Response to phosphorus applied in rainy season crop and . nitrogen applied to wheat (Triticum aestivum) under sorghum (Sorghum bicolor)lcowpea (Vigna unguiculata) wheat cropping system

Abstract

The results of 2 years field experiment showed that fodder yield nitrogen and phosphorus uptake in the rainy season crops increased favourably up to 30 kg P205/ha while grain yield responded up to 60 kg P205/ha. Wheat (Triticum aestivum L. emend. Fiori Paol.) preceded by sorghum [Soghum bicolor (L.) Moench] cowpea [Vigna unguiculata (L.) Walp.] fodder (F), followed by cowpea grain straw incorporation (SI) performed better than grown after sorghum (F). Both these cropping systems contributed 26.38 and 28.62 kg Nlha, respectively, resulting in an increase in wheat yield than sorghum (F) wheat system. Residual effect of phosphorus (applied to rainy season crops 30 and 60 kg P,051ha) increased grain yield of succeeding wheat by 7.53 and 10.13%, respectively, over no phosphorus and also favourably influenced N and P uptake. Grain yield of wheat increased by 26.96 and 32.71 % higher at 75 and 150 kg Nlha, respec tively over the control, while N and P uptake responded only up to 75 kg Nlha.