Corn harvest is well under way and soybean harvest is approaching rapidly. The optimum moisture level for corn harvest is approximately 23 to 25 percent. At these moisture levels, the corn shells easily and there are less stalk problems making harvest more efficient. Also since the seed is a living organism, there is respiration going on in the seed and the longer the grain remains in the field, the more respiration that will occur and will reduce the final yield to a small degree. With a timely harvest, losses should be minimized to one to two percent..
The cost to dry the crop is always a consideration in harvesting corn above 15 percent moisture. The comparison that needs to be made is at what point does the filed losses exceed the cost to dry the grain and is it cost effective. Assume that minimal losses are between one and 2 percent. If you leave the corn in the field and allow it to field dry and incur additional losses what is the economic effect. The price of corn has a lot to influence this decision. If excessive harvest loss is at the two percent level with 200 bushel corn you would lose $12 with corn at $3, compared to an energy cost of $25 to dry the corn from 20 percent to 15 percent. At the 5 percent excessive harvest loss, you would lose $30 compared to an energy cost of $25 to dry the corn down from 20 percent to 15 percent. There is a balance between minimizing harvest losses, cost of drying the grain or dockage charges at the elevator. Currently some elevators are charging 5 cents per point of moisture for drying. On a 200 bushel per acre crop that would cost 25 cents per bushel or $50 per acre. At $50 per acre and $3 corn, this would equal almost 17 bushels per acre or about an 8.5 percent loss. So if under the worst of conditions, an additional loss of 8 percent of your crop due to harvest losses would be a toss-up economically.
Timely harvest of soybeans is critical to minimize losses. Soybeans are more difficult to harvest as the desirable moisture due to its nature of losing and regaining moisture readily. Moisture content can increase with an overnight dew or rapidly decrease under dry and windy conditions. The ideal harvest moisture for soybean harvest is 13 to 15 percent. It is not uncommon to begin harvest at 13 to 15 percent moisture and have the moisture content drop to 10 percent by the end of the day. If soybeans are delivered at 15 percent and discounted at 2 percent per point of moisture, $10 soybeans are actually worth $9.82 per bushel. If soybeans are delivered at 10 percent moisture, then they would only be worth $9.79 per bushel.
Harvesting soybeans at a higher moisture level would reduce harvest losses. Harvest losses due to shattering and grain damage should be reduced at higher moisture levels. Under extreme conditions harvest losses can be as high as 12 percent. Average losses are around 5 percent with shattering losses accounting for 2 percent of that. Losses in the field can be estimated by 4 seeds per square foot indicating one bushel per acre loss. One bushel per acre may seem small in itself but if you have 1000 acres of soybeans and a $10 price, that is a $10,000 loss. Minimizing losses is even more important as the price of grain is lower.