Most New Zealand swards consist of clover and rye/fescue grass. Clovers originate from the Mediterranean, where there are warm summers, high pH soils and high levels of natural soil phosphorus (P). As well as being an efficient form of slow-release nitrogen (N), clovers remove trace elements from the soil and make high-quality animal feedstuff.

New Zealand soils have naturally low P levels and are generally acidic, with a lower pH. For clover to thrive, the soil phosphor levels sometimes need to be raised and the soil acidity controlled using lime or fertilisers high in calcium.

On new pastures, clovers can fix the equivalent of 400kg N/hectare/year. On established pastures it can fix about 100-150kg N/hectare/year – enough to replace the production losses of pastures growing 13 to 15 tonnes of DM/hectare/year.

With nitrogen costing around $1.50/kg N applied, this can save you $150 to $220/hectare/year, every year.