effect of different planting distributions on yield and forage quality of common vetch (vicia sativa l. )

abstract     in order to select the best planting distributions on the rows and study their effects on morphological traits and uptake amount of some nutrients including nitrogen, phosphorus, potassium and calcium in forage of common vetch (vicia sativa) a factorial experiment was carried out with randomized complete block design and 3 replications in research field of mohaghegh ardabili university in ardabil, iran. the first factor was the distance between rows including 25, 35 and 50 cm and the second factor was the distance between plants on the rows including 10, 15 and 20 cm. results demonstrated that the effect of distance between rows was significant on green cover percentage. but the main effects and interaction of distance between rows and between plants on the rows were not significant on traits including number of secondary branches, plant height and plant weight at 10 percent flowering stage. also, effect of distance between rows and between plants was not significant on fresh forage yield and by decreasing these distances, the yield increased. mean comparisons demonstrated that planting distributions of 35×20, 35×15 and 50×20 cm increased phosphorus percentage of plants compared to other treatments and the least amount of phosphorus was acquired by planting distribution of 20×20 cm. the effect of planting distribution was not significant on potassium and calcium percentage. generally, in this experiment the best planting distribution in order to acquire maximum amount of fresh and dry forage in vetch was 20×20 cm, but for the maximum protein content the pattern of 20×50 cm is recommended.