Nearly 100 grain producers and crop advisers braved the weather to attend the 2015 CNY Small Grain Workshop hosted by CCE Oneida County and the CNY Dairy and Field Crops Team of Chenango, Fulton, Herkimer, Montgomery, Otsego, Saratoga and Schoharie Counties.
Speakers at the event included Dr. Kenneth Hellevang of the Agricultural & Biosystems Engineering Dept at the North Dakota State University; Margaret Smith, Cornell University College of Agriculture and Life Sciences School of Integrative Plant Science Plant Breeding and Genetics; Weed Scientist, Dr. Russ Hahn, School of Integrative Plant Science, Soil and Crop Sciences at Cornell University; Dr. Gary Bergstrom, Professor of Plant Pathology, Cornell University Department of Plant Pathology and Plant-Microbe Biology and producer Donn Branton of Le Roy, NY, who told of his farming experience.
Hellevang, a noted expert on managing flooding and indoor moisture and molds, was unable to attend the meeting in person due to inclement weather conditions but successfully gave his presentation by telephone from an airport in Chicago. He spoke on best management practices for drying and storing small grains, focusing on natural air drying, which is frequently used for wheat, barley and other small grains as it allows for rapid harvest, is economical and efficient.
Hellevang said because most small grains are harvested at higher moisture contents than are appropriate for storage, they need to be dried before storing.
“The allowable storage time (AST) of grain is affected by both the grain temperature and moisture content,” he explained.
For instance, corn at 24 percent moisture content would have an AST of approximately 130 days at 30 degrees and 15 days at 50 degrees. Hellevang pointed out that AST is cumulative. “If 18 percent moisture content wheat is held at 70 degrees for 15 days then cooled to 50 degrees, the AST at 50 degrees is 45 days rather than 90 days.”
Various zones within the bin provide key points with natural air drying, with the several feet of buffer zone in the bottom of the bin allowing for fans to be run 24 hours a day without drawing excess nighttime humidity into the grain. “I really encourage people to think of running the fans 24 hours a day and adding a little bit of supplemental heat rather than shutting the fan off at night.”
He noted that fans should be off during rain, snow and fog, as they will pull moisture into the bin.
When designing drying systems, climatic conditions at the time of harvesting and drying is one factor to consider. Equilibrium Moisture Content (EMC) shows that the moisture content of the air is equal to the moisture content of the grain. New York State has an average of about 70 percent humidity during the month of August. Using barley as an example, Hellevang calculated that at 70 degrees and 70 percent relative humidity, natural air dried barley would be at 13.3 percent moisture. The acceptable long term moisture content for barley is about 12 percent. “We can adjust the condition of that air by adding a little bit of supplemental heat. Warming the air reduces the relative humidity.”
Hellevang stressed that although you don’t want the grain too moist, you also don’t want it overly dry and cautioned that drying at a high temperature can affect grain quality. “What we typically want is only enough heat to warm the air about 5 degrees.” He explained many folks don’t understand that friction loss from air going through the fan will provide an extra 3 to 5 degrees of heat.
Warming the air from 70 to 75 degrees causes the relative humidity to drop to 60 percent, making the EMC about 11.7, which falls within the desirable moisture content range.
The maximum grain depth for drying barley and wheat is 20 feet. “As a rule of thumb, to achieve an airflow rate on 0.75 cfm/bu. at that depth will require about one horsepower per 1,000 bushels.”
Hellevang recommends low speed centrifugal fans for efficiency and quietness. Perforated floors and level bins help provide the best airflow.
“Airflow is what does the drying, so it’s important that we have uniform airflow.”
Other factors contributing to accuracy of moisture measurement include kernel physiology, kernel damage, variety and test weight.
Hellevang recommends cooling the grain as outdoor temperatures drop 10 to 15 degrees lower than the grain temperature. “Continue to cool the grain until the grain temperature is near or below freezing. Periodically aerate the grain to keep it cool. Run the aeration fan in late winter or early spring to bring the grain temperature to about 35 or 40 degrees. The goal during spring and summer is to keep the grain as near that temperature as possible.”
Stored grain temperature should be checked every 2 weeks, with grain temperature and moisture content measured and documented. Increases in temperature or moisture indicate storage problems and should be investigated. Observation for insect activity is important, as insect activity, along with mold, is one of the main causes of stored grain loss. Grain should be cleaned before storing and grain bins should be cleaned with attention paid to under floor structures.
Solar radiation, especially on the bin’s south wall should be considered for potential heat damage.
Hellevang also stressed the importance of covering aeration fans when not in use to avoid damage to grain from wind, weather and insects.
For more information on drying and storing small grains go to www.ag.ndsu.edu/graindrying .