In the water-scarce Westlands District of the San Joaquin Valley, John Diener carries on a family tradition of farming in the Central Valley that began in 1929. He began farming Red Rock Ranch in 1980 in Five Points, just south of Fresno. He grows a variety of crops on over 4,000 acres including almonds, grapes, wheat, alfalfa, corn, peas, tomatoes, spinach, and sugar beets.
Farmers on the west side of the San Joaquin Valley face particular environmental challenges. The region gets little rainfall and so depends on a combination of groundwater and surface water delivery from state and federal water delivery projects. In times of drought, surface water deliveries tend to decrease or even stop.
An additional challenge is the high levels of naturally occurring selenium and other salts in the soils that become concentrated when irrigation water drains and gets trapped by the clay layer below the surface in a shallow water table, diminishing the productivity of the farmland. The saline drainage water cannot be discharged into streams and rivers because it presents a danger to wildlife and the ecosystem.
John Diener has approached these challenges with an innovative spirit. Using a system he calls “Integrated On-Farm Drainage Management (IOFDM),” John designed a network of subsurface drain tiles that allow for the salt to leach out of the water table. The salinated drainage water is then cycled through fields growing increasingly salt-tolerant crops, such as canola and mustard, that remove selenium from the soil. After cycling the drainage water through fields of salt-tolerant crops, it flows into a solar evaporator to recover the salt or into a salt-water pond filled with brine shrimp. In the end, his marketable products include seed he processes into biofuel, selenium-rich seed meal for cattle, salt, brine shrimp, and desalinated water.
John’s IOFDM system has reduced his irrigation water use by 20 percent, important in the water-scarce region and also for reducing the energy needed for irrigation pumping and the associated greenhouse gas emissions. Although the drain tiles can cost around $600 per acre, the expenses are offset by the value gained from reclaiming the land for cultivation. The rehabilitated land increases in value by about $1,600 per acre, in addition to the returns from the sale of high-value crops.
In addition to IOFDM, John has installed state-of-the-art center pivot sprinklers with computer-controlled irrigation scheduling on his row crops, which improve water use efficiency by minimizing evaporative losses. The sprinkler system uses 65 percent less energy and 10 to 15 percent less water than a traditional system, a benefit in terms of cutting the greenhouse gas footprint of the farm in addition to saving labor and being cheaper than traditional irrigation systems. In his almond orchards and vineyards, he uses drip irrigation that also significantly improves water use efficiency.
John is also a pioneer in California in conservation tillage, a cropping system in which plant residue from an earlier crop or a cover crop is left on the soil when a new crop is planted. Conservation tillage has been shown to significantly increase carbon sequestration in soils, especially when combined with cover crop planting and/or compost addition. It also reduces tractor fuel use and soil compaction, cuts down on dust pollution, improves water penetration into soil, and reduces irrigation demands. Through conservation tillage at Red Rock Ranch, John has cut tractor work by about 80 percent, resulting in major energy and labor savings. These achievements are underscored by John’s commitment to clean air, a critical issue in Fresno County, home to the highest asthma mortality rate in the country.
For several years, John has recognized the benefits of integrating conservation tillage with overhead center pivot irrigation systems in the San Joaquin Valley. UC Davis cropping systems specialist and conservation tillage research leader Jeff Mitchell describes John as “leading the development of the merger of these technologies in California to tremendous environmental and economic advantage.” John collaborates with Jeff through the Conservation Agriculture Systems Institute (CASI), which brings together farmers, University of California researchers, the USDA Natural Resource Conservation Service, business leaders, public agency representatives, and environmental groups to achieve long-term, system-wide goals related to the development of conservation agriculture production systems.
CalCAN is pleased to partner with John Diener in the effort to protect California agriculture against the impacts of climate change. John’s integration of groundwater remediation, irrigation management, and conservation tillage has led to water savings, decreased energy needs, enhanced soil carbon, and scores of other co-benefits. The climate benefits of John’s integrated management approach are innumerable, as his commitment to research and education has allowed for countless other farmers to adopt similar techniques.