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

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.