A Fully Green Radiative Cooling Foam for Improving Soil Microclimates and Vegetation Growth in Arid Regions

ABSTRACT Desertification control plays a crucial role in expanding habitable land and supporting sustainable land management. In arid environments, intense solar radiation and scarce precipitation cause evaporation rates that far exceed rainfall, resulting in severe soil moisture loss and limiting plant establishment. In this work, a fully green radiative cooling foam (GRCF) was developed from biodegradable polycaprolactone through supercritical CO 2 foaming, enabling a sustainable production–use–degradation cycle without pollution. With a solar reflectance of 98.18% and a mid‐infrared emissivity of 92.75%, the GRCF provides efficient passive daytime radiative cooling and limits soil moisture loss. Outdoor testing confirmed temperature reductions of 5°C relative to bare soil and 7.1°C relative to polyethylene‐covered soil, accompanied by evaporation suppression of 66.1% and 7.4%. During a three‐week cultivation trial, alfalfa grown under GRCF coverage achieved a 68% survival rate—compared with 0% on bare soil—and exhibited a 12.91 times increase in biomass. These findings indicate that GRCF effectively alleviates heat stress, improves soil water retention, and markedly enhances plant establishment, offering a promising tool for ecological restoration under increasing global temperatures and expanding desertification.