Forage yield improvement at proper ratio and seed density of smooth vetch and barley mix cropping under cold rain-fed conditions

Abstract

The mixing ratios of barley (Hordeum vulgare L.) cv. Abidar and smooth vetch (Vicia dasycarpa L.) cv. Maragheh were studied at Dryland Agricultural Research Institute under cold rain-fed conditions during 2009–2011 growing seasons. The mix cropping treatments comprised of pure vetch, vetch with barley at 3:1, vetch with barley at 1:1 seeding ratio and pure barley. There was one seeding rate (100 seeds m−2) for barley and five different seeding rates of vetch including 100, 150, 200, 250, 300 seeds m−2 (D1, D2, D3, D4, D5). Higher dry matter (DM) yields were obtained across different seed rates for the vetch mixtures than related monocultures. The highest DM and the lowest protein content over years were obtained from pure barley. The combination of vetch with barley at 1:1 seeding ratio in the D2 density produced 16 ton ha−1 dry forage and 1 ton ha−1 protein. The highest land equivalent ratio over two years (1.44) was belonged to mixture of vetch with barley at 3:1 ratio in D5 seeding rate. It was concluded that, mixture of vetch with barley at 1:1 seeding ratio in D5 smooth vetch density was the best mixing ratio and seed density regarding both forage quality and quantity under cold rain-fed conditions.