Growth and Nitrogen Use Efficiency Response of Wheat (Triticum aestivum L.) and Wild Mustard (Sinapis arvensis L.) to Increased Nitrogen Levels

To investigate wheat and wild mustard growth and competition to N levels، an experiment was conducted in Ramin Agriculture and Natural Resources University of Khouzestan، located at 36 km North of Ahvaz. Treatments included planting wheat solely، wild mustard solely، and intercropping wheat and wild mustard in pots. These combinations were exposed to N levels including 0، 60، 120 and 180 kg. ha-1. The results showed that grain yield، dry matter and spike number of wheat increased by increased N levels in sole crop treatment. These traits decreased by N levels when competing against wild mustard. Wheat grain and total protein content increased up to 120 kg N. ha-1 by increased N levels، but decreased while competing against wild mustard. The highest N apparent recovery by wheat was obtained from sole cropping of this crop and 120 kg N. ha-1. The lowest rate of this parameter was observed in competition condition against wild mustard and the level of 180 kg N. ha-1. The results showed that wild mustard traits had positive response to increased N levels، regardless to competition against wheat.