The response of vetch (Vicia sativa) growth and yield to planting density and starter nitrogen under conservation and conventional conditions

Considering the ecological adaptation of vetch (Vicia sativa) to dryland cultivation in subtropical regions and the importance of dry land regions for increasing forage production while preserving water and soil resources, it is necessary to conduct agronomic researches regarding vetch production under conservation system in these regions. The current study was conducted to investigate the influence of planting density, starter nitrogen level and tillage practices (conventional and conservation) on vetch (vicia sativa) growth and yield under rain fed semi tropical conditions (Gachsaran dryland research station). The experiment was laid out as a strip split plot in three replicates for three years. The treatments included residues of preceding wheat (with or without), planting density (100, 150 and 200 per m2) and applied nitrogen as starter fertilizer (0, 15 and 30 kg ha-1 N). Based on the results of analysis of variance, none of treatments had significant effect on early growth, days to flowering and ripening and plant height. The results showed that retaining preceding wheat residues caused significant increase in fresh forage and grain yield. For the most studied traits, adding starter nitrogen fertilizer didn’t cause any significant effect especially when the residues were retained upon the soil. If producing forage is the main purpose of seeding vetch, 150 seed per m2 planting density is recommendable while for seed production 100 seed per m2 seeding rate leads to better seed yield.