Forage Yield and Relay Intercropping Advantage of Grass pea (Lathyrus sativus L.) and Annual Cereals at Different Cropping Patterns

In order to evaluate the forage yield, crude protein and advantage indices of grass pea-cereal intercropping systems, a field study (2015-2016 and 2016-2017) was conducted as randomized complete block design (RCBD) with 13treatments and three replications at the research station of Faculty of Agriculture, University of Tabriz, Iran. The treatments were sole planting of grass pea, barley, oat and triticale and intercropping grass pea with each of the above cereals (in the flag leaf appearance stage), in three seeding ratios (grass pea: cereal; 25:100, 50:100 and 50:80). The results showed that the highest and lowest forage yield were obtained in 80% grass pea-100% oat (8410 kg.ha-1), 80% grass pea-100% barley (8094 kg.ha-1 and grass pea sole crop (4758 kg.ha-1), respectively. Also, the highest and lowest crude protein was recorded in grass pea (152 g. kg.DM-1) and triticale (77 g. kg.DM-1) monocrops, respectively. The land equivalent ratio (LER) value was greater than one in most of intercropped treatments with the exception of grass pea- triticale (50:100), which indicates advantage of mixtures compared with monocrops. Economic advantage in terms of relative value total (RVT) was greatest in the cases of grass pea mixtures with oat and barley (1.34 and 1.24, respectively) at the 50:80 seeding ratio. Generally, the results of this research showed that the grass pea intercropped with oat and barley at the 50:80 seeding ratio can be selected as the best legume-cereal intercropping systems due to higher forage yield, crude protein and economic benefit.