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CTF benefits soil over time

Fencerow farming system increases corn yield and changes farmers’ soil biology

Dean Glenney found an abundance of earthworm holes in the non-trafficked areas of his field.

Fifteen years ago, when the bin-full alarm went off on Dean Glenney’s combine as he harvested his corn crop near Dunnville, Ontario, he had no idea what was going on, and he certainly didn’t expect the record yield of 236 bushels per acre he pulled off the field that season. Since then his yields have been as much as 300 bushels per acre, and he understands perfectly why he’s getting these enviable corn yields. It’s thanks to what he calls his “fencerow farming” system.

Fencerow farming combines controlled traffic farming (CTF), (where equipment traverses the field only on established tramlines); strip farming, (where two crops, in this case soybeans and corn, are planted in the same field in six-row strips which alternate between the two crops each year); and no-till.

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Glenney adopted the system 23 years ago, but it took five to six years before he started to see increased yields in his corn crops. From tearing up fencerows over the years as he purchased larger and larger plows, he knew that the undisturbed soil in those areas was highly productive — at least for the first few years. He decided he wanted to create a system where he could replicate those undisturbed areas across the whole field, and try to bring the soil back to its original productive state.

“I wanted to have the soil in a fencerow every 30 inches across my field,” says Glenney, who had to adapt his equipment so everything — tractor, planter, sprayer, combine etc. — runs on 60-inch or 120-inch wheel spacing.

Improving soil biology

Over the past four years, researchers have worked with Glenney to try and figure out what’s happening in his soil and if the benefits his system provides could be replicated on other farms. They’ve made some interesting discoveries.

The study began with a straightforward comparison of the plants and soils on Glenney’s farm and a conventional, neighbouring farm, using the same corn seed and inputs on both. The researchers sequenced the microbes on the plants, the plants’ roots and in the soil.

“The microbiological populations that were colonizing the plants on each farm were totally different, even though those farms were only five miles apart,” says George Lazarovits, research director at A & L Canada Laboratories, who led the research.

Earthworms are so active in Dean Glenney’s soil they are actually pulling the leaves of the corn plants into their holes while they’re still attached and growing.
Earthworms are so active in Dean Glenney’s soil they are actually pulling the leaves of the corn plants into their holes while they’re still attached and growing. photo: Courtesy of Dean Glenney

“We also measured the chemistry of the soils and the chemistry of the plant, and both fungal and bacterial populations were very different. In Glenney’s plants the number of bacteria was significantly higher, and although we expected them to be more diverse, they were in fact more concentrated — there were fewer species than in the conventional system, which had huge diversity in the microorganisms and lower numbers. Somehow he’s created an ecosystem whereby there’s an enrichment of specific microorganisms that are present in that soil that can quickly colonize the plants. And by not tilling it, and leaving the roots in place year after year, you get this buildup of a microbial community that obviously is associated with the corn and soybeans.”

Although Glenney struggles to get similar high yields from his soybean crops, which Lazarovitz suggests may be due to the high nutrient demand of the corn, the system, which includes no-till, has enriched things such as earthworms that aerate the soil. Glenney has seen earthworms actually pull growing plant leaves still attached to the plant into their holes, their activity is so high.

As well, one organism that’s present in the highest proportion in Glenney’s plants can produce antibiotics that protect the plants from disease. “Glenney has long cobs where the corn is right to the tip of the cob. On the conventional farm a lot of cobs were killed back from the tip down about a third of the way, because the cob was colonized by organisms that were destroying the tip of that cob, so seed was not being produced,” says Lazarovits. “Glenney’s cobs were about 40 to 50 per cent longer than the other conventional ones even though it was the same variety with the same genetics.”

Glenney also gets very tall soybeans and a lush crop so he does get issues with white mould occasionally, depending on the weather conditions. But he has noticed that pests such as cyst nematodes aren’t widespread across the field thanks to the strip cropping. “If a pest comes into the field, it pretty well stops at the edge because it comes into the soybean row and then right away it runs into a corn row,” says Glenney.

Great potential for increasing yields

Lazarovitz is extending this research to around 40 farms across Ontario, and is collecting field data using drones equipped with advanced NDVI (Normalized Difference Vegetation Index) technology. The technology maps productivity based on temperature and colour spectrum analysis. Lazarovits has discovered huge variations in the productivity of different areas of the field.

“If you fly a field with a drone and use an infrared spectrum to measure the vigour of the plants, you find that about a third of a field on average is highly productive, a third is mediocre, and a third is under-producing,” he says. “When we first went in we were only sampling the highly productive zones and the low production zones or stress sites. In almost every case we found huge differences in the microbiology. Now we have a correlation with microbiology and productivity but we also have some other correlations coming out from the measurements of soil chemistry and plant chemistry. So the next step is to try and figure out what is driving yield in those productive areas? Is it the microbes or a combination of microbes and chemistry?”

Lazarovits says that he hopes further research will reveal the factors driving productivity and allow them to fix underperforming sites and maximize the unrealized genetic potential that already exists in today’s crop varieties. “If we increased yields from 75 bu./ac. in those areas to 150 bu./ac. we could increase yields across the province and Canada by about 30 per cent,” says Lazarovits.

“About 75 to 80 per cent of the farms we looked at had the capacity to produce as much as Glenney’s farm if not more. The question is, if we could produce 350 bushels of corn on part of a field and we’re planting the same seed and using the same fertility package and we’re only getting 75 bushels at another site in the field, we already have this enormous potential, so why aren’t we paying more attention on how to fix these sites and bring the real potential of those seeds up to where they should be? We’re spending billions on increasing seed genetics when we’re not even using a tenth of their capacity already.”

CTF in the west

Conditions in Western Canada are vastly different to Eastern Canada, but a number of farmers across Alberta have been working on a project with Controlled Traffic Farming Alberta (CTFA) over the past six years to assess CTF on their farms. None of the eight farms, which cover different regions of Alberta, have been in CTF for longer than six years, and some converted within the last year or two, so that may be the reason that most haven’t seen a consistent benefit in terms of yield, says Peter Gamache, project leader at CTFA.

“We are seeing some good results soil-wise, but at this point in time, they’re not translating into yield,” says Gamache. “But I don’t see any of our co-operators going away from their systems because they’re not working or they’re not satisfied with them. They are hoping for yield increases but that could come over time, and they love the other benefits and the positive things that CTF has brought them.”

Research at the University of Alberta has definitely proven benefits to soil physical properties — especially available water holding capacity — in the CTF sites. “We have found that soil quality is improving within more than half of the sites,” says graduate student, Kris Guenette, who has been conducting the research.

In newer sites, which have recently converted from conventional farming practices using random traffic patterns to CTF, the water holding capacity of soil in the un-trafficked areas has increased. In older sites, where CTF has been in use for several years, both water absorption and holding capacity of the soil has increased. “This leads us to the conclusion that the longer the traffic is controlled within the field, the greater the benefits one is perceiving within the soil,” says Guenette, who says in other, drier parts of the world, such as Australia, issues with water use efficiency are driving the adoption of CTF much more so than in North America. “Normally in Alberta we don’t have too many issues with water use efficiencies, as rain-fed and irrigation practices can usually sustain the water requirements for plants. But it could become more relevant, especially with the frequency of severe weather experienced being increased. The whole point of the CTFA project is to see if those practices in other parts of the world are applicable here on the Canadian Prairies.”

Other benefits of CTF include better precision in seeding, applying inputs and harvest, as well as the ability to improve efficiency because the tramlines are already set up and use the same pattern year after year. Other benefits of CTF are tough to put a value on, such as being able to do accurate, precise, on-farm research. “CTF is a powerful system within which to do on-farm research, and I think most of our co-operators feel has become more important because of changes in who is doing research these days,” says Gamache. “One of them has said CTF could allow him to easily adopt new technology such as robotics in the future.”

But in the end, CTF in Western Canada, is likely to fit as part of a bigger system that includes more diverse crop rotations, says Gamache. “When we combine CTF with more diverse rotations, and things like cover crops, that’s where you help move your system along faster,” he says. “Dean Glenney has pretty impressive results. I think we can achieve some of that but it’s going to take time.”

CTF can pay dividends

Glenney doesn’t suggest that CTF is right for every farmer. There are drawbacks such as having to adapt equipment, expensive technology such as GPS systems, and he is still trying to find a closing wheel for his seeder that he’s happy with. “We need the equipment companies to get on board to make every piece of equipment on 120-inch centres,” he says.

Glenney’s success at achieving record breaking corn yields is also giving him a few headaches, especially having to direct seed soybeans into heavy corn residue. He has two practical tips for anyone wanting to give CTF a try. One is go to the skinniest tires on the tractor you can get to help limit the trafficked areas — he uses some nine-inch tires. Second is the cheapest way to create a leading edge coulter on the corn planter is to put a worn coulter next to a new one. And his most important piece of advice is to pay attention to detail. “You have to be on the crop all the time and not miss the cues and know if there’s something out there,” says Glenney. “If somebody’s willing to put the effort in and pay attention to detail then this system will really pay dividends.”

About the author


Angela Lovell

Angela Lovell is a freelance writer based in Manitou, Manitoba. Visit her website at or follow her on Twitter @angelalovell10.



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