Volume 43 Number 2 Summer 1996
Poultry Litter Looks Promising in Surface Mine Land Reclamation
Figure 1. Before: a portion of the Sunlight Mine prior to reclamation.
|Figure 2. During: heavy equipment and technical expertise provided by the Drummond Company's Jasper Revegetation Group during preparation of the site.||Figure 3. After: heavy vegetation now covers the majority of Sunlight Mine. A mixture of legumes and forages following preparation and amendment with poultry litter resulted in greatly improving what was previously a heavily eroded site.|
Jeff L. Sibley, William A.
Dozier, Jr., James O. Donald, David G. Himelrick, John H. Wilhoit, and
E.S. Lyle, Jr.
An Auburn University demonstration project in Walker County shows the potential value of poultry litter as a soil amendment in reforestation and revegetation of surface coal mine land to mitigate nonpoint source water pollution impacts in the surrounding watershed.
Applying poultry litter in surface coal mine reclamation
is especially appropriate for Alabama. These are two major state industries,
both concentrated in the north-central part of the state. Alabama ranks
second in U.S. broiler production, generating $1.4 billion annually,
or one-eighth of the state's economy. The Alabama coal industry ranks
twelfth in the U.S., mining just under 30 million tons annually. Coal-fired
plants supply more than 75% of all electricity used in Alabama, and
about 57% nationwide. About 20% of Alabama is underlain by coal, compared
with 12% nationally. The two industries also face the challenge of converting
In producing more than 900 million broilers annually, Alabama growers also produce more than two million tons of broiler litter. This nutrient-rich by-product potentially could supply the necessary nitrogen for all row crops grown in Alabama. In the past, broiler litter has represented a disposal problem and a potential environmental hazard when applied to farmland at sometimes excessive rates. However, its utilization potential is increasingly being recognized.
More than 100,000 acres in Alabama have been surface mined for coal. If not properly restored through reclamation, surface-mined lands can contribute to significant environmental problems, chiefly nonpoint source water pollution. Prior to the implementation of reclamation laws, removal of vegetative cover and adverse modification of the soil surface increased soil erosion and runoff, resulting in siltation of streambeds. The chemical quality in surface water runoff can be changed as a result of mining activities and may affect water quality if reclamation laws and regulations are not properly followed.
Currently, coal companies are reclaiming surface-mined land systematically as part of the overall mining operation. However, land mined before passage of the Surface Mining Control and Reclamation Act of 1977 (referred to as pre-law land) is reclaimed at a much slower pace.
An on-going AAES study, begun in the spring of 1994, is focusing on reclamation of a portion of the Sunlight Mine, a pre-law mine site adjacent to Blackwater Creek, a tributary of the Upper Black Warrior River. The site is owned by Drummond Company, Inc., which has made a long-term commitment for site land management and contributed heavy equipment operation for the project. Auburn University's role in the project is overall coordination, linking industry and agency interactions to assure successful site reforestation and revegetation to mitigate nonpoint source impacts on, and downstream from, Blackwater Creek. Baseline water quality data and hydrology studies were conducted by the Alabama Department of Environmental Management (ADEM), to determine the impact of remediation on nonpoint source runoff. Auburn also is conducting local and statewide educational programs to involve and educate citizens in the value of reclamation as a water quality improvement tool.
The eight-acre project site was heavily eroded and practically devoid of vegetation. Initial on-site soil samples revealed pH ranged from 3.3-4.2. The site was amended with finely ground limestone at rates ranging from four to eight tons per acre, effectively raising the soil pH to 4.9. A slurry pond with a pH of less than three was eliminated, with the entire project effectively contoured into one watershed, raising runoff pH to 4.5.
Three one-acre plots were established and amended with litter from a Walker County broiler operation at rates of 10, 20, and 40 tons per acre. These plots were compared to a plot that received mineral fertilizer at standard reclamation rates of 600 pounds of 13-13-13 per acre and another plot that did not receive any fertilizer or poultry litter. All soil amendments were disced in to a depth of 12 inches with a D-5 dozer and Rome disc. A mixture of fescue, lespedeza, rye, and clover was broadcast over the entire area and mulched with hay.
Previous research has shown that hardwood trees respond favorably to the nutrient and organic matter content of broiler litter, leading to the selection of a 75% hardwood, 25% evergreen mix of eight tree species. Containerized tree seedlings provided by International Forest Seed Company, Inc., were planted during the winter and early spring of 1994-95 at 600 trees per acre using a dibble matched to the uniform root systems of the seedlings.
By late spring of 1995, the previously bare, highly-eroded site was covered with heavy vegetative growth, with the litter-amended plots showing an advantage over the fertilizer-only plot. Sampling of yields from the grasses and legumes show the benefits of broiler litter amendment from the standpoint of potential for grazing or hay cropping. Forage yields from the litter-amended plots were two to three times higher than the statewide and Walker County averages (see graph). Even the high rates of litter have had no negative effects at this point on ground cover or tree survival, and surface runoff has been nearly eliminated. Additionally, ground water sampling by ADEM has not indicated a significant increase in nitrates (NO3).
Forage yield results, 1995.
This project is demonstrating how the Alabama coal industry can address environmental hazards of prelaw mine sites by utilizing one of Alabama's poultry industry by-products in an environmentally beneficial way. The project also models productive cooperative efforts in a more general way.
Sibley is a Research Assistant, Dozier is a Professor and Department Head, and Himelrick is a Professor of Horticulture. Donald is a Professor and Wilhoit is an Associate Professor of Agricultural Engineering. Lyle is a Professor (retired) of Forestry.
project is unique in that it links major Alabama industries—coal,
poultry, and forestry—with a major educational institution (Auburn
University), under the umbrella of the governmental agency responsible
for the environmental affairs (ADEM). This project is funded in part
by the U.S. Environmental Protection Agency. Major cooperators include
ADEM; AAES; AU's departments of Horticulture and Agricultural Engineering;
Drummond Company, Inc.; International Forest Seed Co., Inc. (IFSCO);
and the Alabama poultry industry.