Dr. Charles R. Hurburgh, Jr., Professor, Agricultural and Biosystems Engineering and Professor in Charge, Iowa Grain Quality Initiative
Updated Oct. 2, 2014.
Every year brings on a new set of challenges for harvest and grain management; in the past five years we have gone from very wet to very dry. Last year's scorching heat at the very end of the season caused large variations in quality even within the same field. In 2014, planting pace was about normal, temperatures were 1-3 degrees below normal and moisture was well above normal - especially in the August and September grain fill period. Western and southwestern Iowa were 3-6 inches over normal for moisture in this period. This combination of weather conditions put the 2014 crop 7-10 days behind normal maturity. Over most of the state, the cold temperatures on September 13-14, 2014, were just above major frost damage levels. Fortunately the 8-14 day outlook from the National Weather Service (NWS) is for above-normal temperatures and normal moisture. Now we need heat for a successful harvest.
On September 1, 2014, USDA projected the corn yield in Iowa to be 185 bu/acre, up 20 bu/acre from 2013, and the soybean yield to be 51.0 bu/acre, up 6.5 bu/acre from 2013. Both crops are anticipated to be at record levels for total production, 2.44 billion bushels for corn and 510 million bushels for soybeans. These numbers are important for grain storage decisions because the production versus carryover versus storage balance for Iowa looks like (numbers in billion bushels):
Production (USDA, September 2014)
Carryover (both) 0.28 USDA, September 2014
To store in 2014 3.23
Storage Capacity (USDA, December 2013)
On Farm 2.10
Off Farm 1.40
This is a tight situation with little slack for working space and grain out of position relative to space.
Quality - Corn
Moderate temperatures and adequate moisture in grain fill should create well-filled kernels, which will give generally high test weights (57 lb/bu and higher). High test weight means above average storage properties. This is good because a considerable amount of 2014 corn is going to have to carry over in to 2016. How high the test weights get will depend on the weather for the next week or two. Warm temperatures will complete the fill; cool and wet will slow down maturity. Either way, the lateness of the growing season will ensure above-average moisture. Average moisture for Iowa is about 17-18%; delaying maturity will take away several high drydown days; expect 20% moisture or more unless October is very warm. A very wet crop like 2009 is not so likely with our current weather conditions and forecasts.
Corn with high test weight stores well, but producers are reminded not to mix 2014 with 2013 corn, which had poor storage properties. For best results, rotate stock for corn that has been carried over, which does create logistical issues when done during harvest. If you have high test weight corn, consider more bin cooling or dryeration, stopping at a percent or so higher moisture than normal. This will increase dryer capacity, as long storage bins have aeration at 0.1 cfm/bu or greater. Identify the highest test weight fields or hybrids and place in long-term storage bins.
Exceptions: Corn with leaf blight, storm damage, or frost damage will need to be harvested quickly to avoid ear loss. This corn will also be on the lower end for test weight and storability. If the cool wet weather is extended, scout for field mold as buyers would be looking primarily for vomitoxin in these cases.
The tight storage situation will mean heavy flow to grain elevators in the later season once farm bins are full. Consider sending some grain to the elevator early and continue with this plan throughout the season. Elevators will have to fill piles covered with tarps and other less flexible storage this year. Allowing elevators to start filling early will even the flow and reduce the risk of having to put wetter corn in these storage locations.
Quality — Soybeans
Expect generally well-filled pods with large beans with good protein and oil, except where frost or sudden death syndrome (SDS) was a factor. A warm period will allow soybeans to take their usual rapid nosedive in moisture, but this will probably occur later than normal. Soybeans will rewet in the field after the initial fall, and from then on field drying is much slower. The window for harvesting at lower moistures may be short this year. Soybean moistures up to 14-15% can be managed with aeration, but soybeans are often stored in bins that do not have this equipment.
The key management actions are the same as always, although there may be a little more leeway in storage times/shelf life.
- Uniform drying and cooling
- Adequate aeration (0.1 + cfm/bu)
- Cooling cycle every 10-15 degree change of outside air versus grain
- Get below 40o F as fast as possible
- Take out the center core of fines immediately
- Regular inspection, temperature monitoring
- Temperature change is important (3 degrees increase in two weeks without aeration being run is significant)
- Stay within temperature-moisture guidelines even if we are on the high end this year
For more information, Iowa State University Extension and Outreach has 20-minute training modules on three grain management operations: Aeration and Dry Grain Storage, Fan Performance, and Dryeration. Go to the Iowa Grain Quality Initiative website, www.iowagrain.org, and select grain storage training.
- Overall quality is likely to be good with a few uncertainties because of weather.
- Carryover of the 2013 crop will create complexities because of its poor storage. Do not mix crops from multiple years in bins and recognize that considerable quantity of 2014 corn will be stored for at least two years.
- Corn will probably be wetter, but not extremely wet. Higher test weight may offer some operational flexibility to increase dryer capacity.
- Basic grain science and management principles still apply; some grain is being prepared for 2016 use or beyond.
Have a safe and productive harvest. Updates will be provided as they arise.
Charles Hurburgh is a professor in the Department of Ag and Biosystems Engineering. He can be reached at 515-294-8629 or e-mail firstname.lastname@example.org.
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