Response of black gram to soil amendments and phosphorus in acidic soil of Nagaland

Aim: To assess the influence of soil amendments and phosphorus on the performance of black gram, and to determine the optimum dose of phosphorus for better seed yield of black gram (Vigna mungo L. Hepper) in acid soil of Nagaland. Methodology: Four soil amendment levels [SA0 (control), SA1 (5% LR), SA2 (PSB), SA3 (5% LR + PSB)] and four phosphorus levels (0, 20, 40 and 60 kg P2O5 ha-1) were laid out in a Factorial Randomized Block Design with three replications. Black gram variety SBC-40 was sown at a spacing of 30×10 cm. The data were statistically analysed by Fisher-Snedecor ‘F’ test at 0.05 level of probability, and the optimum dose of phosphorus was estimated by employing linear regression on the basis of seed yield of two years of field trails. Results: Soil amendments and phosphorus significantly influenced the growth, yield attributes and yield of black gram. The pooled seed and stover yield increased by 29.9% and 35.7% over SA0 in response to SA3, and by 45.3% and 55.9% over control (P0) in response to 60 kg P2O5 ha-1 (P60), respectively. The optimum dose of phosphorus application was estimated to be 49.35 kg P2O5 ha-1. Interpretation: The study inferred that 50 kg P2O5 ha-1 as sole application or SA3P40 (5% LR+ PSB + 40 kg P2O5 ha-1) were found to be most promising for obtaining better yield of black gram under acidic soil of Nagaland. Key words: Acidic soil, Black gram, Phosphorus level, Soil amendments