Coeficiente de escoamento para sistemas de preparo do solo em um nitossolo háplico cultivado com milho, feijão e soja.

Abstract

Soil tillage change soil properties, reduce infiltration and increase runoff, increasing the rainfall water runoff coefficient. A rotating-boom rainfall simulator, operated at constant intensity rainfall of 65 mm h-1 was used to investigate runoff constant rate and runoff coefficient in soil tillage systems on maize, bean and soybean crops, in experiments carried out in a soil Typic Hapludox, in the Southern Plateau of Santa Catarina State, Brazil, from March 2001 to February 2004. Three simulated rainfall test were applied in maize and bean crops and five test in soybean crop, according to the following treatments: conventional tillage without crop (bare soil - BS), conventional tillage (CT), no tillage on burned residue on prepared never soil (NB), no-tillage on desiccated residue on prepared never soil (ND), and no-tillage on desiccated residue on prepared previously soil (traditional no-tillage - NT). In maize and bean crops were investigate still native pasture treatment (NP). The initial time (TI) and the peak time (TP) time, runoff constant rate (RR) and runoff coefficient (RC) changed with soil tillage treatments and with soil crop. The TI and TP were smaller in the CT and BS treatments, while the RR and RC were smaller in ND and NT treatments. The RR change from 18 mm h-1 in NT to 44 mm h-1 in BS treatments, while the RC change from 0,29 in NT to 0,71 in BS treatments.