Effect of levels of nitrogen, phosphorus and potassium on productivity, nutrient uptake and soil fertility in rice (Oryza sativa) in an Alfisols of Tambiraparani tract
Abstract
A field experiment was conducted during the winter (rabi) seasons of 2011–12 and 2012–2013 at Agricultural College and Research Institute, Killikulam, Tamil Nadu, to study the effect of different levels of NPK on productivity, nutrient uptake, economics and soil fertility of rice (Oryza sativa L.). The experiment was carried out in randomized block design and replicated thrice with 7 treatments involving of 3 levels of N and 2 levels of P and K each. Application of 200: 75: 75 kg N: P: K/ha resulted in the maximum plant height (95.7 cm), productive tillers/plant (18.3), panicle length (27.2), grains/panicle (25.3), seed weight (24.1 g), grain yield (7.04 t/ha), straw yield (8.58 t/ha), net returns (52.6 × 103/ha) and benefit: cost ratio (1.65), N, P and K (171.9, 28.6 and 185.2 kg/ha respectively) uptake compared to the control. Significant built up of organic carbon (1.24%), available N (326.7 kg/ha), available P (21.4 kg/ha) and available K (362.7 kg/ha) was registered with 200: 75: 75 kg N: P: K/ha. The maximum balance of N, P and K (50.7, 5.6 and 74.0 kg/ha respectively) were also recorded under the same treatment.
Keywords
Alfisols, Available nutrients, Grain and straw yields, NPK levels, Nutrient content and uptake
