- Author: Jeffrey P Mitchell
- Author: Anil Shrestha, California State University, Fresno
- Author: Jeffery A. Dahlberg
- Author: Lynn Epstein

Since the advent of irrigation in California with the widespread drilling of wells in the 1930s and the proliferation of orchard crops during the past two decades, total annual water use in many watersheds exceeds supply. Partly as a consequence, California enacted the Sustainable Groundwater Management Act in 2014, which limits withdrawals to replenished levels.
Because irrigated agriculture accounts for nearly 80% of total water use, reductions in irrigation will be required, but preferably without decreasing either productivity or food supply. Furthermore, with some climate change projections suggesting a potential 20% water loss by the middle of the century, the need for more efficient water use could become acute....
- Author: Jeffrey P Mitchell
- Author: Tom Willey, Madera County organic farmer
- Author: Paul Muller, Guinda organic farmer

Though humans thrived here for millennia without planting seeds or herding animals, the phenomenal success of California's short-lived agricultural experiment is staggering on a planetary scale, and represents barely over a century of building the highly productive food systems that benefit us all today. The farmers who manage the fields, orchards and vineyards of our Golden State contribute greatly to the common good by providing abundant food from an astonishing variety of crops.
Yet, present and looming challenges of water supply, climate change, air quality and the long-term fertility and sustainability of California's agricultural soils threaten continued productivity. Such challenges compel farmers, researchers and the...