Influence of Organic and Inorganic Nitrogen on Grain Yield and Yield Components of Hybrid Rice in Northwestern Pakistan

Field experiments were conducted to assess the impact of various organic sources, inorganic nitrogen (N) and the different combinations of inorganic N (urea) + organic source on the yield components (YC) and grain yield (GY) of hybrid rice (Oryza sativa L., Pukhraj) under rice-wheat system. The experiments were conducted at Batkhela (Malakand), Northwestern Pakistan, in 2011 and 2012. Our results revealed that YC and GY ranked first for the hybrid rice when applied with sole inorganic N (urea), followed by the application of N in mixture (urea + organic sources), while the control plots (no N applied) ranked in the bottom. Among the six organic sources (three animal manures: poultry, sheep and cattle; three crop residues: onion, berseem and wheat), application of N in the form of poultry manure was superior in terms of higher YC and GY. When applying 120 kg/hm2 N source, 75% N from urea + 25% N from organic source resulted in higher YC and GY in 2011, while applying 50% N from urea + 50% N from organic sources caused higher YC and GY in 2012. Therefore, the combined application of N sources in the form of urea + organic source can produce good performances in terms of higher YC and GY of rice under rice-wheat cropping system.