Hay Storage Barns in the Springfield Area

The Decision

Under a roof or on the ground — the number that settles it

Oklahoma State University Extension measured dry-matter loss in round bales by storage method, and the spread is the whole argument. Stored exposed on the ground, bales lose 5 to 20 percent of their dry matter in the first nine months and 15 to 50 percent by 12 to 18 months. Under a roof with open sides, loss runs 2 to 5 percent at nine months and 3 to 10 percent over a year or more. In an enclosed barn, it is under 2 percent at nine months and 2 to 5 percent at 12 to 18 months. Most commercial producers, by OSU's account, use enclosed barns with no more than one side open.

That loss is not spread evenly through the bale. University of Missouri Extension agronomist Jim Humphrey puts it plainly: in a 5-foot bale, more than 30 percent of the hay is in the outer 6 inches, more than 26 percent in the next 6 inches, and just over 20 percent in the protected 12-inch core. Weather takes the outside first, and the outside is where most of the bale is. Larger-diameter bales lose less — a smaller bale carries about twice the exposed surface for the same amount of hay.

Loss is also not only tonnage. MU's hay guide notes that excessive heating and molding can cost as much as one-third of the feeding value of hay baled at 28 percent moisture — the hay is still there, and worth less. A building is the fix for the weather half of that. The moisture half has to be fixed before the hay ever reaches it.

The moisture rule comes first

No building rescues hay that went in wet. MU Extension's guidance is that hay should not be baled above 18 to 22 percent moisture; above that, bales lose large amounts of dry matter to heating and molding, and in severe cases spontaneous combustion is possible. The split by bale type matters: small rectangular bales under 22 percent, large round bales under 18 percent, because large rounds hold their internal heat much longer. Heating occurs to some extent in all forage unless it is below 15 percent moisture.

Hay baled above 22 percent, per the same guide, should probably not go into storage for at least 30 days — especially if it will be stacked several layers deep. For a barn owner that is a sequencing rule with real stakes: the enclosed building that protects dry hay is the same building that traps heat in wet hay.

Heat, and when to call someone

The fire figures below are MU Extension's, stated as theirs. Heating above 175°F kills the microbes doing the heating; chemical reactions then carry the temperature further, and rapid oxidation can reach an ignition point of 448 to 527°F. The time from heating to combustion runs four to 10 weeks, depending on storage conditions, climate, and forage moisture.

Extension services in several states — Mississippi State, Ohio State, South Dakota State, Purdue, and Cornell among them — publish consistent action thresholds: at 150 to 175°F, remove bales, increase circulation, and monitor every few hours; at 175°F and above, call the fire department, because fire is imminent or already present. Two cautions travel with those numbers. Do not walk directly on stacked hay that may be heating — burned-out cavities collapse underfoot. And moving heating hay introduces oxygen and can itself cause ignition.

How many bales a building holds

Two things about the table before reading it. Stated building dimensions are exterior measurements — a 24-foot-wide building will not fit four 6-foot bales side by side, which is the kind of thing that is obvious after the posts are set. And interior height clearance should be at least two feet above the finished stack. The figures below are Oklahoma State's, for bales stacked vertically with about 4 feet of unused space at one end.

Building (exterior)	5×5 bales, 2-high	5×5, 3-high	6×6, 2-high	6×6, 3-high
26' × 64'	110	165	88	132
32' × 64'	132	198	110	165
42' × 64'	176	264	—	—
50' × 64'	—	—	176	264

Two design points follow from stacking rather than from climate. When bales are stacked on their sides, the sidewalls must be built to withstand the horizontal pressure — a structural requirement, and one post-frame handles through its posts and girts if it is in the design from the start. And the storage space should be clear: interior poles cost bale positions and make loader work slower. Clear-span trusses are the reason the format suits this building.

If it stays outside for now

Plenty of hay in this area is stored outside while the barn is still a plan, and MU Extension's guidance for southwest Missouri — from livestock field specialist Patrick Davis in Stockton — is specific. Bale large rounds at less than 18 percent moisture and make them dense; a bale that sags spoils faster. Choose a well-drained site in open sun, away from trees and shade. Get the bales off the ground on gravel, wood pallets, or poles — OSU found ground contact can account for over half of total dry-matter loss, with as much as 12 inches of a bale bottom lost to wicking. Butt rows end to end, orient them in the direction of the prevailing wind, and keep rows a minimum of 3 feet apart; MU's hay guide adds at least 24 inches between bales stored side by side.

Hay country: the Greene and Christian County numbers

The 2022 Census of Agriculture puts forage — hay and haylage, all types — at 52,536 acres in Greene County and 41,043 acres in Christian County, the largest crop by acreage in each. The same census counted 62,493 cattle and calves in Greene County and 47,798 in Christian at the end of 2022. A hay barn here is not a specialty building; it is the storage half of the area's largest crop, feeding its largest livestock inventory. Those are 2022 figures, the most recent census year.

Permit and cost, briefly

Whether a hay barn is reviewed as an agricultural structure depends on the parcel's zoning, its acreage, and the building's actual use — and the question is worth asking the county desk correctly before designing. The agricultural barn guide covers exactly how to ask it, with the Greene and Christian County numbers to call; that question is the same for a hay barn and is not repeated here. Classification changes paperwork, not loads: the adopted snow and wind figures apply to a roof over hay the same as any other, and they are in the wind & snow load guide.

On cost, a hay barn sits where the ag economics are best — it is a large, open, shell-only building, which is the end of the curve where post-frame's per-square-foot cost drops fastest with size. The site's cost guide puts a 40×60 contractor-built shell at $35k–$55k as a 2026 planning range; a hay barn's price question is mostly about how much larger than that it should be, and the ag guide's advice to size for the five-year operation applies with full force to a building whose contents arrive all at once each summer.

Getting it built

The order that works: settle enclosed versus open-sided against the loss figures above and the hay you actually put up; size the building from the capacity table, in exterior dimensions, with clearance above the stack; ask the county desk the classification question the way the ag guide describes; and price the shell against the cost tiers on the same spec from every builder. The moisture rule runs alongside all of it — the building protects what went in dry.

Storage-loss and moisture figures are from University of Missouri Extension and Oklahoma State University Extension publications; county figures are from the USDA 2022 Census of Agriculture. Verified August 2026. Confirm classification with your county desk and current pricing with a builder.