in Animal Waste Management
March 10, 1995
A large number of diverse research and extension activities pertaining to the management of animal wastes are being conducted by Agricultural Research Service scientists and Cooperative Extension Service specialists and agents in the College of Agriculture and Life Sciences at North Carolina State University. These projects range from laboratory studies of waste degradation processes and odor control to field demonstration projects exploring ways of managing animal wastes that will protect the environment and, in some cases, even turn wastes into useful products. In addition, Extension training and educational programs have emphasized sound waste management concepts.
This compendium briefly describes many current and recently completed projects related to the management of swine production wastes and to the impact of those wastes on environmental quality. Although every effort has been made to include all projects with a direct or indirect relationship to swine waste and odor management, these topics involve many disciplines and a large number of faculty members, and thus some projects with only a peripheral connection to the subject may not be included.
A key objective of research and extension activities in the College of Agriculture and Life Sciences is to develop and disseminate new knowledge that will assist the people of our state to solve problems and improve their quality of life. The projects described here will all contribute to a better understanding of how our agricultural producers can best manage their animal production operations in ways that will make it possible for them to sustain their strong contribution to the states economy while helping to preserve environmental quality for the benefit of North Carolinas citizens.
Johnny C. Wynne, Director Billy C. Caldwell, Director North Carolina North Carolina Agricultural Research Service Cooperative Extension Service
Principal Investigator: Greg D. Jennings
Local public workshops have been conducted in six river basins with over 800 participants to date. A statewide conference in 1994 attracted over 180 participants. An educational video has been distributed to county Extension Centers and to more than 40 private groups.
Interest groups will be more aware of state water quality protection programs and will have input to increase the effectiveness of these programs.
Principal Investigator: John J. Classen
A master's level student has been identified to work on the project. The student has designed and built a model biofilter that will be used to determine the correct blower size needed to move air through 1.5 feet of peat. The overall design of the project has been laid out in general terms, but a specific experimental plan has not been established. Tests will include using different amounts of peanut hulls as bulking agents to reduce the bulk density.
The study is expected to determine whether peat biofilters are effective in removing odorous compounds from the exhaust air of swine buildings. If they are effective, the tests will also determine design parameters such as the bulk density required, the additional power needed to move the air through the filters, the amount of moisture required to keep the filters operational, and the effectiveness of adding inoculant to the biofilter medium.
Principal Investigators: Robert L. Mikkelsen and Arthur G. Wollum
The ratio of plant nutrients found in most waste products is not proportional to plant requirements. Therefore, the phosphorus content of soils receiving waste builds up to concentrations that far exceed the ability of the plant to utilize it. Phosphorus loss from soil can result in serious water quality problems. This research project is focused on (1) identifying the forms of organic phosphorus compounds present in manure alone and in manured soils using NMR spectroscopy; (2) determining changes in the enzymatic properties of soils following long-term application of animal wastes (up to 40 years); and (3) measuring potential losses in runoff from surface applications of animal manure.
New analytical procedures have been developed to identify specific organic phosphorus compounds present in animal waste using nondestructive techniques. Knowledge of the specific compounds aids in making predictions of the behavior of the phosphorus following application to soil. The activity of various phosphatase enzymes in soils receiving wastes was surveyed throughout the state. There appears to be no clear correlation between phosphatase activity, soil properties, and the history of the soil that receives the wastes.
This research will provide a better knowledge of the environmental fate of phosphorus applied in organic wastes. The heavy loading rate of phosphorus through waste application may present a serious environmental threat in the future. This research provides knowledge about the basic nature and behavior of phosphorus in wastes and soils. Studying the potential for phosphorus loss in runoff will lead to development of improved management recommendations for waste application.
Principal Investigator: W. E. Morgan Morrow
The purposes of this project are to determine whether:
This project has been completed. From January 1992 through July 1994, pig carcasses and afterbirth were added to six compost piles built in 2.5-meter by 1.5-meter concrete block pens of an idle hog-growing barn. The ratio, on a weight basis, of ingredients added was 1 part pig carcass, 0.1 part wheat straw (or 0.2 part peanut hulls), 1.5 parts turkey cake, and 33 liters of water per 100 kilograms of carcass. To two of these piles were added either Salmonella sp. or Erysipelothrix rhusiopathiae in culture tubes. In constructing the fourth pile, two sterilewidemouth glass bottles containing scintillation vials with the tonsils of four pigs experimentally infected with Aujeszky's disease virus (ADV) were included. Four pigs similarly infected with ADV were securely wrapped in two plastic biohazard bags each and added to the pile. The piles were monitored for temperature and for the presence of odor and flies.
The composting process disintegrated most of the carcasses, including most of the bones, and reached temperatures sufficient to kill all of the Erysipelothrix and Aujeszky's disease virus and most of the Salmonella. There was little odor and few flies associated with the piles. Consequently, composting can be considered a safe, efficient, and sustainable method for disposing of swine carcasses.
Principal Investigator: Peter R. Ferket
Funding for this project has been approved.
Principal Investigator: Philip W. Westerman
The purpose of this study was to determine quantitative corrosion rates of galvanized steel exposed to animal feces and urine as encountered in agricultural environments.
This project has measured corrosion rates of various metal types over several years. One test with seven types of steel plates measured corrosion rates in four situations for three animal types. The situations or placements were (1) near the animal living quarters, (2) suspended above the manure reception pit, (3) suspended above the liquid level over anaerobic lagoons, and (4) submerged in anaerobic lagoons. The animal types were swine, dairy cattle, and laying chickens. This test ran from January 1986 through December 1994.
The second test ran from January 1988 through December 1994. Five types of metal plates were used and placed in three environments (above the lagoon surface, above manure pits, and in an animal housing area) for three animal types (swine, dairy, and poultry caged layers). The metal plates have been inspected semiannually for corrosion rates. Also, the atmosphere of exposure (atmospheric ammonia concentration and manure characteristics) have also been measured.
Both tests have been completed and a final report has been prepared.
This project was supported by the International Lead Zinc Research Organization, Inc., to determine which metals and metal coatings would exhibit the least corrosion in environments on swine, dairy, and poultry caged layer farms. The results have shown which environments lead to the most corrosion and which metals or metal coatings resist corrosion. For example, in the first test, batch galvanized and stainless steel showed little corrosion in all the environments, but the other metals and coatings tested experienced significant corrosion. For the second test, Galfan GF-90 exhibited the least corrosion of the metals and coatings tested. These data should assist the manufacturers of metal components used in livestock and poultry production in selecting the best metals and coatings to use to prevent excessive corrosion.
Principal Investigator: Greg D. Jennings
The purpose of this project is to reduce nonpoint-source runoff of phosphorus from poultry, beef, and crop farms in the Deep River Watershed of the Cape Fear River Basin.
Planning has begun for educational programs including meetings, demonstrations, and tours to promote nutrient management, soil erosion control, and riparian buffers to control nutrient runoff. This program was developed in response to state monitoring results indicating that excessive phosphorus runoff was causing algae blooms threatening lake water quality. A U.S. Environmental Protection Agency 319 project proposal is being prepared to support additional educational efforts, demonstration of Best Management Practices, and evaluation of success.
Nonpoint sources of phosphorus including animal waste runoff and soil erosion will be reduced, resulting in fewer algae blooms in the watershed.
Principal Investigators: Brinton A. Hopkins and Matthew H. Poore
This project is being coordinated with a Department of Poultry Science survey on the use of pesticides in poultry houses. Samples of litter have been obtained from major poultry integrators and ill be analyzed for residues of the specific pesticides used by each integrator. The initial results of the survey indicate that no pesticides are in use that would be a major concern from a residue standpoint. Litter to be used in the feeding trial has been located, diets have been formulated, and final modifications are being made to the facilities at the Lake Wheeler Road Field Laboratory Dairy in preparation for starting the feeding trial.
The proper inclusion of broiler litter in diets is expected ultimately to reduce the cost of milk production. No dangerous pesticide residues are expected to be found in the litter to be tested, and demonstrating the safety of this feed will increase its adoption for both dairy heifers and beef cattle. Increased demand for broiler litter will not only have economic benefits, but will also result in increased shipping of the material out of areas of concentrated animal production, reducing the total burden of animal wastes disposed of on pastures and cropland in these areas. Broiler litter for feed has the highest value per ton of any animal waste product, making it the material most economically shipped out of these areas. In contrast, swine waste and turkey litter have a much lower value and are not likely to be shipped very far from the site of production. This project will also stimulate the interest of the dairy industry in other "value-added" animal-waste products that will be developed by the Animal and Poultry Waste Management Center in the future.
Principal Investigators: Robert L. Mikkelsen and Arthur G. Wollum
The purpose of this project is to develop rapid, inexpensive, and accurate methods for predicting the release of nitrogen from organic wastes applied to soil. Since current techniques to measure nitrogen release from organic wastes are slow and laborious, they are rarely used. Consequently, estimates of nitrogen mineralization from wastes are often incorrect, resulting in frequent under- or over-application of nutrients. These new laboratory techniques may provide a means to predict the behavior of the organically bound nutrients in wste before field application and may therefore be widely used.
Using techniques adapted from the animal feed industry, an assay has been developed that uses proteolytic enzymes to mimic natural decomposition processes in soil. The nitrogen release from organic wastes following reaction with the protein-degrading enzymes correlates well with long-term measurement of mineralization. Therefore, a 4- to 8-hour laboratory procedure can predict the field behavior of many wastes and potentially eliminate the need for four-month incubation studies.
The development of a rapid test for estimation of nitrogen release from organic wastes will allow users of wastes to predict the nutritional value of the materials for crops. Testing individual waste products or groups of products allows them to be used in the safest and most efficient manner. Applying the appropriate amount of waste to fields can improve crop effectiveness while minimizing environmental degradation.
Principal Investigators: Peter R. Ferket, Larry F. Stikeleather, and Jesse L. Grimes
The goal of this research is to use fermentation and extrusion technologies to reduce the potential waste stream into the environment, further delineate recycle pathways for poultry and crop co-product material, develop alternative feed ingredients for the poultry industries, and provide an alternative on-farm system for handling poultry mortality.
An automated system was developed that grinds whole poultry mortality carcasses, mixes this material with an appropriate amount of invert carbohydrate and inoculum, and dispenses the mixture into an anaerobic chamber. After three days of lactic acid fermentation, the silage (pH<4.5) is stable, is free of coliforms and salmonella, and does not have an offensive odor. A demonstration of this system is being assembled at the poultry teaching and research unit.
In a concurrent study, dried sweetpotato chips were mixed with the poultry silage (described above) at a ratio of 70 percent sweetpotato chips to 30 percent poultry silage and then heat processed by dry extrusion. This extruded material was determined to have a nutrient composition similar to corn and could be included up to 30 percent of chicken or turkey diets without any adverse effects on growth. The extruded sweetpotato-poultry silage product was also found to be a potentially effective bait or feedstuff for crayfish and other aquatic species. The final component of this project is still in progress. Raw, wet sweetpotatoes have been found to be an effective source of invert carbohydrate for the fermentation of poultry mortalities if they make up 60 percent or more of the total silage. The feeding value of this sweetpotato-poultry silage for cattle will be determined.
Principal Investigator: James E. Shelton
The purpose o the project is to develop and evaluate a research filter-composting system and to construct a commercial system on an existing trout farm in Transylvania County. The chemical and physical properties of the compost will be studied and crop response to media using the generated compost will be evaluated.
A prototype wastewater filtering-composting facility constructed at the Mountain Horticultural Crops Research and Extension Center produced a high-quality compost from a feedstock of trout manure and wood chips. For complete monitoring of temperatures, the system was retrofitted with 18 thermocouples wired to a CR-10 Datalogger set to record hourly temperatures. The system is now being loaded for a second run of composting. A full-scale three-compartment system has been constructed on the Cantrell Creek Trout Farm and should be ready for loading soon. Trout processing waste has also been composted using wood chips as a bulking agent in an aerated static-pile composting facility with excellent results. Dwarf nandina, a woody ornamental, is currently being grown in the processing waste compost.
Current and impending provisions of the Clean Water Act pose a threat to trout production in North Carolina. Results of this project should enable trout producers to reduce nutrient discharge into nutrient-sensitive watersheds. Many landfills no longer accept trout processing waste, which is currently being stored and trucked out of state at the producer's expense. Based upon the success of the project, two trout producers have installed aerated static-pile composting systems for handling processing waste. Successful introduction of the technology being developed and implemented on trout farms should enable producers to meet federal and state regulations necessary for continued production while reducing waste handling costs and producing a marketable by-product for agricultural crop production.
Principal Investigator: Charles M. Williams
The referenced protocol has been developed. We are now working with scientists from other universities, including Drs. Ron Miner, Oregon State University, Dwaine Bundy, Iowa State University, and others to establish national testing procedures and a reporting format that can be used to provide consistent odor product information to food-animal producers. Evaluations of commercial products are in progress at the NCSU Animal and Poultry Waste Management facility laboratory.
This project will provide scientific validation of the efficacy of numerous commercial as well as test products, including chemical, enzymatic, and microbial additives for odor control.
Principal Investigators: James C. Barker and Joseph P. Zublena
This project will develop educational materials to assist livestock and poultry producers in improving their animal manure and waste management practices and comply with the nondischarge regulations.
Five informational fact sheets and a folder have been developed and distributed to all 100 county Cooperative Extension Centers. Fact sheets address specific livestock groups and concerns. Copies have also been sent to NCDEM and USDA-NRCS.
This project is expected to result in improved knowledge of and compliance with the North Carolina nondischarge regulations.
Principal Investigators: Greg D. Jennings and Richard A. McLaughlinz
The final phase of publication distribution to the users is currently under way. All other objectives have been accomplished.
Consistent, understandable, and up-to-date information will be available to livestock and poultry producers so that they can proceed toward writing a sound farm waste plan and having it certified and implemented by the deadlines imposed by the water quality rules.
Principal Investigators: James C. Barker and Joseph P. Zublena
The final phase of publication distribution to the users is currently under way. All other objectives have been accomplished.
Consistent, understandable, and up-to-date information will be available to livestock and poultry producers so that they can proceed toward writing a sound farm waste plan and having it certified and implemented by the deadlines imposed by the water quality rules.
Principal Investigators: Frank J. Humenik, P. Hunt (U.S. Department of Agriculture-ARS), Stephen W. Broome, and G. Scalf (Murphy Farms)
The purpose of this project is to evaluate alternative constructed wetland treatment systems for maximum nitrogen and phosphorus removal from swine wastewater.
Wastewater input and effluent from each of the two series cells and three wetland systems were evaluated from August 1993 to July 11, 1994, at a TKN loading rate of 3 kilograms per hectare-day (kg/ha-day). Since then, the systems have been loaded at 10 kg/ha-day. Currently, pretreatment and posttreatment overland flow and media filter units are being installed to obtain an aerobic-anaerobic treatment train for maximum phosphorus removal and nitrogen removal by nitrification-denitrification.
Evaluation at the low loading rate of 3 kg/ha-day did not result in a dischargeable effluent. Therefore, current work is focusing on using a constructed wetland as a component of a total waste treatment system for maximum mass removal of nitrogen and phosphorus to minimize the total amount of land required for swine waste treatment on farms with limited land. Constructed wetlands show a high capability for total mass removal of nitrogen which, if enhanced by a system that will increase nitrogen losses through denitrification, could result in reduced land requirements for the total treatment of swine waste.
Principal Investigator: Charles M. Williams
The project is scheduled to start in April 1995.
This project is expected to result in the development of a practical and cost-effective technology for drying and sanitizing poultry litter to be reused for poultry bedding. It will also establish the requirements, cost, and operating conditions for processing (drying) and reusing fluidized-bed dried poultry litter. Favorable results of this application should prove to be beneficial to the poultry producer because reuse of poultry litter will result in decreased operating costs while also meeting regulatory demands for recycling as opposed to land disposal of poultry production co-products.
Principal Investigators: Rodney L. Huffman and Philip W. Westerman
All field work and laboratory analyses have been completed. The final analysis of data and preparation of the final report are in progress.
The results of this work are very similar to those from an earlier study of older lagoons in the lower coastal plain. Roughly half of the lagoons show moderate to severe seepage losses -- that is, losses that contaminate groundwater in the surficial aquifer to levels above the drinking water standard for nitrate (assuming that all nitrogen forms are converted to nitrate). The only factor that has an obvious bearing on the seepage loss rate is the type of material used for lagoon construction. As seen in earlier work, many sites show very localized seepage that is probably moving in sandy lenses.
Principal Investigator: Jon M. Stucky
One natural wetland in Duplin County was selected and its vegetation characterized during the fall of 1994. Study of nitrogen and phosphorus assimilation by the dominant species in that wetland will commence during April 1995.
It is expected that this work will demonstrate for different species (1) those which are most abundant in natural wetlands receiving elevated nitrogen and phosphorus loadings, (2) the amounts of nitrogen and phosphorus assimilated from wetland sediments and retained in plant tissues, (3) the relative resistance to pathogens and herbivores, and (4) the ability to oxygenate sediment in the root zone, a mechanism that promotes nitrogen and phosphorus removal from wetland waters.
Principal Investigators: Greg D. Jennings and Deanna L. Osmond
The purpose of this project is to educate private property owners on environmental risks on the farmstead.
A series of worksheets is being developed to use in environmental assessment of farmsteads. The worksheets will be piloted in 1995 to test implementation procedures.
Farmers and other property owners will become aware of potential environmental risks on the farmstead and will take action to reduce risks to their water supplies and to the surrounding environment.
Principal Investigator: Evan E. Jones
The primary objective of this research is to produce a genetically engineered microbial species that has an increased efficiency in using ammonia for biosynthesis of citrulline and arginine. As an aside to the primary problem, the study will isolate strains of bacteria and yeast that can be used for fermentation of swine manure and will develop an aerobic thermophilic swine waste treatment process that will have application for the 1,200-sow farrowing unit, the 1,200-pig nursery, or the 1,200-head grower-finisher facility.
Funding for this project has been approved.
The amino acid arginine is essential for poultry and is required for the growth of young animals, including humans. The bacterial strain that this project will seek to produce would be able synthesize large quantities of arginine. The bacterium could also be incorporated into biofilters for purification of air within animal production buildings.
Principal Investigators: J. Wendell Gilliam, Robert L. Mikkelsen, and John E. Parsons
The dramatic increase in the amount of animal waste being produced has raised concerns regarding the impact of wastes on water quality. Most of this waste is applied to agricultural land where it may be subject to loss via runoff. Vegetative filter strips or riparian buffers between the receiving land and surface water may prevent contamination of water. Many questions remain about the effectiveness of vegetated buffers in removing nutrients, sediment, and potentially harmful bacteria. The effects of plant species composition within the buffer and the length of the buffer required for effective water treatment are all poorly understood. This research will lead to information needed to make accurate recommendations to growers, consultants, and regulatory agencies.
This work has been initiated only recently. The field equipment needed for water quality monitoring and the necessary laboratory expertise are now in place to complete this effort. Preliminary results should be available from the first "crop" within six months.
Various regulatory agencies are now advocating the use of vegetated filter strips for water quality improvement, although their effectiveness is still not accurately known. This study will result in information on design parameters for construction of buffers, their necessary length, their plant species composition, their seasonal effectiveness, and their relative removal of nutrients, sediment, and bacteria. This work will also result in a computer model useful in predicting the behavior of other managed and unmanaged vegetated buffer sites.
Principal Investigator: Philip W. Westerman
Research has been conducted at a swine farm in Sampson County for the past three years. During the first year no significant impact on ground-water was observed, but the irrigation application rates were relatively low because of establishing the grass stand. The second year showed no significant impact on groundwater, but there were some variations in nitrate and chloride concentrations in monitoring wells that may have resulted from irrigations. The yield of Coastal bermudagrass for hay was fair the second year, but intensive grazing was at only about 50 percent of the normally recommended level. The third year's data are being analyzed. It appears that there are some significant increases in nitrate and chloride concentrations in some monitoring wells. The farm management of the plots was less than desired the third year, particularly for the grazed plots.
Several million hogs are located in the coastal plain of North Carolina, and many of them are raised on farms that irrigate lagoon effluent. The proper application rate of effluent to ensure good crop performance while minimizing nitrate leaching to groundwater is not easy to determine because of variable crop uptake and variable losses by ammonia nitrogen volatilization, leaching, and denitrification. The protection of groundwater from nitrate leaching is an important issue for the swine industry, particularly in regions of sandy soils and high water tables. This research will provide information for one site regarding the crop, soil, and groundwater effects from irrigating at the normally recommended maximum rates for Coastal bermudagrass hay and intensive grazing.
Principal Investigators: Frank J. Humenik and Maurice G. Cook
The overall goal of this project is to encourage accelerated adoption of managemet practices and technologies that cost-effectively reduce impacts from the heterogeneous mix of activities and land uses on surface water and groundwater and result in documented water quality benefits.
Specific measurable objectives:
Many significant achievements have occurred in the four years of the project -- for example, increased grower adoption of nitrogen Best Management Practices (BMPs); development of nutrient management plans for 2,189 of the 2,700 acres of cropland in the watershed; reduction in nitrogen losses below the root zone of approximately 27 percent (EPIC model prediction); development of pest management plans for 1,578 acres of cropland; a total reduction in pesticide application of 242 pounds of active ingredients; development and demonstration of a state-of-the-art agricultural chemical handling facility; completion of waste management plans for all existing swine operations in the watershed; and evaluation and demonstration of a constructed wetland to treat swine lagoon effluent.
Reduced nonpoint-source pollution, improved water quality, and enhanced quality of life.
Principal Investigator: Robert W. Bottcher
This project is a new U.S. Department of Agriculture Regional Research Project (No. S-261) involving collaboration of researchers in 11 states, with a duration from December 1, 1994, through September 30, 1999.
Misting systems, for use in cool weather to increase indoor humidity during dry periods and precipitate dust out of indoor air, have been installed on two broiler farms. Data logging equipment has been installed and field trials are in progress on both farms to determine effects of cool-weather misting on indoor humidity, dust levels, energy use, and bird performance (weight gain, mortality, and feed conversion efficiency). Preliminary results show that the systems can eliminate periods when indoor relative humidity is below 30 percent.
Vertically directed air movers increased the floor area covered by high air speeds and improved bird performance in hot weather when used in field trials in naturally ventilated broiler housing. A large belt-driven paddle fan (8 feet in diameter) was developed and shown to provide excellent floor coverage with relatively high air speeds (over 200 feet per minute) but avoid excessively high air speeds (over 600 feet per minute), which could stimulate problematic bird migration. Discussions with fan companies are being conducted to determine their interest in further development; an invention disclosure covering variable-pitch paddle fans for this purpose has been filed at NCSU.
Other work being planned includes dust control in swine buildings using sprays of oil or water and analysis of ventilation system and wind environment effects on wind dispersion of odorous emissions from swine buildings.
Improved humidity control and reduced dust generation rates should be facilitated by the cool-weather misting systems. Precipitation of dust by mist and reduction of dust generation through humidity control are expected to be a relatively inexpensive approach to improving air quality in poultry buildings. Improved air mixing control in naturally ventilated housing should reduce energy costs now associated with tunnel ventilation, alleviate heat stress, entrain airborne contaminants in the ventilation airflow, and reduce temperature and humidity variation within the buildings. Analysis of wind dispersion of odors from swine facilities should reveal effects of ventilation system design parameters and atmospheric conditions on dispersion, and the effectiveness of chimneys or stacks for delivering ventilation exhaust to undisturbed wind.
Principal Investigator: Rodney L. Huffman
The project is slated to begin officially on March 1, 1995, and be completed by June 30, 1995. A preliminary investigation determined the configuration of the water table on the site around the lagoon. From that information, a sampling plan was devised to characterize both background conditions and the seepage plume.
This research is expected to verify that the seepage plume is contained in the surficial aquifer and discharges into Kirby's Creek, several hundred feet from the lagoon. It is unlikely that the discharge will materially affect nutrient concentrations in the creek.
Principal Investigators: Joseph P. Zublena and James C. Barker
An assessment was made in 1989. A similar assessment is under way and should be complete in March 1995 using a 1993 data base (the most complete data base available).
This research should lead to improved targeting capabilities for agencies and other interested parties dealing with animal waste management and the environment. It will also result in development of an enhanced data base on manure nutrient distribution.
Principal Investigators: Thomas J. Hoban and William B. Clifford
A statewide telephone survey was conducted in early 1994 with over 1,000 North Carolina producers. The sample included the following types of operations: poultry producers (n=441), swine producers (n=412), dairy producer (n=130), and beef producers (n=76). In the forthcoming project report, information is presented about producers' adoption of waste management practices as well as their attitudes about waste management and government policies. Differences in waste management practices and attitudes based on type and size of operation are also examined.
Results of this project have important implications for future research and extension education programs, as well as for public policy implications. The main outcome should be enhanced producer adoption of waste management practices, resulting in the control or prevention of problems associated with water pollution and odor.
Principal Investigators: James C. Barker and Joseph P. Zublena
All of the raw data have been collected and 80 percent have been summarized. The project should be completed by late spring of 1995.
The statewide nutrient assessment data will be geographically depicted and serve as a tool for
Principal Investigator: Greg D. Jennings
Water quality data have been collected at eight sites within the watershed since April 1993 under a nine-year grant funded by the U.S. Environmental Protection Agency. Best Management Practice (BMP) designs have begun for one dairy farm, one water supply critical area, and 4,000 acres of cropland receiving dairy waste.
Monitoring data will be used to quantify the effectiveness of BMPs, including dairy waste storage and irrigation, livestock exclusion, stream crossings, riparian buffers, nutrient management, pesticide management, erosion control, and streambank stabilization.
Principal Investigator: Robert L. Mikkelsen
The value of organic waste products for crop production is generally focused on the release of nutrients during the first growing season. There may be considerable year-to-year carryover of nutrients from organic compounds that are only slowly degraded. In fields that receive annual or semiannual applications of waste, the residual value of the slowly released nutrients can be significant. This multiyear study is designed to determine the long-term effects of organic waste for crop nutrition and nitrogen leaching through the root zone.
Two years of the five-year study have been completed. The organic nutrient source provides an excellent source of plant-available nitrogen. It is not yet possible to ascertain the long-term value of the waste for crop production. Nitrate leaching through the root zone has not yet been a concern when waste is applied at or below the recommended rates.
When completed, this project will provide improved estimates of nutrient release from organic waste for growers making regular applications. In cooperation with the N.C. Department of Agriculture, more accurate estimates of the long-term release of plant-available nutrients from waste can be made. More precise nutrient management can result in sustained crop production with a minimum of environmental degradation.
Principal Investigator: Philip W. Westerman
Laboratory and field studies have been conducted on the design and operation criteria for methane production in psychrophilic (low-temperature) environments. A demonstration site was established at Randleigh Dairy for a covered earthen digester. Part of the biogas generated was used in a boiler to heat water for the dairy. Another covered earthen digester was established on a swine farm.
Field and laboratory studies on ammonia volatilization from irrigation of swine lagoon effluent have been conducted. One field study also monitored groundwater near the irrigated plots.
Electromagnetic (EM) terrain conductivity surveys have been used to predict pollutant profiles, and groundwater seepage effects surrounding four lagoons were measured.
The laboratory and field studies on low-temperature anaerobic biogas (methane) production demonstrated that covered earthen digesters can be used to collect biogas for utilization. The retention times of flushed waste in the digester should be longer than in mesophilic digesters and shorter than in typical anaerobic lagoons.
The laboratory and field studies on ammonia volatilization indicated that most ammonia loss occurs during the irrigation, and relatively little occurs from the soil after irrigation. Typical losses during irrigation are 10 to 30 percent of the ammonia present in the lagoon effluent. Groundwater monitoring at one site receiving swine lagoon effluent for Coastal bermudagrass hay on one plot and intensive grazing of beef cattle on another plot did not show significant increases in nitrate in the first two years but has shown increases in some wells in the third year.
The electromagnetic terrain conductivity surveys were useful in detecting areas of seepage because of increased conductivity in such areas. Three lagoons constructed in sandy soil without clay lining have shown high levels of ammonia and other parameters in groundwater monitoring wells within 150 meters of the lagoon. Another lagoon constructed in soil with significant clay content did not have a noticeable impact on groundwater near the lagoon.
Principal Investigators: Joseph P. Zublena and James C. Barker
Several workshops have been conducted at which agents have been trained. Those agents are now conducting their own workshops. Producers have been made keenly aware that traditional methods that omit calibration are inaccurate and can negatively impact water.
This training program will improve manure management practices and decrease nonpoint-source pollution from manure nutrients.
<Principal Investigator: Fred R. Cox
Field experiments were initiated in the coastal plain and piedmont of North Carolina. The soils of the regions vary in clay content and thus have different phosphorus buffering capacities. Litter was applied at five different rates to establish a wide range in phosphorus. One rate of phosphorus from triple superphosphate was also applied for comparison with an inorganic source. Two experiments are in the piedmont, one of which is no-till and the other conventional tillage. Simulated rainfall is being applied to these studies twice each spring, once immediately after planting a row crop and the other about a week later after soil crusting. Natural rainfall is being measured at all sites, and runoff is being collected via automatic samplers from one replication of the conventionally tilled piedmont study and via single botles in the coastal plain study. Measured parameters include extractable soil phosphorus, soluble and total phosphorus in runoff, and plant phosphorus and yield.
The application of poultry litter will markedly increase the extractable soil phosphorus level. This increase will be compared with that from the inorganic phosphorus fertilizer on both the immediate extent and overall length of the effect. The increase in soil phosphorus will be less in the piedmont than in the coastal plain because of the greater phosphorus buffering capacity of the piedmont soil. Using no-till production practices will markedly reduce erosion compared to conventional tillage, thus keeping much of the phosphorus in the sediment on the land. The amount of phosphorus eroded from conventionally tilled land will increase with an increase in soil phosphorus and rainfall. This last point needs to be evaluated critically to determine the threat of overfertilizing with poultry litter to the point that soils become a source of phosphorus pollution to streams and lakes.
Principal Investigator: James W. Brown
The conversion of organic material to biogas during waste treatment is carried out by methanogenic Archaea (a.k.a. archaebacteria) during anaerobic digestion. It is not known, however, which species within this diverse evolutionary group of organisms are important in this process. Because the methanogenic Archaea are particularly difficult organisms to cultivate, the species that have been isolated in pure culture from sludge are unlikely to represent, even remotely, those that predominate in this environment and are important in the waste treatment process. This study, therefore, will use modern microbial ecology techniques that do not rely on cultivation to survey methanogen populations in samples of activated sludge taken from anaerobic digesters, identify predominant methanogen species, and attempt to isolate predominant species in pure culture for microbiological characterization.
The research has been initiated by a technician hired for this work. DNA has been extracted from samples of activated, methane-producing anaerobic sludge. This DNA is being purified further to reduce contaminants that, in the current partially purified sample, inhibit amplification of rDNAs by PCR. The yield of DNA has been sufficient for testing several purification methods, and the purity of the DNA (defined operationally) is being assessed by its ability to serve as a template in PCR reactions. Anaerobe, electrophoresis, and computing systems will be ordered and set up when project funds become available.
This project will permit the directed use of microbiology to improve the rate-limiting anaerobic digestion phase of animal and human waste treatment. The identification of the organisms that actually carry out methanogenesis during anaerobic digestion and knowledge of their phylogenetic relationship to cultivated species will make possible the cultivation of these species, the directed manipulation of the conditions present during anaerobic digestion to favor these species, and the eventual manipulation of the organisms themselves to maximize both mass reduction and biogas generation during anaerobic digstion.
Principal Investigator: John Richardson
The project has been completed. Experiences and information gained from the program continue to influence Extension program efforts.
The Extension workers who participated have a greater appreciation of the global nature of agriculture, the diversity of different populations, the importance of international trade, ways of incorporating an international component into educational programs, and the importance of the global perspective in farmer decision making. Specifically, Extension workers who participated in the program gained knowledge about other countries that are challenged with the environmental impacts of intense animal agriculture and what these countries have done to deal with those issues. This knowledge and information have been incorporated into ongoing Extension programs.
Principal Investigators: Robert L. Mikkelsen and Joseph P. Zublena
The purpose of this project is to determine the environmental impacts associated with nitrogen fertilization via swine lagoon effluent of grazed bermudagrass pastures. The input of nitrogen in the waste far exceeds the removal in the tissue and meat of the grazing animals. The nitrogen loss associated with leaching, plant uptake, and gaseous emissions are being measured to determine the long-term sustainability of this popular practice. The potential environmental impacts associated with excessive nitrogen application are being considered.
Two grazed pastures have been monitored during the growing season. The loss of nitrogen via denitrification and ammonia volatilization can result in significant losses under some conditions. Enhancing the conditions favorable for gaseous nitrogen loss can result in less nitrogen leaching through the root zone. The presence of swine-lagoon effluent, cattle urine and manure stimulates denitrification from soil nitrogen. Irrigation scheduling can also provide an important management technique to determine the loss pathways. A new aspect of the study has begun this year to look at how applying swine lagoon effluent affects field runoff and surface water quality.
The appropriateness of grazing cattle on irrigated bermudagrass pastures may be site specific. In some circumstances, the practice may be conducted effectively with no environmentally detrimental impacts. In other situations, significant losses of nitrogen may result in nitrate contamination of groundwater and surface water. The soil properties and the management techniques used will determine the sites on which this popular practice should be recommended and those on which it should be avoided.
Principal Investigators: Joseph P. Zublena, Steven C. Hodges, J. Paul Lilly, James C. Barker, and Robert A. Rubin
Training manuals and instructional materials have been developed and distributed to workshop participants. Three workshops have been completed for a total of 90 North Carolina Cooperative Extension Service (NCCES) agents. Three additional workshops have been completed for a total of 300 U.S. Department of Agriculture Natural Resource Conservation Service (NRCS) engineers and conservationists. One additional workshop each is planned for the NCCES, NRCS, and N.C. Crop Consultants in the spring of 1995.
To date, a total of 80 NCCES agents and 300 NRCS workers have successfully completed the nutrient management workshops and are approved as technical specialists by the North Carolina Soil and Water Commission to help develop and certify farm nutrient management plans required by the North Carolina Water Quality Nondischarge Rules. An additional 150 to 200 participants are expected for the upcoming workshops. The training of these technical specialists will maintain consistency and speed up the process of developing and certifying farm waste management plans.
Principal Investigator: Eric S. Miller
Laboratory research efforts are focusing on the processing of waste animal protein into either value-added by-products or, at the very least, into derivatives that are more rapidly recycled in the environment. The principal approach uses a proteolytic enzyme produced by the soil bacterium Bacillus lichenformis, which was isolated several years ago from an enclosed, anaerobic poultry waste digester. Progress has been made in studying the fundamental properties of the enzyme, with the intention of modifying the enzyme for increased activity. An important substrate degraded by the enzyme is waste feather (keratin), as well as other animal structural proteins. To date, (1) growth conditions of the bacterium have been modified for increased enzyme production; 2) the purification procedure for the enzyme has been modified and enhanced; (3) an antibody against the enzyme has been prepared for use in measuring its synthesis; (4) the substrate specificity of the enzyme has been evaluated using short, synthetic peptides; and (5) the binding and catalytic parameters of the enzyme on defined substrates is being determined. These growth and enzymology studies are performed in parallel with other projects funded by the USDA Competitive Grants Program that have resulted in the cloning and DNA sequence analysis of the "keratinase" gene (kerA).
Enhanced production of Bacillus licheniformis and processing of keratinase enzyme will benefit applications such as recycling feathers and waste proteins into usable amino acids. These molecules are of nutritional value as supplements in feeds or can be used in other industrial applications. As the keratinolytic enzyme is "engineered" for increased thermal stability, higher catalytic activity, or other properties, it should become of even greater value in waste processing, including on-site waste rendering processes. Proteases have extensive commercial applications and are likely to find increased usage in agricultural applications.
Principal Investigator: Charles M. Williams
To determine and optimize factors necessary for blending, enriching, and processing livestock and poultry manures for commercial use as amendments to provide carbon co-substrates and inorganic nutrients for the bioremediation of soil and/or groundwater contaminated with hazardous waste compounds.
The project is scheduled to begin in March 1995.
Principal Investigator: Charles M. Williams
Bench-scale thermophilic anaerobic waste digesters have been established and enriched for bacteria capable of metabolizing swine manure at 50C under anaerobic conditions. Methane is currently being produced under dilute waste loading concentrations (3%VS/10 d RT) in a daily volume approximately equal to the volume of waste contained in the digester. The VS loading rate is now being increased systematically and the retention time (RT) is being decreased to determine if microbial toxicity occurs. Results are being incorporated into proposed full-scale design parameters for retrofit of existing swine production facilities as well as new facilities.
This project will determine the feasibility of using thermophilic anaerobic digestion as an alternative manure handling and processing system capable of addressing environmental concerns, including odor, at swine production facilities.
Principal Investigator: Robert L. Mikkelsen
To determine the quality of processed and unprocessed food and animal wastes as a source of plant nutrients by using enzyme assays for prediction of nutrient release.
Funding for this project has been approved. A variety of organic wastes have been collected from across North Carolina, including animal wastes, industrial wastes, composts, and sludges, for use in this project. They will be thoroughly characterized to determine their important chemical and physical properties. This process must be completed before laboratory experimentation can begin.
If this assay can be developed successfully, landowners receiving organic wastes would be able to obtain timely information about the rate of nutrient release from organic materials. This information is not currently available without performing three- to four-month laboratory incubations. The new assay would reduce the time required to several hours. Using the new test, a waste analysis would provide information both on the nitrogen content of the wastes and the rate at which it will be released.
Principal Investigator: Jason C. H. Shih
This project was initiated February 1, 1995.
Principal Investigator: Philip W. Westerman
Funding has just been approved. Specifications for the purchase of a carbon-nitrogen analyzer are currently being developed.
Removal of solids from flushed swine waste will reduce the loading rate of the lagoon, which should lead to longer "life" of the lagoon before clean-out is required, or reduce the size of lagoon needed, thus reducing construction costs of new lagoons. Solids removal may also result in reduced odor potential from the lagoon because of reduced loading of organic solids that produce volatile organics with high odor potential. The solids that are removed from the flush liquid can be utilized as a soil amendment and fertilizer on the farm or transported (before or after composting) for utilization on the farm or elsewhere as a soil amendment and fertilizer, as a compost ingredient for animal mortality composting, or, after further blending or processing, as an animal feed ingredient.
Principal Investigators: Steven P. Washburn, James T. Green, Geoffrey A. Benson, and Greg D. Jennings
Evaluate the environmental and productivity impacts of pasture-based dairy farming systems.
The NCSU Lake Wheeler Road Field Laboratory Dairy Farm has been renovated to accommodate the research and demonstration center being supported by the U.S. Department of Agriculture Southern Region Sustainable Agriculture Research and Education program and the U.S. Environmental Protection Agency Agriculture in Concert with Environment Program. Two dairy farming systems will be monitored beginning in 1995. The conventional system consists of confined feedlot dairy management with feed and waste conveyed mechanically to and from the cows. The sustainable system consists of rotational grazing of various grass varieties supplemented with a small amount of grain. Monitoring will include milk production, cattle health, runoff water quality, manure deposition, and net farm income. Meetings, tours, and demonstrations will be used to promote sustainable dairy farming.
Monitoring data will be used to evaluate the effectiveness of sustainable dairy farming practices. Educational programs will increase the use of these practices across the state and region.
Principal Investigators: Jesse L. Grimes and Raymond W. Harvey
Research has shown that broiler litter can be separated into fractions, with some fractions having increased nutrient content and consequently enhanced value as a cattle feed supplement or plant fertilizer. In this project, turkey litter will be separated into fractions, enhancing its value as a cattle feed supplement. The objectives of the project are:
Several sources of turkey litter have been tested to determine the feasibility of separating the material into different fractions using both soil screens and air (fan) techniques. For those sources tested so far, the manure and shavings have been found to disintegrate at the same rate. Consequently, fractions separated by size also have nearly the same crude protein levels. For one source it was determined that manure and shavings of a certain size also had the same density, precluding separation by air. In the source tested most recently, the residue from the largest soil screen was separated by hand into two fractions, one containing shavings and the other large manure particles. (This source was composted.) Samples of these fractions are currently being analyzed for crude protein. If the manure particles are significantly greater in crude protein than the raw sample, there may be an opportunity to separate litter from this source into fractions using soil screens, resulting in a material suitable for the cattle-feeding portion of the study.
Litter separators will be constructed to determine the best method and type of unit for separating turkey litter. These units will be a shaker unit, a rotary drum unit, and an air (fan) unit. A working model will then be constructed to generate enhanced litter fractions for the cattle feeding trial. This unit will also be used in conducting on-farm demonstrations for the turkey industry. The cattle feeding trial will compare separated, enhanced turkey litter with accepted feed supplements.
Successful separation of turkey litter with enhancement for cattle feeding will increase the value of turkey litter. The portion of litter with increased nutrient content will have increased economic value to the producer as a cattle feed supplement for his or her own farm or as a co-product available for sale to cattle producers. The other portion(s) of litter may be available and suitable for reuse in turkey grow-out houses. This would decrease litter costs for turkey production and therefore also increase returns to the turkey producer.
Regardless of the turkey house clean-out schedule that a producer or integrator may be following, separation of litter into fractions according to nutrient and material content would provide a method of reusing turkey litter in an environmentally sound manner and would increase the value of turkey litter for the producer.
Principal Investigator: Evan E. Jones
The purpose of this project is to develop a system that can produce consistent materials to be used in value-added products for animal feeding and horticultural purposes.
Work during the first year is focusing on (1) developing a system to compost swine manure and peanut shells to a consistent product and (2) testing the physical and chemical properties of these materials for animal feeds and horticultural uses. Several pilot studies in which swine manure and peanut shells were blended in a compost mixture have been completed. After four days of digestion in the presence of air, the composted product had absolutely no trace of manure odor and had an aroma of freshly turned garden soil. The aroma was due to the presence of bacteria during the fermentation process. The composting process completely eliminated pathogenic microorganisms. Chemical analysis of the starting materials has been completed, and experiments are currently being conducted with different ratios of peanut shells to swine manure.
In the second year the materials produced under different recipes and formulations will be tested in value-added products in feeding and plant growth trials. In the third year studies will be conducted of the feasibility of transferring the technology and composting protocol of the proposed in-vessel system to alternative systems, such as windrows and static piles for on-farm or co-op use, without sacrificing product quality.
The results of this project should provide an alternative means for disposing of both swine manure and peanut shells. With the advent of organically grown vegetables for human consumption, the composted product could have economic value as a soil amendment and as a natural source of fertilizer.
Principal Investigators: Charles M. Williams, Jesse L. Grimes, and Joseph P. Zublena
This project was initiated in January 1995. Enrichment of bacteria for purposes of degrading petroleum hydrocarbons is in progress. Laboratory-scale evaluations to determine the correct concentration of poultry litter to be utilized in biotreatment landfarm applications are under way.
Principal Investigators: Jonathan R. Schultheis and Robert L. Mikkelsen
The purpose of this study is to determine the effectiveness of animal wastes, composts, and sludges as nutrient sources for sweetpotatoes.
A three-year study has shown that when sweet-potatoes are fertilized with organic nutrient sources, their yield, quality, and storability are similar to those fertilized with traditional inorganic fertilizer sources. This finding is encouraging because sweetpotatoes were previously thought to be adversely affected by the high concentrations of ammonium found in many waste products. Sweetpotatoes fertilized with some organic nutrient sources can be marketed as "organically grown" produce and may command a higher market price than traditionally grown sweetpotatoes.
This research will result in identification of another important North Carolina crop that can be used as a receiver of organic wastes. Crop performance is excellent (in terms of both quality and yield) when sweetpotatoes are fertilized with organic nutrient sources. When certified "organic" growing techniques are used, additional revenue may be obtained by marketing specialized produce to consumers.
Principal Investigators: Robert W. Bottcher and Evan E. Jones
This is a new project with a duration from February 1, 1995, through January 31, 1996. A pilot-scale biofilter has been constructed and is being tested to determine pressure demand for peat, as a medium, at various moisture contents. A master's degree student in biological and agricultural engineering is conducting the research.
Analysis of dust and other contaminants in the buildings will enable sizing of dust filtering and emission control systems (to match dust generation rates, for example) as well as quantifying potential benefits of dust control. Some by-products are expected to prove effective as biofilter media and would thus reduce biofilter system costs. Evaluation of dust filtering methods will show feasibility of incorporating dust filtering into biofilter designs and will indicate whether effective dust filtering in swine buildings under current conditions is feasible.
Principal Investigator: Michael G. Levi and John G. Richardson
To increase Extension Service agents' knowledge of waste management issues, legislation, and agencies dealing with waste management, and public policy issues related to waste management.
One hundred Cooperative Extension Service agents were trained in waste management and are using the information they learned to assist the communities in their counties in dealing with waste management issues.
This training program will enhance waste management capabilities in local communities. It will also enhanced the visibility of NCSU and the Cooperative Extension Service as a reliable source of waste management expertise and assistance.
Principal Investigator: Greg D. Jennings
Water quality and land use data are being collected in six watersheds representative of various physiographic provinces of the state and nation. The SWAT/GIS modeling system is being tested, modified, and applied in two of the watersheds to develop a procedure for selecting watershed management strategies based upon their predicted impacts on water quality. Strategies to be evaluated include nutrient and pesticide management, alternative cropping systems, riparian buffers, and in-stream wetlands.
Principal Investigators: Greg D. Jennings
Water samples from over 10,000 private wells have been analyzed for nitrate contamination. Screening programs are being planned for three counties in 1995.
Improved private well protection.