Influence of Soil Test Based Application of Phosphorus Fertilizers on Yield and Economics of Rice in Vizianagaram District of Andhra Pradesh

Indiscriminate use of phosphorous fertilisers for rice cultivation year after year caused accumulations of high levels of soil phosphorous in Vizianagaram district. In order to create awareness on Soil test based phosphorous application through onfarm demonstrations with 75% RDP (recommended dose of Phosphorous), 50% RDP, 100% RDP and farmers practice (200% RDP) were tested in 15 selected farmers fields covering 10 predominant rice grown mandals of Vizianagarm district during rabi, 2011-12, 2012-13. The results revealed that the increase in rice grain yield of 8.20 percent in 75% RDP and 7.18% increase in 100% RDP compared to farmers practice. The cost of cultivation of 50% RDP was low (Rs. 29,904 ha-1), followed by 75% RDP (Rs.30,746), 100% RDP (Rs.31,538) and highest in farmers' practice (Rs.34,730). The benefit cost ratio were 1.93, 1.87, 1.85 and 1.55 in 75% RDP, 100% RDP, 50%RDP and Farmers' practice respectively, indicated the fertiliser phosphorous can be reduced to a tune or 50% without effecting BC ratio.