Exportação de nutrientes em milho cultivado em áreas com diferentes potenciais produtivos

Abstract

Corn production in Brazil is of increasing importance and requires a balanced nutritional intake. Precision agriculture helps in this purpose by directing the efficient use of fertilizers from the definition of homogeneous zones (ZH). The objective of this work was to evaluate variations in the levels of nutrient exports in maize for different population densities and areas of productive potential. Data were collected on a commercial grain production farm, in 44 ha. In the stand, two homogeneous zones were defined: high and low productive potential. In the ZH, experimental plots were arranged considering populations of 60, 70 or 80 thousand plants/ha. Thus, 18 experimental plots were defined considering two ZH and three population densities, with 3 replications each. Data were submitted to analysis of variance using the F test and comparison of means using Tukey's test, at 5% probability. There was a significant difference for N only for the source of variation ZH, with no significance observed for the other nutrients evaluated and for the plant population. The data allowed to evidence variations in the exported N levels when compared to the reference values in the literature. For the exported values of P and K there was a slight reduction in relation to values in the literature. It is concluded that there is a difference in the levels of N exported by the corn grain when considering locations of different productive potential, where obtaining values for the plot itself is advantageous for the nutrient replacement fertilization.