Farmers who have adopted healthy soil practices such as growing cover crops or adding compost say the techniques save money on production costs while enhancing crop yields. A farmland-conservation group says it hopes case studies documenting the benefits will encourage more farmers to use similar methods.
At Okuye Farms in Merced County, Jean Okuye said the farm has used cover cropping for some time, and soil-health improvements added in the past 14 years have benefited both the soil and the farm's bottom line.
Ralf Sauter, Okuye's son-in-law who operates the farm, supplied AFT with information to complete an economic assessment of soil health practices. The case study, released last July, showed Okuye Farms improved its bottom line by $657 per acre—a total of $76,155 on all 116 acres—and experienced a 20% yield improvement. Investment in soil health practices, AFT said, provided a 198% return to the farm.
When Okuye moved to the sandy loam property in 1980, she said, "When we disked, the water only went down to where the disk stopped; it was a hard pan soil with no water penetration."
Also, she said, the almond trees didn't produce as well as trees did at a neighboring farm. Okuye learned the neighbor had applied potassium and manure; she followed the neighbor's example, increased soil health and, in time, had good results.
"The standard should be using the natural materials and getting the organic matter back in the soil, which takes a long time," she said.
Commercial fertilizers should be used, Okuye suggested, when the farm has an imbalance or another problem.
During the last 14 years, Sauter has implemented nutrient management, a conservation cover crop, and mulching and compost applications. There is also a hedgerow planting that, with cover crops, attracts beneficial insects. These practices increased the nitrogen content in the soil and enabled Sauter to reduce fertilizer applications.
"Adding compost is a good way to get healthy soil and make the nutrients work better," Sauter said.
American Farmland Trust reports widespread recognition that adopting soil health practices such as cover crops, no-till and strip tillage, nutrient management, mulching and compost application are critical to improving air quality, strengthening water resilience and lowering greenhouse gas emissions. But it says farmers may hesitate to adopt these methods, in part due to the risk of investment.
The director of sustainability and environmental affairs for the Almond Board of California, Gabriele Ludwig, notes that practices such as cover crops and compost can be complicated in almond orchard systems, for reasons including a farmer's desire to ensure the orchard floor is clean by harvest; for frost protection during and after bloom, where bare ground reradiates better; and because a summer cover crop increases water use.
"These growers AFT worked with are showing that with some creativity, almond growers are figuring out how to include cover crops in their operations and make it work," Ludwig said.
AFT California Director Paul Lum said improving soil health can take a few years before showing significant benefits, but the organization's case studies show almond farmers can improve returns by adopting the practices.
Lum said soil improvements benefit the supply and quality of water, adding, "The other factor in the Central Valley is complying with SGMA (Sustainable Groundwater Management Act), so if soil health can help conserve water, that is important."
Butte County almond and walnut farmer Rory Crowley said he has participated in research projects to benefit soil health, including use of a cover crop and biosolarization to increase organic matter.
"What I realized pretty quickly is that we give a lot of credence to the chemical and physical side of soil health or soil structure and not a lot of credence to the biological side of soil," Crowley said. "Really, it is a three-pronged stool: Biological, chemical and physical work hand in hand."
Crowley said he knows the soil improvements he has made increased organic matter, water-holding capacity and water quality, and added it is important for farmers to have a cost-benefit analysis, so they know the practices will work for them.
"The moment you show a grower that he can save money by doing something, that is the moment it will be adopted," he said. "We want a toolbox that has organic tools and conventional tools, and with soil health tools, soil structure tools and soil chemical property tools. We're trying to create balance."
AFT said it continues to add to its library of case studies to assist farmers interested in soil health. The case studies were developed in partnership with NRCS under a Conservation Innovation Grant.