Know the nuances of handling both high- and low-quality grain
Winter months demand more than a cursory management effort to provide quality grain in the spring. Hopefully, your advanced planning and preparation has included bin cleanout, repairs, empty bin pesticide treatments, structural inspections, and equipment updates.
Moving into the winter months, grain hopefully has been loaded into bins or storage structures. Now is the time for active management steps to protect the quality of the grain and to make appropriate marketing plans.
Segregating Grain
While it is tempting to add high-moisture grain to low-moisture grain to “average out” the mass to moisture content safe for long-term storage, this just does not work as hoped. Unless the grain can be cycled through the bin to a truck and back into the bin several times, pockets of wetter grain develop problems through storage and cause quality degradation in higher-quality, drier grain layers.
Segregating lower-quality, wetter grain from higher-quality, drier grain in separate storage structures provides a safer method of storage. The lower-quality grain should be sold earlier, and the drier, higher-quality grain can be held longer in storage, until the optimal time for marketing.
Each type of grain has its own set of criteria for storage time based on moisture content. Figure 1 on p. 87 gives guidance from the U.S. Department of Agriculture and Iowa State University on storage time expectations for corn and soybeans. Typically, drier, cooler grain maintains quality longer than wetter, warmer grain. Mixing the two tends to move the grain bulk to the lesser-quality storage length much quicker than expected.
Monitoring Stored Grain
When grain goes out of condition, mold growth and insect activity generate heat. Not only does heat generation reduce the quality and marketability of the kernels, but it also decreases safety surrounding the bin.
Self-combustion is a possibility when heat develops to the point of ignition. Even if fire does not result, moldy grain develops hard clumps, sticks to bin walls, develops crusted layers or bridges, and becomes impossible to move through unloading equipment without intervention. Employees are more apt to enter bins to remedy the handling problem. This presents exceedingly unsafe conditions that lead to engulfment, entrapment, and entanglements without using special equipment and training.
But how does a manager know when the grain is in compromised condition? The answer is monitoring. Temperature cables provide a form of “communication” with the grain bulk. Weekly monitoring of temperature cable readings gives early warning signs of grain degradation.
Pockets within the grain bulk that are warmer than surrounding areas means that some kind of biological activity is producing heat. Usually, this is an indication of mold and/or insect activity. The remedy is to move the grain to another bin, thus breaking up the warm spot and interrupting the biological cycle.
Quick marketing of this grain might be prudent, since it may continue to decline in quality, which decreases the safety and profitability of the product.
Other indicators of grain declining in quality are higher carbon dioxide production, odors, insect population growth (measured in traps), and changes in grain appearance.
Probing and coring grain in storage gives an opportunity for quality inspection. While this is more labor intensive and invasive to the bin, managers must resort to these steps to inspect grain quality in bins without temperature cables.
Monitoring weekly is prudent until the grain is cooled to 35 degrees F using aeration. Monitoring every couple of weeks to monthly will suffice, if the grain is dry and cooled to 35F. Running aeration fans once a month when weather is cool and dry can help to defuse odors. Then temporarily seal fans to prevent moisture, insects, and warmer temperatures from entering the bin through the aeration system.
Target Storage Conditions
While most fall-harvested crops go into bins around 70 degrees F, grain out of driers may vary. Cooler is better, but outside air temperatures will dictate how cool the grain can be when depending on aeration for cooling. Therefore, cool as much as possible at the time of placing the grain in the storage structure. Then, using aeration, cool grain down in 15-degree steps as soon as possible. Cooling more than 15 degrees at a time may cause problematic condensation in the bin.
Insects and mold become much less of a problem below 40 degrees F, since many insects cannot populate and feed at this temperature and mold is much less likely to develop. At 35 F, the grain is not frozen and mold and insects become inactive.
Holding the grain as cool as possible until marketing provides for the best chance of maintaining the quality. Grain is an excellent insulator. Therefore, cool grain will continue to be cooler than outside air into the spring and summer if fan inlets are covered and care is taken to not introduce warmer air into the grain bulk.
Marketing Decisions
Deciding when to market grain is a studied science for agricultural economists and grain managers. Many factors go into these decisions – quality of the grain in storage should be one of those factors.
Low-quality and wetter grain should be sold quickly so that further degradation of the grain does not occur. Grain quality never improves in storage; it can only stay the same or decline over time. Grain left in storage too long to maintain quality can cause structural damage to the facility through fire and can create a very unsafe work environment. Not only does the grain have to be handled by salvage companies at this point, but also property damage and legal fees can mount quickly.
Marketing managers should pay close attention to records of grain moisture content and temperatures compared to data such as that presented in Figure 1.
Conclusion.
Making wise binning decisions, marketing at-risk grain quickly, and monitoring grain through the winter will result in safer working conditions for employees and higher profit for the organization. Grain quality never improves in storage and poor-quality grain can cause an organization through low grain prices, structural damage and disastrous working conditions. Take time to manage grain wisely through the winter months.
Dr. Carol Jones, Ph.D., PE, is a professor emeritus at Oklahoma State University, Stillwater, and president and lead engineer at CL Jones Consulting, LLC (405-612-1133/jcarol@okstate.edu).
From the Nov/Dec 2024 Issue of Grain Journal