Keep up quality, keep down loss
Gleaning maximum grain quality and minimum grain loss in your combine may be next to impossible. But, there are ways to get as close as possible to both, one respected ag engineer says.
"If you get too aggressive with your threshing settings you can actually not carry as many bushels back up into the grain tank," says Iowa State University Extension ag enginner Mark Hanna, who addressed the recent University of Missouri Crop Management Conference. "You are beating it up enough that you are blowing some of it out of the combine, not just as whole grain but foreign material and dust.”
Don't only rely on a grain loss monitor in the combine's cab, either, Hanna says. Most such tools don't show the whole machine, typically omitting the area where most grain loss -- 60% for corn and 90% for soybeans -- happens: The head.
"Typically, that grain loss monitor is looking at grain that is coming out over the sieves or back in the cleaning shoe," Hanna says in a university report. "For corn and soybean crops, most of the loss is up at the gathering head, so those sensors aren’t really telling you anything about that."
Hanna recommends these steps to minimizing grain loss in the combine:
Lower rotor speeds
Adjust sieve settings to grain size
Increase fan speeds
Adjust settings one at a time
"We can actually document some yield loss that is occurring because the crop gets beat up so much by the rotor or cylinder. Unless you are checking behind the combine to maintain reasonably low field loss, there is a tendency to overcompensate thresher settings and you end up penalizing yourself in terms of the number of bushels you’re leaving out in the field," Hanna says. "Make some diagnoses of what is behind the machine, what’s on the ground in front of the machine, and look in the grain tank to see what the seed coats look like. It really is responding to observations you make, and it needn’t take a lot of time to do that. Typically, that first day or two in the field you are doing some other things too, but you need to allow some time to set up for adjustment and then adjust as the season changes."