Increasing rates of phosphate fertilizer with and without controlled release on corn and soybean in the Brazilian cerrado region

The objective of this study was to evaluate the efficiency of controlled release technology as well as testing different rates for P fertilization. This research was carried out in Midwest Brazil in the Cerrado region. The soil is characterized as a Ferralsol. We tested two commercial fertilizers with and without P controlled release technology and application rates of 50, 75, 100 and 125% of the recommended rate for each fertilizer. Our results demonstrated that phosphate fertilization significantly increased corn yield components from the second season after the operation. We could see that applications of 50% of the recommended rate resulted in the same crop yield levels of the higher rates (75, 100 and 125%) for both fertilizers. The use of controlled release technology did not result in higher crop yield levels for soybean and corn. The high soil fertility levels of the experimental area may be one of the main responsible for the non-significant effects. We conclude that in areas with high soil fertility in the Cerrado region, a maintenance fertilization with lower application rates is already enough for maintaining high crop yields. Higher rates of P fertilization as well as the use of controlled release technology did not provide better crop yields in this area.