The Effect of Different Sources of Pre-Plant Nitrogen-fertilizers and Humic Acid on Yield and some Physiological Traits of Wheat Pishtaz Cultivar

In order to evaluate the effect of different pre-plant nitrogen-fertilizers (urea, ammonium sulfate, sulfur-coated urea and non-using pre-plant n-fertilizer and humic acid (using and non-using) on grain yield, yield components and nitrogen use efficiency in wheat, an experiment was conducted as a factorial based on randomized complete blocks design with three replications in Research Farm of Iranians Modern Farms Company in Varamin during 2015-2016cropping year. Results indicated that the effect of type of nitrogen-fertilizer on all under studied traits was significant. The highest plant height, biological yield, number of tillers per plant and number of spikes per square meter were obtained at urea fertilizer treatment. But the highest one-thousand grain weight, number of grains per spike, grain yield and harvest index were achieved at sulfur coated urea and application of sulfur coated urea increased grain yield by 10 and 23.2 percent, compared to urea and ammonium sulfate, respectively. Also, humic acid application increased one-thousand grain weight, number of grains per spike and grain yield of wheat by the amounts of 14.0, 17.8 and 24 percent, respectively. The application of sulfur coated urea and humic acid, increased nitrogen use efficiency. Therefore, using urea with sulfur coating as a base fertilizer and application of humic acid, can increase the grain yield of wheat while decrease nitrogen leaching.