LAKE LOUISE, Alta. – An Agriculture Canada researcher in Brandon is working with Manitoba hog producers to compost manure and provide a good soil additive to cultivated fields.
Katherine Buckley told a national composting conference in Lake Louise on Oct. 12 that in Manitoba liquid manure may be stored in an earthen storage system for up to 400 days, producing as much as five million gallons of manure.
Winter spreading often happens because conditions are too wet in the spring.
“The rules are bent quite frequently to accommodate these producers,” she said.
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Some producers are looking at alternative hog housing systems designed to separate liquids from solid manure, which is eventually composted. She is working with a producer who uses a hoop roof type barn with open ends to reduce odour. Measuring 30 metres long by nine metres wide, these are low-cost, low-energy buildings with a semi-circular shape.
Free movement
About 250 pigs go into the barns when they reach 25 kilograms. They are bedded in wheat straw and are free to move about and select their dunging areas.
In summer they tend to rest along the cooler walls and dung in the middle of the barn while in winter they huddle in the centre for warmth and deposit manure along the walls.
A bedding pack of manure and straw builds up and hogs tend to rest on the pack because composting that occurs underneath creates heat for body warmth. Although the barn seems odour free, a tremendous store of ammonia was released when researchers dug into the pack.
The composting operation required experimentation.
“This material behaves differently from feedlot manure,” Buckley said.
The farmer uses an all-in, all-out system so when the pigs leave the barn it is cleaned and the earth floor scraped. The straw and manure are hauled away at about 55 to 60 percent moisture.
When piled in windrows for composting, it is difficult to maintain the moisture levels because of dry winds. Researchers did not add water to windrows but relied on rainfall.
The composting worked reasonably well but Buckley said nitrogen was lost so a better strategy is needed to conserve it. Further studies could involve amendments such as zeolite to hold the nutrients.
