Clarifying the impacts of climatic coupling on plastic-mulching potato production in the loess plateau of China

Context: The ongoing changes in climate constitute a major risk factor for global potato production. Recent studies have underscored the productivity-enhancing effects of plastic mulching for rain-fed potatoes. However, the adaptability of mulching measures to climate change in order to facilitate increased potato yields remains a question. Moreover, the coupling effects of different climatic factors on potato production was unclear. Objective: This study aimed to investigate the impact of different climatic factors and their coupling effects on the yields of mulching and no mulching potatoes in the Loess Plateau. Methods: We utilized multiple crop models and global climate models (GCMs) to predict the yields of mulching and no mulching potatoes on the Loess Plateau based on Shared Socioeconomic Pathway (SSP) 245 and SSP585 scenarios. Additionally, we analyzed the response of yields to the coupling effects of climate, and clarified the effects of main climatic coupling effects to yield of mulching and no mulching potatoes. Results and conclusions: We found that, for mulching potatoes, the contribution of climate coupling to yield under the SSP245 and SSP585 scenarios ranged from 47.05 % to 49.31 % for the period 2021-2060 and increased to 49.09 % to 50.94 % for the period 2061-2100. The mean temperature (T-men)-dominated coupling contributed the most to yield for mulching potatoes, while for no mulching potatoes, precipitation (Pr)-dominated coupling played a dominant role. The maximum temperature (T-max)-dominated coupling significantly reduced potato yields in the future, and mulching measures exacerbated the negative effect. However, mulching measures eliminated the adverse impact of minimum temperature (T-min)-dominated coupling on potato yields. After decomposing the coupling effects of climatic factors, we found that the main factors leading to a reduction in potato yield were T-max and Pr couplings, with mulching measures amplifying the heat-moisture effects. But mulching not only alleviated T-min and Pr coupling but also strengthened the T-mean and Pr coupling, resulting in increased yield. Significance: Hence, understanding how mulching potatoes avoid heat-moisture coupling to promote production was crucial for the future on the Loess Plateau. Our findings contribute to clarifying the impact of climatic coupling on mulching potato production, thereby aiding in the informed development of rational policies.