Influence of annual ryegrass and barley seeding rates on intercrop forage yield and quality

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 ryegras...