The quantitative and qualitative characteristics of sainfoin (Onobrychis viciifolia) under different irrigation and nutrient regimes

To study the effect of nutrition and irrigation systems on growth properties and forage quality of sainfoin, this experiment was conducted as factorial split in time, based on a randomized complete block design with three replications at Research Field of Tarbiat Modares University during the 2015-2016 growing season. The combination factorial of fertilizer treatments (vermicompost, urea and non-fertilizer), irrigation methods (alternate and conventional) and irrigation interval (6, 12 and 18-days) were main factors and two cuts were sub factor. The highest dry weight of forage was obtained by six and twelve days conventional irrigation intervals. The highest dry weight of leaf and stem was observed in six days conventional irrigation intervals with vermicompost application. The first cut had the highest NDF by 34% and Potassium by 3.8%. The highest crude protein of 21.9% was observed in the second cut with application of vermicompost and conventional irrigation. The four-way interaction between cut, fertilizer, irrigation interval and method was significant for phosphorous concentration. According to the results, vermicompost can mitigate the effect of deficit irrigation on sainfoin and in the absence of any fertilizer, there was no significant difference between irrigation regimes in terms of yield. On the other hand, the use of alternate irrigation with longer intervals, especially in the first cut, can be investigated according to weather conditions, cost-effectiveness and low differences with other irrigation regimes.