اثر كود اوره ، اوره با پوشش گوگردي و روشهاي كاربرد آنها بر عملكرد دانه ، بازده و بازيافت نيتروژن در برنج (رقم نعمت )

Effects of Urea and SCU Fertilizer and their Application Methods on Grain Yield, Nitrogen Efficiency and Recovery in Rice (Variety Namat)

Effects of different application methods (surface application, incorporation and deep placement) of urea and sulfur coated urea (SCU) fertilizers on the grain yield of rice were studied in a clay soil at Rice Research Institute of Iran (Rasht). The experiment was performed in post using a factorial experiment based on randomized complete block design with three replications. After puddling the soil inside the container, 3 seedlings of Nemat Variety were transplanted in the center of each pot. Ninty kg/ha of nitrogen (in the forms of urea and SCU) and 54 kg/ha of phosphorus (tripple supper phosphate) were applied based on soil test results. Traits such as of percentage empty spikelets , harvest index, grain yield, plant height, efficiency of nitrogen fertilizer and nitrogen recovery were measured in each pot. The results showed that SCU application, as compared to urea, significantly increased efficiency of nitrogen fertilizer, nitrogen recovery and grain yield of rice. Incorporation of SCU into the surface layer, and its deep placement ( 8-10cm) both significantly increased the nitrogen efficiency, nitrogen recovery and grain yield compared to surface application of urea. Deep placement of urea resulted in higher efficiency of nitrogen fertilizer, nitrogen recovery and grain yield as compared to its surface application.