不同管理方式下吉林省农田黑土流失量

本文利用土壤流失方程式的计算机应用程序1],模拟计算吉林省榆树和德惠两市黄土质黑土坡耕地在不同管理利用方式下的土壤流失强度。结果表明,黑土种植玉米降雨流失量在4～45 t/hm2·a之间。种植大豆流失量高出玉米一倍。流失量随耕地坡度加大和A层变薄而增加。吉林黑土A层厚度正在逐渐下降,下降幅度因土种和管理方式而异,范围在0.5～4.5mm/a。种植玉米,吉林省黑土每年会流失830×104t表土,相当于流失近20×104t有机物质。种植大豆会使土壤和有机质流失量加倍。与传统的耕作方式模拟对比,保护性耕作可以显著降低吉林黑土的流失量。

Erosion Losses of Black soil Under Different Types of Management in Jilin

Using the Revised Universal Soil Loss Equation, erosion losses of black soils in Yushu and Dehui of Jilin province were estimated under different management practices. The results showed that Jilin black soils may lose 4 -45 t hm-2·a -1 topsoil under planting corn, while planting soybean production could double the losses. Soil losses are directly related to soil species, tillage practices and grain yields. The thickness of A horizon of Jilin black soils are decreasing at rates 0.5-4.5 mm·a-1 dependent on soil species and management. Planting corn may has a potential to loss 8.3 million tons topsoil from black soil alone and soybean production could increases this loss.