Fertilidade do Solo e Produtividade de Milho em Sistemas de Adubação Verde no Norte de Minas Gerais

Abstract

Low yield and nitrogen deficiency coexist in corn crop, especially under subsistenceoriented systems. Thus, this work aimed to assess the effect of different types of green manure in maize succession, under minimum and conventional tillage, on soil nutrient input, nutritional state, and maize productive features for ear production. The experiment was arranged in a randomized block design, in a split-plot scheme, with three replications, under field conditions in northern Minas Gerais, Brazil. The main plots were constituted by the following types of green manure: sunnhep [Crotalaria juncea), jack beans (Canavalia ensiformes), fodder turnip (Rafhanus sativus), and green manure mixture (sunnhep + jack beans + fodder turnip), besides a treatment with weeds under fallow conditions. The subplots were constituted by conventional and minimum tillage management. Yield was affected by the different types of green manure, with lower values being identified in weed succession. In general, greater plant growth was observed in minimum tillage and higher maize plant density in conventional tillage. However, ear yield was not affected by soil tillage. Higher contents of potassium and phosphorus in 0-10 cm layer depth were observed under minimum tillage, while better K/Mg balance was observed on maize plants under conventional management.