This work aimed at evaluating the addition of the sterile material resulting from gypsite mining as a soil conditioner on the water availability of a Quartzsandy Neosol collected in the municipality of Petrolina, PE. Field capacity (FC) was obtained by the saturation and subsequent drainage of a simulated soil profile in a column made up of PVC cylinders 100 cm high where doses of 0, 20, 40, 60 and 80 g kg-1 of the sterile material were incorporated to the upper 40 cm. The permanent wilting point (PWP) was determined by the physiological method. In addition, the FC and the PWP were determined by the usual methodology using Richard's pressure plate with the pressures of 10 and 1500 kPa, respectively. The incorporation of increasing doses of sterile material increased the available soil water from 4.8 to 8.67%, determined by the traditional method, and from 14.76 to 15.08% in the same doses when available water was defined with the FC and the PWP determined by the column and physiological methods, respectively. By inserting the gravimetric water content of FC obtained by the column method in the soil water release curve, this parameter was best represented by a matric potencial close to -6 kPa.
water retention and availability; field capacity; wilting point
