Effects Of Different Modes Of Straw-returning On Organic Carbon Pool And Greenhouse Gas In The Soil Under Rice-Wheat Double Cropping System

Straw as a kind of available resources in agricultural production,the production and the rich in China,especially in today's increasing yield and straw yield increases.Straw returned as a conventional agronomic measures are widely used in our country,to find out different ways of returning for the farmland carbon library and the impact of greenhouse gas emissions,this test in June 2013-June 2014 in jiangning district,nanjing city,jiangsu province qinglong globalization without street community,through field plot experiment,studies the four kinds of straw returned way(returning returning rotary tillage,digging,returning returning ditch burying and burning)on soil carbon library and the impact of greenhouse gas emissions,analyzes the way of straw returned on greenhouse gas emissions of specific indicators,preliminary discussed returning wheat straw in different ways on carbon content and the different influence of greenhouse gases.The main results were as follows:The main results are as follows:1.Returning wheat straw to significantly improve the farmland total organic carbon and active organic carbon components In two seasons of rice and wheat,soil total organic carbon in various soil components and active organic carbon content are affected by Hugh of straw returned,organic carbon and straw returned the period of active components of organic carbon content were higher than the comparison is not returning,soil total organic carbon and active carbon component in the vertical variation of soil distribution,with the increase of soil depth,soil total organic carbon and active organic carbon content decreases gradually.0?7 cm soil layer,the rice season,returning returning digging in dealing with soil total organic carbon and active organic carbon content than other processing,the characteristic,in addition to the easy oxidation of organic carbon,soil total organic carbon rotary tillage treatment,easy oxidation of organic carbon and water soluble organic carbon content;7?14 cm soil layer,in addition to the water soluble organic organic carbon,returning in season rice digging in dealing with soil total organic carbon and other active organic carbon content is higher than other processing,the characteristic,the water soluble organic carbon,returning digging soil total organic carbon and other components of active organic carbon content,the biggest returning rotary tillage treatment of water soluble organic carbon content is significantly higher than other treatment;14?21 cm soil layer,the rice season,returning rotary tillage treatment of active components of organic carbon content is higher than other treatment,returning fire processing of total organic carbon content is higher than other treatment but did not achieve significant results.In characteristic,returning rotary tillage treatment of total organic carbon content and oxidative organic carbon content is higher than other treatment,returning and digging in the microbial organic carbon and water soluble organic carbon content is higher than other processing.2.The wheat straw counters-field way can significantly influence farmland greenhouse gas emissions In season rice,straw returned increases farmland greenhouse gas emissions,improve the potential of global warming.In characteristic,returning part way to a certain extent,reduce greenhouse gas emissions,farmland potential of reducing global warming.In rice season,returning rotary tillage of methane emissions is significantly higher than other treatment,returning don't deal with the total emission of methane was significantly lower than other treatment;Returning in characteristic,burning process of methane emissions is significantly higher than other treatment,returning ditch buried treatment of methane emissions and controlled not returning there was no significant difference.In rice season,returning digging in dealing with nitrous oxide emissions is significantly higher than other treatment,returning control not processing of nitrous oxide emissions significantly lower than other treatment;Returning in characteristic,control do not handle the nitrous oxide emissions is significantly higher than other treatment,returning digging in processing of nitrous oxide emissions do not counters-field treatment there was no significant difference with control.Returning in the characteristic,the burning of dealing with carbon dioxide emissions is significantly higher than other treatment,returning control not processing carbon dioxide emissions,the smallest ditch buried type reamer,returning rotary tillage and returning digging in carbon dioxide emissions and returning control not treatment,there was no significant difference in the characteristic,returning rotary tillage carbon dioxide emissions is significantly higher than other treatment,returning control does not deal with the lowest carbon dioxide emissions,returning ditch buried treatment carbon dioxide emissions and returning control don't there was no significant difference.From the perspective of the global warming potential in rice wheat season two season,returning returning ditch burying and burning process of low global warming potential,returning digging in the global warming potential is low,the rice season,returning digging in dealing with the global warming potential is significantly higher than other treatment,in the characteristic,the contrast is not returning to deal with the global warming potential is higher than other processing.