Outdoor storage of large round-bales
There are a number of storage techniques that minimize outdoor storage loss of round-bales, which can range between 5 and 35% depending on the amount of precipitation, location, and original condition of the bale.
Make/buy a dense bale as they will sag less and have less surface area in contact with the ground. A dense surface layer will shed more precipitation and protect the bale from weathering.
Use plastic wrap, net wrap or plastic twine. Net wrapped bales reduced grass hay dry matter losses by 32% compared with twine bales stored outside. Plastic twine will resist weathering, insects and rodents better than natural fiber twines. Twine should be wound tight and spaced 6 to 10 inches apart for best bale storage.
Store bales on a well-drained location. Bales soak up moisture if placed on a wet or poorly-drained site. A well drained, four to six inch coarse rock base will minimize bottom spoilage, as well as using wooden pallets.
Finally, never store bales under trees. It is highly recommended that bales stacked outside have some type of temporary cover placed over them (i.e. a tarp) for the total duration of the storage period.
Storage losses are usually reduced by approximately two‐thirds with indoor storage and by one‐half with good plastic covering (i.e. a tarp) when stored outdoors.