With the early onset of warm temperatures this spring, stored grain operators need to closely monitor their inventories to stay ahead of any problems that may result in a loss of grain quality.
Any sudden changes in temperature and moisture levels in the bin could be a sign of mold or insect activity, say agricultural engineers with the University of Kentucky (UK) College of Agriculture.
Growers dealt with exceptionally wet weather during the 2009 harvest and because of this, much of the grain never dried enough for safe storage through the spring or summer.
"Cooler temperatures provided a margin of storage life last fall, but grain moisture must be controlled as the crop is held in warmer weather," said Sam McNeill, UK Extension agricultural engineer.
For example, corn in good condition will store well at 15% moisture up to 60° F but should be dried to 13% as average temperatures approach 80° F. Corresponding moisture levels for soybeans are 13.5% and 11% at these same temperatures. However, grain in poor condition should be even drier to avoid spoilage as temperatures warm.
Fortunately, good drying conditions this spring will help farmers finish drying wet grain either in the bin or by using a high-speed dryer with low heat.
"Corn and soybeans can be dried to safe storage levels in a bin within one to three weeks of continuous fan operation with good drying conditions," says Mike Montross, associate professor in the UK Department of Biosystems and Agricultural Engineering.
The amount of time it takes the grain to dry down to safe storage levels will depend on the amount of airflow in the bin, outside temperatures and humidity.
Storage life decreases as the temperatures rise. Also, the higher the moisture level is in grain with mold damage and low test weights, the less storage life it has. One percent of moisture can make a huge difference in the crop's storage life, especially for grain in poor condition. For example, mold-damaged soybeans stored at 14% moisture and corn at 16% moisture, respectively, have a storage life of 7.5 months when cooled to 40° F. However, poor quality soybeans with 15% moisture and corn with 17% moisture cooled to the same temperature only have a storage life 4.7 months after harvest. This means some of the grain harvested last season may already have passed its safe storage life and could have lost 0.5% of dry matter and/or loss in market grade.
While monitoring stored grain is important, grain storage operators and all of their employees should be cautious when inspecting stored grain with above-average damage levels. Historically, more entrapment and suffocation accidents occur in years when grain is generally in poor quality.
For more information on drying grain this spring, visit the UK biosystems and agricultural engineering extension Web site.