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Session- Environmental Applications of Compost Utilization

 

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Compost Utilization for Reforestation of Degraded Sites in West-Central Alberta

 

CODY, MICHAEL J.

 

Compost Technology Centre, Olds College Centre for Innovation, Canada

 

Residuals from wood processing (sawdust, shavings, and waste-chips) are an ongoing problem for forest companies in Alberta.  In-spite of an abundance of potential feedstock and a large forest industry, compost utilization for silviculture in western Canada is very limited.  Rocky Wood Preservers Ltd. and the Compost Technology Centre at Olds College Centre for Innovation have embarked on a research project to evaluate the economic and bio-physical viability of compost use in silviculture.  The biophysical performance of compost inputs is being investigated in plantation and greenhouse experiments with white spruce and lodgepole pine.  The plantation experiment compares compost, mineral fertilizer, and a compost/mineral fertilizer combination on a mesic, medium fertility cut-over in west-central Alberta.  Key biophysical performance criteria include physical and chemical changes to forest soil, tree height and diameter growth, and weed competition.  Economic criteria include production, transportation, and spreading costs.    Results and observations from the 2001 growing season are reported.  It is anticipated that compost may be a valuable tool for reforestation of degraded sites such as skid trails, haul roads, and landings.

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Agronomic and Environmental Effects of Compost, Manure, and Fertilizer Use in Vegetable Production.

 

EVANYLO, GREGORY K. and Sherony, Caroline A. (1).

 

(1) Department of Crop and Soil Environmental Sciences, Virginia Tech, USA

 

The value of compost in improving soil properties and supplying nutrients has been documented, but farmers are hesitant to substitute compost for fertilizer or manure because the economic benefits have not been well quantified. The goal of this project is to compare the long-term effects of compost, manure, and inorganic fertilizers on crop yield, soil property, and water quality variables that can be used to develop an economic valuation of compost. The study was initiated in 1999 on two farms and an experiment station in Virginia. Eight treatments included: 1) unamended control, 2) annual low compost rate, 3) annual low compost rate + fertilizer, 4) annual high compost rate designed to supply crop N needs, 5) single high compost rate, 6) single high compost rate + annual fertilizer, 7) annual poultry litter rate designed to supply crop N needs, and 8) annual fertilizer to meet crop needs. Crops were pumpkin in 2000 and sweet corn in 2001. Soil chemical, physical, and biological properties; crop yields; and nitrate-N leachate collected from lysimeters were measured. Treatment effects on yield and soil properties were negligible in the first year but were noticeable by the second season. Annual low compost rates and the single high compost rate did not increase yield or improve soil properties above those of the control. Yields of all other treatments were similar. Soil quality as measured by bulk density, organic C, total N, exchangeable cations, and available P was most improved in the plots that received the annual high applications of compost. There were no differences in the amounts of nitrate-N that leached from the control and any of the annual applications of compost, manure, and fertilizer at rates to supply crop N needs. Soil properties were most improved with the high compost rate but yields were the same for the high annual rates of compost, manure and fertilizer after two years. Continued study will demonstrate whether changes in soil properties influence long term yield response.

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A Unique Composting Partnering Arrangement

 

MULFORD, Mary (1), Heitz, Michael W. (2)

 

(1) Rumpke of Ohio, (2) Metropolitan Sewer District of Greater Cincinnati, USA

 

A novel partnering arrangement is developing between two unlikely entities-the Rumpke Sanitary Landfill (RSL), and the Metropolitan Sewer District of Greater Cincinnati (MSD).  RSL needed a supply of nutrients for sanitary landfill vegetative growth on the intermediate slope and the final cover. Finding a beneficial reuse/alternative disposal opportunity for its ash residuals (from thermal oxidation of biosolids) was a goal for MSD.  Composting/environmental staff presented MSD with a concept to evaluate the ash as an additive to a soil amendment.  If the concept proved acceptable, each partner could achieve measurable monetary benefits - RSL, from supplementing their supply needs for intermediate slope and final cover for the landfill, and MSD, with a beneficial reuse and alternative non-waste disposal of residuals. MSD ash, currently directed to sanitary landfill for disposal, had the potential for beneficial reuse as a nutrient supplement due to the significant level of phosphorus present.  Shale and top soil used at the landfill on slopes has shown to be deficient in phosphorus.  With the addition of the MSD ash, in conjunction with compost, increased levels of nutrients are available for plant uptake and growth.  Following a promising bench-scale study, RSL applied to Ohio Environmental Protection Agency, EPA, to gain regulatory approval for a full-scale pilot project of the concept. This study explored the effects of different ratios of compost/ash blends, a soil amendment, as a function of plant growth on the vegetative layer on the landfill cap.  The application area selected was approximately one acre of barren soil divided into six plots.  Three plots utilized varying compost/ash blends at 1:1, 2:1, and 3:1 ratios respectively.  Three additional non-ash control plots were designated as:  a) control, b) compost only, and c) standard fertilizer mix only.  The landfill standard grass seed mix was dispersed by a seed broadcaster.  Parameters monitored included qualitative visual observation as well as quantitative measurements of seed stalk, shoot, and root length, and biomass, by weight, of yields reflected in the grass crop. Complete study results will be presented and a discussion of the program potential cost saving and other benefits will be presented.