Annual ryegrass (Lolium multiflorum Lam. ’Maris Ledger’) was seeded at rates ranging from 5 to 30 kg ha−1 as either a monocrop or an intercrop with 50, 100 or 150 kg ha−1 of spring barley (Hordeum vulgare L. ’Diamond’). When ryegrass is intercropped with barley, cuts 1 and 2 are usually ensiled and the remainder of seasonal production is pastured (the equivalent of two forage cuts). Monocropped annual ryegrass produced 91% as much dry matter (DM) in the silage cuts as intercropped annual ryegrass and barley but produced 105% as much pasture. Over the season, monocropped ryegrass produced 11.1 t ha−1 of forage compared with 11.7 t ha−1 for intercropped annual ryegrass and barley. Among the intercropping treatments, increased barley seeding rate resulted in greater cut 1 yields, but this was offset by reduced cut 2 yields, so barley seeding rate did not affect the yield of DM for silage. Only 50 kg ha−1 of barley seed was required to obtain maximum yearly forage yields when intercropping with annual ryegrass. No more than 10 kg ha−1 of ryegrass seed was required for optimal yield when monocropping, and no more than 15 kg ha−1 when ryegrass was intercropped with barley. Monocropped ryegrass produced superior quality forage for silage. When quality was weighted for the relative yields of cuts 1 and 2, the monocrop averaged 16% protein and 72% in vitro disappearance of dry matter (IVDDM) compared with 12% protein and 58% IVDDM for the intercrops. Among the intercrops, increasing barley seeding rate from 50 kg ha−1 to 150 kg ha−1 did not affect the protein content of silage cuts, but it decreased IVDDM from 60% to 56%. Pasture forage quality was not affected by barley seeding rate.Key words: Intercropping, annual ryegrass, barley, seeding rate, yield
Effects of the Cutting Time on Forage Yield and Quality in Italian Ryegrass (Lolium-multiflorum Lam.) and Oat (Avena sativa L.) Seeded Singly or in Combination
