Estimativas de perdas de solo pelo método de erosão potencial em solos tropicais sob cultivo predominante de café

Abstract

Water erosion is the main process of degradation of tropical soils, causing environmental, physical and socioeconomic impacts that negatively influence the sustainability of agricultural production systems. In coffee growing, water erosion generates loss of nutrients, organic matter and agrochemicals, besides promoting siltation and contamination of watercourses. In the southern region of Minas Gerais, where coffee cultivation occurs on steep slopes, the erosion process is intensified reaching critical levels. As an alternative to help in the planning of water erosion mitigation practices are modeling, which consists of a technique capable of estimating erosion rates and when associated with Geographic Information Systems, allows the identification of areas with soil losses above tolerance limits. Among the many existing models, the Potential Erosion Method deserves attention for its ease in obtaining the parameters, simplicity and low cost of application. Thus, the objective of this work was to estimate soil loss by water erosion using the Potential Erosion Method in a sub-basin with predominant coffee cultivation, and then to compare the estimated soil loss with the Loss Tolerance limits. Ground. The study area corresponding to the Coroado Stream Watershed, located in the Municipality of Alfenas, southern Minas Gerais, Brazil. The input parameters of the model were determined based on climatic, geological, pedological, topographic, land use and management attributes and degree of erosion features of the sub-basin. The results of the Potential Erosion Method pointed to a predominance of low susceptibility to erosion in the area. The estimated average soil loss in the area was 1.74 Mg ha-1 year-1. The highest severity of the erosion process occurred mainly in areas with exposed soil and higher relief slope, and in only 1% of the sub-basin the erosive rates were higher than the Soil Loss Tolerance limits (4.75 to 7.26 Mg ha-1 year-1). The Potential Erosion Method estimated soil losses by providing a diagnosis of water erosion in the sub-basin that can assist in land use planning and the adoption of conservationist agronomic practices, aiming at the environmental and socioeconomic sustainability of the area