Effect of phosphorus levels and sources on productivity, nutrient uptake and soil fertility of maize (Zea mays)–wheat (Triticum aestivum) cropping system

A field experiment was conducted for two years (2006–07 and 2007–08) at New Delhi during the kharif and rabi seasons on sandy loam soil to assess the effect of single super phosphate and rock phosphate with different levels of phosphorus and biofertilizer on maize (Zea mays L.)–wheat {Triticum aestivum (L.) emend. Fiori & Paol} cropping system. The results revealed with application of 90 kg P₂O₅/ha through single super phosphate and biofertilizers, maize recorded higher mean yield attributes, grain yield, straw yield, and N and P uptake over no phosphorus, 90 kg P₂O₅/ha through rock phosphate and 45 kg P₂O₅/ha through single super phosphate or rock phosphate and no inoculation. Residual effect of 90 kg P₂O₅/ha through single super phosphate or 90 kg P₂O₅/ha through rock phosphate applied to maize being on par, recorded higher mean yield attributes, grain yield (4.29 t/ha), straw yield, and N and P uptake in wheat over lower levels of phosphorus irrespective of sources. Direct application of phosphorus to wheat up to 90 kg P₂O₅/ha enhanced the mean yield attributes, grain yield (4.04 t/ha) and N and P uptake. Application of biofertilizer recorded higher yield attributes, yield (grain and straw) and N and P uptake in wheat crop over no biofertilizer. Phosphorus balance in soil increased with increase in P fertilization to the system.