Assessment of the effect of plastic mulching on soil respiration in the arid agricultural region of China under future climate scenarios

The application of plastic film to agricultural fields has been widely used in the arid and semi-arid regions of China to improve crop productivity and soil organic carbon storage. However, the impact of this practice on soil respiration under future climate scenarios remains poorly understood. Process-based model is a useful tool for simulating the effect of this practice on soil biochemical processes and for predicting future changes in soil respiration under different climate scenarios. In this study, the denitrification-decomposition (DNDC) model was evaluated against measured soil respiration. The DNDC model was used to simulate the temporal variation of soil respiration, and the application of plastic film increased the cumulative carbon dioxide (CO2) emissions compared with that of the fields without plastic film. Sensitivity tests indicated that plastic mulching decreased the sensitivity of DNDC-simulated soil respiration and plant biomass to changes in the temperature, precipitation and CO2 concentration. Across different climate scenarios, the DNDC model predicted that both soil respiration and plant biomass in the mulched treatment slightly changed from -0.2% to -2.1% and from -0.7% to -1.2%, respectively; and in the non-mulched treatment, soil respiration and biomass changed from -4.7% to -10.9% and from -8.7% to -7.8%, respectively. In the arid agricultural region of China, if the pollution of residual mulch film in the fields can be effectively controlled, the application of plastic film is an efficient method for increasing crop productivity and would likely mitigate changes in soil respiration under future climate scenarios.