Dinâmica da drenagem em solos da caatinga em uso com palma forrageira irrigada e culturas de subsistência.

Abstract

Agricultural drainage is a practice that, in addition to allowing the incorporation of poorly drained areas into the production process, prevents flooding, flooding and salinization of soils. Knowledge of the variability of the physical and hydrodynamic attributes of the soil helps in decision making and the adequate use of water resources and soil. The objective of this research was to identify and evaluate the physical and hydrodynamic parameters of the soil in an area with forage palm, and another one for the family agriculture, as well as to identify the need for soil drainage. For this, two experiments were carried out under field conditions, one at the Poço Redondo farm, located in Santa Luzia town/ Paraíba State and another at the Sítio do Meio property, in São José dos Cordeiros town/ Paraíba State. Hydraulic conductivity tests were performed using the inverse Auger Hole method (Porchet), laboratory analysis of the physical parameters and soil salinity through deformed samples, collected at depths of 0-30; 30-60; 60-90 and 90-120 cm, in addition to the installation of a network of permanent observation wells in the water table in the study areas. The investigated properties were analyzed using the classical statistics, which is based on the calculation of averages, standard deviation, coefficient of variation, minimum and maximum values and coefficients of asymmetry and kurtosis. Along with this analysis the histograms were made to verify the nature of the distribution and the variability of the raised variables, besides the correlation analysis between the attributes of the soil and the hydraulic conductivity using the Pearson (r) correlation coefficients and of determination (R²). The hydraulic conductivity of the soil showed high variability in the studied areas. The correlation between the physical properties of the soil and the hydraulic conductivity were weak, being more noticeable the reduction of K0 with the increase of the exchangeable sodium percentage of the soil.