Agriculture in the California Central Valley

John Diener (photo: US Embassy) by Margery Magill

John Diener is the owner, president, and CEO of Red Rock Ranch in Five Points, California. Established in 1986, Red Rock Ranch has over 5,000 acres with 15 full-time employees. Diener grew up on the very farm he now manages and has been an articulate spokesperson for Central Valley agriculture over the years, and a demonstrated leader in a variety of civic, research and policy arenas. Diener has a degree in agricultural economics from the University of California, Davis.

In the early 1990s, Diener led a California Department of Pesticide Regulation/U.S. Environmental Protection Agency-supported and UC Sustainable Agriculture Research and Education Program-administered effort, the West Side On-Farm Demonstration Project, which included 14 large-scale on-farm comparisons of alternative and conventional soil and pest management options for the region.

In this project, Diener shared his innovative and highly successful soil management practices with other farmers in the Five Points/Huron/Mendota region and conducted very successful discussions of his now well-known Four Corners area of his farm, in which he has been using four different management approaches for a number of years with very dramatic impacts. The data set developed from this four-way comparison enabled researchers to work with several University of California and USDA National Soil Tilth Lab scientists to develop a soil quality index for the region, which was summarized in a number of popular and technical manuscripts.

In more recent years, Diener has developed a wide variety of conservation tillage approaches for several of the crops he produces. In 2003, he experimented with no-till wheat and was able to save two spring irrigations due to the reduced soil evaporation. Soon after, he tried a short-season cotton crop immediately following wheat harvest and managed to harvest it before Christmas. He also was a pioneer at trying no-till cotton in heavy residues, as well as no-till corn and canola.

Diener has concluded that the way to make conservation tillage happen in California’s San Joaquin Valley is to couple it with overhead irrigation systems, and in the past few years, he is leading the development of the merger of these technologies in California to tremendous environmental and economic advantage.

The systems he has developed save water, fuel and labor. In 2009, he was the first farmer in California to plant strip-till corn following wheat under center pivot irrigation. These types of systems will very likely have increasing importance in California’s West Side region in the future because of their resource conservation benefits and because they also reduce production costs. It is important to point out that the various conservation tillage approaches that Diener has tested, learned from and developed were not easy and involved considerable risk. They now, however, enable others to move forward more smoothly with their own conservation tillage systems.

The workgroup is indebted to John for his tireless and remarkable efforts with the various UC Davis and conservation tillage workgroup tours that he frequently hosts at his farm. He has met with scores of students in tour groups and it is likely that he has met with and presented information to hundreds of visitors to his farm over the past several years.

“I teach production courses for vegetable and agronomic crops at UC Davis and our visits with John at Red Rock Ranch are always very memorable, enriching, and eye-opening experiences for students,” said workgroup chair and UC Davis professor Jeff Mitchell.

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