Effect of Nitrogen Sources Coating Polymers Irradiated by Gamma Rays on N Uptake and Yield Production of Wheat Plants

An experiment was conducted at the green house of The National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo, Egypt to evaluate the impact of N-fertilizer sources either treated with coating materials or not, N-rates on wheat yield and nitrogen uptake by straw and grains. Fertilizer-Nwas applied at rates of 60, 75 and 90 kg NFed -1 . Irradiated gelatin (cap) and cellulose (cel) acetate were used for coating urea and ammonium nitrate fertilizers. Generally, capsulation and coating of both fertilizers resulted in retardation of solubilization and release in leachate. Capsulated urea or ammonium nitrate was superior over cel ones when applied at rate of 60 and 75 kg N fed -1 , while reversible trend was noticed at rate of 90 kg N fed -1 . This holds true with either straw or grain yield at the 1 st and 2 nd seasons. Despite of N-rate and coating treatments, urea seems to be more effective, with some exceptions, than ammonium nitrate when straw and grain yields were considered. The values of straw and grain yields tended to increase with increasing N-fertilizer rates up to 75 kg Nfed -1 . Interaction between the all experimental treatments showed an effective impact on crop yield improvement. Similar trend were observed with N-uptake by straw and grains. Released data concluded that capsulated urea added at rate of 90 kg N fed -1 resulted in the best values of grain and straw yield.