Straw Returning Affect Soil Greenhouse Gas Emission and Mineral N under Dry-Rewetting Cycling
作者单位：Department of Soil and Water Sciences China Agricultural University
会议名称：《2019年中国土壤学会土壤环境专业委员会、土壤化学专业委员会联合学术研讨会》
会议日期：2019年
关 键 词：Returning strategy of straw charred straw Dry-wet cycling Spatial distribution GHG emissions
摘 要：As an important technical measure in agricultural production,straw returning can sequestrate carbon in soil and facilitate agricultural *** application strategies of straw returning directly determine its influences on agroecosystem,such as soil fertility and greenhouse gas *** aim of this study was to investigate the interactions of the returning forms of straw,spatial distribution and dry-rewetting on greenhouse gas （GHG） and mineral *** kinds of straw returning strategies were considered （1） raw straw and charred straw;（2） straw/charred straw returned in soil homogeneously or *** soil water conditions were set up with either constant moisture （CM,60%of maximum water-holding capacity） or dry-rewetting conditions （DWC）.The emissions of CO,CH and NO from soil were monitored during the entire experimental *** samples were taken at end of each dry-rewetting cycle and the dynamics of soil mineral nitrogen contents were *** results revealed significant interaction of returning materials,spatial distribution of materials and soil water conditions on GHG emissions and mineral N dynamics（1） The effect of spatial distribution on GHG:Straw returning promoted soil CO and NO emissions in the initial of incubation,particularly,heterogeneous distribution induced more NO emissions and limited the CO2 emissions,likely due to that the uniform distribution of straw may be relatively beneficial for straw degradation in soil and promote carbon mineralization.（2） The effect of spatial distribution on mineral N:With faster increase of nitrate contents,charred straw might promote nitrification,due to the improved soil aeration and the stimulated nitrifier activities,spatial distribution of the charred straw was not observed any significant influences on nitrate（3） The interactions between spatial distribution and dry-rewetting cycling on GHG:The NO emissions under dry-wet cycling conditions were significantly lower than those u