Seed losses must be measured for best results

Farmers are told it’s not good enough to just look on the ground when combining because seeds can be hard to see

Most speakers tell a joke to begin a presentation.

Les Hill, the Prairie Agricultural Machinery Institute’s program director for agriculture and bioresources, prefers to fool his audience.

Speaking to a group of farmers at CanoLab, an agronomy workshop held March 11-12 in Brandon, Hill began by asking growers to examine trays filled with soil, crop residue and canola seed.

The canola seed in one 30 by 60 centimetre tray was coated with a blue seed treatment and the kernels were easy to spot. However, it was difficult to detect seed in the other trays on the table because the black canola kernels blended into the black soil

Hill stood back and watched as the farmers attempted to guess the amount of seed in the trays. After leaving his audience hanging for a minute, Hill admitted the exercise was a ruse because it’s nearly impossible to visually gauge seed losses.

“A lot of people will look on the ground. That’s what we’re trying to demonstrate here,” Hill said, pointing to the trays of soil and canola residue.

“Just because you don’t see it doesn’t mean it isn’t there.”

Hill said it’s worth measuring the amount of loss because a substantial amount of canola can wind up on the ground.

“It’s not uncommon to find people who are dropping five bushels per acre and higher,” he said.

“(But) they never looked. Some people say ignorance is bliss. It might be bliss, but it’s awful expensive.”

Chris Holzapfel, research manager at the Indian Head Agricultural Research Foundation, said it’s hard to estimate how many farmers check for combine losses.

“I think much of it would be visual, getting behind the combine and having a look,” Holzapfel said during CanoLab.

“(But) a lot of research is showing that the losses are quite high.”

Hill said growers might assume that modern combines are extremely efficient, but losses can happen with a $45,000 or $450,000 machine.

“People are reluctant (to measure loss) and they may put false faith in the fact that the machines are going to perform based on the settings provided by the manufacturer.”

Combines may be equipped with a loss monitor, but a monitor and measurement are not the same thing.

“A monitor is sensing something but it isn’t measuring in terms of absolute,” said Hill.

He said the sensor detecting the number of lost seeds can be accurate, provided it’s calibrated based on actual measured losses.

To demonstrate a simple measurement method at CanoLab, Hill held up a scoop, which looked like a plastic shovel, and mimicked holding it under a combine spreader.

After separating the kernels from the residue and weighing the seed, growers can follow a basic formula to measure losses per acre:

1 acre = 43,560 sq. feet

1 lb. = 453.6 g

Therefore, 1 lb./ acre = 453.6 /43,560 = 0.0104139 g/sq. feet

With 50 lb. in a bushel, 1 bu. per acre = 0.52065 g/sq. feet

“You end up with about a half a gram (of canola seed) per sq. feet” with a loss of one bu. per acre, Hill said.

He held up the plastic shovel with about 100 seeds in the scoop, to illustrate half of a gram per sq. foot.

“If I threw that (seed) on that black dirt over there, you wouldn’t find it,” Hill said. “How much would it take before you started to even see it?”

In addition to the scoop method, growers may want to consider a more sophisticated approach by attaching a metal tray or drop pan under the combine just ahead of the rear axle.

“They (the operator) will remotely trip it…. The pan will drop down and the combine passes over,” Hill said, holding up a five sq. foot tray.

The drop pan collects more seed than the plastic scoop, which increases the sample size and likely the accuracy of the measurement.

Combine settings can be adjusted to cut losses if a grower determines that a significant amount of seed is in the drop pan, such as three to five bu. per acre.

“Your fan speed, chaffer opening, sieve opening, rotor speed … all of those things,” Hill said.

Slowing down is another option if those steps are unsuccessful.

“If you push that feed rate higher, your losses are going to go higher,” Hill said. “If that machine will give you a bushel an acre (loss) at three m.p.h., (if) you go four or five m.p.h., (it could be) five or six.”

Holzapfel said a measurement takes time, but growers invest a great deal of money in maximizing yield. As a result, they should dedicate the necessary time to reap those rewards at harvest, he said.

“To put all kinds of money and effort into gaining 10 percent yield and then throwing eight percent out the back end is not very effective.”

Hill said several smartphone apps can help with the seed loss calculation, including the Saskatchewan Soil Conservation Association harvest loss calculator at

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