Evaluation of Quantitative Yield and Some Physical Properties of Soil in Three Years Mixed Barley (Khorram)-Vetch Forage (Vicia sativa) Cropping System under Rain-Fed Conditions

The current investigation was carried out in order to compare the different ratio combinations of intercropping vetch, barley regarding forage quantitative yield and soil physical properties. The study was conducted in Gachsaran dryland research station from 2010 for 3 growing seasons based on a randomized complete block design with three replications. The treatments included different intercropping combinations of vetch and barley: 75% + 25%, 50% + 50%, 25% + 75% and sole culture of each plant species. The results showed that the highest forage fresh yield, forage dry yield and grain yield were obtained from barley monoculture (17.2, 5.9 and 3.5 t.ha-1 , respectively) and 25% vetch + 75% barley (15.5, 4.9 and 2.5 t.ha-1, respectively). Maximum land equivalent ratio (LER) was achieved from 25% vetch + 75% barley intercropping treatment with 1.03 which exhibits a slight improvement in forage production compared with monoculture system. Intercropping ratios didn’t affect soil moisture content within soil 0-30 cm depth. Intercropping of barley and vetch improved soil bulk density within three depths of sampling (0-10, 10-20 and 20-30 cm) as soil bulk density after study decreased compared with before the start of experiment. The 10-20 cm layer of soil had the highest bulk density and intercropping treatments particularly with 75% barley + 25% vetch caused significant decline in bulk density in this layer compared with mono-culture (either barley or vetch) treatments. In general, intercropping barley and vetch with combination of 75%:25% is recommended for Gachsaran region due to the positive effect on soil bulk density in long term, producing a yield similar to barley monoculture and increasing variety in agricultural productions. .