1a. Objectives (from AD-416):
Develop improved manure (swine lagoon effluent and poultry litter) application and management practices that reduce nutrient losses to the environment, increases utilization by crop plants, increase recycling of nutrients, and enhance soil quality. Determine and reduce bacterial pathogen levels in manured fields and assess impacts on soil fungal and bacterial ecology, including antibiotic resistance. Determine ammonia and greenhouse gas emissions from broiler houses and manured fields and develop management practices to reduce them. Evaluate the benefits and potential risks from possible new uses of manure and industrial byproducts (e.g. FGD gypsum).
1b. Approach (from AD-416):
Multidisciplinary approach will be utilized in converting “wastes” into valuable inputs for energy, forage, fiber, and grain crops. Presence, prevalence, and fate of nutrients, gaseous emissions, bacterial approaches, antibiotic resistance, and soil fungi associated with swine and poultry manure, municipal biosolids, and waste-impacted soils, plants, air, and water will be addressed. New uses of manure will be investigated, including swine manure for bioenergy crops, poultry litter for plant disease biocontrol, and litter with gypsum for remediation of degraded soil. Experiments employ a combination of traditional methods and state-of-the-art techniques and equipment. Work will be done in cooperator rearing houses and manure storage areas on confined animal feeding operations and in crop fields of manure end users. Contamination of soil, water, air, and plants from land application of manure and biosolids will be assessed and off-site transport of nutrients, pathogens, and antibiotic resistance will be determined. Information will be developed into best management practices to protect the environment and human and animal health by maximizing crop nutrient utilization, minimizing bacterial contamination and antibiotic resistance, reducing ammonia and greenhouse gas emissions, and exploiting biocontrol potential.
3. Progress Report:
Made the final application of poultry litter using two experimental subsurface banding methods of poultry litter application. Napiergrass biomass and uptake of nutrients averaged 3X greater than hybrid bermudagrass and removed 458 kg Nitrogen, 82 kg phosphorus (P), and 978 kg potassium/ha. Biomass yield and nutrient uptake from tall fescue and bermudagrass mix were greatest when poultry litter was provided in either January and September or January and March. Aerosol samples collected from downwind of broiler litter land applications were processed for endotoxin, viable bacteria, and bacterial genes. Samples collected from abandoned mines in Kentucky were processed for bacteria and bacterial genes. Antibiotic resistance characterizations were conducted on isolates from mortality compost, land applied fecal wastes, and newly established broiler houses. Swine mortality composts were tested for effects of aeration and supplemental nitrogen (N), from poultry litter and swine lagoon effluent: levels of nutrients, zoonotic bacteria, and gaseous emissions. Emissions of ammonia and greenhouse gases were evaluated in a commercial broiler house, from corn crops having precision and novel poultry litter/industrial byproduct applications, from novel swine composts. The research provides baseline emission data and prospective avenues for mitigating these pollutants in confined animal feeding operations, in fertilizer utilization and in production of value-added products from animal wastes.
1. Antibiotic resistance as a function of time. Antibiotic resistant bacteria in broiler and other animal feeding operations (AFOs) are influenced by antibiotic use, transfer from outside the operation, and vertical carriage through hatching and birthing procedures. Once present in a newly established poultry AFO, antibiotic resistance can spread rapidly within a house and to other houses located on the farm, subsequently affecting thousands of birds. Scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, traced the colonization of antibiotic resistant Salmonella in two newly established broiler AFO houses. Salmonella was cultured from litter collected throughout the two houses and was found to establish and colonize within the first 3 weeks of operation. Salmonella genotypes within the new houses were relatively few and uniform at the start of operation, but expanded, becoming more diverse with successive flocks, and stabilized by the third flock. Concurrently, antibiotic resistance, measured using the Kirby-Bauer plate diffusion assay, continued to increase to include greater numbers of antibiotics, as the Salmonella population began to stabilize. This research demonstrates that a pathogen, such as Salmonella, can quickly colonize a new poultry AFO through horizontal and vertical transfer from other older houses located on the farm and through the hatching and birthing process, respectively. Likewise, the presence of antibiotic resistance, despite no perceived use of antibiotics, can increase rapidly as a dominant population establishes itself.
2. Mortality compost mixtures characterized. Disposition of mortalities challenges animal feeding operations (AFOs), especially swine farrowing farms. In the Mid-South U.S. where local considerations preclude incineration and high costs make rendering impractical, swine AFOs practice mortality composting in sawdust, an industrial byproduct that is available at the cost of hauling, and which provides a suitable C matrix, but poor nitrogen (N) source. Scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, compared and analyzed sawdust composting mixtures which included additional N from broiler litter and swine lagoon effluent. Temperature, water content, and gaseous emissions (ammonia, carbon dioxide, methane, and nitrous oxide) were measured during composting. Changes in levels of nutrients Carbon (C), N, Phosphorus (P), Potassium (K), Magnesium (Mg), Manganese (Mn), Sodium (Na), Copper (Cu), Zinc (Zn) and zoonotic bacteria (Clostridium perfringens, Escherichia coli, Listeria spp., Salmonella spp., and staphylococci) were also measured. Composting offers environmentally sound disposition of these agricultural and industrial byproducts and manures, and the potential for retaining desirable nutrients and reducing undesirable bacteria.
3. Ammonia losses from poultry litter amplified near watering lines. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, quantified ammonia generation from litter in commercial broiler houses near sidewalls, feeders, and watering lines. Ammonia release to the atmosphere is an environmental concern with potential negative effects for air quality (particulate formation), terrestrial life (decreased ecosystem diversity), and water resources (eutrophication). Reductions in ammonia losses of 38 to 77% can be achieved if litter near watering lines is managed similar to litter near feeders and sidewalls. Practical application to reduce ammonia on the farm includes zone treatment during the middle of the flock and appropriate attention to watering line management, two management techniques which can be easily adapted by farmers.
4. Recommendations for litter moisture and ammonia control in broiler houses conveyed to growers. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, discovered the critical litter moisture content where ammonia generation is maximized. Simple techniques were communicated via a popular article showing how to measure litter moisture and barn ammonia concentration in order to know if improved litter management is needed. House management solutions to limit unnecessary water inputs to litter were provided. Growers and integrators can use this information to produce healthier birds, reduce environmental concerns due to ammonia release, and to improve profits.
5. Ammonia captured by activated carbon derived from broiler litter. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, cooperating with Louisiana State University and ARS Commodity Utilization Research Unit in New Orleans, LA, used activated carbon made from broiler litter to absorb ammonia generated from broiler litter. National air quality regulations require reports for ammonia emissions of 100 pounds per day, a level which may affect large animal production facilities. The litter activated carbon reduced emissions by 25% in a laboratory study. The results show the prospective cyclical waste utilization in using broiler litter activated carbon to mitigate ammonia emissions from broiler facilities.
6. Poultry litter persists longer if applied in subsurface bands than surface broadcast. Unlike synthetic nitrogen fertilizers, poultry litter and other manures persist in the soil beyond the year of application. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, in cooperation with researchers at other ARS locations and Mississippi State University found that this persistence is greater if the poultry litter is applied in shallow bands below the soil surface than as surface broadcast. Cotton planted in soil that had received poultry litter in subsurface bands two years prior produced more lint than cotton planted in soil that received the same amount of litter by surface broadcast. The results suggest that the nutrients from litter applied two years prior to planting cotton were conserved in the soil longer when applied in subsurface bands than as surface broadcast. Applying poultry litter in subsurface bands is an efficient method and may reduce cost of production and increase profit for cotton and other row crop farmers in the southern and southeastern U.S. where the majority of poultry litter is generated.
7. A new soil sampling method for fields that received manures in bands. No effective method of soil sampling exists to characterize the nutrient status of a field that received manures or other bulky fertilizer materials in shallow bands. The conventional random soil sampling method is not appropriate for such fields because the distribution of nutrients across the field is not even or random. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, in cooperation with researchers at other ARS locations and Mississippi State University developed a new method for taking soil samples that accurately represent the fertility level of a field following manure application in narrow bands below the soil surface. The method involves taking several soil cores at predetermined distances from the manure band including one core directly over the band using standard probes and taking one sample following proportional mixing of soil from each core. The number of cores taken between the bands depends on the band width and the spacing between consecutive bands. This method has the potential to be an important tool for practitioners and researchers when it is necessary to accurately measure the fertility level of a field that has received manures in bands.
8. Years to restore and improve surface mined soil quality determined. The time required, for an effective soil reclamation process in the southeastern U.S. to restore the quality of degraded coal mine land to its pre-mined conditions, is unclear. In order to understand the sustainability and functionality of an agro-ecosystem in a reclaimed coal mine soil, it is important to characterize the soil quality indicators and to understand how these indicators change and improve with years after reclamation. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, evaluated the effects of age chronosequence on restoration quality of degraded coal mine soil under different land use and landscape positions and found the current reclamation practices used by one mine improved major soil quality indicators to levels similar to those of pre-mined soil in 7-12 years. The quantity of indicators were greater under grass than under forest vegetations, indicating soil Carbon (C) and Nitrogen (N) pools in degraded coal mine soil are restored faster under grass than under forest ecosystem. The information obtained is useful to the mining industry, reclamation planners, regulators, and landowners in accelerating establishment of healthy and sustainable post-mining ecosystems.
9. Leaching losses reduced by adding industrial by-products to poultry litter. Application of poultry litter to agricultural soils can enhance soil fertility and productivity but little is known about the comparative loss of fresh and composted litter. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, evaluated the effects of fresh and composted litter on nutrient leaching losses in the presence of a low cost coal combustion by-product Flue Gas Derived (FGD) gypsum. Cumulative amounts of Phosphorus (P), Copper (Cu), and Zinc (Zn) losses in leachate from soil amended with compost were 51% less than those amended with fresh litter and the use of gypsum with both types of poultry litter reduced nutrient in the leachate and sustained or increased crop productivity. The technique could be used in nutrient management practices to estimate nutrient fate and dynamics in soil/water systems.
10. Industrial by-products reduce ammonia volatilization. Ammonia volatilization and nutrient losses are major forms of environmental pollution associated with land application of animal manures as fertilizers. Both of these problems might be controlled by the use of cost effective Nitrogen (N) and Phosphorus (P) immobilizing agents. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, quantified the role of immobilizing agents on NH3 emission and losses of nutrients from broiler litter and indicated ammonia emissions were reduced by 30% when zeolite (a microporous aluminosilicate mineral commonly used as commercial absorbent) was used with litter. Flue Gas Derived (FGD) gypsum used with broiler litter also reduced water soluble N, Carbon (C) and P by 83, 71 and 53%, respectively. The results appear to provide good information for the growers in protecting nutrient contents of poultry litter from loss that are essential for plant growth or that may pose environmental hazards.
11. Broiler litter use improves reclamation of soils at a lignite coal mine. ARS scientists in the Genetics and Precision Agriculture Research Unit at Mississippi State, MS, discovered that applying 10 tons broiler litter per acre the first year of seeding of forage to newly re-spread surface soil and applying 5 tons the second year increased forage dry matter yields, as well as, soil levels of Phosphorus (P), Potassium (K), and Sodium (Na) compared with commercial fertilizer of swine effluent. Addition of Flue Gas Derived (FGD) gypsum did not improve yields. The potential impacts include more rapid soil stabilization during land reclamation and additional markets for broiler litter for poultry producers in Mississippi.
Brooks, J.P., McLaughlin, M.R., Gerba, C.P., Pepper, I.L. 2012. Land application of manure and class B biosolids: an occupational and public quantitative microbial risk assessment. Journal of Environmental Quality. 41:2009-2023.