Location: Agroecosystem Management Research
Project Number: 3042-12630-003-000-D
Project Type: In-House Appropriated
Start Date: Jul 13, 2016
End Date: Jul 12, 2021
Objective 1: Measure manure pathogens, antibiotic-resistant bacteria, and antibiotic resistance genes (ARB/G) in animal production systems and manure-impacted environments and mitigate their deleterious impacts. Subobjective 1A. Develop and/or validate methods to detect and quantify antibiotic resistant bacteria and genes ARB/G in beef and swine production areas, with a focus on resistance classes that are ecologically relevant to particular agricultural production systems, microbiologically relevant based on carriage of likely pathogens, and clinically relevant based on kinds of drugs used to treat infections in food animals and humans. Subobjective 1B. Measure survival of microbes and persistence of genes in manure-impacted environments. Objective 2: Improve manure land application practices to enhance crop productivity while reducing losses of reactive nitrogen and phosphorus. Subobjective 2A. Utilize rainfall simulation tests to evaluate the potential for reactive manure nitrogen (N) and phosphorus (P) to be transported in runoff from land application areas. Subobjective 2B. Utilize rainfall simulation tests to evaluate the potential for pathogens, fecal indicators, and antibiotic resistance (AR) to be transported in runoff from land application areas. Subobjective 2C. Determine if a reactive subsurface barrier can limit nitrate movement out of surface agricultural soils and into shallow aquifers. Objective 3: Assess the impact and fate of manure-associated pharmaceuticals in agroecosystems. Subobjective 3A. Evaluate how increasing concentrations of common livestock antimicrobials (monensin, lincomycin, and sulfamethazine) effect nitrification, denitrification, and decomposition in crop and pasture soils that have received beef cattle feedlot runoff or manure with crop, pasture, and stream sediments with no history of manure/runoff. Objective 4: Determine the ability of innovative fertilizer technology to improve nutrient use efficiency of applied fertilizer for crop production and decrease nutrient loss to the environment. Subobjective 4A. Determine the effects of long-term variable fertilizer inputs and crop rotations on nutrient-transforming and antibiotic resistance within the soil microbial community Subobjective 4B. Evaluate seasonal changes in root-associated and bulk soil microbial communities in response to drip irrigation/fertigation or other precision fertilizer application methods that may include Enhanced Efficiency Fertilizers (EEFs), bio-stimulants, manure, or biochar.
Agronomic use of animal manure to build soil fertility and health has been an economical and sustainable practice for centuries, but it is not without challenges. Manure can be a source of human food pathogens and environmental contaminants including excess nutrients, pathogens, antibiotics, and antibiotic resistant bacteria (ARB). The goal of this project is to address substantial knowledge gaps regarding the movement and fate of the chemical and biological components of manure and the fate of fertilizer inputs. In a series of collaborative studies, robust, cross-validated methods to measure antibiotic resistance (Objective 1) will be developed through a multi-location partnership and will assess potential transport issues after manure application and in manure-impacted environments across the nation. Field and laboratory experiments will evaluate setback factors affecting manure nutrient, pathogen, antibiotic, and ARB in runoff and nitrate leaching past the root zone into shallow ground water (Objective 2 & 3). Soil’s capacity to help mitigate specific manure pathogens, including porcine epidemic diarrhea virus, will be explored in laboratory and field studies in addition to determining specific antibiotic thresholds where soil microbial processes are affected to better understand environmental risks for manure application (Objectives 2 & 3). The effects of novel fertilization methods to limit environmental nutrient losses may impact microbial communities. These impacts will be assessed to evaluate sustainability (Objective 4). Information from these studies directly contributes to multiple problem areas/components in National Programs 212 and 108. The research objectives within this study plan will provide important information concerning the fate and transport of manure constituents for producers (nutrient loss, safe manure use for crop production), the public (pathogens, antibiotics and ARB), and other government agencies (nutrients and pathogens impacting water quality).