Effect of Different Sources of Nitrogen on Yield and Quality of Wheat

A field experiment was conducted in Karaj to study the effects of a few nitrogen sources on wheat (Pishtaz var.) yield and quality. Treatments consisted of, T1: Blank (without N fertilizer) T2: Sulfur coated urea (SCU) T3: Ammonium nitrate and T4: Urea. The experimental design was a completely randomized block design with three replications. The Nitrogen rate was 180 kg N ha-1. The wheat grain yield increased with application of N fertilizers and the highest grain yield was obtained with T3 and it was significantly different with blank and SCU was significant. Difference between SCU and blank on grain yield was significant but it was not significant between Ammonium nitrate and urea. T3 had the highest grain N concentration and it was significantly different from other treatments. Ammonium nitrate had the highest N uptake efficiency (NUE). SCU produced 18.7 kg grain per kg N and in Ammonium Nitrate it was 29.8. The correlation between N uptake and grain yield was positive. Increasing the N uptake enhanced elements uptake. The results showed that in conditions similar to those of experiment and with this materials, SCU can not prepare N to winter wheat in amounts needed.