草原土壤系指草原、湿草原和森林草原植被下形成的富含有机质、盐基饱和度高的暗色土壤。世界上此类土壤面积约900万km^2,我国约76万km^2,是粮食生产的重要基地。本文比较了国际上草原土壤分类。不论俄罗斯或中国,均腐土开垦以后土壤有机质开始下降迅速,而后减缓,逐步达到与当地生物气候相适应的水平。所以至今仍保持一定厚度的黑土层。在均腐土资源的利用和保护上,一方面应保持其有机质平衡,另一方面更重要的是严防水土流失,以保证其生产能力。
Glassland soils are mainly developed under steppe, praire and forest-steppe vegetation. Most of them are Isohumosois based on the diagnostic horizon, Isohumosols are mineral soils that have a mollie epipedon (dark-colored surface horizon), with base saturation determined by NH4OAc method higher than 50 percent and Isohumie property. The total estimated area of Isohumosols is 9 million km^2 in the world and 0.76 million km^2 in China. As reclamation of Isohumosols the organic matter content decreases quickly at the first stage, and then slow down corresponding with local bio-climate environment. In order to reserve the organic matter in Isohumosols, it is necessary to prevent soil erosion and adopt reasonable cultivation.