The effect of different levels of nitrogen and green manure on yield and nitrogen absorption efficiency in Purslane as a medicinal plant

In order to study the effect of green manure and different levels of nitrogen on yield and nitrogen use efficiency in purslane, an experiment was conducted as a split plot design based on randomized complete block design with three replications at the Research Farm of Birjand University in 2014-2015. Four green manure (control (no green manure), Vicia villosa L., Eruca sativa L., and a mixture of Eruca sativa L. and Vicia villosa L.) and three levels of nitrogen (0 (control), 50 and 100 kg. ha-1) were considered as main plots and sub plots, respectively. The results showed that using green manure had no effect on grain and forage yields of purslane. The use of 100 kg.ha-1 nitrogen also led to 18.81 percent increase of dry forage yield (3992.3 kg. ha-1) compared with the control (3360.1 kg. ha-1). In addition, green manure with high nitrogen levels improved the yield and nitrogen content of biomass and decreased absorption and agronomy efficiency of nitrogen based on forage yield. The results revealed that, considering the reduction of nitrogen efficiency despite the use of green and nitrogen fertilizers and taking into account production costs and environmental problems, the nitrogen content in the soil (54.6 kg. ha-1) is sufficient for stable grain production and 50 kg.ha-1 nitrogen for forage production of purslane, and more nitrogen consumption will be a luxury aspect.