Response of erosion reduction effect of typical soil and water conservation measures in cropland to rainfall and slope gradient changes and their applicable range in the Chinese Mollisols Region,Northeast China  

作　　者：Qin Zhang Wei Qin Wenhong Cao jian Jiao Zhe Yin Haichao Xu 

机构地区：[1]State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Bejing,100048,PR China [2]Research Center on Soil and Water Conservation of the Ministry of Water Resources,Beijing,100048,PR China

出　　处：《International Soil and Water Conservation Research》2023年第2期251-262,共12页国际水土保持研究（英文）

基　　金：supported by the IWHR Research&Development Support Program(No.SE0145B032021);the National Key Research and Development Program of China(No.2018YFC0507002).

摘　　要：Mollisols are rich in organic matter,which makes them suitable for cultivation and for enhancing global food security.Mollisols are experiencing severe soil erosion due to overfarming and a lack of mainte-nance.Thus,suitable soil and water conservation measures(SWCMs)are needed to protect Mollisols.However,how SWCMs respond to changes in slope gradient and rainfall and their effective application area remain ambiguous.Using a long-term field observation dataset,meta-analysis,and statistical test methods,we reveal the typical erosion reduction effect of SWCMs and their responses to changes in slope gradient and rainfall.Next,we calculated a coupling factor,P.S,by slope gradient and rainfall in flood season to determine the effective SWCMs application threshold.Compared with bare land,no-tillage(NT),contour ridge tillage(CT),ridge hedgerows(RH),and terraced fields(TF)had an average erosion reduction coefficient of 91.5%.There was a significant exponential increase in the correlation between P.S and the soil erosion amount in plots with typical measures.According to this correlation and soil loss tolerance(200 t/km^(2)),the upper limits of PS(NT:564 mm;CT:885 mm;RH:1135 mm)were determined and utilized to determine the effective application areas(NT:311.40103 km^(2);CT:320.86103 km^(2);RH:323.72103 km^(2))at the plot scale.In wet years,the applicable area of SWCMs declined toward the low-elevation foothills and flat terrain.All the results are applicable when slope length within 20 m.These results provide a basis for the precise allocation of SWCMs in Mollisols area and promote the scientific utilization of Mollisols resources.

关 键 词：Mollisols region Watererosion in cropland Soil and water conservationmeasures Erosionreductioncoefficient Effective range 

分 类 号：S157[农业科学—土壤学]