunter & Co. offers a wide range of legumes suited to different pasture and production systems, including Subterranean clovers such as Dalkeith, Leura, Riverina, Nungarin, Seaton Park, and a white-seeded type Riverina.

Aerial-seeded clovers include Paradana Balansa, Casbah Biserrula, Crimson clover, Hykon Rose clover, Kyambro Persian clover, Prima Gland clover, Shaftal Persian, Strawberry clover, and Haifa White clover.

Lucerne varieties include ALPHA 1, Icon and Sceptre.

Serradellas and Medics offered are Cadiz, Eliza, Margurita, Fran2o, Santorini, Serramax and Cavalier Medic.

Additional alternatives include peas, cowpeas, Freyr Sunnhemp, Dash Lablab, and Faba beans.

Irwin Hunter & Co's Nitro Mix of legumes contains all bare seed with no chemical treatments and is suitable for organic farmers.

Nitro Mix is a versatile cover crop and includes a selection of aerial-seeded clovers, Subterranean clovers, hard-seeded Serradella, and Balansa.

Rob Diletti purchased Nitro Mix through Nutrien, Mt Barker, to use as an interrow on the family's vineyard, Castle Rock Estate, in the Great Southern area of Porongurup and has been very pleased with the results.

Nitro Mix offers multiple benefits for soil health, plant growth and sustainability.

A dense legume ground cover suppresses weeds, reducing competition for resources and minimising herbicide use.

Its deep-rooting systems improve soil structure, enhance water infiltration, and help retain moisture during dry periods while preventing waterlogging in wetter conditions.

This contributes to a balanced soil environment that supports consistent productivity.

Plants incorporated back into the soil will also provide accessible nitrogen to neighbouring plants, enhancing soil structure and character.

Beyond soil fertility, legumes promote biodiversity by attracting beneficial insects such as pollinators and predatory species that help control vineyard pests.

Their organic matter contribution enhances microbial activity and long-term soil health.

Hard-seeded varieties, including Serradella and Subterranean clovers, establish a persistent seed bank, ensuring self-regeneration and long-term sustainability with minimal reseeding.

This diverse legume mix provides a cost-effective and environmentally friendly solution.

By reducing reliance on fertilisers, herbicides, and irrigation, farmers can lower input costs while maintaining soil fertility and resilience.

Legumes play a vital role in creating healthier, more productive ecosystems through improved nitrogen fixation, moisture retention, and weed suppression.

Contact your local farm supplier or Irwin Hunter & Co. for more information regarding the extensive range of pasture seed and mixes.