The response of pigeonpea (Cajanus cajan L.) to direct (fresh) application of fertilizer phosphate (P) or to residual P in soil from the adequately fertilized preceding wheat (Triticum aestivum) was investigated in a field experiment conducted for three years on a semi-arid irrigated Gurdaspur loam soil (Udic Haplustalf). Pigeonpea showed significant response to direct application of P up to 40 kg P2O5 ha-1 in plots where previous wheat crop did not receive any fertilizer P. However; in plots where wheat was fertilized with recommended level (60 kg P2O5 ha-1), the following pigeon pea crop did not respond to any fresh application of P. A significant and consistent yield and P-uptake response of pigeonpea was observed to residual P. Thus, in pigeonpea-wheat rotation, direct application of recommended level of P to wheat can meet the P requirement of both the crops.
Phosphorus fertilization
