Avaliação de fontes de enxofre e das formas de micronutrientes revestindo o NPK na cultura do milho

Abstract

In Brazil, as a result of the constant use of concentrated NPK fertilizers, besides some other factors, sulfur became a limiting nutrient for plant development. Two experiments were performed under no till system in November 2008 aiming to evaluate the agronomic efficiency of fertilizers associated to two sulfur sources and two micronutrients forms in corn crops,. one in Ijaci-MG and one in Lavras-MG. The experimental design was randomized blocks with four replications in a 3 x 2 factorial scheme, with three fertilizers, one without sulfur and the other two with different sources of sulfur (elemental sulfur or ammonium sulfate), associated to two forms of micronutrients (granular or coated granule). No differences were observed for sulfur sources and forms of supplying micronutrients. The different sulfur sources affected the characteristics in a similar way and did not depend on the form of the micronutrients. The replacement of sulfur originated from ammonium sulfate by the elemental sulfur in NPK fertilizers or even the absence of this in fertilizers did not affect the efficiency of fertilizer evaluated by productivity.