Is the heavy harrow a useful implement or an expensive piece of equipment that doesn’t pay for itself?
In these days of continual cost cutting, the heavy harrow is the subject of discussion with strong feelings, both for and against.
“In the Peace region and, I suspect, in many other parts of Alberta, farmers continue to ask if it is worthwhile to heavy harrow,” says Nick Underwood, a Reduced Tillage Linkages agronomist for the Peace region.
Underwood believes the operation can be done for less than $3 per acre. At that cost, a 70-foot heavy harrow with a tractor to pull it at 16 km-h costs $240 per hour.
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Gary Ropchan, an agronomist with the Central Peace Conservation Society, started trials in 2001 to evaluate the benefits from using a heavy harrow in a zero-till seeding system. In 2001, the trial was conducted on canola and in 2002 on barley, peas, canola and wheat. Findings so far show an economic disadvantage to using the heavy harrow.
This appears to be for two reasons: the cost of heavy harrowing and the fact it didn’t improve yield. The society is continuing trials in 2003.
Underwood talked to three farmers in the Peace region about how and why they use a heavy harrow.
“Together these three farmers farm almost 10,000 acres with at least 100 kilometres distance between them,” he said. “Their soils vary. None of these direct seeders identified an expected yield increase as the reason that they used a heavy harrow. However, they all felt that the operation helped to provide the seeding conditions that they wanted. This implies that there is an expected yield benefit.”
One farmer from the Fairview area said he likes to spread straw in the spring to stop it sticking to the mud. In wheat stubble that received pre-harvest glyphosate, heavy harrowing eliminates sprayer tracks that can cause plugging during seeding. Harrowing helps ready the land for the seeder. In heavy canola crops that leave lots of chaff, heavy harrowing after harvest spreads that chaff more evenly than the chaff spreader on the combine. After seeding with a three-inch stealth opener, he has tried heavy harrowing to get an even mat of straw, which helps to prevent drying in the seed row.
A farmer from the Debolt area said it is important to have a mellow layer of mulch on the surface at seeding. He applies anhydrous ammonia in the fall with 3/4 inch knives on a 12-inch spacing in a different direction to the planned seeding. In the spring he heavy harrows and then seeds.
In the Hythe and Wembley areas, a farmer said he also likes to see loose mulch on the surface to help “seal it up” to reduce moisture loss. He also bands anhydrous ammonia in the fall. He farms a wide variety of soils and said some might not benefit from the operation.
He heavy harrows in the spring mainly to level tracks from the previous year’s spraying and harvesting, which can cause seed to be left stranded on the surface or at the wrong depth.
Underwood said there may be no universal answer to whether heavy harrowing provides financial benefits.
“As an owner of a heavy harrow myself, I find that it has its uses and has gotten me out of a jam, at low cost, several times,” he said.
“Having a level seedbed to seed into is very important. It may be difficult to prove that a level field is going to yield higher than a rough field, but I sure know which one I would rather harvest.”
For further information, contact Underwood at 780-814-1232.
