Efficacy of maton rock phosphate as a source of P for acid rice soils

Abstract

To evaluate the efficiency of maton rock phosphate (MTRP) as a source of phosphorus for rice, a field experiment was conducted in farmers' field, Coorg district, Karnataka during kliarif 1989-90 iii terms of grain yield, labile-P in soil and P uptake by the crop. Maton rock phosphate and 25% acidulated MTRP recorded 7.8% and 15.68% increase in yield respectively over SSP as source of P. The physical mixture of MTRP + triple superphosphate (3:1) and 25% acidulated MTRP emerged as the best P sources with respect to grain yield and phosphorus use efficiency though the cost benefit ratio was highest with only MTRP.