Manejo de fósforo e potássio em área de sucessão soja e milho safrinha de Mato Grosso

Abstract

The planning of fertilization of soybeans and maize lounge off-season should consider the succession system as a whole, instead of the culture alone. Taking into account the economic appreciation of corn, it is essential to better exploit the productive potential of this crop. Thus, in the present study the objective was to define doses and times of application of potassium and phosphorus in the succession system soybean / corn off-season. For phosphorus, applications of 120 kg ha-1 of P2O5 were tested in soybean and 60 kg ha-1 of P2O5 in soybean and another 60 kg ha-1 of P2O5 in corn. For the management of K, doses of (0; 60; 120 and 180 kg ha-1 of K2O) were considered and applied to soybeans or corn. As a comparison parameter, a control without fertilization was used. The average soybean yield was 3.372 kg ha-1 (56.2 bags ha-1), but was not influenced by the treatments. The dose of 60 kg ha-1 of P2O5 increased the levels in soybeans of N, P, K, Ca Mg and B compared to the dose of 120 kg ha-1 of P2O5. The dose of K in soy increased levels of K in soybean leaves and increased levels of P, K and Ca in soybeans. The average yield of corn was 10.860 kg ha-1 (181 bags ha-1), it was also not affected by treatments. The dose of 60 kg ha-1 of P2O5 applied to soybeans and corn height of corn plants compared to the dose of 120 kg ha-1 of P2O5 applied only to soybeans. Increased K doses increased the height of corn plants, and K and Fe levels in corn leaves. The two doses of P decreased the levels of Zn in the leaves of corn.