Efficiency of Mussoorie rock phosphate as a source of fertilizer phosphorus to guar (Cyamopsis tetragonaloba) and groundnut (Arachis hypogaea)

Abstract

SummaryIn two field experiments, Mussoorie rock phosphate with or without pyrite, farmyard manure or straw was compared with concentrated superphosphate when applied to guar and groundnut. The treatments included rates of 10, 20 and 30 kg P/ha and were located on a soil low in available phosphorus.Mussoorie rock phosphate was 44–52% as efficient as concentrated superphosphate. The incorporation of Amjhore pyrite, farmyard manure or straw in the soil with rock phosphate increased the effectiveness of Mussoorie rock phosphate.Extractability coefficient ratios obtained upon laboratory incubation of soil with concentrated superphosphate and rock phosphate correlated fairly well with the availability coefficient ratios obtained from measurements with plants in the field experiments.