国外评价土壤侵蚀与土壤生产力关系的模式

土壤侵蚀减少了植物可利用的有效水分,损失了土壤的营养物质,破坏了土壤肥力结构,影响农业耕作制度,从而严重地降低了土壤生产力。土壤侵蚀与土壤生产力关系的模式(EPIC),系统地定量地表达了土壤侵蚀与土壤生产力的相互关系。这个模式包括水文、气象、水蚀和风蚀、氮磷元素、土壤温度、作物生长状况、耕作与作物残茬的处理方法、经济因子和土壤排灌与施肥等9个因子,共36个方程。为了保护和提高土壤生产力,我国需要发展这项研究工作,制定具有中国特色的土壤侵蚀与土壤生产力关系的模式。

THE MODELS OF EVALUATING THE RELATIONSHIP BETWEEN SOIL EROSION AND SOIL PRODUCTIVITY ABROAD

Soil erosion reduces the effective water available to plant, and loses the soil nutrient material with the soil fertility structure destroyed, effecting the farm tillage system. So, the soil productivity is cut down to a great extent. Erosion-Productivity Impact Calculators (EPIC) quantify the relationship systematically between soil erosion and soil productivity. The models involve 9 factors, that is, hydrology, meteorology, water erosion and wind erosion, the state of nitrogen and phosphorus, soil temperature, crop growth, tillage and treatment of crop residue, economic factors, and irrigation-drainage of soil as well as fertilization, etc. They are expressed with 36 equations. To protect and raise the soil productivity, we should develop and enhance this research in order to formulate EPIC with distinguishing Chinese feature.