The aim objective of this study was to quantify the soil water storage, plant-available water and extraction of soil water by corn plants under irrigation and terminal drought. Plants were cultivated under no-tillage and conventional tillage systems. Two experiments were conducted in the 1999/00 and 2000/01 growing season on an experimental field of the Agricultural Engineering Department of the Federal University of Santa Maria. Treatments consisted of a 2 x 2 factorial scheme, in a completely randomized design, with four replications. The tested treatments were: Factor A - irrigation management (irrigation and terminal drought, 27 days after emergence, when plants presented seven fully expanded leaves) and; Factor B - tillage system (no-tillage and conventional tillage). Irrigation water was applied to raise the soil water content to the maximum limit of plant-available water, always when the cumulative maximum crop evapotranspiration reached a value of 25 mm. Soil water content was measured three times a week to determine soil water extraction and water availability for corn plants. Results indicated a similar amount of water available to corn plants cultivated in both tillage systems during the two growing seasons. Conventionally cultivated maize plants extracted a higher amount of soil water than plants cultivated in no-tillage system.
soil tillage systems; soil water extraction; maize; soil water management
