三开门自动温室气体测定箱的应用效果

Effect of greenhouse gas measurement of three-side-open automated chamber

为了降低农田自动温室气体测定箱在观测过程中对作物生长环境及作物生长的干扰,本研究在玉米大田环境条件下比较了一种新型的三开门自动温室气体测定箱与传统单开门自动温室气体测定箱对环境空气温湿度、土壤温度与水分、玉米生长以及温室气体排放的影响。结果表明:三开门温室气体测定箱能显著减小与大田环境条件下的空气温度、湿度及土壤温度的差异;相对于单开门箱,三开门箱在箱体打开及关闭条件下气温平均低0.90和0.74℃,空气湿度平均增加1.36%和降低5.69%;在玉米小喇叭口期前土壤温度约降低2℃,小喇叭口期后差异不显著;对土壤水分的影响在玉米苗期有一定的作用,但差异不显著;三开门箱相对于单开门箱能显著降低箱体对作物生长的影响,还能降低CO2平均通量值6.85%及N2O的平均通量值3.68%,而对CH4平均通量值基本无影响。因此,三开门箱相对于传统单开门自动温室气体测定箱能显著减小测定箱对观测环境及作物生长的干扰,应用这种箱体观测能更好地反映田间温室气体排放状况。

In order to decrease the disturbance of automatic chamber on crop growth and its growing environment during greenhouse gases measurement, the effect experiment of a three-side-open automated chamber on greenhouse gases measurement in maize field was conducted in compare with traditional open-at-top chamber. The experiment was to test the three-side-open chamber＇s character on ambient temperature, ambient relative humidity, soil temperature, soil moisture, crop growth and greenhouse gases emission. Results showed that in compare with traditional open-at-top chamber, the three-side-open chamber can significantly decrease the influence of chamber on ambient temperature, ambient relative humidity and soil temperature. It can decrease ambient temperature by 0.90℃and increase air relative humidity by1.36% with chamber closed, and decrease ambient temperature by 0.74℃ and relative humidity by 5.69% with chamber opened respectively. Also the three-side-open chamber can decrease soil temperature by 2℃ before maize little bell stage, but there is no significant difference after little bell stage. The two chambers have no significant influence on soil moisture. The three-side-open chamber can also alleviate the maize height dramatically which influenced by chambers. The greenhouse gases monitor showed that the three-side-open chamber can trade off average CO2 flux and N2O flux by 6.85% and 3.68%, but almost have no influence on CH4 average flux. Therefore compared with traditional open-at-top chamber, the three-side-open automated chamber can significantly alleviate the interfere of chamber on crop ambient and its growth, and has better representative in greenhouse gas emission measurement.