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

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.