Correlation approach: saturated hydraulic conductivity, organic carbon and soil physical attributes in a silvopastoral system in the semi-arid region
Soil physical properties, soil water movement, agroforestry systems, semi-arid.
Understanding the dynamics of water in the soil is of paramount importance for the development of agricultural and silvopastoral systems. In this context, the saturated hydraulic conductivity (Ksat) is relevant to conclude about the flux and transport of water and sediments, and for soil water management strategies. As this parameter is influenced by the physical properties of the environment, it is also used to evaluate the effects of soil management, being fundamental for studies on the modeling of hydrological processes. Thus, this research aims to analyze the existing correlations between Ksat, organic carbon and soil physical attributes in a silvopastoral system, through the elaboration of multiple linear regression equations that estimate Ksat. The study was developed in a silvopastoral system, in Serra Talhada, Sertão Pernambucano. A fragment of native forest of the caatinga biome was used as a reference area. Soil sampling was carried out in eight representative trenches in each experimental area of the study, with dimensions of 1.0 m x 1.0 m x 0.40 m, at depths of 0-0.10 m, 0.10-0.20 m, 0.20-0.30 m and 0.30-0.40 m, totaling sixteen trenches. Deformed and undisturbed soil samples were collected to determine Ksat, bulk density, total porosity, macro and microporosity, granulometry, clay dispersed in water, particle density, total organic carbon, humic fractions, light organic matter and labile carbon. Analyzes of Pearson's linear correlations and multiple linear regression were also applied to select the most significant variables for the generation of mathematical equations that estimate the Ksat. The expected results consist of the determination of these equations, enabling the verification of the physical quality of the soil under a silvopastoral system in the semi-arid region by a simpler and more accessible method and a better management of productive areas regarding the application of the right amount of water in the areas and adequate intensity during irrigation, minimizing the environmental risks of erosion and loss of productivity.