Challenges: Perspectives of Expert Growers

Transitioning to Cover Cropping: How do Growers Get Started?

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Cover cropping is an opportunity to use an under-utilized space, bringing many potential ecosystem service benefits to orchards, but some challenges and unknowns may hinder adoption. Here we share insights from experienced growers on how they got started with cover cropping. Many started small, and as they noticed benefits and became comfortable with cover crop management, they expanded. Overall most growers spend many years experimenting with seed mixtures and fine-tuning operations or investing in equipment to fit their operations. They found ways to start cover-cropping despite not having ideal equipment, and then typically managed to acquire better equipment later on.

While many growers began experimenting with cover crops on their own, several growers interviewed have been part of trials with various organizations that have helped get them started. However, they do not always permanently adopt the new practices.

 

Erdman Family Farms

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Kim Gallagher is a fifth-generation farmer growing 380 acres of almonds south of Arbuckle in Colusa County. "Sustainability, which encompasses everything, is a huge goal on this farm." They have used cover crops throughout their entire orchards for the last two years but started cover-cropping 11 years ago, mainly to try and attract pollinators on the edge of an almond tree block. When they began planting cover crops in the orchard, they first did every other or every third row. Xerces Society helped provide California native seeds, which have been too expensive to continue to use, but some species reseed well depending on weather conditions. "It's a mix every year. I still haven't dialed it in completely. We have worked with a lot of programs and partners, that's for sure. The benefit is the knowledge they bring to someone trying to figure it out and then just sharing the cost of the seed. We're doing all the work, everything else is our dollar, but the seed is really expensive. You have to start somewhere. There's the goal, and then there's the reality, and you can't always hit the goal. That's what I'm learning. I have these huge lofty goals,... but we're not going to get there next year." The Community Alliance with Family Farmers (CAFF) has helped provide seeds for areas that have had erosion issues. Project Apis m. has also helped to provide cover crop seeds. Finally, the NRCS Conservation Stewardship Program has helped them to move to cover cropping all of their orchards.

Four years ago, they bought a drill planter. At first, to plant the cover crop seed, they disced, broadcasted, and then used branches to cover it up. They still use this method in the blocks where their planters are too big to enter.

Detailed information about Erdman Family Farm's cover cropping practices:

• Erdman Farms: Bearing almonds
• Erdman Farms: Non-bearing almonds
• Erdman Farms: Walnuts

 

Kelsey Creek Orchards

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David Mostin of Kelsey Creek Orchards organically farms 15 acres of walnuts and 15 acres of pears. The previous owner of the walnut orchard would cover crop, so he has continued that practice since he acquired the walnuts in 1986 and added cover cropping into his pear orchard a few years ago. Mostin was primarily motivated to learn more about cover cropping due to issues with his soils in one particular area. He visited a University of California Cooperative Extension (UCCE) office and got a book about cover cropping. At first, he planted Purple vetch and Montezuma oats, noticing a change within the first year. He would disc and then broadcast his seeds but found they often ended up in the strip and became harder to manage. Now he uses a drill to seed his cover crops and finds it much more straightforward. Mostin initially found it challenging to fertilize his trees effectively. He used to broadcast compost but felt it got lost in the cover crop, which already provides some nitrogen, so now he bands compost along the tree row and is pleased with the outcome of this technique. Mostin has also partnered with Dr. Astrid Volder and her lab in the Department of Plant Sciences at the University of California, Davis on a project about cover-cropping in pear orchards.

Detailed information about Kelsey Creek Vineyard's cover cropping practices.

 

Full Belly Farm

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Full Belly Farm is a highly diversified 500-acre farm in Capay Valley, Yolo County, with 70 acres of orchards. Full Belly Farm wanted to use cover cropped orchard blocks amongst their diversified vegetables as biological reservoirs for beneficial insects, hoping that flowering cover crops would provide habitat and the insects would migrate to the vegetable fields. Although it is unclear if this strategy works, they have found many other benefits of cover-cropping in their orchard, so they continue to do so. As they have progressed in experience with cover cropping, they have upgraded their equipment and methods "we've been all over the board…we did more discing at times, and then putting seeds in the ground [by] broadcasting and then hoped the leaf litter would cover it up. I think the worms ate a lot of that seed, or they just disappeared. Trying to get a good stand was important, so it was a matter of getting the tools to do that. When we began, we didn't have those tools." Now they have a no-till drill and a roller to roll down the cover crop instead of mowing it in some areas. They often start with an organic orchard seed mixture (Clover, ryegrass trefoil) from TSL Seeds and then add in other seeds they grow themselves, or barley, oats, and peas. They are also experimenting with adding sunflowers and tillage radish. They have found a tool called Smartmix Calculator by Green Cover Seed Company that helps them design cover crop mixes depending on desired benefits. Says Paul, "When the tools are easily accessible, it makes it easier to go out and actually put the cover crop in the ground."

Detailed information about Full Belly Farms cover cropping practices.

 

Unruh Farming

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Daniel Unruh farms 193 acres of walnuts in Colusa county, alongside the Sacramento River. The orchards have been managed as no-till since 2011. In 2013, they started cover cropping and have done a lot of experimenting over the years. The first time they planted cover crops, they used a 20-foot seed drill without first working the soil and found it wasn't enough pressure, and seeds just spilled on top of the soil. However, they still got decent germination. Now they use a vacuum drill and can put similar-sized seeds in separate bins. The main aim of planting their first cover crop was to help with nematode control. After trying some chemical products against nematodes without success, Unruh realized that some nematicides used a mustard derivative, so he decided to plant mustard directly as a cover crop. He managed to get a 40% reduction in nematode numbers after using a mustard dominant cover crop. His cover crop mixes now include more grasses to improve soil organic matter, although he never plants the same mixture twice as he constantly reassesses his soil and its needs from one year to the next. Like some other growers, Unruh also uses the Green Cover Seed SmartMix Calculator to select his seed mixes and then sources the seeds from local dealers. Unruh used to use a shredder to terminate his cover crop but now uses a roller-crimper and has started to incorporate sheep, letting them graze the cover crop down to 30% and then rolling the rest, so the soil is covered.

Detailed information about Unruh Farming's cover cropping practices.

 

Juneco

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Seth Cooley manages a thousand acres of orchards in the Dixon Ridge area of Solano County. He had heard obscure references to cover cropping but wanted to learn more and thought cover cropping might be a beneficial practice for orchards they planted on marginal soils. He had the "experience that when we plant certain grasses in some heavier clay soils, such as sudangrass, and ryegrass…the crop residue gets intermixed back into the soil [and] really helps to make the dirt feel better in your hands." He adds that, from "personal observation, I really felt that including a cover crop in our orchard could dramatically improve the soil compared to the absence of a cover crop."

He started cover cropping when a neighbor told him that the Community Alliance with Family Farmers (CAFF) was looking for farmers to do cover crop trials in orchards, and they would provide the seeds. The trial only covered a small area, 55 acres. The three-year cover crop trial has ended, and he is unsure if he will continue the practice. While he is sure that there are benefits to the soil from cover cropping, the economic realities of low walnut prices and the desire to continue navel orangeworm sanitation practices make it difficult to continue the practice at the moment.

Detailed information about Juneco's cover cropping practices:

• Juneco: Bearing walnuts
• Juneco: Non-bearing walnuts