farmgate: I Have All Of This Wet Grain And I Need Help!
Farming is usually fun. But flooded fields, deteriorating crops, and the potential for substantial quality discounts have combined to take the fun out of farming. You are lying awake at night concerned when you can return to the combine cab, whether your dryer is doing the job, and how much field loss you can sustain before profitability disappears. We can’t do much about the weather and your bottom line, but let’s tackle the issue of grain quality.
You probably have many questions you would like to ask regarding grain drying procedures, shrink, test weights, and many other issues related to grain storage and whether the 2009 crop can be stored without quality deterioration. Helping answer those questions is Charles Hurburgh, grain quality specialist at Iowa State University. His recent newsletter will probably address many of the issues you already have.
1) Should fans be shut off during rainy weather to avoid pumping humid air into the grain? Hurburgh says keep the air moving, especially if you are using heat, because you do not have an unlimited amount of time and space to dry grain, and when you return to the field, you will need space to store wet grain that needs to be dried. If you are not using heat, keeping the fans going will depend on the moisture level of the grain. If corn is below 17% and beans are below 15%, the fans can be shut off if the outside air is below 50ºF. If the moisture is higher than those levels or the air temperature is warmer, then the fans should be kept running. He says, “Grain picks up moisture from the air at about one-fourth the rate at which it dries so rewetting over short periods is not usually an issue.”
2) If corn moisture is higher than the upper 20% range and the dryer cannot keep up with the demand on it, what options are there? Hurburgh says don’t count on much more drying in the field, and if ears are pointed up, some kernels may begin to sprout. He says natural air and low temperature drying will still work, but that is a slow process, and natural air will not finish drying this fall. Hurburgh says there is a solution, but it requires a lot of management, time, and labor. He suggests heated air drying for batches, then shifting it to a cooling bin, while another batch is transferred to the dryer bin. He says dry corn down to 24%, cool it, hold it at steady moisture with natural air, then redry it to below 20% moisture, and use natural air to finish the job.
3) What is the impact of low test weights for corn? Kernels did not fill completely with the lack of maturity of the corn crop, and test weights of dry corn are in the 52 lb range and the loss of weight per acre is about 5%. He says low test weight corn spoils faster, breaks more, and there will be storage issues next spring and summer. He says the problem should not be a concern to ethanol refiners, but livestock feeders should test for mycotoxins and should expect lower protein levels.
4) Soybean moisture levels are too high for storage, so how should they be dried? Hurburgh says beans will probably not dry much more in the field than they have at this point, and 15% moisture soybeans handle about like 17% moisture corn. He says natural air drying is best for soybeans, and November air should be able to dry them to 13.5%, which is sufficient for winter storage. If heated air is used, set a target for 14% moisture and hold with aeration or whatever is acceptable to the market. He says elevators are drying corn and are not set up to drying a second crop simultaneously. And he says if elevators have a few wet beans, they are blended with dry beans, if they have sufficient quantities. Hurburgh says crushers cannot handle wet beans because they will not split correctly and the hulls are hard to remove.
5) Why are elevators charging more for drying and increasing shrink levels? Hurburgh says elevators are not set up for drying beans, and that is best left to on-farm systems. Elevators attempt to calculate shrink by determining the remaining dry bushels after moisture is removed, and the lot of grain can be identified for settlement. Drying grain to the market acceptance level of 15% for corn and 13% for soybeans removes 1.18% percentage points for moisture for corn and 1.15% for soybeans. If the elevator is charging a 1.4% shrink factor, they are capturing 0.22% for a handling allowance, and that increases for each percent of moisture removed. Hurburgh says scientific tests have shown that grain elevators lose about 1% in storage and handling, and that loss is about 0.5% for on-farm storage beyond moisture removal. He says problems arise when discounts are levied for shrink, and it should be used for weight only since farmers need to know exact bushels delivered for production records. Hurburgh says drying costs charged by the elevator need to cover the variable costs of operating the dryer, plus the fixed costs return to the dryer investment. Farm dryers will have lower variable costs, but the fixed costs must be calculated as well, and that may equate what is charged by the elevator.
Summary:
Corn and soybeans may not dry much more in the field than they already have dried, and when the crops are stored on the farm, then care must be taken to avoid spoilage because of moisture levels that are too high for storage. Wet soybeans should not be dried with heat if possible, but outside air should maintain them through the winter. Corn will need heat to help remove moisture, but batch drying may be the only alternative for many farmers. Remove moisture in stages, hold with air flow, and then return to a drying bin for more heat as space is available. The inability of the crop to fully mature may result in lower test weights for corn, and that means breakage and potential storage problems. Commercial storage may result in shrinkage being applied to settlement sheets, which is an attempt to determine both water loss and handling loss.
Posted by Stu Ellis on November 2, 2009 12:34 AM to farmgate