冬小麦生育中期农田水分与二氧化碳通量研究

A Study on the Water,Heat,and CO_2 Flux During Mid-growth Period of Winter Wheat Field

以大兴实验站冬小麦为研究对象,采用涡度相关技术监测农田显热、潜热和二氧化碳通量,依据实测数据分析了冬小麦碳、热通量的变化特征,并研究各分量在抽穗期的关系和农田群体水分利用效率的变化规律。结果表明,①CO2通量的日变化成单谷型下凹曲线,极值出现在12：00左右,潜热和显热通量则呈单峰型上凸变化;②抽穗期,CO2通量与净辐射和潜热通量都呈现出极显著相关关系,而与显热通量在晴天成极显著相关关系;③作物农田水分利用效率在08：00—11：30较高,范围在0.02-0.04 g（CO2）/g（H2O）。

The heat flux、latent heat flux and CO2 flux of winter-wheat on Daxing station were measured by eddy correlation technique.Then analysis the characteristics and the relationship between heat and carbon flux and the variation of water use efficiency of winter filed during wheat heading stage.Main findings are as follows： Firstly,the curve of CO2 flux in diurnal course is single vale,and the extremum value appeared about 12：00 am,the shape of heat and latent heat flux is single kurtosis;Secondly,in the heading stage,The CO2 flux was found significantly associated with latent heat flux、 net radiation and the heat flux in clear day.