Nitrogen-Fixing Legume Seed Mix

Grow legumes that fix their own nitrogen. Well-nodulated pasture legumes typically fix around 20–30 kg of nitrogen for every tonne of shoot dry matter they grow, feeding the pasture and the crops that follow. Our NITROMIX combines sub clover, aerial clovers and a hard-seeded serradella to do just that, while also improving soil structure, organic matter and water retention. The more legume you grow, the more nitrogen you fix, so good establishment, effective nodulation and a soil pH of 5.5 (CaCl2) or above all matter.

Sow NITROMIX at 5–10 kg/ha. That looks light next to a ryegrass mix, but clover and serradella seeds are small, and these legumes are normally sown at only a few kilograms per hectare each. Paradana balansa, for example, is sown at 1–4 kg/ha on its own. Use the higher rate where you want a denser legume stand sooner. NITROMIX suits areas with 400 mm or more annual rainfall, sands through to heavy soils, and a soil pH of 5.5 (CaCl2) or above.

Yes, they use different rhizobia. The clovers in NITROMIX (Paradana balansa, arrowleaf, Hykon rose, Riverina sub clover and crimson) need Group C inoculant, while Margurita serradella needs the serradella inoculant, Group G/S. NITROMIX is coated with BioNPK Powder S, a biological that helps make nitrogen, phosphorus and potassium available to plants. It doesn't replace rhizobia, so check the bag label, or ask us, to confirm the seed is inoculated before sowing, and use fresh inoculant for any component that isn't.

A blend of legumes is the best way to cover variable country, because each species does best where it suits. In NITROMIX, Paradana balansa and Riverina sub clover tolerate waterlogging on the wet flats, while Margurita serradella is well adapted to acidic, infertile sands and Hykon rose clover suits lighter, low-fertility soils. Arrowleaf adds deep roots that reach subsoil moisture. Avoid saline patches, though: Paradana has low salt tolerance, and arrowleaf doesn't suit saline or highly alkaline soils.

Sow a mix that includes hard-seeded legumes. Hard seed doesn't all germinate on the first rain, so if a false break kills the first flush of seedlings, seed held in reserve can still come up later. NITROMIX blends soft and hard-seeded varieties. Paradana balansa, Margurita serradella and arrowleaf carry high levels of hard seed, and Hykon rose clover's high hard seed level means it tolerates false breaks. Crimson clover, being soft seeded, is susceptible to germinating after a false break, so it relies on the others for back-up.

Graze lightly in the first year and ease off during flowering so the plants set plenty of seed. That first seed set builds the seed bank every later year depends on. In NITROMIX, Paradana balansa should be lightly grazed in year one with limited grazing during flowering, and it will regenerate poorly if cut for late silage or hay. Hykon rose clover is very palatable, so avoid overgrazing it in late spring. Crimson and Hykon rose self-regenerate when they're allowed to set seed.

Yes. Bloat is a risk whenever stock graze young, lush pasture with a high legume content. In NITROMIX, arrowleaf and Hykon rose clover are non-bloating, but the other clovers don't carry that rating, so treat the paddock as a bloat risk. Fill stock up on hay before introducing them, restrict intake with strip grazing or limited grazing time, and consider anti-bloat products during lush growth. Watch stock closely in the first few days and talk to your vet about a prevention plan.

Yes. A legume phase adds nitrogen for the following crop, and NITROMIX is suited to break crop, cover crop and grazing use. Its hard-seeded components, including Margurita serradella, build a seed bank that makes it easier to switch between cropping and pasture phases. Let the legumes set seed in the pasture year so they can regenerate after cropping. Before sowing, check paddock herbicide history, as residues from the cropping phase, particularly sulfonylurea herbicides, can damage pasture legumes.

Add later-maturing, deep-rooted legumes to stretch the season. Arrowleaf clover grows tall and erect with deep roots that reach subsoil moisture, producing feed into late spring and summer, and crimson clover produces high-quality, palatable feed into late spring. NITROMIX combines these with Riverina sub clover, known for excellent autumn and winter growth, and early-flowering Hykon rose clover with good spring production. That spread of early and later flowering clovers extends both the growing season and flowering.

Sow as shallow as possible into a well-prepared seedbed with good soil moisture and the chance of follow-up rain. Spray out existing pasture and persistent weeds first, and apply lime or gypsum if your soil test calls for it. On sand, take care that seeding troughs don't fill with wind-blown sand and bury the seed. If broadcasting, run a light roller behind the seeder to improve seed-soil contact, but not on wet soils that may crust. In NITROMIX, expect Paradana balansa to establish slowly in cool weather.