Ask the Doctor: Scientific Insights on Protecting Grain During Harvest

Ask the Doctor: Scientific Insights on Protecting Grain During Harvest

AGI’s leading grain researcher Dr. John Lawrence answers how to best prepare for and avoid common mistakes when storing grain this harvest season.

Dr. John Lawrence is AGI’s in-house grain researcher and subject matter expert on how to safely store grain in optimal conditions. During harvest season farmers can set themselves up for success by preparing their grain storage systems. However, even well-prepared farmers can face spoilage issues if common mistakes are made. Read on and heed Dr. John’s advice for successful storage all season long.

What can farmers do to prepare for harvest?

1. Clean and disinfect your storage bin(s)

2. Learn what you can about the safe storage content of any new hybrids you are trying

3. Have a conditioning plan for if you harvest at a higher or lower moisture than what you want

4. Test/check your fan operation

5. If you have a monitoring system, ensure it’s working properly

6. Clean and disinfect your storage bin(s)

7. Learn what you can about the safe storage content of any new hybrids you are trying

8. Have a conditioning plan for if you harvest at a higher or lower moisture than what you want

9. Test/check your fan operation

10. If you have a monitoring system, ensure it’s working properly

What are the most common mistakes farmers can make when storing grain?

1. The first most common mistake is not knowing the safe storage moisture content (MC) of the hybrid they’re growing. The belief that all corn hybrids and soybean hybrids can be stored safely at 15% and 13% MC, respectively, is not true. Some hybrids of corn have a safe storage moisture of 13% and some hybrids of soybean have safe storage moisture content of 10.5%. If these hybrids of corn and soybean are stored at 15% and 13%, respectively, they may have spoilage issues in the bin.

2. The second most common mistake is not knowing the difference between a storage bin and conditioning bin. A conditioning bin normally has a diameter of less than 48', a grain depth of less than 25' and an airflow rate in the range of 0.75-1.0 cfm/bu whereas a storage bin can be of any size available in the market with an airflow rate less than 0.2 cfm/bu. If a farmer is trying to dry corn in a storage bin with 0.2 cfm/bu, he will end up losing that grain due to mold spoilage.

3. The third most common mistake is not designing a proper ventilation system for their storage bins. The under-designed vents may lead to condensation surface crust on the headspace. A good rule of thumb is for every 1 sq ft of vent area, 1000 cfm should be followed.

4. The fourth most common mistake is not cleaning the grain before storing. Many farmers want to take advantage of the 3% broken and trash allowed in the market while selling, normally they won't clean their grains before loading into the bin. Because of this, they end up losing grain in spoilage. If we load grain without cleaning, all fines and foreign materials will accumulate in the center core and block airflow. If a farmer is conditioning their corn from 20% to 15%, due to airflow restriction in the core, there will be spoilage in the core. To solve this issue, one can core the bin after loading which will remove the fine and foreign materials.

5. The fifth most common mistake is not having a monitoring system in the bin. For example, a 20,000 bu bin of corn has a value around $80,000 based on $4/bu corn. If that grain is not properly managed, they end up losing all that money. A monitoring system can notify the farmer if the stored grain is going to be out of condition. Based on that alert, he will be able to make a management decision to safeguard or sell that grain.

Can you tell us about Safe Storage this time of year?

To know the safe storage moisture content of a grain type at a particular temperature, we need to determine first the equilibrium moisture content (EMC) characteristics of that grain type. For people who don't know about EMC, it tells us at what moisture content it is safe to store grain before mold starts growing and spoils the grain. More scientifically it is the moisture content at which vapor pressure (RH) inside the grain is equal to RH outside the grain surroundings at a particular temperature.

Based on location temperature, at 65% RH is when EMC is the safe storage moisture content of that hybrid. Why 65% RH? Scientists believe based on data, mold activity on grain is less below 65% RH.

For August to September, the temperatures are normally in 60-70°F range. For the winter storage season, grain temperature will be kept between 35°F and 40°F.

For example, if a corn hybrid has a safe storage moisture content of 14% at 40°F, it's safe storage moisture content at 60°F will be 1% less, that is, 13%.