Odor Control 12

Odor Control for Manure Storages

Manure storages are not designed to provide anaerobic treatment of manure. However, manure in a storage will decompose anaerobically and has the potential to release strong odors. The amount of odor produced from outside storages is greatly effected by temperature, and ration fed. If short or long-term manure storage is provided below the slotted floor of the barn then see the section Floor Design.

Covers for Manure Storages

Covering a manure storage tank or earthen basin can reduce odors from storages to negligible levels (see Table below). Dairy cow manure will form a crust if minimal water is added to a storage. Such a crust serves as a biological cover and has been shown to reduce odor emissions from dairy storages by 75%. Hog manure will almost never crust. Many different types of materials have been used to cover swine manure storages. Some of the most promising cover materials are: barly straw, vegetable oil, vegetable and barly straw mixtures, polystyrene floatation panels with barley straw, peat moss, concrete, floating tarps, air supported hypalon covers, floating foam pellets, floating permeable matts, and structurally supported panels.

Reduction in Odor Emissions Using Covers

Type of Cover Reduction in
Odor Emissions
Sealed Lid95%
Straw 50-80%
Straw & Floating Pellets 70%
Natural Crust 75%
Uncovered 0%

The most cost effective cover has yet to be determined, but the straw, air-supported sealed structures, and floating panels appear to be fairly inexpensive. A Canadian study reported that the cost of barly straw covers was $41/1,000 square feet/year, and would last for one month before the straw began to sink. Polystyrene panels were used as floating supports to increase the useful life of the straw cover to two months. The polystyrene floatation increased the annual costs to $76/1,000 square feet/year. Waste storages do not freeze during a typical South Carolina winter. Therefore, the cost of straw covers in South Carolina would be expected to be double or triple the cost determined by Canadian researchers. An air-supported, hypalon tarp was used to cover the waste storage for a 200 sow farrow-to-finish operation (also in Canada). The cost of the covering system was $28 per sow and very effective at reducing odor.

Return to Management of Odor and Sources
Return to Odor Control
Return to The Land Application of Animal Manure.