Location: Food Animal Environmental Systems Research
2020 Annual Report
Objectives
Obj 1: Enhance the benefits of using animal manure as means of improving soil productivity for longterm production systems. 1.1 Improve soil health/quality through a longterm mngmnt practice involving animal manure, cover crop, & crop rotation. 1.2 Determine if poultry litter application timing (fall/spring) & cover crop (cover crop/no cover crop) affects on corn N use efficiency & yield. 1.3 Develop improved models for describing phosphorus cycling in soils amended with animal manure. 1.4 Develop an energy-efficient & cost-effective method of capturing ammonia from animal facilities & subsequent usage as fertilizer. 1.5 Evaluate poultry litter application on the incidence of Clostridium botulinum in haylage forage harvest systems & stand persistence. 1.6 Improve sustainability through a management strategy using cover crop grazing & animal manure to improve soil quality & fertility while increasing grain & livestock production. 1.7 Combining a multi-proxy investigation of agricultural contaminant transport in Karst groundwater systems & informal education to improve stewardship & best management practices.
Obj 2: Develop strategies for managing the survival & transport of antibiotics, pathogens & indicator species through agroecosystems. 2.1 Determine whether biochar-amended sand filters are an effective management practice for removing pathogenic & indicator microorganisms from tile drainage waters. 2.2 Characterize persistence and transmission of antibiotics, antibiotic resistance (AR) genes, AR mobile genetic elements and AR bacteria through agro-ecosystems. 2.3 Determine factors controlling adhesion & survival of manure-borne pathogens in manured soils & on crops & identify mitigation strategies. 2.4 Develop of methods for measuring antibiotics in agricultural samples & the correlation of the presence of antibiotic resistant bacteria. 2.5 Develop a strategy for rapid detection & deletion of antibiotic resistance genes using DNA-binding domain based nucleases.
Obj 3: Assess gaseous & particulate matter emissions resulting from animal prod. facil. & manure application sites. 3.1 Develop methods for the determination of VOC that contribute to malodorous emissions from field applied manures & use these methods to compare emissions from different manure application methods to field crops. 3.2 Obtain field measurements of the temporal variability of gas & particulate matter emissions. 3.3 Determine the fate of atmospheric N and sulfur emissions from agricultural systems. 3.4 Measure & model the fates of VOCs, PM, & GHGs from agricultural systems. 3.5 Model the chemical partitioning of N compounds between gas & particulate phase.
Obj 4: Improve production efficiency & emissions management of renewable bioenergy production systems using technologies such as anaerobic digesters. 4.1 Investigate biogas production and substrate utilization of poultry litter & use microaeration to improve biogas production. 4.2 Optimize anaerobic digestion of poultry wastes to reduce emissions & obtain bioenergy for sustainability. 4.3 Develop novel & cost-effective composite alginate filter materials to capture ammonia, GHG, odors from livestock prod. facil.
Approach
This project was conceived as a cooperative/partnership and comprehensive research program between ARS and Cooperator. The project is designed to utilize the scientific expertise and facilities of both institutions to conduct problem-solving research related to animal waste management in Kentucky and the southeastern U.S. Through a series of innovative, cooperative research experiments at the animal production facilities and manure application sites, we will investigate manure microbial and nutrient losses as gas and through runoff water and odorous compounds from land and animal production sites. We will also determine levels of these compounds/contaminants in manure, application sites, and loading rates in agroecosystems. We will also investigate and find solutions to the environmental and agronomic problems such as nutrients, pathogens, greenhouse gases (GHGs), ammonia, odor-causing VOCs, particulates, dust, and sediment associated with animal production facilities and manure application lands. This will be accomplished based on new knowledge gained through the multidisciplinary approaches and the expertise of the scientists at this location through basic and applied research in the laboratory and in real farming sites and animal production environments. We will use the research results and develop best management practices (BMPs) for crop production on land receiving animal manure with regard to manure application timing, rate, nutrient, and loss of hazardous compounds within the agroecosystem of the unique “karst topography” common to this region. The research effort will be multi-disciplinary and multifaceted in support of decision making and systems development. Information generated from this research will be integrated into regional and national databases and statistical models to contribute towards improved environmental quality, sustainability, and economic viability of farms.
Progress Report
The research conducted under the objectives/sub-objectives of the project plan addresses environmental and agronomic problems related to the use of animal manure and other agricultural waste including nutrients, pathogens, greenhouse gases (GHGs), odor causing volatile organic compounds, dust and sediment associated with animal production facilities and manure application sites. The research also determines best management practices (BMPs) for crop production on land receiving animal manure and agricultural waste with regards to crop management and soil types particularly in unique “karst topography.” Following are research related activities and progress for the past year:
1. Laboratory analysis is ongoing to evaluate the impact of organic fertilizer as soil amendment on the antimicrobial resistance of bacteria cultured from soil samples. Longitudinal experiment consisting of poultry litter, commercial fertilizer and untreated control plots was conducted on cornfield for 172 days post treatment applications spanning the entire corn cropping and growing season. A total of 576 soil samples were collected on six occasions. Samples were cultured for quantification and detection of generic-, tetracycline resistant- and third generation cephalosporin resistant- Escherichia coli, generic-, tetracycline resistant- and macrolide resistant- Enterococcus species, extended spectrum beta-lactamase producing bacteria, carbapenem resistant enterobacteria. These bacteria are being confirmed by polymerase chain reaction (PCR) and targeting specific DNA sequences and characterized for their antimicrobial resistance using susceptibility testing and by PCR to detect genes responsible for resistance.
2. Laboratory analysis is underway for Subobjective 2.3 to evaluate the impact of continuous in-feed use of tylosin, an antimicrobial compound, in feedlot cattle on the antibiotic resistance of bacteria isolated from the fecal samples of cattle. A cohort of weaned calves was randomized at arrival at feedlot to receive tylosin medicated feed (10 calves) or non-medicated feed (10 calves). Animals were followed for about a year during which feces from the rectum, manure from pen-surface and animal feed were collected and cultured for antibiotic resistant Enterococcus species and E. coli. Bacterial isolates are being confirmed by PCR and further characterized for antibiotic resistance using susceptibility testing and PCR to detect genes responsible for resistance.
3. Animal manure is often applied to agricultural fields to add nutrients and organic matter to the soil to enhance soil quality and fertility. Manure, however, can also be a source of pathogenic microorganisms that pose a threat to humans. Because tile drainage significantly alters field hydrology, when manure is applied to tile-drained fields, the movement of pathogens from agricultural fields to drinking water can be greatly enhanced. Research is ongoing to investigate the potential of using biochar – a charcoal-like material generated during the pyrolysis of biomass – as an amendment to sand filters as a management strategy for removing pathogenic and indicator microorganisms from tile-drainage waters. Laboratory experiments are being conducted to determine the best combination of biochar concentration and sand grain size for maximizing both retention capacity and flow. Results indicate that the addition of the biochar reduces the transport of E. coli and Salmonella through laboratory-scale biofilters and that the amount of retention is strongly dependent on biochar application rate. Results also show that sand size is a strong determinant on the ability of the biochar to retain bacteria, with retention decreasing with increasing grain size. Current research is investigating whether treating biochar with iron-hydroxides can increase retention of bacteria in biochar-amended sands. Preliminary results indicated that iron-coated biochar can increase bacterial retention in sand-packed columns by several orders-of-magnitude compared with untreated biochar.
4. Two pilot-scale anaerobic digester/sequencing batch reactor wastewater treatment systems have been successfully operated for the last 15 months under prevailing weather conditions. One of the systems has been operated exposed to sound from an underwater speaker system developed by unit researchers to enhance sludge degradation, and the other operated as a control. Overall, the system exposed to sound has produced 44% more biogas than has the control system and has been capable of producing biogas at lower temperatures than has the control system. Sludge degradation has been enhanced in the system exposed to sound, which at least partially explains the enhanced gas production. Collaborations with ARS scientists in Florence, South Carolina, are ongoing to exploit bacteria associated with anaerobic ammonium oxidation (Anammox) to reduce ammonium from the wastewater. Utilizing wastewater effluent from the system, Anammox bacteria have been acclimated and have shown ability to greatly reduce nitrogen levels.
5. Data analysis on gas and particulate data from all field sites are completed. Two papers are submitted on sampling from Utah, as well as one from a poultry house. Three other papers being prepared on gas and particulate data from a poultry house, a mink house, and comparing several different facilities (poultry, dairy, swine). (Objective 3)
6. Analysis of the data from the most recent set of experiments at the University of California, Riverside, is complete. Two publications are under consideration at journals currently from this topic. Three more are currently in preparation. (Objective 3)
7. Continuing field study in monitoring and optimization of methane production from an anaerobic digestion system (15 million gallons) of poultry litter mixed with food wastes, and evaluation of different lignocellulosic enzymes on biogas production from recalcitrant livestock waste feedstocks. Copolymer hydrogel impregnated with nanoparticles was studied to examine its feasibility in air pollution reduction and delivery of enzyme treatment. In addition, a pilot-scale sequential filtration-scrubber system (8000 L) to utilize nanoparticles and nanofibers from agricultural residues for agricultural air pollution mitigation is in progress. Evaluation of nanotechnology in antimicrobial and odors reduction in livestock production is ongoing.
8. Research activities (soil, plant, and manure sampling and analyses, planting, harvesting, etc.) continued on two field experiments under Objective 1. The crop rotation, cover crops, and timing of manure subsurface application are being studied to investigate how maximizing the soil health management practices can improve soil’s physical, biological, and chemical properties. Cover crops were rolled down or killed by chemical application prior to the planting of the next rotation crop. We began to process the collected data for manuscript preparation for publication in scientific journals.
Accomplishments
1. Tetracyclines persist in the animal manure after anaerobic digestion. Microbial digestion of animal manure in the absence of oxygen, while also producing renewable energy, is a promising technology for the management of animal manure. Antibiotics in the animal manure exert selection pressure on native soil bacteria leading to propagation and spread of antibiotic resistant bacteria contaminating surface waters through run-offs from animal manure amended soils. ARS scientists in Bowling Green, Kentucky, in collaboration with a researcher from Western Kentucky University, investigated the effect of anaerobic digestion on the removal of tetracyclines in cattle, poultry and swine manure. Manure samples collected from farms in Kentucky were spiked with chlortetracycline, oxytetracycline, and tetracycline and digested for 64 days. Results indicate that degradation rates and persistence of the tetracycline antibiotics depend on the animal species and affected by the organic and metal contents of the manure. The antibiotics degraded fastest in cattle manure and persisted longer in the poultry litter, which also had the highest concentrations of organic matter and metals. Although the levels of the three tetracycline drug concentrations reduced from their original concentrations as a result of anaerobic digestion, they were not completely eliminated. This study suggests that anaerobic digestion must be tailored for each animal species, and that longer duration is required to effectively remove antibiotic residues and to reduce its environmental impacts.
2. Identified important limitations with a commonly used method for estimating maximum phosphorus sorption capacity of soils. The maximum phosphorus sorption capacity of a soil is an important parameter controlling phosphorus availability to plants and the release of soil phosphorus to water during runoff and leaching events. The maximum sorption capacity is often measured using time-consuming methods, called sorption isotherms. Alternately, another method called the single-point P sorption index requires much less time and effort to measure and is often used to estimate maximum soil sorption capacity. While studies have found good correlations between single-point sorption index and phosphorus sorption capacity as determined by more sophisticated methods, a thorough analysis of the efficacy of this parameter for estimating sorption capacity of soils has not been thoroughly investigated. Research at Bowling Green, Kentucky, focused on comparing the single point index with maximum phosphorus sorption capacity using computer simulations and experimental data collected from agricultural soils. Results from this research show that the concentrations traditionally used for calculating the single-point index can potentially result in large errors when estimating sorption capacity. Results also show that by doubling the concentration, the correlation improves significantly. Results from this research are expected to lead to modifications in how the single-point sorption index is measured when it is used as a surrogate for phosphorus sorption capacity.
3. Testing of phosphorus saturation indices for predicting phosphorus in soil solution. In response to concerns over elevated phosphorus (P) concentrations in surface waters across the world, there is high demand for developing simple indicators for evaluating a soil’s risk of releasing P into solution. The degree of soil P saturation – calculated from the ratio of soil P concentration and soil sorption capacity – is a commonly used indicator. Various methods exist for estimating both soil P concentration and P sorption capacity. Research at Bowling Green, Kentucky, in collaboration with the Swedish University of Agricultural Sciences, investigated the accuracy of different methods for calculating the degree of soil P saturation with the goal to find an inexpensive and readily available method to predict release of P into soil solution. Correlations between different estimates of P sorption capacities and measures of soil P saturation were investigated for soil samples representing a wide range in texture, phosphorus content, and sorption capacity. Results from this research show that each of the P saturation indices were similarly correlated with dissolved phosphorus, and thus each can be used for estimating degree of P saturation for predicting risk of P loss from soil. This research enhances our understanding of the factors controlling P loss from agricultural soils. Results from this research are expected to guide policymakers in Sweden for adopting indicators for identifying soils with high risk of P loss.
4. In situ acoustic treatment of anaerobic digesters to improve biogas yields. Sound at audible frequencies can increase biogas yields and enhance the degradation of sewage sludge. To assess this potential, two wastewater treatment systems were constructed, one acting as a control and one with a novel system composed of a specially developed waster proofed sound system and hydrophones to monitor the system. Sounds used to treat the wastewater were sine waves, broadband noise, and orchestral compositions. Weekly biogas production from sound-treated digesters was 18,900 L, more than twice that of the control digester. Background recordings from the sound-treated digester were louder and had more conventional events than those of the control digester, which we ascribe to enhanced microbial growth and the resulting accelerated sludge breakdown. Acoustic cavitation, vibrational energy imparted to wastewater and sludge, and mixing due to a release of bubbles from the sludge may all act in concert to accelerate wastewater degradation and boost biogas production.
5. Synthesis of silver nanoparticles from bitter melon extracts and their effectiveness on agricultural pathogens. Antibiotic resistant microorganisms are on the rise in the environment due to the increasing use and/or inappropriate use of antibiotics in human medicine and livestock production. Nanoparticles with antimicrobial properties along with medicinal plants hold a great promise in this arena, especially nanoparticles that can be synthesized from eco-friendly methods. Scientists from Bowling Green, Kentucky, along with researchers from universities in South Korea and Mexico carried out silver nanoparticle synthesis mediated from bitter melon extract as a model to utilize and examine the level effectiveness of these nanoparticles against agricultural pathogens in solution. The results show that these silver nanoparticles are effective against agricultural pathogens such as Escherichia coli. Synthesized silver nanoparticles have increased potency against E. coli in optimum culture media in comparison to silver ions alone. Silver nanoparticles treated microcosms achieved 100% killed in less incubation time and lower dosage than bulk silver ion. Based on these findings, the current method can be suitable for the industrial scale production of silver nanoparticles from a commonly available edible plant with known medicinal benefits in a fight against agricultural pathogens that could harbor antibiotic resistance genes.
6. Improving biogas production from high lignocellulosic agricultural wastes via different operating parameters. Agricultural wastes with high lignin and cellulosic contents, such as woody plants (tomatoes and peppers), can serve as the feedstock for biogas production (mainly methane) that could be used as an alternative energy source. However, these high lignin and cellulosic feedstocks are quite recalcitrant to be readily utilized by methanogens to produce beneficial biogas, methane. Therefore, a pre-treatment and change in digestion parameters are necessary to improve biogas production from these materials. In this study, scientists from Bowling Green, Kentucky, and University in Mexico carried out an evaluation of various enzymes, substrate and inoculum ratios, temperatures on methane production from crop residues with high lignin and cellulosic materials. Aerobic and anaerobic batch reactors containing different mixtures of fungal enzymes, operating temperatures, different inoculum feedstocks were set up to evaluate methane production. The results showed that more methane production was observed from feedstocks with enzymatic pre-treatment, higher operational temperatures, and medium substrate to inoculum ratios. Thus, biological pre-treatment of recalcitrant feedstock helps improve biogas production along with higher operating temperatures and low inoculum ratios.
Review Publications
Sarr, S., Gebremedhin, M., Coyne, M., Tope, A., Sistani, K., Lucas, S. 2019. Do conservation practices bring quick changes to key soil properties for resource-limited farmers. Journal of the Kentucky Academy of Science. 80(1):6-16. https://doi.org/10.3101/1098-7096-80.1.6.
Gebremedhin, M., Sarr, S., Coyne, M., Sistani, K.R., Simmons, J.R. 2019. The combined influence of cover crops and manure on maize and soybean yield in a Kentucky silt loam soil. Sustainability. 11(21):6058. https://doi.org/10.3390/su11216058.
Gebremedhin, M., Sarr, S., Coyne, M., Freytag, A., Sistani, K.R. 2020. Does potentially mineralizable nitrogen predict maize yield in newly cropped soil. Agrosystems, Geosciences & Environment. 3(1). https://doi.org/10.1002/agg2.20023.
Hiko, A., Agga, G.E., Brautigam, L., Irsigler, H., Ameni, G., Reinhard, F. 2019. PFGE XbaI® Indistinguishable properties of Salmonella Kastrup and Salmonella Larochelle isolates at beef processing and distribution continuum. Ethiopian Veterinary Journal. 23(2):1-12.
Agga, G.E., Raboisson, D., Walch, L., Alemayehu, F., Semu, D.T., Bahiru, G., Woube, Y.A., Belihu, K., Tekola, B.G., Bekana, M., Roger, F., Waret-Szkuta, A. 2019. Epidemiological survey of peste des petits ruminants in Ethiopia: Cattle as potential sentinel for surveillance. Frontiers in Veterinary Science. 6:302. https://doi.org/10.3389/fvets.2019.00302.
Kasumba, J., Appala, K., Agga, G.E., Loughrin, J.H., Conte, E.D. 2019. Anaerobic digestion of livestock and poultry manures spiked with tetracycline antibiotics. Journal of Environmental Science and Health. 55(2):135-147. https://doi.org/10.1080/03601234.2019.1667190.
Bucher, M., Zwirzitz, B., Oladeinde, A.A., Cook, K.L., Plymel, C., Zock, G., Aggrey, S., Ritz, C., Looft, T.P., Lipp, E., Agga, G.E., Sistani, K.R. 2020. Reused poultry litter microbiome with competitive exclusion potential against Salmonella Heidelberg. Journal of Environmental Quality. 49(4):869-881. https://doi.org/10.1002/jeq2.20081.
Gutema, F.D., Teferi, S., Agga, G.E., Abdi, R.D., Hiko, A., Tufa, T.B., Hailu, Y. 2020. Bovine cysticercosis and human taeniasis in a rural community in Ethiopia. Zoonoses and Public Health. 67(5):525-533. https://doi.org/10.1111/zph.12716.
Camarena-Martinez, S., Martinez-Martinez, J.H., Saldana-Robles, A., Nunez-Palenius, H.G., Costilla-Salazar, R., Valdez-Vazquez, I., Lovanh, N.C., Ruiz-Aguilar, G. 2020. Effects of experimental parameters on methane production and volatile solids removal from tomato and pepper plant wastes. BioResources. 15(3):4763-4780.
Bolster, C.H. 2019. Role of sand size on bacterial retention in biochar-amended sand filters. Biochar Journal. 1:353-363. https://doi.org/10.1007/s42773-019-00027-0.
