Estimates of soil losses by the erosion potential method in tropical latosols

ABSTRACT Water erosion is one of the main problems faced in coffee cultivation, as it promotes environmental degradation and crop yield decrease. Erosion estimates support the planning of conservation management practices and allowing determining the rates of soil losses. Thus, the objective of this paper was to estimate the soil loss by water erosion using the Erosion Potential Method in a sub-basin predominantly covered by coffee cultivation and then to compare the results with the Soil Loss Tolerance limits. The study area is the Coroado Stream Sub-basin, located at Alfenas Municipality, south of Minas Gerais, Brazil. The sub-basin presented an Erosion Coefficient of 0.272, indicating a predominance of low-intensity erosion. The total soil loss estimate was 1,772.01 Mg year-1 with an estimated average of 1.74 Mg ha-1 year-1. Soil Loss Tolerance limits range from 4.75 to 7.26 Mg ha-1 year-1 and, according to the Erosion Potential Method, only 1.0% of the sub-basin presented losses above the limits. The areas with the highest slopes and bare soil concentrated the highest losses rates and should be prioritized in the adoption of mitigation measures. The Erosion Potential Method estimated soil losses in tropical edaphoclimatic conditions in a fast, efficiently and at low cost, supporting the adoption of conservation management practices.

摘要：水蚀是咖啡种植面临的主要问题之一，其会加剧环境退化并导致作物减产。侵蚀评估可为水土保持管理措施的规划提供科学支撑，同时可用于确定土壤流失速率。为此，本研究以巴西米纳斯吉拉斯州南部阿尔费纳斯市的科罗阿多溪子流域（Coroado Stream Sub-basin）为研究区域，该子流域以咖啡种植为主。研究采用侵蚀潜力法（Erosion Potential Method）估算该子流域的水蚀土壤流失量，并将估算结果与土壤流失容许量限值（Soil Loss Tolerance limits）进行对比。该子流域的侵蚀系数为0.272，表明区域以低强度侵蚀为主。总土壤流失量估算值为1772.01 Mg·年⁻¹，平均土壤流失量为1.74 Mg·公顷⁻¹·年⁻¹。土壤流失容许量限值介于4.75至7.26 Mg·公顷⁻¹·年⁻¹之间，依据侵蚀潜力法的计算结果，仅1.0%的子流域区域流失量超出该限值。坡度较高且裸地集中的区域流失速率最高，应优先针对此类区域采取侵蚀减缓措施。侵蚀潜力法可在热带土壤气候条件下快速、高效且低成本地完成土壤流失量估算，可为水土保持管理措施的落地提供科学依据。