南方冬季种养结合模式对双季稻田CH_4和CO_2排放的影响

Effects of Winter Green Manure Crops With and Without Chicken Grazing on CH_4 and CO_2 Emissions in a Double-Crop Rice Paddy Field in South China

以不同冬季种养结合模式下双季稻田系统为研究对象,采用静态箱-便携式温室气体自动分析仪法研究了冬闲田不同种养制度下双季稻田CH_4和CO_2排放特征,同时分析了CH_4和CO_2排放与主要环境和植株因子的相关性。结果表明:与冬季休闲-双季稻相比,冬季种植绿肥或绿肥结合养鸡对稻田CH_4和CO_2排放的季节变化模式无明显影响,但对排放通量有影响。2个稻季,冬季种植紫云英(Astragalus sinicus)结合养鸡处理CO_2累积排放量较冬闲、冬季种植黑麦草(Lolium perenne)、冬季种植紫云英、冬季种植黑麦草结合养鸡处理分别提高150.23%、2 034.43%、102.08%和98.68%(P<0.05)。与冬闲-双季稻相比,冬季种植紫云英结合养鸡显著降低2个稻季CH_4累积排放量的42.67%(P<0.05),冬季种植黑麦草结合养鸡和冬季种植紫云英处理分别提高21.40%和48.55%(P<0.05)。CH_4排放通量与气温呈极显著正相关,与植株地上部干物重和体积呈极显著负相关。CO_2排放通量与植株地上部干物重和体积呈极显著正相关,与土温呈极显著负相关,与光合有效辐射(PAR)呈显著负相关。

A field experiment in the＂winter green manure-double cropping rice＂and the ＂ winter planting and breedingdouble cropping rice＂ was conducted to measure the CH4 and CO2 emissions under different planting and breeding systems.The gas emissions were measured using the static chamber plus a greenhouse gas analyzer. The correlation between CH4 and CO2 emissions and main environmental factors and plant factors was also analyzed. The winter plants include ryegrass（Lolium perenne） and milk vetch（Astragalus sinicus）. The goal of this rotation system is to return green manure and chicken manure to soils and reduce the application amount of fertilizers during the rice growing period. The results shows that compared with the winter fallow-double cropping rice,winter planting green manure or planting and breeding had no obvious effect on the seasonal variation of CH4 and CO2 emission in the paddy field,but affected the magnitude of the fluxes. The CO2 cumulative emissions of the＂milk vetch and grazing chickens treatment＂were higher than the＂winter fallow treatment＂,the ＂ryegrass treatment ＂,the ＂milk vetch ＂,and the ＂ryegrass and chicken treatment ＂ by 150. 23%,2 034. 43%,102. 08% and 98. 68%,respectively（P〈0. 05）. Compared with the winter fallow-double cropping rice,the milk vetch and chicken treatment significantly reduced the cumulative emissions of CH4 by 42. 67%（P〈0. 05）,and＂ryegrass and chicken treatment ＂ and ＂milk vetch treatment ＂ increased by 21. 40% and 48. 55%,respectively（P〈0. 05）. CH4 flux was positively correlated with air temperature,and negatively correlated with dry weight and aboveground volume. There was a significant positive correlation between CO2 flux,dry weight and aboveground plant volume. The CO2 flux was negatively correlated with soil temperature and PAR.