In a perfect world as we plan for corn and soybean grain harvest, weather provides favorable drying conditions in the field, lodging is non-existent, and there are no worries regarding stalk quality deterioration so that harvest can be planned and executed without any or very minimal, grain drying expense. Hey, as long as it’s a perfect world, we might as well throw in that grain prices are so favorable that there is no need to plan for grain storage because we can sell everything right at harvest.
The reality is that our current markets dictate some grain storage as part of a marketing strategy and grain storage means managing grain moisture. In addition, weather often does not cooperate so field dry down is slow or prolonged, wet conditions prevent timely harvest, stalk quality deteriorates, lodging occurs, and all these factors add up to field harvest loss. Some potential harvest challenges that I see for the 2018 crop, especially corn grain harvest, are storm systems keeping fields wet, stalk quality issues because the crop ran out of nitrogen and cannibalized nitrogen from stalks, and the potential for ear rots and possible mycotoxin development. We have a range of crop maturities in our area, and for those later maturing fields, an important question to ask is; does an early harvest make economic sense? By early harvest, I mean taking advantage of favorable weather conditions to take off a crop without waiting for field dry down after it matures. Do additional drying costs offset the potential yield losses that can accompany delayed harvest?
According to researchers at Iowa State University, it requires about 0.02 gallons of propane for each percentage point of moisture removed per bushel. According to South Dakota Extension specialist Dick Nicolai, the equivalent number for a natural gas dryer is approximately 1840 cubic feet of gas for each percentage point of moisture per bushel. In addition, those drying systems have an electricity expense as well. Iowa State University researchers use a figure of 0.01 kilowatt-hours (kWh) for each percentage point of moisture removed per bushel. Natural air drying systems that use only electricity have a higher charge. Iowa State University uses an average rate of 0.33kWh for each point of moisture removed per bushel.
Total energy cost is then dependent upon how many points of moisture will be removed multiplied by the energy used per point multiplied by the price (per gallon, cubic foot, and/or kWh) of the energy source. To get an estimate of the total costs involved in drying it is necessary to assign a labor cost as well. You need to know how many bushels can be dried per hour and how much labor is needed for that hour times and hourly labor rate. Iowa State University Extension has a good calculator spreadsheet to look at corn drying vs. shrink and harvest loss for delaying harvest. That decision aid is available on line at https://www.extension.iastate.edu/agdm/decisionaidsall.html. Scroll down to the Storage and Markets section. I can also send the calculator decision aid out via an email Excel spreadsheet attachment. Contact me at 330-264-8722 or by email at email@example.com.
Market plans and crop condition will determine how far down to dry the grain. Market moisture standards are 15.5% moisture for corn and 13% moisture for soybeans. Drying corn to 15.5% moisture is fine for short-term storage through the winter months, but longer-term storage into spring or summer requires drying to 14% moisture or lower. The development of ear rots in a cornfield raises the possibility, depending upon the type of ear rot, of mycotoxin concerns. For help in ear rot identification see the CORN newsletter article by Pierce Paul on line at https://agcrops.osu.edu/newsletter/corn-newsletter/2018-28/ear-rots-corn-telling-them-apart. If a mycotoxin is detected, or a concern, then early harvesting and drying becomes a management strategy. Mycotoxins develop with certain types of ear rots and levels can increase throughout a delayed harvest and even in storage if grain moisture is above 13%. Drying corn down to 13% moisture will not reduce the mycotoxin already present but will stop any further development of mycotoxin.
Finally, there may be some other non-yield and non-grain quality benefits associated with an early harvest. One potential benefit is that early harvest may provide an opportunity for a timely planting of a cover crop, leading to better soil coverage, and more biomass and root growth. Another potential benefit is that early harvest may allow time to do some fall weed control. This could be advantageous in fields scheduled for rotation to soybean production.
For more information about grain storage management, contact the Wayne County Extension office at 330-264-8722.