Globally increased cropland soil exposure to climate extremes in recent decades

Cropland soil quality is fundamental to nutrient-rich food production and cropland soil management strategies are decisive for sustainable agriculture. However, inappropriate agricultural practices often lead to persistent soil exposure to air and sunlight, which largely increases the losses of soil microorganisms and organic carbon, particularly under climate extremes. Here, we provide a satellite-based mapping of daily soil exposure occurrence across global croplands from 2001 to 2022 and evaluate the associated degradation risks caused by extreme climate events. We find that 57% of global croplands experienced a reduction in soil exposure duration in the past two decades (23% significant at p < 0.05), mainly located in India, the United States, and China, while 43% experienced an increasing trend (11% significant at p < 0.05). On average, the duration of global cropland soil exposure decreased by five days during 2001–2022. Yet, despite the overall reduction in exposure duration, 86% of the global cropland soils are increasingly subjected to climate extremes (30% significant at p < 0.05). The areas exposed to increasing climate extremes tend to have higher soil organic carbon levels than areas with decreasing exposure, indicating an intensified degradation risk of global nutrient-rich cropland soils. Our study offers insights into global cropland soil exposure and its vulnerability to climate extremes under climate change, providing evidence to support improvements in sustainable land management practices.