Agronomic response, physiological and bio-chemical composition of transplanted rice influenced by nutrient management practices

Field experiment was conducted at wetland farm of Tamil Nadu Agricultural University, Coimbatore during kharif season to study the effect of integrated nutrient management practices on transplanted lowland rice. The experiment was laid out in randomized block design with three replications and nine treatments. Rice CO(R) 48 was used as a test variety. Based on N equivalent basis, required quantities of dhaincha, vermicompost, farmyard manure were incorporated before transplanting of rice. The P and K requirement was supplied separately through inorganic sources as per treatment schedule. The results revealed that yield attributes (number of productive tillers m-2 (288), total number of grains panicle-1 (217), percentage of filled grains (89.4) and yield (6248 kg ha-1), panicle parameters (panicle length (28.3 cm), panicle weight (4.64 g ), test weight (18.1 g), physiological and bio chemical parameters (chlorophyll index (36.02), chlorophyll stability index (72.22 %), relative water content (78.43%), soluble protein content (15.58 mg g-1) were significantly influenced with application of 100% NPK through inorganic fertilizers + 6.25 t dhaincha followed by application of 100% N through dhaincha + balance P & K through inorganic fertilizers. Maximum soil enzyme dynamics (urease activity (47.1 µg NH+ g-1 soil 24 h-1), soil dehydrogenase activity (37.1 µg of TPF released g-1 of soil 24 h-1), soil phosphatase activity (39.1 µg of p - nitrophenol released g-1 of soil 24 h-1), nitrogen use efficiency (agronomic efficiency, physiological efficiency and apparent N recovery) and chemical composition like protein (7.41 %), carbohydrates (78.53%), amylose content (27.07 %), fat (0.58 %) and fibre (0.231 %) were high with application of 100 % N through dhaincha + balance P & K through inorganic fertilizers.