Water in the West: Trends, production efficiency, and a call for open data.

Climate change is projected to transform US agriculture, particularly in places reliant on limited irrigation water resources. As water demand and scarcity increase simultaneously over the coming decades, water managers and growers will need to optimize water use on their irrigated lands. Understanding how growers maintain high yields in arid, water stressed places, while conserving water, is of key importance for the future of US agriculture in the West. We explore water use management and trends in irrigated agriculture in the Western US using operator-level USDA-NASS Farm and Ranch Irrigation Survey/Irrigation and Water Management Survey data aggregated for the first time to the county-scale. In this exploration, we build the first county-level, openly accessible dataset linking farm(er) characteristics to irrigation behaviors in the West. We find notable spatial and temporal variability in Western irrigation practices, with neighboring counties exhibiting large differences in efficiency, water use, and crop yields, as well as in the sources of information, scheduling methods, and technological improvements employed. To produce effective management initiatives in the West, we call for the express and open dissemination of USDA irrigation data at sub-state scales. These data will contribute to our understanding of irrigated production and could support a pathway that will prepare growers for a more resilient agricultural future.

Blue orchard bee (Hymenoptera: Megachilidae) origin and orchard growing region affect female retention at artificial nest sites in cherry orchards.

The blue orchard bee, Osmia lignaria Say (Hymenoptera: Megachilidae), is a solitary, cavity-nesting species used for pollinating spring blooming crops. Commercial stocks are sourced from a few locations in the western United States but are sold across the country. However, the existence of local adaptations of these bees is unknown, such as the propensity to nest in nearby provided materials or to disperse broadly beyond release sites. In spring 2019, California- and Utah-sourced blue orchard bees were introduced into cherry orchards in both source and reciprocal states. Nest boxes were placed near (within 78 m) and far (500 m-1 km) from central bee release points. Paint-marked bees were released when floral resources were available. Observations of marked bees at nest boxes were used to evaluate female retention and dispersal pattern. Nesting bee counts in March-blooming California orchards revealed a significant difference in female retention by population source; over twice as many UT bees established nests than did CA bees. Few females were found at far nest sites. In May-blooming Utah orchards, counts of CA and UT bees were similar at near and far nest sites; neither female retention nor dispersal was significantly affected by bee origin. It is concerning that CA females were less likely to be retained in California orchards because the demand for commercial pollination is high for early-blooming California almond and cherry. Our results highlight the need to understand potential consequences of bee origin and their management on pollinator performance and reproduction in target crops.