Abstract:
Natural conditions and human activities can induce severe soil and water losses,which results in the worldwide soil degeneration and ecological depravation.China is among the nations that are most seriously affected by the problem.Thus,the Chinese government has devoted much attention to the water and soil conservation(SWC)in recent decades.To a certain degree,the efforts have reduced the soil erosion,improved the environment,maintained and promoted the soil quality,and ensured a sustainable development. Nonetheless,further improvement is needed.This article introduces the critical concept of SWC and soil quality,as well as the biological,engineering and tillage measures to alleviate the losses.The soil quality,which encompasses visual,physical,chemical and biological aspects,is explained.Furthermore,the degree of soil erosion and SWC measures and their restoration and improvement effects on soil quality were reviewed.Three representative SWC projects,i.e.,the World Bank Loan Loess Plateau Rehabilitation Project,the Zhuxi Watershed Project in Eroded Red Soil Area in Fujian,and the Soil Erosion Control in Typical Eroded Black Soil Area in Northeast China,are presented for illustration.The effects of conservation tillage on soil have been analyzed for further understanding of the various issues associated with the loss of soil and water,the resource and ecology,as well as the conservation.In conclusion,directions for future research in the following specific areas were suggested:(1) methods and standardization of soil quality evaluation;(2)studies on key factors for effective SWC;(3)fundamentals of SWC.This paper aims to provide important references for traditional layout of SWC measures,scientific agricultural production and management,and comprehensive and objective evaluation of effects of soil erosion control.