Brothers Dave, Dennis and Neal Nelson convinced the owners of a farm they rent outside of Belmond, IA, to convert a towering blue Harvestore into temporary dry corn storage. After that proved successful, six more silos at the farm were converted, and now the Nelsons pay 10¢/bu. annually to store approximately 120,000 bu. of corn there.

With corn acres up 19% this year versus last and many farmers wanting to retain control of their crop to capture top prices, on-farm corn storage is stretched to the limit. Short of forking out thousands of dollars and squeezing in line to purchase a new grain bin, resourceful farmers like the Nelsons are using alternatives such as old silos, barns, machine sheds, hoop barns and even bags for storing corn these days.

The Nelsons' rented Harvestores were converted with a commercial aeration package from Sukup Manufacturing, Sheffield, IA, (www.sukup.com). Each package includes a perforated metal floor with supports and flashing, an unloading tube and sweep, an aeration transition, an aeration fan and motor, a roof vent plus other components. A package for a 20 × 60 ft. structure currently lists for just under $11,000.

The Nelsons, who farm a combined 5,000 acres, aim to fill the silos with corn that's 17% moisture or less on dry days with temperatures in the teens or lower. They rely on the aeration fans for cooling the grain, rather than drying it. “The most moisture we've ever gotten out is two points,” says Dennis. If corn is wet coming out of the field, they run it through a drying bin before filling the Harvestores.

Three stations are set up to fill the silos. First, a portable auger moves corn through a small porthole cut into each side of three, 80-ft. tall silos. Meanwhile, a grain vacuum blows corn up through the silo tubes to top off each of the silos filled with the auger. Across the driveway, four 60-ft. silos are filled using an existing stationary elevator leg with the aid of a lateral conveyer. The process takes about a week and a half to fill all seven silos.

The brothers have learned to empty the Harvestores before spring hits or problems with condensation may cause mold and spoilage. “This is really just freezer storage,” says Dennis. “As long as we get them cold and keep them cold, they are pretty good. It works.”

Richard Golinghorst and his family at Walcott, IA, wanted a place to stash corn while they wait for favorable basis pricing at nearby Mississippi River barge terminals. By avoiding selling corn when grain is flooding the terminals, they typically add 10-20¢/bu. in premiums.

“When they tighten up the basis in December, that's when we like to deliver our corn,” says Golinghorst's son-in-law Brian Ehlers. Golinghorst and Ehlers, along with Golinghorst's son Joe, raise corn, soybeans, seed corn and seed soybeans in Iowa's Scott and Muscatine counties.

The family considered buying a new steel grain bin but bought a 62 × 80 ft. Cover-All hoop barn in 2003 instead (www.coverall.net). “We needed more machinery storage, as well as corn storage, so we went with a multipurpose building,” Richard says.

They also considered a steel machine shed but chose the less expensive hoop-style building to save a little cash, and they liked the high, open ceiling. “With the hoop barn you can get the pile high enough to fill the space,” says Ehlers.

Corn is dried down to 14% moisture in a nearby grain-drying bin and then augered to the hoop barn through a porthole cut in the metal base wall. Corn is dumped in a small pile in one corner of the barn. A second portable auger then shuttles the corn up to just below the 30-ft. ceiling peak and dumps it below to make a 20,000-bu. pile in the center of the barn. The pile is contained by a 60-ft. diameter × 4.5-ft. high ring, created by bolting together a single layer of Harvestore sheets which Richard salvaged from a neighbor.

“Rather than making the walls of the barn so sturdy they could hold the corn, we thought the ring was a good option,” says Richard.

No aeration is incorporated, so using the hoop barn for corn sold in mid-December is ideal, but longer storage stretches have worked too, says Ehlers. “It's just like the quality coming out of a bin as long as we sell it before late spring,” he says.

Moving corn out of the hoop barn is a bit of a project. A grain vacuum sucks it into the Golinghorsts' semi trailer and then a skid loader and hand brooms finish the cleanup. Once the grain is moved out, the blue sheets nearest the overhead door are removed so machinery can be moved in. Ehlers says it takes about an hour (not counting filling or unloading grain) to convert the barn back and forth between grain and machinery storage.

The Golinghorsts and Ehlers also use an old cattle shed with a 48-ft. diameter ring for additional temporary corn storage. “It's tougher to fill because we have to put the auger in and move it around,” says Ehlers.

This year's corn storage dilemma has also sparked interest among U.S. farmers in storing grain in plastic bags. Grain Bag System (GBS) provides a complete package, including a bagger for filling and an extractor for unloading (both manufactured in Argentina), along with 9 × 200-ft. polyethylene bags that store up to 8,000 bu. corn/bag (below).

“Bagging grain has been done before but there have been some problems,” says Terry Twiestmeyer, Grand Island, NE, who along with associate Steve Hood of Springfield, MO, studied Argentina's grain bagging industry before starting to distribute GBS in the U.S. Twiestmeyer says that the bags he and Hood sell are specifically designed for grain versus other bags used for forages. The grain bags have added ultraviolet light protection and are thicker and more durable to avoid the “pillowing” that can occur when grain goes in lighter-weight bags.

According to Hood, grain can be stored safely for up to 18 months at 15.5% moisture or less. “If you put 18% moisture corn in the airtight, sealed environment (of the bags) it will be fine but it won't last as long,” Hood says, who believes the key to the success of the bags is the environment. “If you lock away the oxygen, you don't have heating problems.”

The GBS loading and unloading equipment costs about $40,000 combined and the bags are priced at about 7¢/bu. capacity. (As of July, GBS was nearly sold out in the U.S. for the 2007 harvest.)For more information, visit www.grainbagsystem.com.

Temporary Storage Considerations

Dirk Maier and William Wilcke, professors and Extension engineers at Purdue University and the University of Minnesota, respectively, offer the following checklist for growers to consider when determining suitability of temporary grain storage facilities:

Sanitation: Storage facilities should be free of manure, ag chemicals, petroleum products, strong odors, rodents and birds.

Drainage and vapor barriers: A vapor barrier (such as 6-mil. plastic) can prevent ground moisture from going into grain. Avoid leaks and moisture.

Sidewall loading: A dry grain pile exerts about 23 lbs. of pressure/ft. of grain depth to sidewalls. Therefore, walls of buildings not designed for grain may need to be reinforced.

Storage capacity: To learn more about determining capacities, see handout “Calculating Bushels” at www.bbe.umn.edu/extens/postharvest.

Aeration cooling: Cooling stored grain is very important to limit moisture condensation, mold and insects. Perforated ducts on the floor can work well for flat buildings. Run fans to minimize temperature differences between grain pile and outside air. Roofs of buildings where positive pressure aeration is used should have vents at 1 sq. ft. of vent area for every 1,000 cu. ft. of air per minute to minimize condensation.

For outdoor piles: Dry corn (15% moisture or less) can be stored in outdoor piles during cooler weather without covering or aeration. In the spring or summer, tarps and aeration should be used. Good drainage is crucial and a vapor barrier (such as 6-mil. plastic) is recommended. Low retainer walls can be used to increase pile capacity.

For converted dairy silos: Dry grain exerts a lot more pressure than forage crops so it is important to make sure any type of silo used for grain is designed or reinforced to withstand the extra pressure. Silos should be adapted with an adequate aeration system to control temperature and reduce moisture migration and mold and insect activity.