Modelagem da erosão hídrica em latossolos sob cultura de café

Abstract

Soil is one of the main natural resources for maintaining life in terrestrial ecosystems. However, problems related to improper use and management can accelerate the impacts of water erosion. The losses of soil and water in this process cause the carrying of nutrients essential for the growth and maintenance of the plants with interference in agricultural and environmental sustainability. In addition, they can have impacts on water bodies through silting and eutrophication. The estimation of soil losses by water erosion in sub-basins is essential in predicting the soil degradation stage, especially in areas of semi-intensive cultivation, such as coffee. Thus, the aim of this work was to estimate soil losses in relation to the limit of Soil Loss Tolerance in the Red Oxisols Dystrophic under coffee plantation. The study was conducted from March 2015 to January 2017 in the Córrego da Laje Hydrographic Sub-basin, in the municipality of Alfenas, in the southern region of Minas Gerais, Southeastern Brazil. Soil losses due to water erosion were estimated by Revised Universal Soil Loss Equation and compared to Soil Loss Tolerance. For that, the morphological, physical and chemical attributes of the soil were used, as well as geoprocessing techniques, remote sensing images and specialized literature data. The results show soil losses between 0.01 and 18.77 Mg ha-¹ year-¹, with an average of 1.52 Mg ha-¹ year-¹. The Soil Loss Tolerance ranged from 5.19 to 5.90 Mg ha-¹ year-¹, with 7.35% of the area with losses above the minimum limit. Areas with steeper slopes and absence of sustainable practices are decisive for the increase of soil losses above soil loss tolerance, being priority for the adoption of mitigating measures of erosive effects. The Revised Universal Soil Loss Equation has been able to model water erosion and identify the areas with the highest rates of soil loss quickly, which contribute to the assessment and conservation of soils in watersheds and sub-basins.