Valuation for the ecosystem services of maize under plastic mulch in China based on a meta-analysis

Agriculture ecosystem provides diverse services for human being, which is sensitive to management measures. Plastic mulch is an important agricultural practice that has made significant contributions to the agricultural ecosystem, particularly in terms of yield growth and water conservation. However, comprehensive assessments of the influence of plastic mulch on agricultural ecosystems are still limited. This study aimed to quantify the effects of plastic mulch on ecosystem functions and further evaluate its effects on the ecosystem services and ecosystem disservices of maize cropping systems in nine agricultural regions in China. A further analysis of plastic mulch effects response to annual precipitation and nitrogen application were considered as well. A meta-analysis was introduced in the study, and a total of 175 publications and 1139 data pairs were used to qualify the effect on ecosystem functions. Furthermore, a monetary method was applied to evaluate the ecosystem services, including 4 key aspects: ecosystem services (product supply, water conservation, nutrient retention) and ecosystem disservices (greenhouse gas emissions). Plastic mulch significantly enhanced yield and water use efficiency of maize production by 33% and 32%, respectively. In addition, plastic mulch increased CO2 emissions by 28% and decreased CH4 uptake by 58%. In terms of ecosystem services value, plastic mulch promoted the value of product supply and water conservation by 47% and 4%, respectively, and decreased nutrient retention by only 1%. Plastic mulch increased ecosystem disservices by 31%. In total, plastic mulch increased the total value of ecosystem services by 7%. Northern arid and semi-arid regions had the most total value under plastic mulch. The effect of plastic mulch on ecosystem functions varied with the average annual precipitation and nitrogen application. The findings of this study indicated that plastic mulch was beneficial for maize planting ecosystem services. More attention is needed on the tradeoffs between the effects on product supply and greenhouse gas emissions of plastic mulch to create more profit for human welfare. Our findings enhance the knowledge of the impacts of plastic mulch technology on ecosystem services, which is vital to promote a more sustainable development of plastic mulch in the field.