Estudo da condutividade hidráulica de um solo aluvial franco-arenoso em experimentos de lisímetros.

Abstract

The hydraulic conductivity of a sandy loam alluvial soil was performed in three lysimeters of 1.25x1, 1.25x1.25m in size, located in the Irrigated Perimeter of São Gonçalo, Sousa-PB. The instantaneous profile method was used, using the procedure suggested by HILLEL et alli (1972) and the said water balance method for the evaporation phase. Finally, mathematical adjustments were made with k (0) data based on the minimization of squared deviations by exponential, polynomial, sum of two exponentials, and Brooks & Corey model without any transformation of variables. For the preparation of this work, tensiometers were installed in the depths of 10, 20, 30, 50, 70, 90 and 105cm and an aluminum tube in the center, going to the base, to access the neutron probe. The soil of each lysimeter was saturated and covered with plastic ion to avoid evaporation. From this moment the internal drainage test was carried out, taking readings on the tensiometers and with the neutron probe, in the course of time. After 15 days the plastic protection was removed and the evaporation continued for more than 13 days, making the same measurements. The results of k (0) obtained were well compatible and the adjustment with the sum of two exponentials without logarithmic transformation of variables was presented as the most representative.