AMES, Iowa – Wet conditions and a late harvest last fall could create the perfect storm for spoilage this spring if winter-stored hay, grains and silage for feed aren’t immediately and thoroughly dried, according to Iowa State University (ISU) agricultural engineers.

“Any time harvest is late and the crop has to be dried because of high harvest moisture content, there are challenges to maintaining stored grain quality because farmers generally neglect to implement best management practices,” said Dirk Maier, ISU professor of agricultural engineering, and post-harvest engineer.

When grain is not cored and left peaked, Maier said it takes three to five times as long to move air through the top of the peak. 

“Often people turn off the fans well beforehand, which results in self-heating and thus spoilage and crusting that gives us all of the trouble, including dangerous conditions that cause entrapments and engulfments,” he said.

Kristina TeBockhorst, ISU agricultural engineering field specialist, said many farmers put grain in the bin that was wetter than normal last fall, yet were somewhat rescued by the cold weather that allowed them to put cold grain into storage. 

“In the coming weeks, as spring starts to bring warmer temperatures, grain held through the winter at a high moisture content should be dried or marketed as soon as possible to prevent mold growth,” she said.

Kent Nolting, feed department manager at NEW Cooperative, Inc., in Fort Dodge, said the 2019 crop was large, and conditions during harvest made it tough to get it out of the field and stored. 

“We have found the grain’s nutrient content to be lower than normal, which continues a downward trend over recent years, as yields grow bigger,” he said. “Wet conditions and field stress triggered elevated mycotoxin levels in 2019’s corn, especially Zearalenone.  

“The levels we are currently finding are manageable, but we still have some animal producers adding binding agents in their feed, to minimize the risk of feeding it,” he added. “Stored grain yet to arrive could become an issue, depending on how well the grain was managed while in storage.”

In fact, Nolting said grain elevators are currently struggling to maintain grain quality. 

“We have all of our elevator personnel on high alert to constantly monitor our stored grain’s condition and temperature, as we are still drying corn here going into March,” he added.  

TeBockhorst advised farmers to “monitor grain condition and act fast if hot spots – a musty/moldy smell, or elevated CO2 levels (above 600 ppm [parts per million] and rising) – are observed.” 

“Grain held this winter at a very high moisture content (above 20 percent) may have already used its safe allowable storage life,” she added. “For this grain, it may not be advised to attempt to store it any longer after drying it this spring.”

Maier said farmers should get “a CO2 monitor, which costs less than $500 and sniff your grain. (This) tells you quickly whether grain is stable (and will store into spring and beyond), or is having spoilage issues (and will not continue to store well). (It’s) an easy decision (as to) what to move, sell, market, feed, or what to keep longer.”

Klein Ileleji, Purdue University associate professor of agricultural and biological engineering, recommends keeping bin vents closed and avoiding aeration until May or June.

“Aerating the grain early in the spring will warm it up to temperatures conducive to mold and insect pest growth, and thus the security provided by cold winter aeration is rapidly lost,” he said. “It is also advisable to cover the fan intake when it is not being used in order to prevent passive warm air from aerating and warming up the stored grain.”

Because monitoring grain for temperature and moisture content is essential, he also advised farmers to use temperature sensors to help determine if stored grain is at risk from mold and insect development.

TeBockhorst said with the potential for poor quality grain in the bin, it is especially important to use good grain safety practices. 

“Poor quality grain can cause problems such as surface crusting, hollow spots in the grain mass, grain that won’t flow when unloading, and sidewall buildup in the bin,” she said. 

“Do not enter a bin if any of these occur,” she added. “If you have good quality grain and you must enter a bin, have an observer with you, use a harness, and use a lockout/tagout to keep grain equipment off.”