Phosphate application methods for soybean under no-tillage system

Abstract

The objective of this research was to evaluate the effect of application methods and phosphate sources in the no-tillage system, on grain yield of soybean, in a Dark-Red Latosol clay-sandy. The experiment design was a complete randomized block with four replications. The treatments were arranged in split-plot. The plots were constituted of application methods (applied broadcast on the surface and in the band), and the subplots of the control with no phosphorus, of fertilization with 120 kg ha^-1 and 80 kg ha^-1 of P₂O₅, in the first and second soybean cultivation, respectively, with triple superphosphate (TS), Gafsa phosphate (GP) and the combination of these two sources (67% TS+33% GP and 33% TS+67% GP). The results showed that the mixtures of triple superphosphate and phosphate of Gafsa result in smaller agronomic efficiency, when compared to the triple superphosphate. The phosphate of Gafsa, when applied broadcast, is equivalent to the triple superphosphate, however, when applied in the band, it is inefficient for the soybean crop.