Moisture retention curves and pedotransfer models in Andosol under different land uses

Abstract

The purpose of this research was to determine the behavior of the moisture retention capacity of an Andosol considering different land uses (forestry and agricultural (conventional avocado, organic avocado and macadamia)), and to determine the field capacity (CC), the permanent wilting point (PMP) and the available water (AD [CC-PMP]), as well as to validate six pedotransfer functions for CC and PMP. The moisture retention curve (CRH) was applied with the pressure plate and pressure membrane method at different voltages: 33 (CC); 50, 150, 500, 1 000 and 1 500 ([PMP] kPa), using plate extractors on samples collected at two different depths (0-20 and 20-40 cm). The results show that there are significant differences between land uses and between tensions. The CC registered values ranging from 55.95 to 69.03 %, and the PMP, values between 33.54 and 45.66 % at a depth of 0-20 cm, and of 40.99 to 62.02 % and 25.27 to 36.89 % at a depth of 20-40 cm, respectively, for an Andosol. According to the results, the FPT that exhibited the greatest predictive capacity for the determination of water content was that of Rawls and Brakensiek. The change of land use from forest land to agricultural crops modifies the moisture retention capacity of Andosols.