Yield and Nutrition of Rice under Upland and Waterlogged Conditions —Effect of Nitrogen, Phosphorus and Silica

Studies on the influence and interaction of N, P and Si applied to rice plants have shown that nitrogen and phosphorus benefitted the dry matter yield more under waterlogged than under upland conditions. Silica also increased the yield irrespective of the conditions of growth. Nitrogen under waterlogged condition did not influence either the total uptake or composition of both N and P. No significant interaction occurred between nitrogen and conditions of growth as regards per cent fertilizer phosphorus uptake, utilization and ‘A’ value. On application of phosphorus, both per cent utilization of added P and ‘A’ value increased under waterlogged condition but the crop met its major demand from the soil. With silica, per cent fertilizer phosphorus uptake and ‘A’ value remained unaffected but utilization of applied phosphorus and total nitrogen uptake decreased under waterlogged condition Silica content increased under both but more markedly under the upland conditions.