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为探讨寒地玉米秸秆还田条件下土壤CO_2排放规律,研究不同秸秆还田方式下农田土壤CO_2与耕层土壤温度的关系,采用静态箱法测定了不同秸秆还田方式下寒地黑土区春玉米生长季土壤CO_2排放及土壤温度的变化情况。结果表明:玉米生育期土壤CO_2排放量与土壤温度均呈现明显的季节变化,春季及秋季CO_2排放通量小、土壤温度低,而CO_2排放峰值及土壤温度最高值均出现在夏季,不同土层土壤温度在6月末达到最高值,而排放峰值出现在7月末至8月初;秸秆还田的排放通量显著高于不还田处理。对二者进行指数方程拟合,发现秸秆不还田条件下土壤CO_2排放与土壤温度的相关性要高于秸秆还田处理;在5~25cm耕层范围内,随着土层深度的增加,土壤CO_2排放与土壤温度的相关性逐渐增加,且10、15、20、25cm四个层次的相关性显著高于5cm土层,表明10~25cm土层的土壤温度变化能够更好地表述黑土农田CO_2排放通量的变化趋势。
In order to investigate the CO 2 emission from soil under field conditions of maize straw returning to the field, the relationship between soil CO_2 and topsoil temperature under different straw returning conditions was studied. The static box method was used to determine the soil moisture Soil CO_2 Emission and Soil Temperature Changes during Corn Growing Season. The results showed that both CO 2 emission and soil temperature showed significant seasonal changes in maize growth stage, with small flux of CO 2 in spring and autumn, low soil temperature, and peak CO 2 emission and soil temperature all occurred in summer. The soil temperature reached the highest value at the end of June, while the emission peak appeared from the end of July to the beginning of August. The discharge flux of straw returning was significantly higher than that of non-return treatment. The exponential equation was fitted to the two. It was found that the correlation between soil CO 2 emission and soil temperature was higher than that of straw returning without straw returning. With the increase of soil depth in the range of 5-25 cm soil layer, The correlation between soil CO 2 emission and soil temperature increased gradually, and the correlation among four layers of 10, 15, 20 and 25 cm was significantly higher than that of 5 cm soil layer, which indicated that the soil temperature change in 10 ~ 25 cm soil layer could better describe the characteristics of black soil farmland CO 2 emission flux trends.