Richards Farms planted a month early in Circleville, OH, at a time when local rainfall was 90% above normal this spring. Thanks to controlled traffic farming (CTF), the family has 30-year-old established traffic lanes in its corn and bean fields. They provided improved traction and drainage, while neighboring growers sat on their hands as a soggy April and May turned to June. Richards Farms was among only 1% of Ohio farms with corn planted by the first week in May, according to USDA statistics.
The farm’s CTF tracks, compacted from years of traffic, are so dense that they retain less moisture, making them like virtual paved roads.
The farm’s CTF system limits wheel tracks to the same lanes to limit soil compaction, says veteran grower Bill Richards. This separates the traffic lanes from the crop-growing zones.
Less than 10% of his family’s ground is compacted by the traffic of ammonia tanks, planters and sprayers.
If you add harvest traffic, 25-30% of their soil is driven on. Compare that to over 75% of fields commonly driven on in more conventional farm settings.
“No-till and CTF have helped to keep our family farm profitable, competitive and, really, beyond sustainability these past 40 years,” Richards says. With more than 30 years of continuous no-till, he and his three sons (Rich, Steve and E. R.) have “seen soil improvements beyond our dreams. Planting and stand establishment get easier and easier each year. Yields are increasing while fuel, labor, herbicide use and machinery costs decrease.”
Richards was one of the first in the U.S. to use conservation tillage, 45 years ago, and switched to continuous no-till and CTF 30 years ago. “And it’s working,” says the grower and former chief of the Soil Conservation Service (from 1990-1993).
CTF often accompanies no-till and precision-agriculture adoption, because they all benefit from the same guidance technologies, and conserve resources.
All of Richards Farms’ equipment except the combine has 80-in. tire spacing (center to center). Corn and soybeans are planted in 20-in. rows. The ammonia rig, planter and sprayer share the same 20-in. rows with a fallow 40-in. row behind the wheels. “We plant in a 55-ft. pattern: 31 rows with two vacant, making a 33-row pattern,” Richards says. “What we lose from those two rows we more than make up in the rest of the field.”
The corn head is one-third the width of the planter, so the combine runs on the tramlines one-third of the time, explains Randall Reeder, Ohio State Extension specialist and ag engineer. The grain platform is 30 ft. wide. With 30-in. tires, the combine runs on about 16-20% additional ground.
There is a definite difference in soil structure between the traffic and non-traffic lanes. “A soil probe shows you how much firmer the tramline
(compacted tracks) soil is, with noticeable compaction,” Richards says. “Running equipment on such firm ground reduces our fuel and horsepower needs by about 30%, and allows us into the fields earlier.
“In between the tramlines we have super soil quality with high organic matter, great infiltration and abundant earthworms.”
Richards Farms grows corn and soybeans, plus about 450 acres of corn silage.
“What got me started with controlled traffic and conservation tillage was visiting the USDA Auburn University soils lab where Albert Trousespoke about the evils of compaction,” Richards says. “They pioneered the system of keeping wheels in the same place from year to year. Today you see a lot more controlled traffic in Australia and Europe than you do in the States.”
Australian ag engineering consultant Jeff Tullberginitiated CTF research in the early 1980s at the University of Queensland. He says that half the power output of a tractor doing tillage is used in compacting and breaking up its own wheel tracks.
“We’ve known for many years that 75% tractive efficiency is pretty good for a tractor on tilled surfaces,” Tullberg says. “It’s another way of saying that 25% of tractor power is used to compact soil under the tires. A tillage implement needs about the same amount of extra power to repair the tractor’s compaction damage.
“The same power loss occurs on soft no-till surfaces, but instead of a penalty in tillage fuel use, we pay a greater penalty in crop performance. Better to grow crops in permanently non-compacted soil, while improving timeliness and equipment efficiency by operating on hard, permanent traffic lanes,” Tullberg says.
CTF in Australia is almost always associated with no-till, and adoption rates have increased steadily among larger grain farmersover the past 15 years.
CTF really pays off in dry years, due to better soil-moisture storage and rainfall infiltration, Reeder says. But wet years also benefit from less traffic and compaction due to improved soil structure, moisture storage and drainage. Uncompacted soil has more pore space for drainage.
For example, severe drought in Australia (10-12 dry years of half-normal rainfall) “made us think of ways to improve our system, and CTF was one of them,” says Andrew Newall, agronomist and owner of New Ag Consulting, Victoria, Australia. He advises growers on CTF systems. “We needed to be able to store any moisture and then be able to access it again.
“Many skeptics said that once the rains return (to Australia), we won’t see the gains (from CTF). Well, the last three years have been average to above-average rainfall, and the results are even more pronounced in favor of CTF crops; they’re even further ahead,” Newall says.
“Growers don't realize how compaction is costing them because they don’t have to write a check out to pay for the damage. But if growers had to pay $50 every time they saw a compaction issue, they’d quickly go out and spend some money to make the changes,” Newall says.
“CTF has really taken off here the last six or eight years. About 12% of Australian farmers now practice CTF. Still, the stumbling block is how to alter machinery. It’s easy enough to match sprayer widths to planters, but people struggle when they get to the combine,” Newall says.
“We recommend they begin with the combine width and work backwards from there. Instead of buying new equipment, you can extend tractor axles with cotton reels to space wheels out (see photo). For planters and sprayers, we often make axle extensions or cut them up and add to the axles to match up,” Newall says. “It doesn’t have to cost much at all. Machinery people often tell you it can’t be done but we do it anyway. Still, you need to consider choppers in headers, wheel diameter and planter accuracy.”
CTF “is the future of farming,” says Phil Needham, Needham Ag Technologies, Calhoun, KY. “You can’t drive a large combine across your field with a loaded grain cart and expect it not to subtract from yields.”
In Alberta, Canada, a group of CTF growers “sees very little weed growth in the tramlines, and they are holding up well,” says Peter Gamache, project leader of Controlled Traffic Farming Alberta (CTFA), a farmer-led project assessing CTF’s fit for Alberta.
“To me, CTF is a no-brainer most of the time, and I cannot understand why it’s so slow to catch on in the U.S.,” says John Norman, University of Wisconsin professor emeritus of soil atmospheric and oceanic science. “I have relied on a combination of experiments and computer models to gain insight, and to me it is absolutely clear that CTF is the way to go for most soils.”
Crops and equipment have opposing needs. Crops need porous soils to transport air, moisture and nutrients, and encourage root growth.
Controlled traffic farming (CTF) restricts soil compaction to narrow traffic lanes, allowing the remaining undamaged soil area improved soil structure and moisture storage for cropping.
A farmer standardizes his fleet’s operating width (sometimes working in multiples of that standard) to accommodate these field highways, which some call tramlines. Tires are slimmer, operate at higher inflation pressures, and may be “split duals” to accommodate heavy loads and row spacing.
“The consequential benefits to the soil structure and soil biodiversity are incredible,” wrote U.K. farmer and Nuffield Farming Scholarship winner Nick Ward, in his report after touring innovative farming systems on several continents. “The lack of compaction in these soils allows plants to produce deeper roots and access more of the available nutrients and water. Cultivation leads to reductions in soil organic matter by oxidation and losses to the atmosphere as carbon dioxide,” Ward wrote.
“As organic matter levels increase, so does the nutrient-holding capability of the soil and the amount of biological activity within it. The soils then become better at cycling nutrients and effectively feeding the crop,” Ward says.
"Hard, permanent traffic lanes reduce wet-weather delays, and also eliminate ruts in the crop zone,” according to Australian Engineer Jeff Tullberg says. “The improvement in timeliness is often critical to (Australian) double-cropping” (because the second crop can be seeded right behind a combine, even in very wet conditions).
The potential benefits and drawbacks of controlled-traffic farming (CTF), according to Jacob Bolson, an agricultural engineer who researched CTF as a student, include:
*Improved soil structure
*Increased water infiltration and storage
*Increased nutrient-use and moisture-use efficiencies
*Reduced fuel consumption and pesticide costs
*CTF offers a risk-management bonus, by improving soil-moisture retention and use when it’s dry, and by allowing equipment access in the fields even under very wet conditions. CTF growers say they can access their fields when neighbors are bogged down in mud.
Compacted soil does not hold water; it lacks pores for air, water and plant roots for easy movement in the soil profile. The tracks become compacted and trafficable most of the time.
* The overall soil health in a three-year-old U.S. on-farm CTF system he studied “appeared to be substantially better.”
*On the minus side, CTF requires more intensive management.
*”There is no more ‘just drive into the field,’” Bolsonn says. “Wheel-track locations need to be strictly recorded to derive year-to-year CTF benefits and harvest logistics carefully planned.
*Rutting can also occur over time. “The wheel-track height can drop below the adjacent crop bed. In heavy rains, the height difference can lead to the wheel tracks acting as waterways, leading to erosion problems if they are not oriented properly in a field,” Bolson says.
*The initial cost of CTF can be large, to match implement widths, or to be multiple widths of one another. And, an investment in guidance technology is almost mandatory for effective CTF. RTK guidance technology has been a gateway to making modern-day CTF feasible.
For a video explaining how to affordably plan a CTF system, go to
http://cornandsoybeandigest.com/conservation/controlled-traffic
www.controlledtrafficfarming.com/content/default.aspx
http://canola.ab.ca/ctfalberta.aspx.