耕作措施对华北农田CO2排放影响及水热关系分析

    Effects of different tillage practices on CO2 emission fluxes from farmland in North China Plain and the analysis of soil temperature and moisture

    • 摘要: 为探讨不同耕作措施对农田土壤呼吸排放的影响及其与土壤温度、水分之间的关系,该研究利用长期定位试验研究翻耕、旋耕、免耕3种耕作措施下冬小麦、夏玉米生育期农田CO2的排放通量及其季节变化规律,并通过农田土壤温度、水分对CO2的排放通量进行回归统计分析。结果表明:不同耕作措施下农田CO2排放通量具有明显的季节排放规律,冬小麦、夏玉米生育期农田CO2排放通量:翻耕>旋耕>免耕,且处理间差异都达到显著或极显著水平。不同耕作措施对农田土壤温度及土壤含水率具有显著的影响,免耕条件下农田各层土壤温度最低,冬小麦季免耕农田土壤水分含量高于其他两处理。各处理条件下农田CO2排放通量与土壤温度具有显著的相关性,其中翻耕处理的CO2排放通量与10 cm土温相关性最高,旋耕和免耕则均与20 cm土温相关性最高。当土壤温度高于10℃时CO2排放通量与5 cm土壤含水率具有显著的相关性,此时土壤水分成为CO2排放的主要影响因素。

       

      Abstract: In order to discuss the effects of different tillage measures on soil respiration emission and the relationship between soil respiration emission and soil temperature, soil respiration emission and soil moisture, experiments were conducted at long-term sited station to investigate the CO2 emission fluxes and their seasonal variation of winter wheat and summer maize with different tillage measures (conventional tillage, rotary tillage and no-tillage). The CO2 emission fluxes, soil temperature and soil water were analyzed by regression statistical analysis. The results showed that the CO2 emission fluxes had obvious fluctuating with the different seasons. The order of CO2 emission fluxes were CT (conventional tillage) >RT (rotary tillage) >NT (no-tillage) during the growing periods of winter wheat and summer maize, and the differences between the tillage measures were significant or very significant. Soil temperature and moisture were significantly affected by tillage practices, so soil temperatures in all layers of NT were the lowest, and the data of moisture were higher than the other two treatments. The CO2 emission fluxes and the soil temperature showed significant correlation, especially at the depth of 10 cm of CT and at the depth of 20 cm of RT and NT. When the temperature was higher than 10℃, the CO2 emission fluxes showed a significant correlation with soil moisture at the depth of 5 cm. In this circumstance, the CO2 emission fluxes was mainly affected by soil moisture.

       

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