Corn harvest has begun and every field will be different this fall. Some fields will be highly productive, and others will barely pay the harvesting costs. Some fields will have good stalk strength and other fields have already gone down, with heavy lodging from wind, fragile stalks, rootworm or some other reason.
If you are fighting an uncooperative cornfield, there are some good tips that can make life easier and your efforts more profitable.
Harvest losses can be one of several types, say University of Tennessee researchers, “The following four losses with a combine are:
- Preharvest losses are parts of the crop that are detached from stalks or pods and lying on the ground prior to harvest. These losses should not be charged to the machine.
- Gathering unit losses are losses caused by the header or picker unit of the combine. These losses are usually 90% of the total harvest loss.
- Cylinder losses include unthreshed seeds or kernels that are passed out the rear of the combine. These losses are only about 5% of the total losses from modern combines.
- Separation losses are threshed seeds or kernels that are carried out the rear of the combine with the crop residue. These losses are about 5% of the total harvest loss with modern combines.”
The Tennessee researchers also want you to know that you are not going to get every kernel, so don’t worry about some grain loss, “Ideal combine efficiency is 97% for most harvested crops. This figure means that acceptable losses are 3% of the crop. No machine is capable of harvesting 100% of the crop. Average harvesting losses are closer to 10% in most crops. This indicates that a producer can increase crop harvest and reduce losses by improving combine operation skills and efficiency.”
At Ohio State University, researchers say most of the loss occurs because the grain never gets into the combine, particularly in a droughty year, “Growers need to consider the impact of premature plant death on corn maturation. Within fields, significant variation in grain moisture may exist among plants that died prematurely and those that matured more normally. In such fields, growers should be prepared for stalk lodging problems (associated with drought stress) that may slow harvest and contribute to yield losses. The loss of one “normal” sized ear per 100 feet of row translates into a loss of more than 1 bu./acre. In fact, an average harvest loss of 2 kernels/square foot is about 1 bu./acre. Keep in mind that most harvest losses occur at the gathering unit. Average gathering unit losses accounted for about a 1.2 bu./acre loss out of the total 1.5-bu./acre machine loss. The results indicate that approximately 80% of the total machine loss is caused by corn never getting into the combine.”