Storing grain in polyethylene bags offers a viable option to on-farm storage or holding grain in commercial elevators and is particularly useful during bumper crop years when traditional storage is limited and harvest delays are likely.
“The Coastal Bend and Upper Gulf Coast of Texas are major grain sorghum and corn producing areas,” says Mac Young, Texas AgriLife Extension economist. Young and Extension entomologist Roy Parker discussed the advantages and concerns of short-term grain storage in polyethylene bags during the recent Texas Plant Protection Association Annual conference in College Station.
“Bumper crops often back up delivery trucks at elevators, cause harvest delays and storage capacity may be exceeded,” Young said. “Producers have had only two options — commercial elevators or on-farm storage bins.”
He said the high cost of building new facilities presents economic hardships for individual farmers and grain merchants. Storage bags provide a short-term, economical solution.
Young examined the three options in a recent study to evaluate feasibility of storage bags. He estimated corn price at $4.03 per bushel. He assumed a 6-month storage period and no financing expenses.
He estimated 2009 storage and handling costs at 73 cents per bushel for elevators, 33 cents for on-farm storage and 22 cents per bushel for grain bags. “Actual costs may vary by location, elevator, age of bins and individual producers,” he said.
The most significant advantages were harvest flexibility and minimal capital investment for grain bags. Disadvantages included inability to warehouse receipt grain stored in bags and inability to load or unload bags in wet weather.
“Under proper handling and management, grain bags provide cost effective, temporary storage,” he said.
Parker said quality of grain stored in polyethylene bags should not deteriorate during a five to six-month storage period. But he cautioned producers to follow basic recommendations to assure quality retention.
“Put the storage bags on hard ground and be cautious not to break the side of the bags (during loading).”
He said farmers should position the bags so that the open end is away from trees. “Don’t exceed the stretch limit and prevent animal intrusion. Electric fencing may help.”
Parker said rats, raccoons, birds and other animals could chew into the bags and cause damage. “We haven’t witnessed damage from feral hogs yet, but we expect it."
Parker said moisture level when filling the bags should be 14.5 percent or less. “We don’t recommend storing grain higher than 14.5 percent in grain bags. Moisture level does not change in storage.”
He said farmers should check temperature in the bag regularly. “In our study the temperature in the bag dropped every month.
“Sample for insects.” Parker said rice weevils were the dominant insect pest identified as the grain went into the bags. “The numbers dropped with every sample,” he said.
Sampling requires a farmer to punch holes into the bag. These should be sealed tightly following sampling. “Seal holes with special tape and we recommend wide tape.”
Parker said unloading grain from storage bags takes only about 15 minutes per bag. “The bag rolls back as it’s unloaded. It rolls out as grain goes in.”
Unloading requires a cutter to gain access to the grain. “Bag’s are a one-time use,” Parker said.
Equipment needs for in-field grain bag storage include the bags, a small tractor (70 horse power) and a loader.
It’s not a new concept, Young said. “They were using storage bags in South America 25 years ago, mostly for forage. He also suggested farmers might want to partner with local, commercial elevators to weigh and dry grain “as needed to help with marketing.”
“Check it often,” Parker said, “especially for animal damage.”