Effectiveness of different sources of phosphates on yield,available soil phosphorus and phosphorus content of bluebelle rice

Summary The effect of three sources of P, hyper rock phosphate (HRP), basic slag (BSG) and triple super phosphate (TSP) applied at two rates, 9.6 kg P/ha and 19.2 kg P/ha, was studied at Central Agricultural Station (C.A.S.) and Mahaicony Abary Rice Development Scheme (M.A.R.D.S.). The experiments were carried out for two seasons at both the sites. Though, different P sources used gave some increase in the yield of rice, but, this effect was statistically non significant. The efficiency of P - kg of rough rice per kg of P applied - was the highest with TSP and BSG added at a lower rate.The estimations of available soil P made indicated, that Truog's and Bray no. 1 methods underestimate the available P. The available P determined by Bray no. 2 method, appeared to be more in agreement with the results of yield response noted.The percentage P content of rice grains was not significantly affected by different P treatments.