Response of irrigated rice to the application of poultry manure and inorganic fertilizers N, P, and K in Karnataka, India

The integrated use of organic manures and inorganic fertilizers is important to sustain a higher level of soil fertility and productivity. Poultry manure is a rich source of nutrients and is available in abundant quantity near poultry farms. It has not been fully exploited as a source of organic manure. Hence, we studied the response of rice to poultry manure and NPK under irrigated conditions. The poultry manure used in this experiment contained 3.03% N, 2.6% P, and 1.4% K. The field experiment was conducted during the 1998 and 1999 wet seasons (Aug-Dec). The soil has pH 8.2, 260 kg available N, 42 kg available P, and 650 kg available K ha -1 . The available N, P, and K were estimated by the Kjeldahl, Olsen's, and flame photometer method, respectively. The experiment was a split plot conducted at ARS with poultry manure in the main plot and NPK levels in the subplot, replicated thrice. The agronomic efficiency of N (AEN) was calculated by taking the ratio of rice yield to total N applied (Venugopalan and Prasad 1992).