In the present work, the influence of the corn crop residue on the soil water evaporation was analyzed. The experimental treatments consisted of three rates of corn residue (stalk), 0, 50 and 100% of the dry matter yield by irrigated corn crop system; three evaporative demands of 3, 6, and 8 mm d-1; and two soils of different texture, sandy loam and clay soil, with 84% of sand and 76% of clay, respectively. The experiment was carried out in laboratory, with the soil conditioned in PVC columns of 45 cm in height and 20 cm in diameter. The water evaporative demands of 3, 6 and 8 mm d-1 were obtained by means of incandescent lamps, fixed on the soil columns at a height of 10 cm. The daily data collection was accomplished by means of weighing the soil columns, using a digital scale with maximum capacity of 32,100 g and precision of 1.0 g. The direct water evaporation rate from the soil columns presented different behavior for the three water evaporative demands. The reductions in the soil water evaporation for the dry matter yield rates of 100%, for the corn crop equivalent to 10.000 kg ha-1, for the water evaporative demands of 8, 6, and 3 mm d-1, were 13, 17 and 25%, respectively.
crop residue; water evaporative demand; Zea mays, L.
