Setting a combine to minimize grain loss during harvesting requires some preplanning and a little effort. But
spending the time to reduce those losses can pay big dividends.
Have you ever driven down the road and noticed combines working across a field so quickly they would outrun a good jogger? It’s no wonder deer seem to favour these fields later in the fall — harvesting too quickly can blow a surprising amount of grain out the back of a combine.
If you feel the need for speed when operating a combine, you’re going to pay a price for it, according to research done by North Dakota State University (NDSU). Their work reveals overloaded combine losses can reach 20 per cent of a crop’s total yield.
How much money would that cost a farmer? Assuming a 30-bushel-per-acre canola crop worth $8 per bushel, a 20 per cent combining loss amounts to $48 per acre.
“There is a myth that started when rotaries came out: people said you’re just not filling it up enough, push it harder,” says Les Hill, manager of business development and technical services at PAMI (Prairie Agricultural Machinery Institute). “But in all the years we tested combines, it was a rarity that you ever saw losses go down the faster you went. When they (combines) start to lose r. p. m. and work hard, that loss curve starts going up. The reality is speed determines loss; the more material you stuff in there the more loss you’re going to get.” And that applies to both conventional and rotary combines.
HOW TO MINIMIZE LOSSES
It’s impossible to avoid threshing losses completely; getting a clean sample in the hopper and minimizing grain losses amounts to a trade-off. But by carefully adjusting a combine and timing field operations correctly, total harvesting losses can drop to no more than three per cent in cereals, according to NDSU. Here are some tips on how to shoot for that target.
1. First, get the grain into the combine. The NDSU study found as moisture content decreases, losses from cutting a crop increase. If cereal grains are swathed at less than 20 per cent moisture, losses from shattering can be unacceptably high. If moisture content is below that, leaving crops standing until they have dried to safe storage levels and straight combining them is NDSU’s recommendation.
2. If you are going to swath cereals, do it when they are in the 20 to 35 per cent moisture range. Most cereal kernels at or below 35 per cent are mature, according to NDSU’s findings.
3. Setting the reel height so the bottom of each fixed bat is just below the lowest grain heads is optimum. The centre of the reel should be six to 10 inches (15 to 25 cm) ahead of the cutter bar. It should travel just slightly faster than the machine’s ground speed.
Adjusting the combine pickup speed is the next step. When it’s properly set, it should appear to gently lift the windrow as the pickup moves underneath it. That should keep a smooth, even flow of grain into the feeder house. Once again, travel speed is critical. High ground speeds increase losses, even with a pickup. The NDSU notes those speeds should not exceed four to five m. p. h. (6.5 to eight km/h).
TAKE THE TIME TO MAKE ADJUSTMENTS
When it comes to the combine, Hill says producers should be prepared to spend most of a day getting the initial adjustments correct. “It’s especially important with a new (or new-to-you) machine,” he says.
Going through that process will help familiarize producers with a combine’s performance characteristics, and it will help save time in the long run. “Once you have it established that you know where to look and what to look for, then you can do it (make adjustments) fairly quickly,” says Hill. “Until you know that, you’re just guessing.”
If the combine has a chopper on it, be prepared to take it off, at least for the initial setup. It’s
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