Alleviating heat stress in cultivated plants with a radiative cooling and moisturizing film

Global warming intensifies heat stress, posing substantial challenges to cultivated plants and agricultural yield production. The high solar absorptance of soil results in elevated temperatures, pushing plants beyond their ideal growth range. Additionally, this rise in soil temperature accelerates soil moisture evaporation, further aggravating existing water scarcity issues. Common cooling solutions tends to consume significant amounts of water or offer limited cooling capacities. In response, a radiative cooling and moisturizing film composed of biodegradable ethyl-cellulose was developed. With a solar reflectance of 97% and a thermal emissivity of 0.93, this film provides efficient zero-energy cooling for soil surfaces. Field tests have demonstrated that compared to commercial cooling mulch, the radiative cooling film significantly reduces soil temperature and moisture evaporation by 50% and 60%, respectively. Furthermore, it boosts plant growth by 30% by moderating leaf temperatures and augmenting the exposure to reflected sunlight, crucial for photosynthesis on hot days. Global heat-water simulations reveal that the film increases soil moisture preservation by over 80% and alleviates agricultural water scarcity by over 60% in arid regions during hot seasons. This work offers a practical and sustainable solution to mitigate heat stress and promote resilient cultivation practices in the context of global warming. © 2024 Elsevier Ltd.