中文摘要：

为探讨不同利用模式下的冬季稻田土壤活性碳氮变化和系统净碳交换变化特征。本研究对冬闲（F）、单种黑麦草（R）、单种紫云英（M）、种黑麦草养鸡（RC）以及种紫云英养鸡（MC）的冬季稻田土壤微生物量碳氮、可溶性碳氮及系统净碳交换量进行了定量分析。结果表明,1）RC和MC短期内增加了系统净碳排放,在早稻播种前,白天总体表现为碳汇（RC为817.38g/m2,MC为472.90g/m2）;且所有处理对CH4表现为弱汇（3.06~22.88mg/m2）。2）R和M固碳量显著高于F和RC、MC处理。3）RC,MC,R和M与F相比显著提高了土壤活性碳氮含量。4）虽然RC和MC土壤微生物量碳平均值低于R和M,但其土壤可溶性碳含量平均值更高。5）R,M,RC,MC提高了土壤有机碳含量,增加了土壤碳汇。综上所述,种养结合既提高了土壤活性碳氮,同时增加了冬季稻田系统固碳量。

英文摘要：

In this study,we investigated the effects of different forages and chickens on the transformation of soil active organic carbon and nitrogen and net carbon exchange in paddy fields in south China in winter.The five treatments were as follows：fallow（F）,planted with ryegrass（R）,planted with Chinese milk vetch（M）,planted with ryegrass and presence of chickens（RC）,and planted with Chinese milk vetch and presence of chickens（MC）.Net carbon emissions increased in the short term under RC and MC,but these systems were carbon sinks（817.38g/m~2 under RC and 472.90g/m~2 under MC）before the planting of early rice.All treatments were weak methane sinks（3.06-22.88mg/m~2）.The amount of fixed carbon was significantly higher in R and M than in F,RC,and MC.Compared with F,the R,RC,M and MC treatments significantly increased the contents of soil active carbon and nitrogen.Although the average contents of soil microbial biomass carbon were lower under RC and MC than under R and M,the average contents of soil soluble carbon were higher.The R,RC,M,and MC treatments increased the contents of soil organic carbon and promoted soil carbon sequestration.The results of this study revealed that integrated forage planting combined with the presence of chickens can not only improve soil active carbon and nitrogen,but also increase carbon sequestration in paddy fields in south China in winter.