EXTRAÇÃO E EXPORTAÇÃO DE MACRONUTRIENTES EM LAVOURAS DE MILHO DE ALTA PRODUTIVIDADE

Knowledge on the variability of plant nutrition and productivity in corn plantations with high productivity may provide important subsidies in the restructuring of inputs and in the management of soil fertility. Current research determines extraction and export standards of nitrogen, phosphorus, potassium, calcium, magnesium and sulfur in high productivity corn plantations. Fifteen corn rows cultivated within the traditional system, featuring high productivity, were sampled in the Alto Paranaiba, MG, Brazil, for the agricultural year 2014/2015, and the productivity, extraction and export of N, P, K, Ca, Mg and S were assessed. Accumulation of these macronutrients in the grains and total extraction had positive effects in corn productivity. Mass of one thousand grains was the most relevant productivity´s component. N, P, K and S extraction and export increased linearly with increase of productivity. Results provide important data on the absorption and partition of nutrients of hybrids and allow the improvement of fertilizing recommendations for corn production.