Effect of Organic and Inorganic Sources of Nitrogen on N, P, K and S Content of Rice Grain at Harvest and Straw at Different Stages of Rice (Oryza sativa) Crop Growth

The soil of experimental site was sandy clay loam in texture with normal pH, low in nitrogen and phosphorus and medium in organic carbon and potassium contents. The experiment was laid out in Randomised Block Design with nine treatments replicated thrice. The treatments were applied to rice crop during kharif season. Application of N through chemical fertilizer (T₉) increased the N, P, K and S contents significantly at different stages including grain and straw at harvest by the crop over no fertilizer/manure (T₁). Among various organic N sources, N application through combination of D.S, P.M and C.W @ 40 kg N ha⁻¹ each (T₈) resulted in higher N, P, K and S contents in plants over all other organic N sources at all the stages of straw and grain. Application of N through chemical fertilizer (T₉) brought about significant improvement in grain and straw yields of rice crop and established superiority over rest of the treatments. Among organic N sources, supplication of N through combination of D.S + P.M + C.W @ 40 kg N ha¹each (T₈) increased the grain and straw yield significantly as against the application of rest of the organic N sources and the control (T₁) except the straw yield due to incorporation of P.M alone (T₃) which remained at par.