HOW CLEAN GRAIN CAN GENERATE PROFITS
Most corn is going to be stored for a least a year before it hits the market. Cleaning can generate net profits in storage-based operations, despite the lack of market premiums for clean grain in the following areas:
Cleaning grain reduces the air pressure resistance of the grain, this increases airflow and reduces the size of spoutlines that divert airflow and increase fan running time. Center spoutlines in large tanks and piles usually contain about 10 times the fines percentages as the edges. The spoutlines divert airflow but still control total operating time because that is where spoilage will start first. Reducing spoutlines through cleaning can reduce yearly aeration times for No. 3 corn by 30-50 percent.
Mold and Insect Growth:
Molds and insects prefer to attack broken grains and fines. Fines will support mold growth at 1-1.5 percent lower moistures than will whole kernels. Furthermore, removing the fines will clean out many insect larvae, egg masses and highly spore-laden particles. The fines absorb fumigants to a higher concentration, reducing their effectiveness in the remaining grain. Insect and molds generate their own heat; in the poorly aerated environment of a spoutline, they will grow even in cold winter weather. Any increase in molds or insects will, in addition to creating damaged kernels, cause a weight shrink, Estimate about 0.5 percent weight loss per 2-3 percent increase in damage.
Unnecessary aeration brought on by uneven air distribution removes valuable moisture content. Removing one percent moisture (for example, From 14 to 13 percent) from the cleaner grain at the edges contributes little to storage life but costs about 1.6 cents per bushel in lost weight. Overly dry grain breaks up more when handled; breakage potential of corn roughly doubles for every two percent reduction in moisture.
Clean grain will have fewer hot spots, therefore less need for turning. Turning grain is expensive, creates bcfm and causes dust shrink. Just not having to rotate long-term storage grain so often would be a significant savings.
A Balance Sheet of Corn Cleaning:
Expenses and Cost Savings Cents/Bushel EXPENSES Loss of saleable weight 6.0 Cleaning cost 2.0
Total expenses 8.0
COST SAVINGS AND REVENUES Feed value of screenings (75 percent of corn) 4.5 Freight savings ($18/ton) 2.0 Aeration cost savings 2.0 Dust shrink savings (0.2 percent 0.3 Mold insect shrink savings (0.5 percent) 0.8 Moisture shrink savings (0.5 percent) 0.8 One less turning 1.0
Total savings & revenues 10.6
Net profits 2.6
Assumptions: Corn value $1.50/bu. aeration rate 0.1 cfm/bu. corn contains 4.0 percent bcfm, electricity cost $0.05 kwh, nine months storage.