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Guard Your Grain by Investing in Grain Bin Technology

Iowa farmers protect their assets in the bin by investing in technology.

The grain bin has become an important tool in your marketing plan. While in storage, you must ensure that crop maintains its quality and is in good condition once it’s time to haul. Yet, every year you might have problems with corn sticking to walls, crusting on top, or plugging center wells – all of which are signs that proper steps were not taken to safeguard the precious commodity.

“If you’re a farmer who has invested in on-farm storage, you fall into two categories. You have either had grain go bad or you are going to have grain go bad,” says Terry Johnston, HTS Ag. “Generally, it’s not through any fault of your own, but it happens to every farmer. Things just go wrong. With so much money invested in that crop, you can’t afford to just let it go once it’s in storage.”

Informal surveys of Midwest farmers, says Dirk Maier, professor and postharvest engineer, Iowa State University, reveal that they only check their stored grain every four to six weeks, primarily visually or by odor.

“That is more than enough time for biological organisms to flourish and cause spoilage, especially when excess moisture has infiltrated the storage structure and dripped or condensed onto the grain surface,” he says. “Grain has a finite shelf life, and these biological organisms flourish based on how grain temperature and moisture are managed.” 

Maintaining the quality of stored grain requires a combination of tools and practices to ensure that it does not deteriorate over time, explains Maier.

more bushels

According to the USDA, on-farm storage grew by about 65 million bushels to 13.45 billion bushels in 2017. Iowa (2.10 billion bushels), Minnesota (1.55 billion bushels), and Illinois (1.47 billion bushels) led the way and account for 38% of total on-farm grain storage.

With so many bushels being stored, it’s no surprise that it’s become more difficult to stay on top of what’s going on inside the bin. Despite decades of research and the availability of advanced monitoring technology, Maier says combating pre- and postharvest mold infection and insect infestation during storage remains a challenge. In fact, less than 5% of on-farm grain bins have some form of technology to monitor what’s happening once that bin door closes.

“When margins are tight, it wouldn’t take much of a mistake in a grain bin to have a large impact on my bottom line,” says Caleb Hamer, who farms in Traer, Iowa, with his father, Ted. “It can be an expensive lesson to learn.”

For years, the father and son have cooled hot corn in the bin to keep harvest moving. 

“We would run the fans for two weeks and not really think about it because we knew that’s what needed to be done to cool that grain,” he says. “However, I had trouble sleeping at night knowing there was hot corn in the bin.”

The Hamers are not alone. “A lot of farmers are overly cautious and will run fans longer than they need to,” says Johnston. “The net effect is that they’ve wasted a lot of electricity and likely overdried their corn.”

investing in tech

In 2017, the Hamers invested in OPI Blue to better manage the approximately 120,000 bushels of storage on their farm. They spent around $40,000 to install the technology on 10 grain bins, and they should see a payback in about seven years.  

Temperature and moisture cables are key components of the system. They control humidity, aeration, and temperature, which can be managed from the palm of your hand or from a desktop computer. After the first season in use, the Hamers discovered that corn cooled down to ambient temperature within about 72 hours. 

“Rather than run the fans for about 14 days, we were able to shut them off within three to four days,” he says. 

The system is then switched to automatic mode, allowing the technology to take over and maintain the temperature and moisture parameters the Hamers have set. Information about the ambient temperature and relative humidity conditions is provided by OPI’s weather station. It then calculates the equilibrium moisture content, which helps with fan control.

“We try to maintain a grain temperature of around 40°F.,” Hamer says. “Based on weather conditions, the technology automatically turns the fan on and off to maintain where we want the grain to be. Email alerts are sent regularly, especially as we go through the different weather cycles.”

This technology allows them to know – with confidence – whether or not they’re getting the corn cooled down and keeping it cool. “If we’re not, those alerts enable us to take action and correct the issue before it’s too late,” he says.

“Using a system like this is simply about peace of mind,” says Johnston. “You’re not lying awake at night wondering what’s going on in your bins because you know with this technology.”

Along with that peace of mind, this system also creates a more uniform product that comes out of the bin.

“Once we started hauling corn and were able to verify what the system said the moisture was in the bin and what the scale tickets at delivery showed the moisture was, we ended up trusting the technology rather rapidly,” Hamer says.

“A lot of technology, like a fire or home alarm, is designed specifically to monitor your valuables,” says Johnston. “Why wouldn’t you have that same mentality when it comes to your grain?” 


OPI Blue is a wireless system that delivers hourly grain storage information to your mobile or desktop devices. It also allows you to turn on fans remotely.

monitoring co2

Approximately 25% of food crops are affected by mycotoxins worldwide.

“Mycotoxins cause millions of tons of foodstuff to be lost each year,” says Dirk Maier, professor and postharvest engineer, Iowa State University. “As a result, grain producers often suffer the consequences of reduced marketability in the form of discounts or outright rejection of their commodities.”

Maier explains that insects and molds are aerobic organisms that respire and release carbon dioxide into the interstitial air of stored grain. “Past research showed that a stable grain mass has a CO2 concentration of 400 to 600 parts per million,” he notes. “Higher levels indicate biological activity above normal.”

Research at Purdue University, Kansas State University, and Iowa State University, as well as INTA in Argentina, reveals that CO2 sensing can monitor stored grain quality and detect early the onset of grain spoilage.

“This technology was tested and validated in 20 different size grain storage silos in Kansas and Indiana during several storage seasons,” he says. “The results clearly demonstrate that CO2 sensors can detect grain spoilage due to insects and molds usually about three to five weeks earlier than detection by traditional methods such as visual, odor, or temperature detection.”

CO2 sensors are now commercially available to mitigate spoilage in bins.

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