Crop diversification enhances cropland water-use efficiency across California's Central Valley

Worsening global water scarcity demands more sustainable water management in agriculture. Diversifying annual crop rotation patterns by incorporating additional species can reduce water consumption by improving soil health and water retention. However, studying crop diversification's effects on water consumption across broad regions has been challenging due to limited availability of spatially-explicit cropland productivity and water consumption information. Here, we analyze cropland water-use efficiency (WUE), the ratio of gross primary productivity to evapotranspiration, in California along a spectrum of monoculture to complex species rotations using novel remote sensing products. We find temporal crop diversification is an important driver of spatial WUE disparities, and increasing the number of species planted in the previous six years from two to four can increase WUE anomalies by approximately 20%. Our results provide large-scale evidence of the potential for temporal species diversification as a climate adaptation strategy that reduces water consumption while maintaining high crop productivity.