Soil respiration in a triple intercropping system under conservation tillage

Abstract

Drivers of soil respiration (Rs) in farmland ecosystem have already been widely studied. However, the relationship between Rs and soil fauna (Fs), hydrothermic factor in the triple intercropping system remains poorly known. An LI-6400 XT portable photosynthesis measurement system equipped with a soil respiratory chamber was adopted in the experimental field. Straw mulching treatment increased soil respiration rate but ridge tillage treatment did not have a consistent effect. A regression analysis of the relationship revealed that exponential equation fitted well the relationship between Rs and soil temperature at 10 cm soil depth. However, the relationship between Rs and soil moisture was best confirmed by a parabolic function. The common dominant groups of Fs in wheat, corn, and soybean farmland were Collembola and Acarina, while Diptera emerged in the two rear crops farmlands. Compared to the control, ridge tillage reduced the number of Fs, but straw mulching increased it and improved the index of soil fauna diversity. In conclusion, the higher was the amount of animals being active above soil surface, the stronger was the soil respiration.