Beef Cattle Manure Research Articles

Emission of Volatile Organic Compounds as Affected by Rate of Application of Cattle Manure

<abstract> Beef cattle manure can serve as a valuable nutrient source for crop production. However, emissions of volatile organic compounds (VOCs) following land application may pose a potential off-site odor concern. This study was conducted to evaluate the effects of land application method, N application rate, soil moisture content, and time since manure application on VOC emissions. Manure from cattle fed a diet containing 30% wet distillers grains was applied to a cropland area at rates required to meet the 0.5, 1, or 2 year N requirement for corn. Land application methods included surface-applying manure (i.e., no tillage) or incorporating manure using disk tillage. The effect of soil moisture content on VOC emissions was determined by adding water to the experimental plots approximately 24 h after manure application. Volatile sulfur compounds (i.e., dimethyl disulfide and dimethyl trisulfide), isovaleric acid, and butyric acid contributed 43.4%, 14.0%, and 13.9%, respectively, of the total measured odor activity value (OAV). Emissions of each of the principal VOC odor compounds were reduced by manure incorporation. In general, no significant differences in VOC measurements of volatile fatty acids (VFAs) and aromatic compounds were found among varying manure application rates. However, an increase in emissions of volatile sulfur compounds resulted from increased manure application. Measurements of VFAs and aromatic compounds usually decreased and sulfide emissions increased following the application of water. Application method, N application rate, soil moisture content, and time since application may all influence VOC emissions following land application of cattle manure.

Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment

Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane® 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were better explained using both soil physicochemical test values and bacterial community structure data than using soil tests alone. Pursuing a better understanding of bacterial community composition and how it is affected by farming practices is a promising avenue for increasing our ability to predict the impact of management practices on important soil functions.

Phosphorus source coefficient determination for quantifying phosphorus loss risk of various animal manures

Quantification of phosphorus (P) loss risk of animal manures is essential to scientifically sound P risk assessment and environmental friendly nutrient management, but has faced significant challenges due to the shortage of appropriate techniques. This study was conducted to determine P source coefficients (PSC) for quantifying differential P loss risk of various manures relative to soluble chemical fertilizer. After 2-d, 2-week, 8-week, and 26-week soil incubations with various manures, P-amended soils were analyzed for Olsen P (Ol), Mehlich-3 P (M3), water extractable P (WEP), and Fe-oxide coated filter paper strip P (FeO), each of which was then used to calculate manure PSC. Manure PSCM3 had the strongest linear relationships (r2=0.95–0.97) among different incubation durations, compared with PSCWEP (r2=0.79–0.91), PSCOl (r2=0.85–0.94), and PSCFeO (r2=0.88–0.91). The 2 week incubation yielded PSCM3which had the strongest linear relationships (r2=0.87–0.97 with a mean of 0.95) among the tested soils, compared with those from 2-d, 8-week, and 26-week incubations. In addition, laboratory PSCM3 had the strongest linear relationships with those PSCM3 measured under field conditions, relative to PSCOl, PSCFeO, and PSCWEP. Hence, the 2-week incubation along with Mehlich-3 P yielded the most consistent PSCs for various manures across soil types, incubation durations, and soil conditions, and can be recommended as a common protocol for determining manure PSC. The recommended default PSC values are 110, 65, 46, and 43% for liquid swine, liquid dairy, solid poultry, and solid beef manures, respectively, for the new P index of Ontario.

Composting for Biocontained Cattle Mortality Disposal and Associated Greenhouse Gas and Leachate Emissions.

Composting can be an effective means of biodegrading livestock mortalities in emergency disposal situations, such as disease outbreaks. Within the past decade, our knowledge detailing composting has increased substantially. However, research data linking the environmental impact of composting to atmospheric and terrestrial systems are limited. We investigated composting efficacy, greenhouse gas emissions, and leachate properties from two static compost piles, each containing 16 cattle mortalities, built with either beef manure (BM) or wood shavings (WS) as envelope material. Wood shavings achieved a greater maximum temperature than BM (60 vs. 50°C) and maintained higher temperatures over 200 d ( < 0.001). Greenhouse gas emissions were evaluated using a static chamber and gas chromatography. Emissions of NO ( < 0.001), CH ( < 0.01), and CO ( < 0.05) were lower from WS than BM, resulting in 3-fold lower total CO equivalent emissions. After 250 d of composting, piles were relocated, and soil cores were taken (i) from beneath the piles, (ii) adjacent to the piles where leachate had accumulated, and (iii) in a control zone without compost exposure. Elevated concentrations of ammonium ( < 0.05) and chloride ( < 0.05) were found in soil beneath both BM and WS. Microbial DNA profiles suggested that leachate from BM compost increased bacterial diversity in soil, maintaining a biological soil impact after pile removal. Degradation of bovine mitochondrial DNA fragments was monitored by polymerase chain reaction. Limited migration of genetic bovine material from compost into soil was observed. Based on the mortalities decomposition and leachate contents, both BM and WS are suitable envelope materials for composting.

Dissipation of Antimicrobials in Feedlot Manure Compost after Oral Administration versus Fortification after Excretion.

Fortification of manure with antimicrobials is one approach to studying their dissipation. However, fortified antimicrobials may not accurately model dissipation that occurs after antimicrobials have been administered to livestock in feed and excreted in manure. This study examined the dissipation of antimicrobials excreted in manure versus those added directly to manure (fortified). Steers were fed a diet containing (kg feed) (i) 44 mg chlortetracycline, (ii) 44 mg each of chlortetracycline and sulfamethazine, (iii) 11 mg tylosin, and (iv) no antimicrobials (control). Fortified antimicrobial treatments were prepared by adding antimicrobials to control manure. Manure was composted for 30 d, sampled every 2 to 3 d, and analyzed for antimicrobials and compost properties. Antimicrobial dissipation followed first-order kinetics. The dissipation rate constant was significantly greater (based on 95% confidence limit) for excreted (0.29-0.54 d) than for fortified chlortetracycline (0.11-0.13 d). In contrast, dissipation rate constants were significantly greater for fortified sulfamethazine (0.47 d) and tylosin (0.31 d) than when the same antimicrobials were excreted (0.08 and 0.07 d, respectively). On average, 85 to 99% of the initial antimicrobial concentrations in manure were dissipated after 30 d of composting. The degree of dissipation was greater ( < 0.0001) for fortified (99%) than for excreted tylosin (85%). Composting can be used to reduce environmental loading of antimicrobials before field application of beef cattle manure. Dissipation rates of fortified antimicrobials during manure composting may not accurately reflect those of antimicrobials that are consumed and excreted by cattle.

Transport of Three Antimicrobials in Runoff from Windrows of Composting Beef Cattle Manure.

Rain runoff from windrowed or stockpiled manure may contain antimicrobials with the potential to contaminate surface and ground water. To quantify the concentration of antimicrobials transported in runoff from windrowed manure, antimicrobials were administered continuously in feed to beef cattle () as follows: 44 mg of chlortetracycline kg feed (dry weight), a 1:1 mixture of 44 mg of chlortetracycline and 44 mg sulfamethazine kg feed, and 11 mg of tylosin kg feed. Cattle in a fourth treatment group received no antimicrobials (control). Manure from the cattle was used to construct two windrows per treatment. On Days 2 and 21 of composting, a portable Guelph Rainfall Simulator II was used to apply deionized water at an intensity of 127 mm h to each windrow, and the runoff was collected. Manure samples were collected before rain simulations on Days 2 and 21 of composting for antimicrobial analysis. On Day 2, average concentrations of chlortetracycline, sulfamethazine, and tylosin in manure were 2580, 450, and 120 μg kg, respectively, with maximum concentrations in runoff of 2740, 3600, and 4930 μg L, respectively. Concentrations of all three antimicrobials in runoff were higher ( < 0.05) on Day 2 than on Day 21, reflecting the higher concentrations in manure on Day 2. Maximum estimated masses of chlortetracycline, sulfamethazine, and tylosin that could be transported in runoff from a windrow (3 m long, 2.5 m wide, 1.5 m high) were approximately 0.87 to 0.94, 1.57, and 1.23 g, respectively. This study demonstrates the importance of windrow composting in reducing antimicrobial concentrations in manure. The runoff from windrows can be a source of antimicrobials and demonstrates the need for containment of runoff from composting facilities to mitigate antimicrobial contamination of surface and groundwater resources.

Dissipation of Antimicrobial Resistance Determinants in Composted and Stockpiled Beef Cattle Manure.

Windrow composting or stockpiling reduces the viability of pathogens and antimicrobial residues in manure. However, the impact of these manure management practices on the persistence of genes coding for antimicrobial resistance is less well known. In this study, manure from cattle administered 44 mg of chlortetracycline kg feed (dry wt. basis) (CTC), 44 mg of CTC and 44 mg of sulfamethazine kg feed (CTCSMZ), 11 mg of tylosin kg feed (TYL), and no antimicrobials (control) were composted or stockpiled over 102 d. Temperature remained ≥55°C for 35 d in compost and 2 d in stockpiles. Quantitative PCR was used to measure levels of 16S rRNA genes and tetracycline [(B), (C), (L), (M), (W)], erythromycin [(A), (B), (F), (X)], and sulfamethazine [(1), (2)] resistance determinants. After 102 d, 16S rRNA genes and all resistance determinants declined by 0.5 to 3 log copies per gram dry matter. Copies of 16S rRNA genes were affected ( < 0.05) by antimicrobials with the ranking of control > CTC = TYL > CTCSMZ. Compared with the control, antimicrobials did not increase the abundance of resistance genes in either composted or stockpiled manure, except (M) and (2) in CTCSMZ ( < 0.05). The decline in 16S rRNA genes and resistance determinants was higher ( < 0.05) in composted than in stockpiled manure. We conclude that composting may be more effective than stockpiling in reducing the introduction of antimicrobial resistance genes into the environment before land application of manure.

Observaciones, desafíos y oportunidades en el manejo de efluentes de feedlot en la provincia de Buenos Aires, Argentina

The accumulation of beef cattle manure on feedlot pen surfaces generates large effluent volumes which can impact surface and groundwater quality. The aim of this study is to examine and summarize the available information on feedlot effluents management in Buenos Aires Province, highlighting the environmental effects and the weaknesses and future actions suitable to be implemented. We describe the environmental effects of this activity over waterbodies quality and analyze the existing regulations, with special emphasis on criteria and/or discharge levels proposed by legislation. This study reveals some gaps and incongruence as well as needs and opportunities for adjustment and expanding of existing regulations. Finally, an operating scheme used to frame the analysis of different aspects involved in feedlot effluent management is proposed. Such scheme identifies four components defined considering the development of a Nutrient Management Plan (NMP) and the determination of an Effluent Control Criterion (ECC).

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement.

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg O2/g VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS’s optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust’s coarse particle size and bulking effect.

Estrogenic activity and nutrient losses in surface runoff after winter manure application to small watersheds

Confined Animal Feeding Operations generate large amounts of wastes that are land-applied to provide nutrients for crop production and return organic matter to the soil. Production practices and storage limitations often necessitate that wastes be applied to frozen and snow-covered soil. Use of application setbacks have reduced concerns related to nutrient losses in surface runoff from manure, but the estrogenic activity of runoff under these conditions has not been evaluated. Therefore, we measured and sampled surface runoff when manure was applied in the winter at a rate to meet crop N needs and measured estradiol equivalents (E2Eqs) using E-Screen. In year one, six small watersheds used to produce corn were evaluated, treatments: 2 no-manure controls, 2 liquid swine manure with 30-m setbacks, and 2 turkey litter with 30-m setbacks. In addition, beef manure was applied to six frozen plots of forage. For years 2 and 3, applications were repeated on the swine manure watersheds and one control watershed. E2Eqs and nutrient concentrations generally peaked in the first runoff event after application. The highest measured E2Eq (5.6ngL−1) was in the first event after swine manure application and was less than the 8.9ngL−1 Lowest Observable Effect Concentration (LOEC) for aquatic species and well below the concentrations measured in other studies using ELISAs to measure hormone concentrations. No runoff occurred from plots planted with forage, indicating low risk for environmental impact, and therefore plots were discontinued from study. In years 2 and 3, estrogenic activity never exceeded the Predicted No Effect Concentrations for E2 of 2ngL−1. When post-application runoff contained high estrogenic activity, strong correlations (R2 0.86 to 0.96) of E2Eq to Ca2+, Mg2+, and K+ concentrations were observed, indicating under some condition these cations might be useful surrogates for E2Eq measurements.

Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method

Ige, D. V., Sayem, S. M. and Akinremi, O. O. 2015. Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method. Can. J. Soil Sci. 95: 305–319. A major challenge facing the widespread use of manure is the uncertainty about its fertilizer equivalence. This study was carried out to determine the fertilizer equivalence of locally available manures in two soils in Manitoba. A randomized complete block design was adopted with six treatments [nitrogen fertilizer, a liquid swine manure (LSM), three solid beef manures (SBM) and a control] and four replicates. Each treatment was applied to a cylindrical soil column installed at the site at the rate of 100 kg ha−1of “available N”, and leached NO3-N was captured by resin bags at the bottom of the cylinder. The soils and resin bags removed from the cylinders were sampled at 0, 1, 2, 4, 6, 8, 10, 14, and 18 wk following treatment application. Ammonium nitrogen in the amendments was nitrified within the first 2 to 3 wk with significant build-up of NO3-N in the soil above the control (P&lt;0.05). The greatest available N was in the fertilizer treatment, followed by the LSM and the smallest was in the SBM. The available N in the three SBM was statistically similar (P&gt;0.05). Approximately 50% of the inorganic N in LSM was available during the growing season, while 68 to 100% of SBM inorganic N was available. Between 4 and 25% of the organic N in the three SBM was mineralized during the growing season. High soil moisture hindered N mineralization and enhanced N loss in the clay soil. LSM has the greatest fertilizer equivalence, with a mean of 65 to 68%, of the four manure types used. The fertilizer equivalence of the three SBM ranged between 42 and 59% and was influenced by the manure C:N ratio and the soil environmental conditions. Our study suggests the need to revise the assumptions regarding manure N availability by considering soil environmental factors in the estimation of available N.

Compositional characteristics and energy potential of Chinese animal manure by type and as a whole

In this study, 838 representative animal manure samples were collected from 552 sites across China. Chemical analyses of 19 parameters, including the proximate analysis, ultimate analysis, heating values and some essential mineral elements, were conducted on the samples. The energy potential of animal manure in China was quantified based on the chemical analysis. The results showed that the chemical characteristics of the different types of animal manure were highly variable. Principal component analysis results demonstrated that the closest compositional characteristics were between dairy manure and beef manure. Several strong and important associations, namely phosphorus–magnesium, phosphorus–copper, phosphorus–zinc, copper–zinc, calcium–potassium, fixed carbon–calcium, volatile matter–iron and ash–volatile matter–fixed carbon–carbon–hydrogen–higher heating value–lower heating value, were identified. The calculated outputs of total potential annual thermal energy, syngas and methane yields from the five types of animal manure in China were 4400.63TJ, 983.40×109m3 and 188.89×109m3, respectively. The air gasifier energy conversion efficiency (t=850°C, equivalence ratio (ER)=0.3) for different animal manures was in the range of 66.80–83.22%.

COMPOSIÇÃO QUÍMICA E DIGESTIBILIDADE DA PORNUNÇA SOB DUAS FONTES DE ADUBAÇÃO ORGÂNICA E CORTES

RESUMO: O objetivo do presente trabalho foi avaliar o efeito da adubação orgânica e cortes sobre a composição química e a digestibilidade in vitro da fitomassa aérea da pornunça. Foi utilizado o delineamento experimental de blocos casualizados em parcelas subdivididas com quatro cortes, duas adubações e quatro repetições. Os cortes foram realizados nos meses de fevereiro, junho e outubro de 2011 e fevereiro de 2012. A adubação foi com esterco bovino e ovino aplicados nos meses de maio de 2010 e março de 2011 na quantidade de 20 Mg ha-1. Foram avaliados os componentes estruturais da parte aérea, tais como limbo foliar, pecíolo, ramo e completo (limbo foliar mais pecíolo e ramo) da pornunça. Os estercos bovino e ovino não influenciaram (P&gt;0,05) a composição química dos componentes estruturais da parte aérea. Diferenças foram verificadas entre os cortes, exceto para a matéria seca (MS) do limbo foliar e do componente completo de extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e hemicelulose (HC). Houve efeito (P&lt;0,05) para a digestibilidade in vitro da MS dos componentes estruturais nos diferentes cortes, sendo a maior digestibilidade para os componentes estruturais no corte realizado em fevereiro de 2011. Menores teores de proteína bruta foram encontrados nos componentes pecíolo e ramo. A pornunça deve ser considerada como alternativa alimentar para os animais em função dos valores da composição química apresentada neste estudo, sendo o limbo foliar a parte da planta que apresenta o melhor valor nutritivo.

Does manure management affect the latent greenhouse gas emitting potential of livestock manures?

With livestock manures being increasingly sought as alternatives to costly synthetic fertilisers, it is imperative that we understand and manage their associated greenhouse gas (GHG) emissions. Here we provide the first dedicated assessment into how the GHG emitting potential of various manures responds to the different stages of the manure management continuum (e.g., from feed pen surface vs stockpiled). The research is important from the perspective of manure application to agricultural soils. Manures studied included: manure from beef feedpen surfaces and stockpiles; poultry broiler litter (8-week batch); fresh and composted egg layer litter; and fresh and composted piggery litter. Gases assessed were methane (CH4) and nitrous oxide (N2O), the two principal agricultural GHGs. We employed proven protocols to determine the manures’ ultimate CH4 producing potential. We also devised a novel incubation experiment to elucidate their N2O emitting potential; a measure for which no established methods exist. We found lower CH4 potentials in manures from later stages in their management sequence compared with earlier stages, but only by a factor of 0.65×. Moreover, for the beef manures this decrease was not significant (P<0.05). Nitrous oxide emission potential was significantly positively (P<0.05) correlated with C/N ratios yet showed no obvious relationship with manure management stage. Indeed, N2O emissions from the composted egg manure were considerably (13×) and significantly (P<0.05) higher than that of the fresh egg manure. Our study demonstrates that manures from all stages of the manure management continuum potentially entail significant GHG risk when applied to arable landscapes. Efforts to harness manure resources need to account for this.

Fluidized bed gasification of high tonnage sorghum, cotton gin trash and beef cattle manure: Evaluation of synthesis gas production

Fluidized bed gasification using high-tonnage sorghum, cotton gin trash and beef cattle manure was performed in a pilot scale bubbling fluidized bed reactor equipped with the necessary feedback control system. Characterization of biomass showed that the high-tonnage sorghum had the highest energy and carbon content of 19.58MJkg−1 and 42.29%wt, respectively among the three feed stocks. At 730°C reaction temperature and equivalence ratio of 0.35, comparable yields of methane, nitrogen and carbon dioxide (within±1.4%vol) were observed in all three feed stocks. The gasification system produced synthesis gas with an average heating value of 4.19±0.09MJNm−3 and an average yield of 1.98±0.1Nm3kg−1 of biomass. Carbon conversion and gasification efficiencies indicated that most of the carbon was converted to gaseous products (85%average) while 48%average of the energy from the biomass was converted into combustible gas. The production of hydrogen was significantly affected by the biomass used during gasification. The synthesis gas heating value and yield were relatively constant at reaction temperatures from 730°C to 800°C. Utilizing high-tonnage sorghum, the optimum hydrogen production during gasification was achieved at a reaction temperature of 780°C and an equivalence ratio of 0.40.

Understanding Nitrogen Availability from Applications of Anaerobically Digested Beef-Cattle Manure in Florida Sandy Soil

Anaerobic digestion of livestock manure is a microbe-mediated process carried out in vessels or tanks, where the livestock wastes are digested slowly in environment absent of oxygen. The main products are biogas, anaerobically digested liquid (ADL), and solid (ADS), which can be land-applied as an organic soil amendment or a source of plant nutrients. This 4-page fact sheet provides research-based information about using anaerobically digested beef-cattle manure as an organic source of nitrogen for supplementing crop nutrition in Florida sandy soils, including initial N concentration, application timing, rate of application, and method of application. Written by Rishi Prasad and George Hochmuth, and published by the UF Department of Soil and Water Science, April 2015. (Photo: George Hochmuth, UF/IFAS)&#x0D; SL424/SS637: Understanding Nitrogen Availability from Applications of Anaerobically Digested Beef-Cattle Manure in Florida Sandy Soil (ufl.edu)

Assessment of a composting process for the treatment of beef cattle manure

The intensive breeding of beef cattle in Juncosa de les Garrigues (Catalonia, Spain) leads to the production of a large volume of manure that needs appropriate management. Land application in the area at agronomic rates is not enough to ensure good management practices, making necessary extended on-farm storage and the export of part of the production to long distances. In this context, the implementation of a collective treatment based on composting could help in enhancing the handling of manure. We assessed a full-scale composting process based on turned windrows (W), and involving treatment of beef cattle manure (CM) alone (two typologies were considered according to carbon-to-nitrogen ratios of ~25 (CM1, W1) and ~14 (CM2, W2)), or mixed with bulking agent (CM2/BA, W3) and dewatered digested sewage sludge (CM2/BA/DDSS, W4). Composting significantly improved the transportability of nutrients (final volumes were 40–54% of the initial volume). Temperature >55°C was reached in all the treatments but following different time patterns. Under the applied conditions of turning and rewetting, 14 weeks of processing did not ensure the production of stable, and mature, compost. Thus, only compost from W1 attained the maximum degree of stability as well as concentration of ammonium–N < 0.01% (with ammonium–N/nitrate–N ratio of 0.2) and low phytotoxicity. However, high pH, salinity, and heavy metal contents (Cu and Zn) may limit its final use. Addition of BA was advised to be kept to minimum, whereas use of DDSS as a co-substrate was not recommended in agreement to the higher loss of N and levels of heavy metals in the final compost.

Characteristics of pollutant gas releases from swine, dairy, beef, and layer manure, and municipal wastewater

Knowledge about characteristics of gas releases from various types of organic wastes can assist in developing gas pollution reduction technologies and establishing environmental regulations. Five different organic wastes, i.e., four types of animal manure (swine, beef, dairy, and layer hen) and municipal wastewater, were studied for their characteristics of ammonia (NH3), carbon dioxide (CO2), hydrogen sulfide (H2S), and sulfur dioxide (SO2) releases for 38 or 43 days in reactors under laboratory conditions. Weekly waste additions and continuous reactor headspace ventilation were supplied to simulate waste storage conditions. Results demonstrated that among the five waste types, layer hen manure and municipal wastewater had the highest and lowest NH3 release potentials, respectively. Layer manure had the highest and dairy manure had the lowest CO2 release potentials. Dairy manure and layer manure had the highest and lowest H2S release potentials, respectively. Beef manure and layer manure had the highest and lowest SO2 releases, respectively. The physicochemical characteristics of the different types of wastes, especially the total nitrogen, total ammoniacal nitrogen, dry matter, and pH, had strong influence on the releases of the four gases. Even for the same type of waste, the variation in physicochemical characteristics affected the gas releases remarkably.

Cattle Manure Application Reduces Soil Compactibility and Increases Water Retention after 71 Years

Current interest in integrating livestock with crop production systems warrants further understanding of the impacts of manure application on soil physical processes and properties such as soil's susceptibility to compaction (compactibility) and water retention. We quantified the 71-yr cumulative impacts of beef (Bos Taurus L.) cattle manure (0 and 27 Mg ha−1 yr−1) and inorganic N fertilizer (0, 90, and 180 kg N ha−1 yr−1) application to conventionally tilled and irrigated corn (Zea mays L.) on soil compactibility, water retention, available water, and soil organic C (SOC) on a Tripp very fine sandy loam (coarse-silty, mixed, superactive, mesic Aridic Haplustoll) at the centennial Knorr-Holden plots of the University of Nebraska's Panhandle Research and Extension Center, Scottsbluff, NE. Manure application improved soil properties at the 0- to 30-cm depth, but inorganic fertilization had no effects. Across N levels, manure application reduced maximum Proctor bulk density by 6% and increased Proctor soil critical water content (water content at which maximum compactibility occurs) by about 17%, indicating that manured soils can be slightly less susceptible to compaction and trafficked at higher water content without being excessively compacted compared with nonmanured soils. Manured plots also retained 18% more soil water at −0.033 MPa and 21% more at −1.5 MPa potential, resulting in about 16% more plant available water compared with nonmanured plots. The SOC concentration increased two-fold with manure addition and was negatively correlated (r > −0.77) with soil compactibility and positively (r > 0.72) with water retention. Overall, 71-yr manure application reduced compactibility and increased water retention in this semiarid soil.

Evaluation of essential oils in beef cattle manure slurries and applications of select compounds to beef feedlot surfaces to control zoonotic pathogens.

To evaluate natural terpene compounds for antimicrobial activities and determine whether these compounds could be used to control microbial activities and pathogens in production animal facilities. Thymol, geraniol, glydox, linalool, pine oil, plinol and terpineol were tested in laboratory studies for ability to control the production of odorous volatile fatty acid compounds and reduce pathogen levels in manure slurry preparations. Thymol is a terpene phenolic compound and was most effective for reducing fermentation products and pathogen levels (P < 0.05), followed by the extracts linalool, pine oil and terpineol, which are terpene alcohols. Select compounds thymol, linalool and pine oil were further evaluated in two separate studies by applying the agents to feedlot surfaces in cattle pens. Feedlot surface material (FSM; manure and soil) was collected and analysed for fermentation products, levels of coliforms and total Escherichia coli, and the presence of E. coli O157:H7, Campylobacter, Salmonella, Listeria and L. monocytogenes. The reduction in fermentation products but not pathogens was dependent on the moisture present in the FSM. Treatment with 2000 ppm thymol reduced the prevalence of E. coli O157:H7 but not Listeria. In a separate study, treatment with 4000 ppm pine oil reduced E. coli O157:H7, Listeria and Campylobacter (P < 0.05). Linalool was tested at two levels (2000 and 4000 ppm) and did not affect pathogen levels at either concentration. Natural compounds bearing terpenes can control pathogenic bacteria in treated manures and when applied to the feedlot surface in production cattle systems. Pine oil is a cheaper alternative to thymol and may be a useful treatment for controlling pathogens. The control of bacterial pathogens in animal productions systems is an important step in preharvest food safety. Waste products, such as pine oil extract, from the pulp wood industry may have application for treating feedlot pens and manures to reduce the pathogen load.