SAFS Newsletters

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Fall 2006 - Vol. 7/No. 1


Part II: Growers review winter cover crops, conservation tillage

by Lyra Halprin, Gene Miyao and Aaron Ristow

[Editor’s Note: This article was originally printed in two parts, with Part I appearing in Vol. 06, No. 3 and Part II appearing in Vol. 07, No. 1. This HTML version contains the complete article.]

Several growers and UC Cooperative Extension personnel who cooperate on the SAFS project discussed farming practices at Sano Farms in Firebaugh. L-R: Yolo County farm advisor Gene Miyao, Sano Farms farm manager Jesse Sanchez, Yolo County farmers Bruce Rominger and Tony Turkovich, and UCCE vegetable crops specialist Jeff Mitchell. (photo by Z. Kabir)

Growers have been part of the interdisciplinary SAFS/CIFS team since the project's inception at UC Davis in 1988. From the start, the project's focus was to combine the best features of both on-farm and experiment station research. It was established under controlled conditions on a research farm, yet considers the practical applicability of its farming practices, which are regularly evaluated by farmer cooperators. At least three growers representing organic and conventional farming operations and two UC Cooperative Extension farm advisors have participated in all major project decisions. One of the basic premises of the project was that organic and low-input farming systems must be economically productive to be adopted by farmers. Research at the SAFS project has long demonstrated the importance of premium prices, and the need for cost-effective and reliable fertility and weed management practices to achieve economic viability.

Farmer Adoption

The SAFS project receives attention each year from farmers, industry, researchers, and the general public. Ideas that were once considered to be impractical or radical are gaining in popularity. As consumer demand for organic foods increases, more growers are considering the transition to organic farming systems and seek out the SAFS/CIFS team to get information and advice. Others are simply interested in reducing costs or improving soil quality. Information and experience generated by the project since 1989 is valuable in informing growers of some of the agronomic, economic, and ecological consequences of their many options.

At a panel discussion at the SAFS field day in June 2004, four growers representing diverse farm sizes and growing practices discussed the importance of crop and system diversity in their operations (

We recently checked back with them and several other growers who have worked with the SAFS project to discuss their use of conservation tillage and cover crops, and what researchers could do to help other farmers adopt these practices.

Jeff Main. Jeff and Annie Main have farmed organically on 20 acres in the Capay Valley since 1984. They continue to plant a variety of cover crops on their farm, where they grow 60 to 80 different tree and annual crops. Cover crops can be used to provide much more than weed suppression and nitrogen, Jeff Main said.

"Farmers have just scratched the surface on cover crops," he said. "There are lots and lots of varieties. We don’t want to limit ourselves to what we traditionally consider to be cover crops, i.e. legumes and grasses."

Main said he hasn’t made major changes in his farming systems, which includes the use of deep-rooted cover crops instead of deep tillage.

"Good farmers would put more back into their soil if they could, but if the resources aren’t there, obviously they cannot," he said. "Farmers are innovators, but without time or money, it’s hard to expect innovation and creative thinking."

Main noted that this year his farm must pay $600 for a new insurance policy "strictly to cover our presence at the Davis Farmers Market for liability."

"It’s a brand new cost, forced on us," he said. "This new coverage equals our cover crop budget for the whole farm. The trend is toward more protection and more regulation, and every one costs more time or money or both."

Charlie Rominger. Charlie Rominger is a partner in a 2700-acre family farming operation in Yolo County, which is moving toward more organic, more no-till and less conventionally farmed land. In 2005, they enrolled in the federal government’s Conservation Security Program through the Natural Resources Conservation Service, which pays farmers for using conservation practices rather than for producing commodity crops. Some of the Rominger fields qualified for incentive payments, but others did not.

"Even though on one field we had hedgerows, a tail-water pond and a windbreak, we did not qualify for incentive payments because we used conventional tillage at that site," Rominger said. "In order to expand our conservation tillage, we bought a conservation tillage bed implement, which chews up the residue but leaves most of it on the surface."

His biggest disappointment was that the federal conservation program couldn’t pay.

"We made the changes, but then the government froze the budget for the conservation program and we didn’t get the reward," he said. "Incentive programs do encourage farmers to be innovative, but only if there is follow-through."

Rominger said he has learned from conservation tillage research, and would like to see research on a "true no-till farming system" for irrigated row crops in the Sacramento Valley, including a more diverse crop rotation and livestock.

Frank Muller. Yolo county farmer Frank Muller uses winter cover crops and conservation tillage to various degrees on different crops he farms both organically and conventionally with his large family operation, Joe Muller and Sons.

“We do include winter cover crops on some target crops,” he said. “We use them ahead of our later-planted tomatoes so we can follow best management practices and not fight putting them in when the ground is too wet. But we avoid practices that compromise our yield goal.”

Muller said he is interested in learning about practices that help him save money while producing the same or increased yields.

“You want your expectations to always be high—we want to incorporate these more sustainable practices and hopefully increase yields,” he said. “Once our yield bar has been set, we will not lower our expectations.”

He noted that his operation’s use of conservation tillage has been very successful in some crops.

“We raise a lot of sunflower seeds,” he said. “We have our tillage program down to one pass with a stalk chopper after the sunflower harvest before we plant wheat. Without a doubt, we are successful using conservation tillage there.”

Muller noted at the other end of the spectrum, he uses more conventional tillage in high-value crops like tomatoes or peppers.

“With tomatoes we can’t have a lot of residue on top of the bed because trashy conditions make harvest difficult,” he said. “We’re numbers people here. If it’s less cost effective in the big picture, it doesn’t make sense.”

Muller said his operation’s tillage has changed quite a lot in the last few years; the number of field passes has been reduced 60 percent, but many standard implements are still used.

He said if farmers can see that alternative farming practices consistently provide greater returns, they would readily adopt them.

“People can see that some farmers are having success using cover crops and reduced tillage, and they see diesel prices rising so they want to adopt these practices,” he said. “But we also have to see that they provide short-term profitability.”

The problem for him, Muller said, is that what works on one farm in one microclimate, may not work for his operation.

“I’d like to see a project that focuses on maximizing return. Researchers should identify the model of best management practices, including conservation tillage and winter cover crops,” he said. “The goal of this project would be to create an economic model that is superior to conventional models. Lower costs, higher yields, and greater environmental benefits will draw a crowd.”

Paul Underhill. Yolo County organic farm partner Paul Underhill said he has increased the planting of fall cover crops (grasses) on 220-acre Terra Firma Farm. The cover crops are irrigated in October and mowed after they have “frosted down,” which has worked well as preparation for summer cash crops. Unfortunately, during 2006’s very wet spring, winter cover crops like vetch were still green and weren’t turned under in time.

Several growers and UC Cooperative Extension personnel who cooperate on the SAFS project discussed farming practices at Sano Farms in Firebaugh. L-R: Yolo County farm advisor Gene Miyao, Sano Farms farm manager Jesse Sanchez, Yolo County farmers Bruce Rominger and Tony Turkovich, and UCCE vegetable crops specialist Jeff Mitchell. (photo by Z. Kabir)

“Our vetch cover crops will work better this year if we wait to plant the cash crops until fall and winter,” he said. “That takes some of the stress out of using winter cover crops.”

He said the extended rain, which made it impossible to incorporate or mow winter cover crops on time, is what big growers fear—they can’t get into fields and plant 500 acres of a cash crop quickly on saturated fields.

“We like to plant cover crops before our biggest cash crops,” he said. “Our organic plants produce way bigger yields after winter cover crops.”

Although Underhill said it would be useful for smaller farmers to share the use of expensive planting and mowing equipment for cover crops, he noted that wet years underscore why it is hard to share equipment: “during the few dry windows for mowing or planting, everyone wants to use the equipment.”

He said he appreciates reading the SAFS/CIFS project research results and was especially interested to see that researchers had documented a phenomenon he and other organic growers have seen on their land—the use of cover crops has helped build up soil nitrogen, but plants don’t seem to be able to access it.

“We know we’re building up nitrogen in our soils, but we still have to apply expensive organic nitrate fertilizer,” he said. He said he has been watching commercial microbial products such as “EM” and “Microlizer” that purport to increase the availability of existing nitrogen in the soil, but he would like university researchers to conduct “an objective test on all those products.”

“We know the nitrogen is in the ‘nitrogen bank’ in the soil, and we’re trying to do ‘withdrawals,’” he said. “We’d like to know if these microbial products would help.”

Tony Turkovich. Grower Tony Turkovich farms several thousand acres in Yolo and Solano counties as a partner in Button & Turkovich Ranches. He said his operation has used cover crops and conservation tillage for many years in varying degrees.

“We grow a lot of alfalfa using conventional tillage to get it established, but use minimum tillage on most of the other ground,” he said. “We have used no-till in corn and wheat, but we’re trying not to grow those crops, which tend to be unprofitable.”

Turkovich said that they do not generally plant cover crops before high-value crops like tomatoes and peppers, which must be planted early, although the later-planted tomatoes are sometimes preceded by cover crops.

“The majority of our fields have cover crops, including the orchards,” he said. “This year we planted garbanzo beans on some fields, which although they are harvested as a cash crop, also function as a winter cover crop.”

“All told, around three-quarters of our fields have some kind of winter cover crop,” he said. “Cash crops that provide some of the benefits of a winter cover are certainly a consideration in our crop selection.”

Turkovich noted that in the north part of the state, farmers have traditionally thought of winter cover crops as “big, lush, leguminous plants.”

“But with diesel reaching $3 a gallon, and many costs associated with working the cover crops in, we’re rethinking the legumes and looking at the cereal cover crops reported to be used more in the southern San Joaquin Valley,” he said.

He said he is interested in finding out more about plants that can be used as cover crops “whose roots improve soil structure, but don’t have as much above-ground biomass and therefore wouldn’t require significant spring tillage.”

Turkovich said he’d like to see more research investigating new cover crops that enrich the soil and improve water quality, as well as equipment and techniques that growers can use to plant directly into residue, which would reduce the need to spend time and money working plant trash into the soil.

“With fuel and fertilizer costs going up, conservation tillage is definitely more attractive as a way to save field costs,” he said. “Cover crops need to be reevaluated in relation to the rising costs of fuel and fertilizer and whether we can manage them in a cost-effective way.”

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