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Cline, J. A. and G. McKenna, 1996. Utilization of Zebra Mussel Shells as a Soil Conditioner, Liming Agent, and Mulch for Agricultural Soils, Ontario Ministry of Agriculture, Food and Rural Affairs, Ontario Hydro Abstract from The Sixth International Zebra Mussel and Other Aquatic Nuisance Species Conference, Dearborn, Michigan, March 1996 Utilization of Zebra Mussel Shells as a Soil Conditioner, Liming Agent, and Mulch for Agricultural SoilsOne of the major consequences of the recent invasion of the zebra mussel (ZM) (Dreissena polymorpha) in the Great Lakes, has been the colonization of water intake structures and piping systems at industrial plants. At facilities such as electrical generating stations, ZM shells originate from colonization of pumpwell walls and intake screening systems, as well as deposition of dead mussels from the lake into the station forebay. Periodic mechanical pumpwell cleaning and forebay dredging results in sizeable quantities of ZM shells that require disposal. Currently the ZM waste product is classified as a nonhazardous solid industrial waste by the Ontario Ministry of Environment and Energy, and must therefore be disposed of only in approved landfills. Considering the high economic and environmental costs associated with landfilling a material which is natural in origin, is composed primarily of calcium carbonate and contains less than 5% organic matter, two research trials on apples (Malus domestica Borhk.) were initiated in 1995 to evaluate the potential use of ZM shells as a soil conditioner, liming agent, and mulch for agricultural soils. In one study, ZM shells were applied as a surface mulch to 12-year-old ‘Red Delicious’ trees on M.26 rootstock at rates ranging from 2.5-15 cm depths, 1 m on each side of the tree. Additional treatments included an untreated control and wheat straw mulch applied to a depth of 20 cm. Fruit quality, yield, and changes to the chemical and moisture status of the soil will be monitored on an annual basis. In a second study, ZM shells were applied and incorporated into the soil as a pre-plant treatment at rates ranging from 5-20 cm depths, across a 2 m row width. A equal number of trees received no shell material for comparison purposes. Following application and incorporation using a rotovator, one-year-old ‘Empire’ whips on M.9 rootstock were planted into the treated area. Tree growth, productivity, soil moisture and soil chemical properties will be monitored on an annual basis. The overall objective of this research is to identify alternate, environmentally acceptable routes for disposal of the ZM shells with the intention of safely diverting this material from landfills to agricultural soils, where soil and plant benefits may be realized. Data pertaining to tree performance, and soil chemical and moisture status properties will be presented.
Key Words: Zebra_mussel, Disposal, Industry |