Forage production from irrigated oats or ryegrass grown with annual legumes or nitrogen in south-eastern Queensland

Abstract

The production of irrigated Saia oats (Avena strigosa) and Wimmera ryegrass (Lolium rigidum) grown with annual temperate legumes or nitrogen fertilizer was studied over two years on a black earth at Gatton, south-eastern Queensland. Jemalong medic (Medicago truncatula) grown with oats or ryegrass, was more productive than alternative legume/grass forage combinations. Total dry matter and nitrogen yields of both Jemalong and snail (M. scutellata) medic mixtures were similar to those of oats or ryegrass fertilized with 205 kg ha-lN in 1974. In 1975, Jemalong mixtures gave higher dry, matter and equivalent nitrogen yields to the respective forages fertilized with 336 kg ha-1 N. Snail medic gave the best early production, reaching maximum growth in late winter, about a month earlier than Jemalong. The other legumes did not contribute to production until spring. In 1974, total production of oats and ryegrass was similar, but in 1975 ryegrass production was the greater.