Currently research verified that glyphosate or ammonium glufosinate herbicides use for cover crop desiccation in conservationist systems may reduce N amount in straw. The aim of this study was to evaluate nitrogen mineralization in millet straw after glyphosate or ammonium glufosinate application and the N uptake by corn plants. A complete randomized design was used with six treatments and five replications, in a 3 x 2 factorial scheme: cover crop management (without herbicide application, glyphosate or ammonium glufosinate desiccation) and soil type (Typic Quartzipsamment and Red Oxisol). The residual millet straw dry matter on the soil surface was higher after herbicide desiccation than in the control. The soil mineral N, originated from millet straw, the microbial biomass C and nitrification were lower in herbicide-desiccated millet than in the control. Chemical millet desiccation did not affect the dry matter production and total N of the following corn crop, although the corn nitrogen content, derived from the straw, was reduced by millet desiccation with glufosinate herbicide. The nitrogen mineralization of millet straw was reduced by herbicide desiccation with glyphosate or glufosinate.
decomposition; Pennisetum glaucum; glyphosate; ammonium glufosinato
