Responses of sweet sorghum to sources and rates of phosphorus under greenhouse conditions: II. Dark red latosol - medium texture

Abstract

The efficiency of Catalão Rock Phosphate (FG) was studied in comparison of that of triple superphosphate (ST). Four rates of P2O5were used both in the presence and in the absence of liming. The residual effect was evaluated in two successive crops. The chief conclusions were the following: ST proved to be a better source of P2O5, its effect being increased by liming; P uptake from both sources was increase by liming, especially in the last two croppings; there was a positive correlation between residual P (Olsen) and dry matter production in the same harvests; in the third crop, however, a better correlation was found to exist between soil - Ca and yield than with soil - P and yield.