Yield and composition of short-term pasture mixtures containing Italian ryegrass, red clover and balansa clover

Abstract

The inclusion of red clover and/or balansa clover in short-term seed mixtures with Italian ryegrass might improve the yield and weed suppression of the sward. A field experiment was conducted to investigate the effect of combining red clover and balansa clover with Italian ryegrass in thirteen mixtures of different proportions of the three species sown at two total amounts (20 and 30 kg/ha). The experiment was conducted from 10 March to 18 October at Lincoln, Canterbury. Accumulated yield was greater (P<0.01) for plots sown at 30 kg/ha than those sown at 20 kg/ha (7040 vs 7420 kg DM/ha), but no effect of mixture was found. At the first harvest (11 May), yield decreased as sown proportion of Italian ryegrass was reduced from 810 kg DM/ha for the Italian ryegrass monoculture to 420 kg DM/ha for mixtures containing 50% legume. Tiller population was 1830/m² compared with 1600/m² for mixtures sown at 30 and 20 kg/ha respectively. Tiller population and tiller weight were unaffected by seed mixture at subsequent harvests and tiller weight was unaffected by either factor at harvests. Weed content was suppressed by all seed mixtures at each harvest. The Italian ryegrass contributed at least 85% of the yield over the 7 month period, but balansa clover contributed more yield than red clover in spring.