Soil type and wetting intensity control the enhancement extent of N_(2)O efflux in soil with drought and rewetting cycles  

作　　者：Panpan Jiao Lei Yang Zhongwu Li Peng Zheng Xiaodong Nie 

机构地区：[1]School of Geographical Sciences,Hunan Normal University,Changsha 410081,China [2]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,The Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling 712100,China [3]Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China

出　　处：《International Soil and Water Conservation Research》2024年第1期137-144,共8页国际水土保持研究（英文）

基　　金：This work was financially supported by the‘Hundred-talent Project’of the Chinese Academy of Sciences(A315021407).

摘　　要：Climate change alters the intensity and frequency of drought and rewetting(D/W)events;however,the influence patterns of D/W on soil N_(2)O efflux in the water-limited area were not fully understood.Therefore,the impacts of D/W cycles varying in different extent of rewetting and frequency to N_(2)O efflux in two kinds of soil on the Loess Plateau were investigated.The incubation conditions consisted of 1)D/W treatments with four 7-day cycles from 10%water holding capacity(WHC)to 60%WHC or 90%WHC,2)constant moisture of 60%WHC and 90%WHC.The pulse of N_(2)O efflux rate under 10-60%WHC treatment was higher than that under 10-90%WHC treatment in calcic cambisols,while opposite trend was observed in earth-cumuli-orthic anthrosols.Meanwhile,the pulse of N_(2)O efflux rate decreased as cycle number increased for different wetting intensities and soil types.The direct N_(2)O efflux under 10-60%WHC and 10-90%WHC treatments were 5.49 and 1.89μg N_(2)O-N g^(-1)soil in calcic cambisols,with those being 1.92 and 10.85μg N_(2)O-N g^(-1)soil in earth-cumuli-orthic anthrosols,respectively.The N loss in earth-cumuli-orthic anthrosols was approximately 5.74 times greater than that in calcic cambisols under 10-90%WHC treatment,whereas the N loss under 10-60%WHC treatment was about 2.86 times greater in calcic cambisols than that in earth-cumuli-orthic anthrosols.This study suggested that extreme rainfall events can enhance the N_(2)O efflux and N loss in agricultural soils on the Loess Plateau in terms of soil type and wetting intensity,which should not be ignored in the N fertilizer management.

关 键 词：Drought/rewetting cycles N_(2)O efflux Wetting intensity Microbial biomass N Dissolved organic N Loess plateau 

分 类 号：S157[农业科学—土壤学]