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Fourth of July in the Horse Heaven Hills.
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WestBred

FARMER'S TOOLBOX

Rounding up the gains of conservation tillage

No-till, direct seeding have many benefits, but one important tool is causing conflict

May 2020
By Trista Crossley


There’s very little disagreement that no-till and direct seed cropping systems are responsible for dramatic improvements in soil health and a reduction in erosion in Eastern Washington. There is, however, lots of disagreement over one of the main tools that makes those cropping systems viable—herbicides, especially glyphosate (also known commercially as Roundup).

Both no-till and direct seeding are considered low-disturbance systems where farmers don’t plow their fields but instead fertilize and seed through the previous year’s crop residue. According to Ty Meyer, executive director of the Pacific Northwest Direct Seed Association (PNDSA), direct seeding usually involves up to two passes over a field and causes a little more disturbance than does no-till, which generally only involves a single pass. That’s compared to three or more passes in a conventional tillage operation.

One of the main obstacles growers face when practicing no-till and direct seeding is the management of weeds, volunteer crops and disease, which in conventional farming is done, at least in part, by more tillage. If a farmer doesn’t want to till their fields, they have to turn to other methods.

“Where other people sometimes have the capacity to take care of weeds and other challenges with tillage, in direct seed and no-till operations, we utilize glyphosate to keep from doing a lot of tillage on the ground,” Meyer explained. “There’s multiple benefits to that. One being that we are not disturbing the ground enough to have to deal with heavy erosion during critical periods around the region.”

Another reason farmers need to kill any plants in a field before seeding is to prevent the “green bridge.” That term refers to the ability of plants, usually weeds or volunteer crops from the previous year, to harbor pests and diseases and pass them onto the new crop. So herbicides provide both weed control and disease control for no-till and direct seed farmers.

“I think glyphosate has really enabled producers to advance these systems and become successful in conservation-based systems,” Meyer said. “Without tillage, you need another tool to be able to manage (weeds and disease). That’s been glyphosate, which up to this point, has been one of the main tools.”

That’s certainly true for Larry Cochran, a Whitman County wheat farmer who transitioned to 100 percent direct seeding about 15 years ago after experimenting with the practice since the 1970s. As a child, he recalled seeing erosion ditches so big a combine couldn’t cross them.

“Erosion in the Palouse area was always horrendous,” Cochran said. “My analogy when talking about no-till/direct seeding is it is a puzzle, and glyphosate was the final piece to complete the puzzle. We had farmers trying no-till before Roundup came out, and they could get by one year, but then it would be a disaster. They couldn’t get rid of volunteer.”

In a paper printed in a 2008 issue of Scientific American, David R. Huggins, a soil scientist with the U.S. Department of Agriculture’s Agricultural Research Service in Pullman, Wash., and John P. Reganold, regents professor of soil science at Washington State University, estimated that by the late 1970s in the Palouse, soil erosion had removed 100 percent of the topsoil from 10 percent of the cropland, along with another 25 to 75 percent of the topsoil from another 60 percent of that land.

Up in Douglas County, Howard McDonald and his son, Travis, started transitioning some of their ground to direct seeding five years ago and use glyphosate to help control weeds. McDonald has also seen huge improvements in wind and water erosion but admits there’s a learning curve as he figures out how to deal with crop residue.

“We don’t have big dust storms like we used to,” he said. “Glyphosate is a tool, and we use it on both our conventional ground and direct-seeded ground.”

Today, Meyer estimates that more than 50 percent of the cropland in Eastern Washington is either in no-till or direct seed systems. PNDSA estimates that reduced soil disturbance and increased crop residue on the soil’s surface can reduce water and wind erosion by at least 90 percent, improving air and water quality. Other benefits of conservation-based tillage systems include increased water retention in the soil; improved soil health; reduced soil compaction; reduced fuel costs and greenhouse gas emissions; and better wildlife habitat.

Cochran said since moving to 100 percent direct seeding, he’s increased his production while decreasing expenses, mainly in the amount of fuel he uses. He also says his soil structure is much better.

“I’ve got these clay ridges that used to turn to marbles after plowing them. I couldn’t do anything to them after that. Now, after Rounduping those hills and seeding them, the ground is mellower and works better. My organic matter is increasing, and yields are increasing. The erosion is almost gone,” he said.

McDonald has also seen an improvement in the soil he direct seeds.

“I’m gradually seeing places that didn’t grow wheat or had no straw now getting some straw and micro-organisms,” he said.

The use of glyphosate isn’t without criticism. While the Environmental Protection Agency has determined that glyphosate does not cause cancer when used according to label instructions, that hasn’t stopped consumers from filing lawsuits against Monsanto, which originally produced Roundup, and then Bayer AG, which acquired Monsanto in June 2018. Some states and other countries have either banned the use of glyphosate or are attempting to ban it.

Any producer who applies glyphosate is required to have an applicator’s license and be trained on the proper use of the chemical. If glyphosate is banned, growers will need to find other ways to control weeds and volunteer plants. Meyer suggests those methods might not necessarily be chemical in nature. He pointed to research showing that cover crops and more diverse crops can help in limiting unwanted growth.

“Certainly, I think we will see successful operations without glyphosate in the future, but it’s dependent on what alternatives there are, and what we will do to manage some of the issues that will pop up if we don’t have a tool like that,” Meyer said. “Glyphosate is just one tool, and there are other tools in the toolbox in the form of chemicals that could potentially be used, but they may be more expensive and have different impacts on the system. I’m not going to judge one or another. The challenge I see for us, maybe it’s not just a glyphosate issue. Maybe it’s a chemical or pesticide issue we are dealing with overall. The focus is on glyphosate, but what else can we do? What can we change on our farms that’s under our own control to have an impact on reducing the use of some of these inputs to manage diseases and weeds?”

Without glyphosate as a tool to control weeds, McDonald said he’d have no other choice but to till his ground. He pointed out that there’s a generation of farmers who haven’t raised wheat any other way but no-till or direct seeding, and many of them don’t even have the right equipment for conventional tillage.

“There’s a lot of young farmers who are very good farmers and passionate about what they do (direct seeding and no-till),” he said. “But unless we have another tool like Roundup, kids wouldn’t know how to run this older equipment. Glyphosate is only a tool. If there’s a better mousetrap out there, tell us what it is, and let us use it.”

Cochran isn’t sure what he’d do.

“I wrack my brain trying to think what I would do (without glyphosate),” he said. “I still have the tillage equipment to go back to the old way, but I don’t want to destroy what I’ve spent the last 40 years building.”

Herbicide resistance BMPs
Wherever and whenever herbicides are used, the potential for developing herbicide-resistant weeds exists, and it is a growing problem across the Pacific Northwest, not only to glyphosate, but to other chemicals as well. Washington State University (WSU) has compiled a list of best management practices (BMPs) to help growers manage herbicide-resistant weeds. According to WSU, BMPs are critical to the long-term sustainability of wheat production in the Pacific Northwest. Using BMPs is the most effective way to address herbicide-resistant weeds, especially when they are incorporated into a long-term weed management plan. To download a copy of the BMPs, visit WAWG at wawg.org/herbicide-bmps/.