FORAGE YIELD AND QUALITY FROM INTERCROPPED BARLEY, ANNUAL RYEGRASS AND DIFFERENT ANNUAL LEGUMES

Six annual legumes were evaluated as components of cereal-grass-legume intercrops in two experiments at two sites differing in elevation by 789 m. Barley (Hordeum vulgare L.) and Westerwolds ryegrass (Lolium mu ltiflorum Lam.) were seeded on all intercrop plots. Dry-matter (DM) yi eld, crude protein (CP) and organic matter digestibility (Ohio) were m easured. DM yield and N content were used to estimate legume N fixatio n. Experiment 1 was conducted at both sites, At the lower site, Persia n clover (Trifolium resupinatum L.) and annual alfalfa (Medicago sativ a L.) accounted for 70% of the DM yield in harvest 1 (July), increased CP and OMD, but did not affect intercrop yield. They increased harves t 2 (August/September) intercrop yield by 263% and CP concentration by 65 g k g(-1) DM. They increased harvest 3 (October) yield by 275% and CP concentration by 78 g kg(-1) DM. Inclusion of striate lespedeza (L espedeza striata) did not affect intercrop yield or quality. Annual le gumes failed to establish at the higher elevation sire and therefore h ad no effect on Dh? yield or forage quality. In Experiment 2, in which the performance of Westerwolds ryegrass was also compared with that o f Italian ryegrass, and conducted at the lower site only, Persian clov er and berseem clover (T. alexandrinum L.) increased CP of all three o f the year's harvests, These two species contributed 29% of the DM yie ld in the first harvest (July) but did not affect total intercrop yiel d, They increased harvest 2 (August) yield by 313%. Persian clover inc reased harvest 3 (October) yield by 318% and berseem clover increased harvest 3 yield by 405%. Barrel medic (Medicago truncatula) and snail medic (M. scutellata) contributed 29% of harvest 1 yield, and increase d both DM yield and CP content, Medics did nor regrow. Aubade Westerwo lds ryegrass contributed a greater percentage of the DM yield than did Maris Ledger Italian ryegrass at harvests 1 and 2. Ryegrass type did not affect total DM yield but did affect forage quality; intercrops co ntaining the Italian ryegrass had higher CP at harvest 2 and higher OM D at harvest 3 than those containing the Westerwolds ryegrass. Over bo th experiments, at the lower elevation site, stands with Persian clove r, berseem clover or alfalfa produced 80% of the yield of barley-ryegr ass receiving 250 kg N ha(-1), and 165% of the yield of unfertilized b arley-ryegrass, Berseem and Persian clover fixed about the same amount of N over the growing season; 188 kg N ha(-1)in Experiment 1 and 134 kg N ha(-1) in Experiment 2.