Effect of different levels of nitrogen and phosphorus on cowpea [Vigna unguiculata (L.) Walp] under rainfed conditions of Rajasthan

Abstract

An field experiment was conducted during kharif 2014 and 2015, at Central Sheep and Wool Research Institute, Avikanagar (Rajasthan) to study the effect of nitrogen and phosphorus levels on growth attributes, herbage yield and quality of fodder cowpea [Vigna unguiculata (L.) Walp.]. All growth attributes were significantly (plant height, branches/plant) higher with 30 kg N/ha applied to cowpea. Maximum green fodder, dry matter yield and crude protein content were recorded (178.11 and 36.12 q/ha and 18.07%) with the use of 30 kg N/ha. Besides, Crude protein content was increased greater extent upto 30 kg N/ ha, but the differences between 20 and 30 kg N levelswas found remained at par with each other for protein content in haulm of cowpea. The application of phosphorus upto 60 kg P2O5/ha resulted maximum raised in green fodder and dry matter yield (179.06 and 35.83 q/ha) as compared to other levels. Crude protein content in dry matter was responded well upto 60 kg P2O5 /ha and it was increased by (12.50%) higher over control. The higher net return in terms of gross income (Rs. 28896/ha), net return (Rs. 17044/ha) and benefit: cost ratios (1.69) were realized under 30 kgN/ha. Similarly, 60 kg P2O5 /ha in cowpea gave the additional gross return (Rs. 8100/ha) and net return (Rs. 1769/ha) as compare to without use of phosphorus. Significant interaction of nitrogen and phosphorus levels was noted on green fodder yield.