By Natalie Noble
Something many farmers don’t want to think about, but guaranteed it’s already on their minds, is preparing the land and soil for the best success with next year’s planting. Another question likely will be what happens to all that leftover plant material and straw that doesn’t go into the bin? This is where straw and residue management practices come into play.
There are several factors that influence straw management practices, such as moisture, crop type, stand, leafy growth and yield. Perhaps the biggest determining factor to managing crop residue in Western Canada is region.
“It’s very regionally specific,” says Bentley farmer Jason Lenz, who farms 2,000 acres of barley, wheat, canola and faba beans. “For example, in west-central Alberta, there’s still a lot of tillage that occurs in the fall. Going into eastern Alberta, they don’t want to till their fields because they need to seal that moisture in until next spring for the best chance to germinate that new crop.”
Brent Johnson, who farms 5,000 acres of seeded grain and hay land east of Strasbourg, Sask., adds that weather conditions are also a major factor in determining straw management practices.
“In the wetter years, when we were growing big crops, straw management was a bigger issue. But, we’ve had two years in a row now where rain’s been scarce. We’re at the point of trying to save straw to bale,” he says.
In addition to region and weather, increasingly larger equipment has added challenges.
“Combine headers are getting to be in excess of 40 feet wide, compared with about 30 feet 10 years ago,” says Brunel Sabourin, owner and lead agronomist with Antara Agronomy. “This means there’s more difficulty in spreading straw evenly.”
Fortunately, most newer combines and harvesters are coming equipped with fine-cut choppers and straw spreaders with added ability to adjust to issues such as wind.
“Sometimes, if the wind is blowing across your direction of travel, the straw will move further on one side than the other. The newer equipment adjusts the speed left or right and the angle at which the straw is thrown out the back of the combine. This helps us get our residue across the full swath of the combine unit,” says Sabourin.
Johnson says that in his case, having the combine equipped with a good straw chopper means he can often get the job done with that alone.
“If there’s any one thing we find works best in straw management, excluding flax straw, it’s chopping it well on the combine to start with,” says Johnson. “We tell our operators to cut lower, take a little more straw through the combine and let the chops deal with it. That’s the best straw management tool we have. They’ve been making straw choppers a lot better over the last 10 years for sure.”
Johnson runs Case rotary combines, which he says as long as they have good spreaders, work well. His John Deere combines with original choppers are not as ideal unless the choppers have been upgraded. He adds that there are several brand manufacturers who offer kits for upgrading straw choppers.
There are also differences in residue management practices according to the crop. Johnson talks about this in his canola, which makes up the largest acreage on his farm.
“We don’t have trouble with the straw, but we do have trouble with the chaff residue. We have to make sure the chaff spreaders are all working well,” he says. “Otherwise, in the spring we can end up with lots of chaff row issues and we find they can actually kill the new crop coming up if they’re too heavy.”
In these cases, Johnson uses heavy harrows in the spring to remedy the problem. He uses a brand called Flexi-Coil, an affordable option, but perhaps not as tough as some of the products on the market today such as Degelman or Bourgault.
“The harrow is the last machine we go to. If there are problems, the harrow will fix them all,” he says. “But, we prefer to keep the chopper on the combine doing the right thing; get it right the first time so we don’t have to go back in.”
Johnson also grows flax, and managing its residue brings less options.
“The only thing we find we can do with that is take the choppers off, drop the straw on the ground, and burn it. Or we bale it. It’s the only efficient solution we’ve found with flax. Harrowing it is awkward and takes a lot of time. We’ve seen neighbours try chopping it and still have to harrow it,” he says.
One-third of his baled flax straw is used in a burner Johnson’s father uses to heat his home and shop.
The Johnsons also bale about 25 per cent of their cereal straw. The rest is chopped and spread with the combine. Over the last few dry years in their region, straw crops have been lighter and not required more management than that. However, in wetter years, where the crop was heavier and tougher to break down, they were heavy harrowed in the fall or spring.
Over to the west, Lenz’s residue management has been a different experience.
“For us, wheat and barley straw often come out of the back of the combine in huge volumes,” he says. “Depending on the year and how high yielding the crop is, the more straw and residue we have to deal with.”
Lenz’s combines are Case 9230s, which come with chopper options from the “standard” to “Magna-cut” range upon purchase, with more blades as you upgrade.
“We have the Magna-cut chopper and it chops up the straw the most, but when you’re running material through the combine and you have more knives, it takes more horsepower to run,” says Lenz.
Because Lenz Farms is located in a region that typically produces high-yielding, denser crops, heavy harrowing is a big part of their straw management practices. The heavy harrow breaks down and spreads the straw evenly across the field for faster decomposition. It’s operated at speeds between 16 and 19 km/h.
“That might not sound very fast, but when you’re pulling a heavy harrow across the field in a big tractor, it’s pretty fast,” says Lenz.
He uses the Elmer Super 7 Harrow, which has seven rows of harrow teeth, as opposed to the average harrow with only four rows.
“With those seven rows of teeth, it’s more multipurpose,” he explains. “It also does a good job of rubbing out the dirt. The tillage can leave the soil a little ridged, so when we go across our fields in the spring with these heavy harrows, it levels the soil almost to the same quality you’d see in your garden.”
After Lenz has picked a dry day and gone over his wheat and barley fields with the heavy harrow, he’ll use a deep-tillage cultivator. This tool goes down about four to five inches into the soil, lifting and turning the soil over, burying some of the straw at the same time.
Deep-tillage cultivation allows for faster decomposition of residue, which is necessary in areas like his where heavy crops are more common. He estimates that a 100 bushel per acre crop in his region likely means 70-80 bushels per acre to the east, with a lot less residue and where a heavy harrow can take care of it.
The next tool Lenz is considering for straw management is the Degelman Pro-Till. “It does a really good job of cutting and mixing up the straw and dirt, producing quicker decomposition. It also leaves a more level seedbed and you can travel at higher speed, almost twice as fast.”
Sabourin says this type of tillage has become more popular over the last 10 years. “A lot of farmers are investing in vertical-tillage equipment,” he says. “Vertical-tillage units help us size up the residue and incorporate it better. This is more efficient and removes the need for any heavy tillage or cultivation.”
Sabourin also discusses plant growth regulators (PGRs) to ease straw management. These synthetic compounds are applied just before plants enter the vegetative state of growth, affecting their hormones and preventing plants from growing too tall or leafy.
“PGRs are gaining in popularity across the Prairies, mostly for cereals right now,” he says. “They can shorten up the length of the straw, which means less residue to deal with.”
While Johnson has not used PGRs yet as he keeps an eye on the progression of regulations surrounding it, Lenz is testing out a brand called Manipulator on an 80-acre CWRS plot.
“It’s showing that it’s working,” he says. “In mid-July, there was already an eight-inch difference between where we sprayed and where we didn’t. Visually, it’s almost like a wall going through the field.”
Lenz says Manipulator is easier to use than some other PGRs in that it has a bigger window for application. It was passed for safe use this spring and costs about $15 per acre plus about $5 per acre to run the sprayer.
As for Johnson, he believes Mother Nature is doing the trick in his area. “Right now, we’ve got the best straw-growth regulator you can get, it’s called no rain. That holds the straw down about as good as anything.”