Almond and Walnut are the major irrigated crops in the Northern San Joaquin Valley (NSJV) of California. The recurring droughts and climate change in California will likely increase the uncertainty in water supply to almond, walnut, and other specialty crops. Site-specific irrigation is critical to cope with these challenges. Knowing the water consumption of these water use intensive crops is imperative for optimizing irrigation management since it affects nut quality, productivity, and composition. This requires accurate estimates of crop water use (Evapotranspiration, ET). Traditional methods for estimating crop water use are spatially limited, whereas satellite remote sensing of ET offers the advantage of large-scale coverage and is increasingly adopted in irrigated agriculture. This study compares OpenET models, an open-source database providing ET estimates, against calculated ET from weather stations that are commonly used by growers in their irrigation management. Evaluation of OpenET against estimated ET might provide a good opportunity for growers to improve water use efficiency. Such improvements could lead to the adoption of publicly available irrigation management tools and ensure healthier tree development, better resource utilization, and more resilient orchards in the face of climate change. This presentation delves into the preliminary findings of the OpenET evaluation against calculated ET from weather stations in estimating water use for almonds and walnuts, while also examining the potential and challenges associated with each approach for implementation in growers' fields.
