Early in the fall, Salford Farm Machinery Ltd., a tillage equipment manufacturer, announced its sales of plows have been on the rise lately. That announcement may have taken many casual observers by surprise. Zero till has been the mantra of a growing number of Prairie farmers all across North America, and plowing seems to represent the extreme opposite of that practice.
There are a couple of reasons for the plow sales spike, says Jim Boak, Salford’s national sales manager. First, Salford remains one of the few North American manufacturers that haven’t abandoned plow production, so it has gained market share. Second, a plow can handle very high residue volumes without plugging. Today’s new crop varieties and monster yields mean more biomass to worry about. Heavy tillage provides a soil management advantage in some cases, particularly when growing corn.
But many Prairie farmers have never seen a plow anywhere than in the trees at the back of an old farmstead. Notorious for heavy draft requirements, discs and a variety of other implements seem to provide much more efficient options. “That’s the misconception,” says Boak. “The fuel use per acre isn’t a lot greater than with discs. If you were to compare it on a working depth basis, the horsepower requirement is about the same.”
Plows typically work deeper than other implements, and Boak says that can be an advantage when dealing with heavy residue. “As you go deeper, the soil benefit is greater.” He says burying trash can increase the rate at which it breaks down, reducing the risk of disease when growing the same crop frequently in a rotation.
But if a little plowing is good, more isn’t necessarily better, “We don’t advocate plowing every year,” he says. “I think we’ve learned that’s not necessary.”
TERMINATING FORAGE STANDS
But if farmers have the proper soil profile, a plow may have some advantages in specialized applications like terminating forages. “It’s a quick and easy way to get rid of hay land,” says Harry Brook, a crop specialist with Alberta Agriculture and Rural Development. And its possible no-till farmers who have one may be tempted to use it occasionally in established fields. “(Farmers) who have been no tilling for 14 years are trying to bring some soil to the surface,” he says.
WORKING DOWN HEAVY CROP RESIDUE
Residue levels in high moisture areas across the Prairie can become pretty high over time under no-till conditions and cause problems. “If you put seed in the ground with high residue, even if you get good germination, it could use up all its resources before emerging through a residue cover,” he says.
But while grain-only farmers would have no option but to turn to tillage under those circumstances, mixed farmers may be able to deal with heavy residue in another way. They have a small army of eager residue reducers just waiting to go to work, without the need for diesel fuel. “We see a lot more producers putting cattle out in harvested fields,” notes Panchuk. Livestock can help incorporate residue into the soil, he says, “Cattle act like heavy harrows. When they walk through they tramp a lot of standing stubble.”
BREAKING UP COMPACTION
The occasional use of tillage may provide an advantage by breaking up soil compaction. “I think there’s been renewed interest in compaction,” says Brook. “We’ve relied on our winters to break up hardpan. But we’ve had a lot of years where we’ve gone into winter very dry, so there hasn’t been any hard frosts.” That reduces the ability of the freeze-thaw cycle to break it up.
Some farmers find using deep tillage to loosen soil has improved a field’s production capacity. “We think that we are seeing some compaction problems,” says Ben Settler of Lucky Lake, Sask. “I rent one quarter that has been displaying some peculiar problems for several years — poor drainage and low yield — and yet soil tests showed everything was fine.”
Settler decided to see if tillage would correct the problem. “I did a test plot on the worst part of the field last fall. This particular part of the field had grown virtually nothing last year,” he says. “ I took an old 22-foot Case cultivator we had sitting in the weeds and outfitted it with spikes. I set it to rip as deep as possible, and did about twenty acres with it in late November. The spikes went down about 10 or 12 inches.” The results were encouraging.
“Unfortunately that quarter flooded out, but the spot that I had worked the previous fall grew the best of what did grow. There was a fairly obvious line between what had been worked and what hadn’t.” Settler planned to work the remainder of the field this fall. “I think it had just got to the point where the roots couldn’t even penetrate the soil, and I’m interested to see what difference tillage makes in a more normal year. I think it will make quite a difference, just judging by what I saw this year.”
But he says any tillage work on the farm will remain localized. “As for large-scale tillage, we really try to avoid that if possible. We are typically quite short of moisture around here, so we try to conserve as much as we can.”
“We came out of an era when there was a lot of tillage,” says Boak. “I think we’re coming to a more mature point where we’re learning to marry the two (conventional tillage and no till) together. And we’ve arrived at a pretty good spot.”
USE WITH CAUTION
Ken Panchuk, a provincial soil specialist with Saskatchewan’s Ministry of Agriculture understands the reason for using plows in corn production, but cautions against their use on a larger scale. “The residue of corn is heavy and coarse,” he says. “The easiest thing to do is turn it over.” But, he says, there are alternatives to tillage, even for that crop. Heavy rotary cutters can be used to chop residue, leaving it on the surface to gain a ground cover advantage and still speed up decomposition. Rotary cutters could also be used in the spring to chop stubble on other crops, such cereals or canola, to make direct seeding easier.
For most of the Prairies, Panchuk rules out the plow as a viable alternative for regular field work. “The plow has never been a western Canadian tillage tool, other than for breaking land,” he says. Among other things, the shallow topsoil profile in much of the region just won’t support it. Boak agrees that farmers with thin topsoil layers will need to look to other implements.