Soil nutrient dynamics as influenced by varied agrotechniques in Rabi pigeonpea

A two year study was conducted during rabi 2012–13 and 2013–14 to investigate soil and plant nutrient dynamics as influenced by times of sowing, nutrient levels and foliar applications to pigeonpea. The experiment was laid out in split-split design replicated thrice, with three replications having three times of sowing [II FN of September (T₁), I FN of October (T₂) and II FN of October (T₃)] in main plots, three nutrient doses [10-40-0 kg N, P₂O₅ and K₂O ha 1 (N₁), 20-50-10 kg N, P₂O₅ and K₂O ha 1 (N₂) and 30-60-20 kg N, P₂O₅ and K₂O ha 1 (N₃)] in sub-plots and two foliar sprays [NAA (25 ppm) and DAP (2 per cent) applied at 60 DAS (F₁) and NAA (25 ppm) and DAP (2 per cent) applied at 60 and 80 DAS (F₂)] in sub-sub plots. Crop sown during II FN of September (T₁) significantly improved seed and stalk yield relative to late sowings. Application of 30-60-20 kg N, P₂O₅ and K₂O ha 1 (N₃) enhanced seed and stalk yield, during both the years. Foliar spray of NAA (25 ppm) and DAP (2 per cent) at 60 and 80 DAS (F₂) significantly improved seed and stalk yield of redgram during both the years. Crop sown during II FN of September receiving 30-60-20 kg N, P₂O₅ and K₂O ha 1 (T₁N₃) significantly improved seed and stalk yield. Seed yield was the highest with II FN of September sowing along with foliar spray of NAA (25 ppm) and DAP (2 per cent) at 60 and 80 DAS (T₁F₂), during both the years. The highest nutrient (nitrogen, phosphorus and potassium) uptake and lowest post harvest soil nutrient status were with the earliest sown crop during II FN of September (T₁) during both the years. Application of 30-60-20 kg N, P₂O₅ and K₂O ha 1 (N₃) resulted in the higher nutrient uptake and soil nutrient status at harvest. With regard to foliar sprays, nitrogen uptake during first year and phosphorus uptake during both the years, were the highest with NAA (25 ppm) and DAP (2 per cent) foliar spray at 60 and 80 DAS (F₂). The highest phosphorus uptake during both the years and potassium uptake during second year were with crop sown during II FN of September along with the nutrient dose of 30-60-20 kg N, P₂O₅ and K₂O ha 1 (T₁N₃). Significant improvement in post harvest soil fertility status (nitrogen, phosphorus and potassium) after rabi redgram was with the crop sown during II FN of October (T₃). Among the nutrient doses, 30-60-20 kg N, P₂O₅ and K₂O ha 1(N₃) resulted in the improved residual soil fertility status, during both the years.