Viabilidade técnica e econômica da adubação fosfatada e potássica na produção de soja e milho em sistemas de plantio direto e convencional

Abstract

In the current system of soybeans and corn production, where almost always the profit margin is short, the balanced fertilization is essential for maximum economic efficiency. The objective of this study was evaluating the effect of P2O5 and K2O applied in different levels in no-tillage and conventional systems in the corn and soybeans production, through soil fertility analysis, vegetative, reproductive and economic components. This work was developed in Dourados, MS in the period of 2006/2007 and 2007/2008 (agricultural year), in area of municipal airport. The experimental design was randomized complete block with four replications in split plot. The main plot consisted of two soil management: the conventional system and no tillage plots and five fertilizer levels: 40, 60, 90, 120 and 150 kg ha-1 P2O5 and K2O. Increasing levels of P2O5 and K2O promoted accumulation of these elements in soil from the first year of cultivation, influencing in corn productivity but these were not significant for the cultivation of soybean and “off season corn”. In media of results in years, the soybean was most productivity in no-tillage system. In this crop, the differences between maximum economic efficiency (MEE) and maximum technical efficiency (MET) were more expressive to corn crop and the differences between MEE and MET to no-tillage system was lessees than conventional system.