Getting a handle on compaction starts with knowing how much equipment weighs and how some practical techniques can alleviate the iron load.
Farmers, agronomists, and equipment dealers gathered at Elgin Compaction Day in Shedden on Aug. 7 and 8 to discuss how compaction happens, as well as how to fix and prevent it.
Why it matters: Compaction hurts soil health, crop health, and your bottom line. Prevention is much less costly.
“We all know, particularly as we get to bigger equipment, we’re going to get compaction,” says Peter Johnson, an agronomist with RealAgriculture. “It’s all about trying to define the right technology that reduces that compaction load.”
Johnson along with Greg Stewart, agronomy lead with Maizex, hosted an equipment demonstration during the event. Using soil probes to measure pressure at six, 12, and 20 inches, attendees were shown how a variety of tire and track technologies, as well as equipment types, affect compaction risk.
Tires and pressure
Johnson and Stewart say better tire technology such as more flexible sidewalls than those of standard tractor tires can help lessen compaction in the top layer of soil.
“A 28,000-pound combine with the right technology has about the same compaction as the 19,000-pound combine with old technology,” Johnson says.
However, tire pressure makes the real difference to surface layers. This is particularly true for grain carts and other equipment that can often be overloaded.
Johnson says maintaining full pressure when driving on the road helps improves fuel mileage, reduces tire wear and makes equipment safer and easier to handle. But in the field, lowering pressure significantly reduces surface layer compaction. He says tires can often be deflated to the point where they look flat with no problem.
“It’s very hard to inflate tires to what you need visually,” says Johnson.
The first step should be to weigh your equipment, then look at tire size and if it can be used at a lower pressure. Doing so can help reduce compaction without spending any serious money. When buying new tires, wider ones that can run at a lower psi are preferred.
Darryl Burnett, a farmer from Bellwood, told attendees that flat-looking tires are a common and intentional sight on his operation. A built-in deflation and inflation system allows him to run with a low psi in the field and a high psi on the road.
Despite running this way for many years, he says there have been no major problems such as tires rolling off rims. The inflation and deflation system has been the “number one investment” toward reducing compaction on his farm.
Burnett adds new technologies like his air system and better tires are by no means cheap, so the best time to invest is while trading or buying a new piece of equipment.
Tracks — boons and drawbacks
Several track configurations were highlighted at the event. Overall, Johnson and Stewart say rubber tracks offer similar compaction to appropriately inflated tires if the right flat-plate area is found. Rutting on the surface is also less of a problem if the ground is wet.
However, tracks often add a lot of weight to the machine. Stewart says this should be considered because that additional weight inevitably pushes pressure deeper into the soil profile. Johnson adds tracks don’t spread weight as easily, leading to pressure spikes as the axle goes over an area.
For Mac Ferguson, a farmer from the St. Thomas area, tracks proved to be an effective way of dealing with excess moisture. He says since adopting tracks on some of his equipment, rutting has not been an issue in years where they are forced to harvest in wet ground.
On the downside, Ferguson says his tracks are not as comfortable for the operator, slower on the road, and will bring higher maintenance cost in the future. There was also “a substantial capital cost at the beginning,” though daily maintenance is minimal.
“We just don’t get ruts,” he says.
Equipment such as forage balers and overburdened pickup trucks can add to compaction, particularly on the surface layer. “The big gear doesn’t necessarily compact more than the smaller gear” says Stewart.
The positioning of the front or rear parts of a given piece of equipment also matters. Keeping headers higher on combines, for example, exerts less force on the back tires — which Stewart says are themselves often overlooked. For self-propelled sprayers, keeping the booms folded reduces the weight on the axle closest to the boom.
Stewart also cautioned against unnecessarily weighing down equipment.
“When we have extra ballast, we have to ask, what it’s there for?”
Regardless of the equipment, Stewart reiterates farmers can take immediate action to prevent compaction by weighing their equipment, knowing the axle load, and checking tire spec-sheets to determine if tire pressure can be reduced.
He encourages producers to consider implementing inflation and deflation air pressure systems, as well as new tire types.
Till smart and avoid compaction
Knowing which soil layers are compacted is critical to finding an effective remedy, say Dale Cowan, senior agronomist and sales manager for AGRIS Co-operative and Wanstead Farmers Co-operative and Adam Pfeffer, agronomic systems manager with Bayer Canada.
They say producers can use a soil probe to determine compaction location. Several spots should be checked, some of which should be in the wheel track.
Cowan also reminded participants that effective tillage requires dry conditions since tilling wet ground does not break up soil outside the immediate line formed by the tillage shank. It’s possible, too, to incorporate precision into tillage activities — that is, just tilling specific problem areas instead of the entire field.
He also stressed spending money on new equipment is not the only option. Those who want to till deep into the soil but only have a conventional plow, for example, can rent equipment for the day, try to borrow from a neighbour, or hire someone for the job.
Overall, he says don’t ignore the problem, do something that doesn’t work, or something that might make the issue worse.
“One way to fight soil compaction is to avoid it in the first place. Lifting the hardpan only fixes compaction until the next axle goes over,” says Cowan.
Cover crops for soil resilience
For Cowan, a full-systems approach with cover crops is critical. Other speakers including Anne Verhallen and Christine Brown — soil management specialist (horticulture) and field crop sustainability specialist with OMAFRA respectively — expressed the same sentiment.
As with mechanical tillage, Verhallen and Brown say it’s important to consider where the compaction is in a field, and what type of root will help alleviate it. Even in places where compaction is less of a problem, cover crops and cover crop mixes help prevent future issues by building soil structure and promoting healthy environments for soil organisms. This includes earthworms, which both experts say are very important for field drainage.
“If you feed them they will come,” Brown says.