Ken Hellevang, North Dakota State University Extension agricultural engineer, has the following recommendations for spring-time natural-air drying for soybeans, wheat and barley.
Soybeans. Use an airflow rate of at least 1 cubic foot per minute per bushel to natural-air dry up to 16% moisture soybeans. The expected drying time with this airflow rate will be about 50 days. The allowable storage time for 18% moisture soybeans is only about 40 days at 50 degrees F, so use a minimum airflow rate of 1.5 cubic feet per minute per bushel to natural-air dry 18% moisture soybeans.
Wheat. Normally start the drying fans in late April when temperatures are averaging in the upper 40 degrees. The estimated time to dry 17% moisture wheat using an airflow rate of 0.75 cubic feet per minute per bushel is about 40 days at 47 degrees. Adding supplemental heat that warms the air 3 to 5 degrees permits drying at a higher humidity but will approximately double the cost of drying.
Barley. Malting barley germination will be lost if adequate airflow is not provided so the barley is dried within the allowable storage time. The allowable storage time (or drying time) is related to the grain temperature and moisture content. The allowable storage time, based on germination, for 17% moisture barley is about 140 days at 50 degrees, 65 days at 60 degrees and only 30 days at 70 degrees.
Germination will be lost before mold growth is visible. An allowable storage time chart for malting barley is available at the NDSU grain drying and storage website. Allowable storage time is cumulative, so if the 17% moisture barley was stored for 60 days last fall at 50 degrees before it was cooled for winter storage, the allowable storage time this spring is only about 60 days at 50 degrees before germination is lost.
Drying 17% moisture barley will take about 40 days with an airflow rate of 0.75 cubic feet per minute per bushel at 50 degrees. Therefore, an airflow rate of 0.75 cubic feet per minute per bushel is the minimum recommended airflow rate to dry 17% moisture barley in the spring.Source: NDSU, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.