Agronomic performance of summer forage crops on a Waikato dry-stock farm

Abstract

Forage crops options are required by dry-stock farmers to fill summer feed gaps. This trial compared a brassica monoculture with simple and hyper-diverse mixtures containing up to 21 forage species sown in October on a Waikato dry-stock farm. Two of the twelve treatments were established at paddock scale. Species included rape, oats, plantain and red clover. Seedling emergence was assessed four weeks after sowing and herbage production, metabolisable energy and botanical composition in mid-January. Rape was common in all mixtures for the provision of high-quality forage. Oats suppressed rape production, even at low sowing rates (<13 kg/ha), and reduced weed ingress. Plantain, sown at <2 kg/ha, contributed negligible dry matter in mid-January but provided ground cover and additional forage by late February. Red clover failed to establish. Most diverse treatments provided a similar energy yield (MJ ME/ha) to rape. Simple mixtures and hyperdiverse mixtures were similar for most metrics. Results at plot and paddock scale were consistent for the energy yield effects. When these data were combined with production costs, the energy costs were similar for most treatments. The most promising was a rape dominant mixture, with high energy yield, low weed abundance and low energy costs.