Relationships Between Soil Respiration and Crop Productivity in Different Crop Fields

Investigating the seasonal variations in soil respiration in different crop fields and their relationships with crop productivity is crucial to understanding the key biotic controls of soil respiration. A field experiment was performed during the 2020-2021 winter wheat-soybean, canola-maize and broad bean-sweet potato growing seasons. The seasonal variations in soil respiration, soil temperature and moisture were measured. The variables that were associated with crop productivity were also determined. The results showed that crop types significantly (p < .05) affected the mean seasonal soil respiration. Most variables that were associated with crop productivity exhibited obvious seasonal variation patterns. The soil temperature, moisture and crop productivity comprehensively influenced the soil respiration, and models based on these potential controlling factors explained 45.7%-59.2% (R-2 = 0.457-0.592) of the variation in soil respiration in the different crop rotation fields. A model based on the mean seasonal soil temperature, moisture, leaf area index, and root carbon content explained 68.3% (R-2 = 0.683) of the variation in the mean seasonal soil respiration across the different crop fields. We demonstrated the potential of effectively characterizing the variations in soil respiration in agroecosystems using temperature, moisture and crop productivity.