Impacts of drip irrigation and plastic-film mulching on regional climate in Northwest China: Implications for climate-resilient agriculture in dryland regions

Drip irrigation with plastic-film mulching (PM) is a vital agricultural practice that improves crop productivity in arid and semi-arid regions by raising soil temperature and conserving water. While climate effects of irrigation have been studied with climate and Earth system models, PM has been only considered in land-only models. The limited spatial coverage of field experiments and lack of fully coupled land-atmosphere modeling studies hinder a comprehensive understanding of the interactions between PM and the atmosphere at a larger scale, particularly in conjunction with drip irrigation. In this study, we developed a PM scheme within a regional climate model and validated it against field measurements in Northwest China. By examining the individual and combined effects of drip irrigation and PM, we found that drip irrigation increases the convective available potential energy and precipitable water, which may further enhance the precipitation by 70 % in Xinjiang. PM, however, only enhances precipitation in some parts of eastern Xinjiang and eastern parts of Northwest China through atmospheric circulation adjustments. Drip irrigation with PM ultimately increases precipitation in the entire Xinjiang, primarily through increasing the frequency of rainy days. The rising drip irrigation with PM croplands may have contributed to the observed trend of wetting. This study provides first insights into the crucial roles of PM and drip irrigation in modulating precipitation in arid and semiarid regions. It underscores the importance of effective agricultural management practices in advancing sustainable and climate-resilient food systems.