A quick guide to tarping hay

Everything is more costly when energy and commodity prices run high. Hay is no exception, so it’s worth taking a little extra time to stack it and tarp it properly.

Stored outside without cover, the average big round hay bale will lose about 20 percent of its mass to spoilage. That 20 percent is consumed by a mere 3-inch band of spoilage around the perimeter of a 5-foot diameter bale. When you figure the cost of that spoilage, the time and resources invested in covering bales become more attractive. I’ve penciled out the following costs using a bale that measures 5 feet in diameter by 4 feet wide.

You can see from the math, the value of the hay being tarped is a positive gain per bale. And, with the life expectancy of 3 to 5 years for a properly installed tarp, it would be pure profit after the first year. If these same 72 bales were stored outside in a row, considering a 20 percent spoilage rate, you would have lost approximately 14 bales.
But to save money and keep hay from spoiling, you need to keep the tarp on the bales through the non-feeding season, which means you’ve got to have the tarp secure and prevent it from blowing into the fencerow.

28-foot by 48-foot hay tarp will cover 72 bales pyramid stacked 3-2-1
Tarp Cost: $250/72 bales= $ 3.47 per bale per year
Tie-down Rope: $19.50/72 bales = $ 0.27 per bale per year
Total Cost: $ 3.74 per bale per year
Spoilage Loss: 20 percent @ $25 per bale = $ 5 per bale per year loss
Net gain of hay tarp use: $ 1.53 per bale
 

Here are some tips to follow while stacking and tarping hay:
Be sure to size the tarp properly. A smaller tarp is better than too big. A proper sized tarp should be at or just below the widest portion of the bales on the bottom row.
Ropes under bales work best. This allows the tarp to be tightened securely against the stack preventing wind from getting under the tarp and creating a big sail on a windy day. A 25-foot span of quarter-inch poly propylene rope placed every 3 feet under the bales while they are being stacked works well.

Plastic pipe is better to use than steel as it will follow the contour of the bales more closely, thus creating a tighter fit.

Ropes securing tarp need to be kept tight at all times. You need check the ropes frequently as the hay settles. Slack in the rope from settling bales invites in the biggest culprit in tarp damage—wind. The main objective while securing the stack is preventing the wind from getting under the tarp. If this is accomplished you should get several years out of your investment.

Allen Huhn is a farm supply product manager for MFA Incorporated.