Department of Soil Science and Agrl. Chemistry, TNAU, Coimbatore-641 003, India.
Pot experiments conducted to study the effect of rock phosphate-elemental sulphur granule (RP-S° G) on the yield, nutrient availability and P fractions in soil revealed that application of R-PS° granule at the rate of 60 kg P2O5 ha−1 recorded the highest yield of onion and blackgram. The availability of nutrients like N,P and S were increased due to the addition of 60 kg P2O5 ha−1. There was no significant influence on the availability of K. At initial stage, the P fractions (NaCI TEA-P, NaOH-Pi) were increased at 60 kg level, but other fractions (NaOH-Po, HCI-P and residual P) were increased due to 75kg P2O5ha−1. Better residual effects were reflected in black gram yield and nutrient availability. Addition of RP-S° granule at 75 kg P2O5 ha−1 also performed well but its effect was on par with 60 kg P2O5 ha−1.
