Yield and economics of blackgram crop effected by green manures and phosphorus levels in riceblackgram cropping sequence

Abstract

A field experiments was conducted during 2015 and 2016 to study the effect of green manures and phosphorus levels in blackgram crop at Agricultural College Farm, Bapatla. The experiment was conducted in split- split plot design on sandy clay loam soil with three main treatments three subtreatments to Kharif rice and three sub-sub treatments to Rabi crop. The treatments consisted of Dhaincha green manure crop, sunnhemp green manure crop and without green manure as main plot treatments and three phosphorus levels to rice crop comprising of 45 kg P2O5 ha-1, 60 kg P2O5 ha-1 and 75 kg P2O5 ha-1 as sub- plot treatments and are replicated thrice. The Rabi experiment was laid out on the same site in a split-split plot design without disturbing the soil for succeeding blackgram crop and each of the Kharif plot was divided into three sub-sub plots to receive three levels of phosphorus (No P, 50% RDP and 100% RDP) to each plot. Yield and economics of blackgram which received Dhaincha green manure incorporation with 75 kg P2O5 ha-1 to Kharif rice crop and 100% RDP to Rabi blackgram was recorded significantly higher and it was on a par with sunnhemp green manure incorporation with 75 kg P2O5 ha-1 to Kharif rice crop and 100% RDP to Rabi blackgram.