Carbon and nitrogen dynamics in agricultural soil after application of cattle manure and eastern redcedar wood chips.

Uncontrolled proliferation of eastern redcedar tree (Juniperus virginiana) in the Midwest United States requires new alternatives for utilization of waste wood, such as mulching, that promotes efficient tree management by landowners. Similarly, efficient use of manure from animal feeding operations in cropping systems can reduce negative environmental impacts and increase cropland productivity. The objectives of this study were to quantify the nitrogen (N) and carbon (C) decomposition rates, availability, and effects on soil chemical properties of eastern redcedar wood chips (WC), cattle manure (CM), and the combination of cattle manure and wood chips (MW).

Corn stalk residue may add antibiotic-resistant bacteria to manure composting piles.

Manure is commonly used as a fertilizer or soil conditioner; however, land application of untreated manure may introduce pathogens and antibiotic-resistant bacteria (ARB) into the soil, with harmful implications for public health. Composting is a manure management practice wherein a carbon-rich bulking agent, such as corn (Zea mays L.) stalk residue, is added to manure to achieve desirable carbon/nitrogen ratios to facilitate microbial activities and generate enough heat to inactivate pathogens, including antibiotic-resistant pathogens.

Antibiotic resistance gene profile changes in cropland soil after manure application and rainfall.

Land application of manure introduces gastrointestinal microbes into the environment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agricultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff.

Effectiveness of composting as a biosecure disposal method for porcine epidemic diarrhea virus (PEDV)-infected pig carcasses.

Background: Porcine epidemic diarrhea virus (PEDV) is an enteric disease of swine that has emerged as a worldwide threat to swine herd health and production. Substantial research has been conducted to assess viability of the virus on surfaces of vehicles and equipment, in feed and water, and on production building surfaces, but little is known about the persistence in PEDV-infected carcasses and effective disposal methods thereof. This study was conducted to quantify the persistence of PEDV RNA via quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at various time-temperature combinations and in infected piglet carcasses subjected to composting.