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MSU Research Addresses Animal Waste Management
MISSISSIPPI STATE -- Livestock producers, especially those involved in swine, dairy, and poultry operations, are seeking answers from Mississippi State University researchers about the proper storage and use of animal waste as a soil nutrient.
Mississippi Agricultural and Forestry Experiment Station scientists are looking for methods Mississippi producers can use to manage animal wastes and allow animal industries to grow in an environmentally friendly manner. Research efforts draw on the resources of animal scientists, agronomists, agricultural engineers, agricultural economists, statisticians and chemists to find solutions that will benefit agriculture and the environment.
"One of our goals is to have environmental research that will help create a more sustainable agriculture by showing producers how to farm profitably in harmony with the land, water, people and animals," said Dr. Nancy Cox, assistant director of MAFES.
Proper animal waste management uses an important source of nutrients for crop and forage production with minimal negative impact on the environment. If not managed properly, animal wastes from concentrated hog, beef, dairy and poultry operations can affect the farm site and water quality, as well as human health.
Many states enacted requirements for large operations during the past legislative sessions. The federal government is also examining its regulations. Research is needed on the contribution of all sources of potential contamination including municipal waste, fertilizer, urban runoff and animal agriculture.
The choice of sawdust or sand bedding presents a dilemma for many dairy producers. Sand bedding can be superior to sawdust, but it can prematurely fill dairy waste lagoons if not properly trapped and removed. Lagoons filled with sand have reduced treatment capacity and many producers are not aware of the high costs of removing accumulated sand.
Dr. Tim Burcham, assistant professor in Agricultural and Biological Engineering, leads a multi-disciplinary team of researchers examining the impact of sand bedding on the dairy lagoon system. Burcham's research team has constructed a manure/sand solids separation facility at the Experiment Station's Bearden Dairy Research Center in Oktibbeha County.
"This research will help identify management procedures and specific equipment needed to effectively remove sand bedding from the waste stream as it flushes from the barn but before it gets into the dairy lagoon," Burcham said. "Overall, our findings indicate those dairy producers using sand bedding need to use a gravitational settling basin in their waste treatment system to prevent sand from accumulating in the treatment lagoon."
Mississippi produces about 280,000 swine a year. The larger farms generally confine and feed 8,000 to 10,000 hogs in concrete-floored barns and flush their waste into lagoons. The waste then is sprayed onto hay fields as liquid fertilizer. Stringent restrictions for applying waste to land help protect the groundwater and reduce the offsite odor.
Burcham and MAFES agronomist Dr. Jac Varco are examining the impacts of runoff from agricultural lands irrigated with swine lagoon effluent. Additionally, Varco's research focuses on the cycling of nutrients in a forage production system.
Varco said an important finding for the research was determining acceptable rates for applying effluent to crops.
"This research shows that effluent serves as a very good nutrient source as well as providing some irrigation water," Varco said.
Another research team is examining the impacts of poultry-waste management practices on soil, water and crop quality in Mississippi. A broiler house can produce more than 100 tons of waste, or litter, every 18 to 24 months.
Along with other animal wastes, poultry litter is an excellent fertilizer because of its nutrient content. The majority of the waste in Mississippi is applied to pastureland. A concern is that continual application over a number of years could increase levels of nutrients in nearby sources of ground and surface water.
Data are being collected on the runoff of waste-associated nutrients. These are being used to develop management programs to reduce the possibility of water contamination and to determine poultry-waste application rates that better protect water quality.
Preliminary results from a field study suggest that some practical soil and water conservation measures will help producers in nutrient-management planning.