In December of 1999 DGH Engineering Ltd. received a research grant from Manitoba Livestock Manure Management Initiative to evaluate changes in the composition of manure during its storage in covered earthen manure storage basins. The primary purposes of the study were twofold: to determine the impact of covers on the conservation of nutrients in stored manure; and to evaluate the role of covers in the stabilisation of organic matter in manure. This study was conducted at two locations, the van Aert Family Farm near St. Clement, Manitoba and the
Preun Family Farm near St. Andrews, Manitoba.

From the study, it has been found that nitrogen losses can be reduced by as much as 82% through the use of a cover, and that although the extent of stabilisation of organic matter in manure is comparable for both covered and uncovered earthen manure storages during the winter and spring, covered earthen manure storages experience stabilisation of organic matter, as evidenced by reductions in VFA concentrations, at an earlier point in time in the summer than uncovered earthen manure storages.