一个新公式在美国,用经验公式来估算农田的土壤流失量,已经成为水土保持者进行农场规划的有用工具.在北方中部和东北部的一些州,这样的公式已使用了十五年.这些公式用来估算在特定的坡度、种植作物制度和其他管理工作的状况下的年平均土壤流失量.经过培训的水土保持工作者和农民使用这些公式一起工作.用这些公式作为制定土地利用规划和决定最适宜土壤要求和农民需要的水士保持措施的准绳. A NEW FORMULA In the United States, empirical equations used to estimate the amount of soil loss in a farmland have become a useful tool for soil and water conservation for farm planning and have been used for fifteen years in some northern and northern Central States. The formula is used to estimate annual average soil loss for a given grade, cropping system, and other management practices trained soil and water conservation workers and farmers work with these formulas and use these formulas as a basis for developing land-use planning and Decide on the most appropriate soil requirements and peasants need to maintain the standards of measures.