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Journal of Environmental Quality : Just Published


Accepted, edited articles are published here after author proofing to provide rapid publication and better access to the newest research. Articles are compiled into issues at dl.sciencesocieties.org/publications/jeq, which includes the complete archive.

Citation | Articles posted here are considered published and may be cited by the doi.

Maguire, R.O., P.J. A. Kleinman, C.J. Dell, D.B. Beegle, R.C. Brandt, J.M. McGrath, and Q.M. Ketterings. 2011. Manure application technology in reduced tillage and forage systems: A review. J. Environ. Qual. doi: 10.2134/jeq2009.0228

Current issue: J. Environ. Qual. 46(2)


    • Rivka B. Fidel, David A. Laird and Timothy B. Parkin
      Impact of Biochar Organic and Inorganic Carbon on Soil CO 2 and N 2 O Emissions

      Biochar has been shown to influence soil CO2 and N2O emissions following application to soil, but the presence of carbonates in biochars has largely confounded efforts to differentiate among labile and recalcitrant C pools in biochar and establish their timeframe of influence. Understanding the mechanism, magnitude, and duration of biochar C pools’ influence on C and N dynamics is imperative to successful implementation of biochar for C sequestration. Here we therefore aim to assess biochar organic and inorganic C pool impacts on CO2 and N2O emissions from soil amended with two untreated biochars, inorganic carbon (as Na2CO3), acid (HCl) and bicarbonate (NaHCO3) extracts of the biochars, and acid and bicarbonate/acid-washed biochars during a 140-d soil incubation. We hypothesized that (i) both biochar labile organic carbon (LOC) and inorganic carbon (IC) pools contribute significantly to short-term (<1 mo) CO2 emissions from biochar-amended soil, (ii) biochars will influence the size of soil NH4+ and NO3 pools, and (iii) changes in soil inorganic N pools will affect soil N2O emissions. (continued)

      Core Ideas:
      • Biochar IC and OC contributed to soil CO2 produced during initial 48 h of incubation.
      • Washing biochars with acid and bicarbonate both reduced CO2 produced.
      • Acid and bicarbonate biochar extracts increased C loss more than untreated biochars.
      • Biochar treatments did not influence N2O emissions despite inorganic N impacts.
      • Labile biochar IC and OC pools are likely stabilized by the recalcitrant C pool.

      Published: April 27, 2017

    • Sven G. Sommer, Timothy J. Clough, Nimlesh Balaine, Sasha D. Hafner and Keith C. Cameron
      Transformation of Organic Matter and the Emissions of Methane and Ammonia during Storage of Liquid Manure as Affected by Acidification

      Acidification of livestock manure can reduce emission of the greenhouse gases methane (CH4) and nitrous oxide (N2O), as well as ammonia (NH3). We examined the relation between emission of these gases and transformation of organic matter as affected by acidification. Liquid cattle manure was acidified with sulfuric acid to pH 5.5 at a pilot scale (100 L), and we measured effects on CH4, N2O, CO2 and NH3 emissions and on transformation of pH buffer components and organic matter. Acidification reduced NH3 emissions by 62% (47 d) and emission of CH4 by 68% (57 d). (continued)

      Core Ideas:
      • Acidification reduced emission of NH3 and CH4, but the effect diminished over time.
      • Dissolved organic carbon may be a predictor for greenhouse gas emission.
      • The majority of carbon loss during the early stages of storage was as CO2.
      • VFA and TAN concentrations in surface layers may be higher than at the center.

      Published: April 6, 2017

    • Kyoung S. Ro, Philip A. Moore, Ariel A. Szogi and Patricia D. Millner
      Ammonia and Nitrous Oxide Emissions from Broiler Houses with Downtime Windrowed Litter

      An emerging poultry manure management practice is in-house windrowing to disinfect the litter. However, this practice is likely to increase emissions of ammonia (NH3) and nitrous oxide (N2O) from the windrowed litter. The objective of this study was to quantitatively compare NH3 and N2O emissions from broiler houses with and without in-house windrowing. Two broiler houses at a commercial farm were used to compare the NH3 and N2O emissions. (continued)

      Core Ideas:
      • Significantly high NH3 and N2O emissions from a downtime windrowing house.
      • 31% of NH3 and 16% of N2O emissions per bird were attributed to windrowing litter.

      Published: March 23, 2017


    • Marianne F. de Faria, Iraê A. Guerrini, Fernando C. Oliveira, Maria Inês Z. Sato, Elayse M. Hachich, José Raimundo S. Passos, Lívia M. L. Goulart, Thiago T. de S. Silva, José L. Gava, Joel C. Furches, Jason James and Robert B. Harrison
      Persistence of Ascaris spp. Ova in Tropical Soil Cultivated with Eucalyptus and Fertilized with Municipal Biosolids

      In many countries, the main reason for severely restricting or outright banning the land application of class B biosolids is the lack of risk assessment for adverse human health impacts. Among pathogens that are not often studied are helminth ova, including that of the Ascaris spp. Almost all of the knowledge about the persistence of Ascaris spp. ova in soils fertilized with biosolids is based on studies developed in North America, Europe, and Asia. (continued)

      Core Ideas:
      • Climate conditions, mainly temperature, influence the viability of Ascaris spp. ova.
      • Viable Ascaris spp. ova were not found after 7 wk of study in tropical soil.
      • Agricultural use may be the best practice for disposal of biosolids.

      Published: April 27, 2017


    • Shawn E. Loo, M. Cathryn Ryan, Bernie J. Zebarth, Shawn H. Kuchta, Denise Neilsen and Bernhard Mayer
      Use of δ 15 N and δ 18 O Values for Nitrate Source Identification under Irrigated Crops: A Cautionary Vadose Zone Tale

      Source nitrogen (N) identification of leachate or groundwater nitrate is complicated by N source mixing and N and oxygen (O) isotope fractionation caused by microbial N transformations. This experiment examined the δ15NNO3 and δ18ONO3 values in leachate collected over 1 yr at 55 cm below raspberry (Rubus idaeus L.) plots receiving either synthetic fertilizer (FT) or poultry manure (MT). The large ranges of δ15NNO3 (FT: −2.4 to +8.7‰, MT: +1.6 to +9.6‰) and δ18ONO3 (FT: −9.9 to −0.3‰, MT: −10.9 to +1.7‰) values in leachate collected under crop rows prohibited the reliable identification of the applied N sources on individual sampling dates. However, the mass-weighted average δ15NNO3 (FT: +3.2‰, MT: +7.3‰) values in leachate were significantly different and can be explained by accounting for the estimated contributions of nitrate and δ15NNO3 values of the various N sources, including applied fertilizer (−0.7‰) or manure (+7.9‰), nitrate-rich irrigation water (+9.0‰), and nitrate from soil N mineralization and nitrification (FT: +3.7‰, MT: +4.6‰; the seasonal timing of which is unknown). (continued)

      Core Ideas:
      • Temporal variation in δ15NNO3 and δ18ONO3 prevented reliable N source distinction.
      • N treatments differed using mass-weighted annual average δ15NNO3 and δ18ONO3 values.
      • Annual average δ15NNO3 was predictable using estimated N source contributions.
      • Soil N and irrigation water NO3 contributed significantly to the leachate mass flux.

      Published: April 27, 2017


    • Barbara J. Cade-Menun, Donnacha G. Doody, Corey W. Liu and Catherine J. Watson
      Long-term Changes in Grassland Soil Phosphorus with Fertilizer Application and Withdrawal

      Long-term phosphorus (P) applications can increase soil P concentrations in excess of agronomic optima, posing a risk to water quality. Once fertilization stops, however, it may take time for soil P concentrations to decline. Whereas P fertilization adds orthophosphate, little is known about changes in other soil P forms during P buildup and drawdown. This study examined changes in P pools (total P, Olsen P, Mehlich P, and water-extractable P) and P forms determined by 31P-nuclear magnetic resonance spectroscopy (P-NMR) in grazed grassland plots from Northern Ireland. (continued)

      Core Ideas:
      • Investigated soil P forms with P fertilization and then without P fertilization.
      • Adding inorganic P in fertilizer increased inorganic P in soil.
      • Inorganic P concentrations decreased in soil after fertilizer cessation.
      • There were few changes in organic P during fertilization and after fertilizer cessation.

      Published: April 27, 2017


    • Wangcang Su, Hongle Xu, Hongdan Hao, Renhai Wu, Hengliang Wang and Chuantao Lu
      Effect of Environmental Conditions on the Degradation of Florasulam in Typical Soils of Northern China

      The widespread use of florasulam in China makes residues from this herbicide in soil a serious concern due to their potential to pollute the soil environment and groundwater. Accelerating the degradation of these residues will reduce their pollution potential. In this study, we investigated the degradation and adsorption of florasulam in four typical soils in northern China and examined the degradation of florasulam in Inceptisols at different temperatures, soil moisture contents, and pH values, as well as the influence of microorganisms and the use of organic matter and biogas slurry as soil amendments. The half-lives of florasulam in the four soils were 13.6 d (Ultisols), 13.9 d (Vertisols), 15.1 d (Alfisols), and 19.3 d (Inceptisols), and the adsorption ability of the four soils followed the order Inceptisols > Alfisols > Vertisols > Ultisols. (continued)

      Core Ideas:
      • Florasulam degraded faster as temperature and soil moisture increased and soil pH decreased.
      • Microorganisms played an important role in florasulam degradation.
      • Small amounts of added organic matter increased the florasulam degradation rates.
      • The addition of biogas slurry to soil increased florasulam degradation rates.
      • Results can help agricultural managers reduce the risk associated with florasulam use.

      Published: April 13, 2017

    • Jinhao Zhao, Likun Wang, Jingli Cheng, Wei Wang and Qingfu Ye
      Fate Characterization of Benzene Kresoxim-Methyl (a Strobilurin Fungicide) in Different Aerobic Soils

      Benzene kresoxim-methyl (BKM) is a promising broad-spectrum strobilurin fungicide widely used to control fungal pathogens in crops. However, information on its environmental fate is limited. To broaden our understanding of this fungicide’s kinetic fate in aerobic soils, we labeled BKM with 14C on its benzoate ring and used ultralow-level liquid scintillation counting coupled with high-performance liquid chromatography analysis. Results show that degradation, mineralization, and bound residue (BR) formation of BKM was controlled by soil type and microbial community composition. (continued)

      Core Ideas:
      • The fate of benzene kresoxim-methyl (BKM) is characterized for the first time.
      • This fungicide has low mineralization and moderate bound residue formation in soil.
      • BKM persisted in soil, which may influence soil organisms.
      • This fungicide shows leaching/long-distance transportation potential in soil.
      • Dissipation and distribution of BKM residue depends on soil type and soil microbes.

      Published: March 23, 2017


    • John J. Meisinger and Kristin A. Ricigliano
      Nitrate Leaching from Winter Cereal Cover Crops Using Undisturbed Soil-Column Lysimeters

      Cover crops are important management practices for reducing nitrogen (N) leaching, especially in the Chesapeake Bay watershed, which is under total maximum daily load (TMDL) restraints. Winter cereals are common cool-season crops in the Bay watershed, but studies have not directly compared nitrate-N (NO3–N) leaching losses from these species. A 3-yr cover crop lysimeter study was conducted in Beltsville, MD, to directly compare NO3–N leaching from a commonly grown cultivar of barley (Hordeum vulgare L.), rye (Secale cereale L.), and wheat (Triticum aestivum L.), along with a no-cover control, using eight tension-drained undisturbed soil column lysimeters in a completely randomized design with two replicates. The lysimeters were configured to exclude runoff and to estimate NO3–N leaching and flow-weighted NO3–N concentration (FWNC). (continued)

      Core Ideas:
      • Nitrate-N leaching was lower with winter cereal cover crops than without covers.
      • Nitrate-N leaching was similar among the cultivars of barley, rye, and wheat.
      • Fall rainfall quantity had larger effects on NO3–N leaching than cover crop species.
      • Winter cereal covers reduced NO3–N leaching 95% in a dry year and 50% in wet years.

      Published: April 27, 2017


    • Dharini Paramashivam, Nicholas M. Dickinson, Timothy J. Clough, Jacqui Horswell and Brett H. Robinson
      Potential Environmental Benefits from Blending Biosolids with Other Organic Amendments before Application to Land

      Biosolids disposal to landfill or through incineration is wasteful of a resource that is rich in organic matter and plant nutrients. Land application can improve soil fertility and enhance crop production but may result in excessive nitrate N (NO3–N) leaching and residual contamination from pathogens, heavy metals, and xenobiotics. This paper evaluates evidence that these concerns can be reduced significantly by blending biosolids with organic materials to reduce the environmental impact of biosolids application to soils. It appears feasible to combine organic waste streams for use as a resource to build or amend degraded soils. (continued)

      Core Ideas:
      • Landfilling or burning biosolids is an expensive waste of a valuable resource.
      • High rates of biosolids restore degraded soil but cause excessive nitrate leaching.
      • Combining biosolids with other biowastes can mitigate nitrate leaching.
      • Dried, but not wet, wood waste effectively mitigates nitrate leaching.
      • Partial pyrolysis of wood waste may provide energy-neutral drying.

      Published: April 27, 2017

    • Lisa M. Reedich, Michael D. Millican and Paul L. Koch
      Temperature Impacts on Soil Microbial Communities and Potential Implications for the Biodegradation of Turfgrass Pesticides

      Maintaining healthy turfgrass often results in the use of pesticides to manage weed, insect, and disease pests. To identify and understand potential nontarget impacts of pesticide usage while still maintaining attractive and functional turfgrass sites, it is important to improve our understanding of how pesticides degrade in various environments throughout the growing season. Temperature heavily influences microbial community composition and activity, and the microbial community often heavily influences pesticide degradation in soil ecosystems. Pesticide transformation products generated through the action of soil microbial degradation networks can vary in their toxicity, with the potential result that a pesticide applied in the spring at 10°C could produce different transformation products with different toxicological impacts than the sample pesticide applied to the same site at 22°C. (continued)

      Core Ideas:
      • Microbial organisms drive pesticide breakdown in the soil.
      • Temperature heavily influences soil microbial structure and function.
      • Altered microbial activity can result in altered pesticide transformation products.
      • Soil temperature variations can result in altered toxicological pesticide effects.

      Published: April 6, 2017


    • Bei Chu and Frieda Eivazi
      Enhanced Dissipation of Selected Herbicides in a Simulated Organic Matrix Biobed: A System to Control On-Farm Point-Source Pollution

      Most farms have a centralized location to fill spray tanks with pesticides and to flush and clean application equipment. These sites, depending on the frequency of use, could be significant sources of surface and groundwater contamination. One approach to minimize this contamination is to install a treatment system, such as a biobed. This study sought to construct a biobed and test the effects of different biomix materials in enhancing the dissipation of herbicides widely used in crop production. (continued)

      Core Ideas:
      • Biobed material composition and ratio were evaluated.
      • The dissipation rates of atrazine and pendimethalin were enhanced in biomixes.
      • Phenol oxidase was higher in peat biomixes than in compost.
      • A mobile, low-cost system was designed to capture contamination on-farm.

      Published: December 28, 2016

    • Ying Wang and Nora Fung Yee Tam
      Glutathione–Ascorbate Cycle Is an Early Warning Indicator of Toxicity of BDE-47 in Mangroves

      Mangroves are often exposed to contamination by polybrominated diphenyl ethers (PBDEs) from wastewater discharges and solid waste dumping. As one of the most prevalent and toxic PBDE congeners in the environment, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and its oxidative stress deserves more attention. In plants, the glutathione–ascorbate (GSH-AsA) cycle plays an important role in the defensive processes against oxidative stress. However, the importance of this cycle in mangroves to defend against PBDE toxicity has not been reported. (continued)

      Core Ideas:
      • BDE-47 posed oxidative stress to Kandelia obovata seedlings.
      • Leaf and root biomass of K. obovata was suppressed after short BDE-47 exposure.
      • GSH-AsA cycle-related antioxidants changed significantly immediately after exposure.
      • GSH-AsA cycle was a more sensitive indicator to BDE-47 toxicity than growth.
      • AsA and GPx were early warning indicators to PBDE toxicity in mangrove plants.

      Published: October 13, 2016


    • Jason W. Stuckey, Jianjun Yang, Jian Wang and Donald L. Sparks
      Advances in Scanning Transmission X-Ray Microscopy for Elucidating Soil Biogeochemical Processes at the Submicron Scale

      Organic matter, minerals, and microorganisms are spatially associated in complex organo-mineral assemblages within soils. A mechanistic understanding of processes occurring within organo-mineral assemblages requires noninvasive techniques that minimize any disturbance to the physical and chemical integrity of the sample. Synchrotron-based soft (50–2200 eV) X-ray spectromicroscopic techniques, including scanning transmission X-ray microscopy (STXM), transmission X-ray microscopy (TXM), X-ray photoemission electron microscopy (X-PEEM), and scanning photoelectron microscopy (SPEM), coupled with microspectroscopy (e.g., near-edge X-ray absorption fine structure; NEXAFS) allow for determining the spatial association and speciation of most elements found in soils while maintaining sample integrity. (continued)

      Core Ideas:
      • Analysis of soil processes requires techniques able to speciate light and heavy elements.
      • STXM-NEXAFS determines the speciation of spatially associated light and heavy elements.
      • STXM-NEXAFS enables elucidation of microaggregate and biomineral formation mechanisms.
      • Advances in synchrotron-based STXM will allow for wavelength-limited spatial resolution.

      Published: April 13, 2017

    • Stephen R. Sutton, Antonio Lanzirotti, Matthew Newville, Mark L. Rivers, Peter Eng and Liliana Lefticariu
      Spatially Resolved Elemental Analysis, Spectroscopy and Diffraction at the GSECARS Sector at the Advanced Photon Source

      X-ray microprobes (XRM) coupled with high-brightness synchrotron X-ray facilities are powerful tools for environmental biogeochemistry research. One such instrument, the XRM at the Geo Soil Enviro Center for Advanced Radiation Sources Sector 13 at the Advanced Photon Source (APS; Argonne National Laboratory, Lemont, IL) was recently improved as part of a canted undulator geometry upgrade of the insertion device port, effectively doubling the available undulator beam time and extending the operating energy of the branch supporting the XRM down to the sulfur K edge (2.3 keV). Capabilities include rapid, high-resolution, elemental imaging including fluorescence microtomography, microscale X-ray absorption fine structure spectroscopy including sulfur K edge capability, and microscale X-ray diffraction. These capabilities are advantageous for (i) two-dimensional elemental mapping of relatively large samples at high resolution, with the dwell times typically limited only by the count times needed to obtain usable counting statistics for low concentration elements, (ii) three-dimensional imaging of internal elemental distributions in fragile hydrated specimens, such as biological tissues, avoiding the need for physical slicing, (iii) spatially resolved speciation determinations of contaminants in environmental materials, and (iv) identification of contaminant host phases. (continued)

      Core Ideas:
      • X-ray microprobes are powerful tools for environmental biogeochemistry.
      • Upgraded GSECARS XRM operates down to the sulfur K edge.
      • Capabilities: spatially resolved elemental analysis, spectroscopy, and diffraction.
      • Advanced Photon Source upgrade will further advance XRM capabilities.

      Published: February 23, 2017

    • Ranju R. Karna, Matt Noerpel, Aaron R. Betts and Kirk G. Scheckel
      Lead and Arsenic Bioaccessibility and Speciation as a Function of Soil Particle Size

      Bioavailability research of soil metals has advanced considerably from default values to validated in vitro bioaccessibility (IVBA) assays for site-specific risk assessment. Previously, USEPA determined that the soil-size fraction representative of dermal adherence and consequent soil ingestion was <250 μm. This size fraction was widely used in testing efforts for both in vivo and in vitro experiments. However, recent studies indicate the <150-μm size fraction better represents the particle size that adheres to skin for potential ingestion. (continued)

      Core Ideas:
      • Identified critical knowledge gaps regarding the <250-μm vs. <150-μm particle size used for IVBA.
      • Wider implementation of the <150-μm size fraction maintains past validation with <-250 μm fraction.
      • Regardless of increase in total and extractable Pb and As, %IVBA results remained consistent.
      • Using <150-μm particle size for IVBA requires much higher volumes/masses of soils.
      • Synchrotron-based speciation is significant in bioavailability studies to understand the fate and transport of contaminants.

      Published: February 23, 2017

    • Marina Colzato, Marcos Y. Kamogawa, Hudson W.P. Carvalho, Luís R.F. Alleoni and Dean Hesterberg
      Temporal Changes in Cadmium Speciation in Brazilian Soils Evaluated Using Cd L III –Edge XANES and Chemical Fractionation

      Chemical speciation of soil cadmium (Cd) dictates its mobility and potential toxicity in the environment. Our objective was to compare temporal changes in speciation of Cd(II) reacted with samples from six Brazilian soils having varying Cd(II) sorption capacities. Cadmium LIII–edge X-ray absorption near edge structure (XANES) analysis showed there were short-term changes in speciation after reaction with 4.45 mmol Cd kg−1 for 0.5 and 6 h. Chemical fractionation evaluated changes in Cd extractability after reaction with 89 μmol Cd kg−1 for up to 4 mo. (continued)

      Core Ideas:
      • Cadmium speciation showed weak and variable evidence for temporal changes.
      • No evidence for progressive natural attenuation of soil cadmium was found.
      • Cadmium(II) bonded preferentially with soil organic matter and oxide minerals.

      Published: February 2, 2017

    • Peter M Kopittke, Peng Wang, Enzo Lombi and Erica Donner
      Synchrotron-based X-Ray Approaches for Examining Toxic Trace Metal(loid)s in Soil–Plant Systems

      Elevated levels of trace metal(loid)s reduce plant growth, both in soils contaminated by industrial activities and in acid agricultural soils. Although the adverse effects of trace metal(loid)s have long been recognized, there remains much unknown both about their behavior in soils, their toxicity to plants, and the mechanisms that plants use to tolerate elevated concentrations. Synchrotron-based approaches are being utilized increasingly in soil–plant systems to examine toxic metal(loid)s. In the present review, brief consideration is given to the theory of synchrotron radiation. (continued)

      Core Ideas:
      • Synchrotron analyses allow in situ analyses of metal(loid)s in soils and plants.
      • This review provides a brief introduction to the theory of synchrotron radiation.
      • The distribution and speciation of metal(loid)s in soils and plants is reviewed.

      Published: February 2, 2017


    • Claire Baffaut, Nathan O. Nelson, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino and Charles S. Wortmann
      Multisite Evaluation of APEX for Water Quality: I. Best Professional Judgment Parameterization

      The Agricultural Policy Environmental eXtender (APEX) model is capable of estimating edge-of-field water, nutrient, and sediment transport and is used to assess the environmental impacts of management practices. The current practice is to fully calibrate the model for each site simulation, a task that requires resources and data not always available. The objective of this study was to compare model performance for flow, sediment, and phosphorus transport under two parameterization schemes: a best professional judgment (BPJ) parameterization based on readily available data and a fully calibrated parameterization based on site-specific soil, weather, event flow, and water quality data. The analysis was conducted using 12 datasets at four locations representing poorly drained soils and row-crop production under different tillage systems. (continued)

      Published: April 13, 2017

    • Zachary M. Easton, Peter J.A. Kleinman, Anthony R. Buda, Dustin Goering, Nichole Emberston, Seann Reed, Patrick J. Drohan, M. Todd Walter, Pat Guinan, John A. Lory, Andrew R. Sommerlot and Andrew Sharpley
      Short-term Forecasting Tools for Agricultural Nutrient Management

      The advent of real-time, short-term farm management tools is motivated by the need to protect water quality above and beyond the general guidance offered by existing nutrient management plans. Advances in high-performance computing and hydrologic or climate modeling have enabled rapid dissemination of real-time information that can assist landowners and conservation personnel with short-term management planning. This paper reviews short-term decision support tools for agriculture that are under various stages of development and implementation in the United States: (i) Wisconsin’s Runoff Risk Advisory Forecast (RRAF) System, (ii) New York’s Hydrologically Sensitive Area Prediction Tool, (iii) Virginia’s Saturated Area Forecast Model, (iv) Pennsylvania’s Fertilizer Forecaster, (v) Washington’s Application Risk Management (ARM) System, and (vi) Missouri’s Design Storm Notification System. Although these decision support tools differ in their underlying model structure, the resolution at which they are applied, and the hydroclimates to which they are relevant, all provide forecasts (range 24–120 h) of runoff risk or soil moisture saturation derived from National Weather Service Forecast models. (continued)

      Core Ideas:
      • Advances in weather forecasting, data management, and modeling improve nutrient management.
      • New tools facilitate improved farm decisions in response to real-time weather.
      • Nutrient management can be performed operationally and strategically with real-time tools.

      Published: April 13, 2017

    • Nathan O. Nelson, Claire Baffaut, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino and Charles S. Wortmann
      Multisite Evaluation of APEX for Water Quality: II. Regional Parameterization

      Phosphorus (P) Index assessment requires independent estimates of long-term average annual P loss from fields, representing multiple climatic scenarios, management practices, and landscape positions. Because currently available measured data are insufficient to evaluate P Index performance, calibrated and validated process-based models have been proposed as tools to generate the required data. The objectives of this research were to develop a regional parameterization for the Agricultural Policy Environmental eXtender (APEX) model to estimate edge-of-field runoff, sediment, and P losses in restricted-layer soils of Missouri and Kansas and to assess the performance of this parameterization using monitoring data from multiple sites in this region. Five site-specific calibrated models (SSCM) from within the region were used to develop a regionally calibrated model (RCM), which was further calibrated and validated with measured data. (continued)

      Core Ideas:
      • Regionally calibrated APEX produced very good estimates of site-specific runoff.
      • Regionally calibrated APEX failed to adequately estimate sediment loss.
      • Regionally calibrated APEX P-loss estimates were worse than site-specific models.
      • APEX runoff estimates are adequate for rigorous evaluation of P Index runoff components.
      • APEX sediment loss estimates are unsuitable for evaluation of P Index.

      Published: March 30, 2017

    • Quirine M. Ketterings, Sebastian Cela, Amy S. Collick, Stephen J. Crittenden and Karl J. Czymmek
      Restructuring the P Index to Better Address P Management in New York

      The New York Phosphorus Index (NY-PI) was introduced in 2001 after the release of the state’s first Concentrated Animal Feeding Operation (CAFO) Permit that required a nutrient management plan developed in accordance with NRCS standards. The stakeholder-based approach to development of the NY-PI, combined with a requirement for all regulated farms to determine a NY-PI score for all fields, ensured widespread adoption. While P management greatly improved over time, the initial NY-PI overemphasized soil-test P (STP), allowing for P addition if STP was low, even if the risk of P transport was high. Our goal was to develop a new PI approach that incentivizes implementation of best management practices (BMPs) where P-transport risk is high, building on feedback from certified planners (survey), analysis of a planner-supplied 33,000+ field database with NY-PI information, and modeling of the impacts of specific BMPs on P runoff using data from a central NY CAFO farm. (continued)

      Core Ideas:
      • Stakeholder engagement is essential to develop improved Phosphorus Indices (PIs).
      • A “Transport × BMP”-based PI incentivizes BMP use where risk of P transport is high.
      • In a “Transport × BMP”-based PI, soil-test P sets rate limits to enhance P balances.
      • A “Transport × BMP”-based PI can reduce barriers to regionalization of PIs within watersheds.

      Published: March 2, 2017

    • Carl H. Bolster, Adam Forsberg, Aaron Mittelstet, David E. Radcliffe, Daniel Storm, John Ramirez-Avila, Andrew N. Sharpley and Deanna Osmond
      Comparing an Annual and a Daily Time-Step Model for Predicting Field-Scale Phosphorus Loss

      A wide range of mathematical models are available for predicting phosphorus (P) losses from agricultural fields, ranging from simple, empirically based annual time-step models to more complex, process-based daily time-step models. In this study, we compare field-scale P-loss predictions between the Annual P Loss Estimator (APLE), an empirically based annual time-step model, and the Texas Best Management Practice Evaluation Tool (TBET), a process-based daily time-step model based on the Soil and Water Assessment Tool. We first compared predictions of field-scale P loss from both models using field and land management data collected from 11 research sites throughout the southern United States. We then compared predictions of P loss from both models with measured P-loss data from these sites. (continued)

      Core Ideas:
      • We compared predictions of P loss between an empirically-based and process-based model.
      • Predictions from both models were well correlated with each other.
      • The process-based model did not result in noticeably better predictions of P loss.
      • APLE predicted greater DP loss and TBET predicted greater PP loss.
      • Results indicate the need for improving accuracy of both models.

      Published: January 19, 2017

    • Peter A. Vadas, Laura W. Good, William E. Jokela, K.G. Karthikeyan, Francisco J. Arriaga and Melanie Stock
      Quantifying the Impact of Seasonal and Short-term Manure Application Decisions on Phosphorus Loss in Surface Runoff

      Agricultural phosphorus (P) management is a research and policy issue due to P loss from fields and water quality degradation. Better information is needed on the risk of P loss from dairy manure applied in winter or when runoff is imminent. We used the SurPhos computer model and 108 site–years of weather and runoff data to assess the impact of these two practices on dissolved P loss. Model results showed that winter manure application can increase P loss by 2.5 to 3.6 times compared with non-winter applications, with the amount increasing as the average runoff from a field increases. (continued)

      Core Ideas:
      • Winter application of dairy manure can significantly increase P loss in surface runoff.
      • Producers have few options to reduce P manure loss by avoiding near-term runoff.
      • Models can help quantify the effect of management on manure P loss in runoff.

      Published: January 19, 2017

    • David B. Baker, Laura T. Johnson, Remegio B. Confesor and John P. Crumrine
      Vertical Stratification of Soil Phosphorus as a Concern for Dissolved Phosphorus Runoff in the Lake Erie Basin

      During the re-eutrophication of Lake Erie, dissolved reactive phosphorus (DRP) loading and concentrations to the lake have nearly doubled, while particulate phosphorus (PP) has remained relatively constant. One potential cause of increased DRP concentrations is P stratification, or the buildup of soil-test P (STP) in the upper soil layer (<5 cm). Stratification often accompanies no-till and mulch-till practices that reduce erosion and PP loading, practices that have been widely implemented throughout the Lake Erie Basin. To evaluate the extent of P stratification in the Sandusky Watershed, certified crop advisors were enlisted to collect stratified soil samples (0–5 or 0–2.5 cm) alongside their normal agronomic samples (0–20 cm) (n = 1758 fields). (continued)

      Core Ideas:
      • P stratification increases surficial soil-test levels by 55% over agronomic cores.
      • Agronomic soil-test levels are not good indicators of surficial soil-test levels.
      • Soils in maintenance range account for the largest proportion of DRP runoff risks.
      • Targeted stratification reduction could reduce DRP runoff more than drawdown.
      • Stratification reduction could reduce DRP runoff more quickly than drawdown.

      Published: January 19, 2017

    • Ammar B. Bhandari, Nathan O. Nelson, Daniel W. Sweeney, Claire Baffaut, John A. Lory, Anomaa Senaviratne, Gary M. Pierzynski, Keith A. Janssen and Philip L. Barnes
      Calibration of the APEX Model to Simulate Management Practice Effects on Runoff, Sediment, and Phosphorus Loss

      Process-based computer models have been proposed as a tool to generate data for Phosphorus (P) Index assessment and development. Although models are commonly used to simulate P loss from agriculture using managements that are different from the calibration data, this use of models has not been fully tested. The objective of this study is to determine if the Agricultural Policy Environmental eXtender (APEX) model can accurately simulate runoff, sediment, total P, and dissolved P loss from 0.4 to 1.5 ha of agricultural fields with managements that are different from the calibration data. The APEX model was calibrated with field-scale data from eight different managements at two locations (management-specific models). (continued)

      Core Ideas:
      • The APEX model has limited ability to simulate effects of changing management.
      • If available, multiple management should be used to calibrate and validate the model.
      • Policy makers must exercise caution in using model-estimated P losses to evaluate PIs.

      Published: December 15, 2016

    • William I. Ford, Kevin W. King, Mark R. Williams and Remegio B. Confesor
      Modified APEX model for Simulating Macropore Phosphorus Contributions to Tile Drains

      The contribution of macropore flow to phosphorus (P) loadings in tile-drained agricultural landscapes remains poorly understood at the field scale, despite the recognized deleterious impacts of contaminant transport via macropore pathways. A new subroutine that couples existing matrix-excess and matrix-desiccation macropore flow theory and a modified P routine is implemented in the Agricultural Policy Environmental eXtender (APEX) model. The original and modified formulation were applied and evaluated for a case study in a poorly drained field in Western Ohio with 31 months of surface and subsurface monitoring data. Results highlighted that a macropore subroutine in APEX improved edge-of-field discharge calibration and validation for both tile and total discharge from satisfactory and good, respectively, to very good and improved dissolved reactive P load calibration and validation statistics for tile P loads from unsatisfactory to very good. (continued)

      Core Ideas:
      • The field-scale APEX model is modified to account for macropore P contributions.
      • APEX modifications significantly improve hydrology and P simulations for a case study.
      • Macropore flow contributes approximately 48% of flow and 43% of P annually.
      • The model has potential for informing pathway partitioning in P site assessment tools.

      Published: December 1, 2016

    • Alisha Spears Mulkey, Frank J. Coale, Peter A. Vadas, Gary W. Shenk and Gopal X. Bhatt
      Revised Method and Outcomes for Estimating Soil Phosphorus Losses from Agricultural Land in the Chesapeake Bay Watershed Model

      Current restoration efforts for the Chesapeake Bay watershed mandate a timeline for reducing the load of nutrients and sediment into receiving waters. The Chesapeake Bay watershed model (WSM) has been used for two decades to simulate hydrology and nutrient and sediment transport; however, spatial limitations of the WSM preclude edge-of-field scale representation of phosphorus (P) losses. Rather, the WSM relies on literature-derived, county-scale rates of P loss (targets) for simulated land uses. An independent field-scale modeling tool, Annual Phosphorus Loss Estimator (APLE), was used as an alternative to the current WSM approach. (continued)

      Core Ideas:
      • APLE estimated P losses were compared with the Chesapeake Bay Watershed Model’s (WSM) losses.
      • Substituting the APLE estimated P loss into the WSM improved calibration performance.
      • Findings suggest the importance of well-estimated transport factors in modeling P losses.

      Published: October 6, 2016

    • Mark R. Williams, Kevin W. King, Gregory A. LaBarge, Remegio B. Confesor and Norman R. Fausey
      Edge-Of-Field Evaluation of the Ohio Phosphorus Risk Index

      The Phosphorus Index (PI) has been the cornerstone for phosphorus (P)-based management and planning over the past twenty years, yet field-scale evaluation of many state PIs has been limited. In this study, P loads measured in surface runoff and tile discharge from 40 agricultural fields in Ohio with prevailing management practices were used to evaluate the Ohio PI. Annual P loads were highly variable among fields (dissolved reactive P: 0.03–4.51 kg ha−1, total P: 0.03–6.88 kg ha−1). Both measured annual dissolved reactive P (R2 = 0.36, p < 0.001) and total P (R2 = 0.25, p < 0.001) loads were significantly related to Ohio PI score. (continued)

      Core Ideas:
      • Measured P loads from 40 fields were used to evaluate the Ohio Phosphorus Index.
      • Risk of P loss was linearly related to both measured annual and averaged P loads.
      • Field P management recommendations varied among local, state, and national metrics.
      • Field datasets should be used to improve and calibrate the Ohio Phosphorus Index.

      Published: September 15, 2016

    • Adam Forsberg, David E. Radcliffe, Carl H. Bolster, Aaron Mittelstet, Daniel E. Storm and Deanna Osmond
      Evaluation of the TBET Model for Potential Improvement of Southern P Indices

      Due to a shortage of available phosphorus (P)-loss datasets, simulated data from an accurate quantitative P transport model could be used to evaluate a P Index. The objective of this study was to compare predictions from the Texas Best Management Practice Evaluation Tool (TBET) against measured P-loss data to determine whether the model could be used to improve P Indices in the southern region. Measured P-loss data from field-scale study sites in Arkansas, Georgia, and North Carolina were used to assess the accuracy of TBET for predicting field-scale loss of P. We found that event-based predictions using an uncalibrated model were generally poor. (continued)

      Core Ideas:
      • Predictions from an accurate P transport model could be used to evaluate a P Index.
      • Predictions from an uncalibrated TBET model were generally poor.
      • A calibrated TBET model was better but did not meet the performance criteria.
      • A curve number approach for runoff could be incorporated into P Indices.

      Published: January 19, 2017January 19, 2017


    • Kirsten M. Hammett, Elizabeth J. Mullin, Diana S. Aga, Gary K. Felton, Daniel J. Fisher and Lance T. Yonkos
      In Vitro and In Vivo Assessment of Aqueously Extractable Estrogens in Poultry Manure after Pilot-scale Composting

      Poultry manure contains free and conjugated forms of the natural estrogens 17β-estradiol and estrone, which can be transported to receiving waters via runoff when land-applied. Previous studies have demonstrated estrogens in runoff from poultry manure–amended fields but have not tracked changes in estrogenicity within this water over time. Microbial conversion of conjugated estrogens (a major portion of water-extractable estrogens) to parent forms may result in temporary increases in estrogenicity in natural water bodies. The present study created 80-L batches of simulated poultry manure runoff, which were investigated over 10 d for estrogenicity by bioluminescent yeast estrogen screen assay and fathead minnow (Pimephales promelas) vitellogenin induction model. (continued)

      Core Ideas:
      • Aqueously extractable estrogens were studied in pre- and postcompost poultry manure.
      • Estrogenic activity increased in aqueous poultry manure mixtures over several days.
      • Initial estrogenicity in aqueous manure extracts did not predict later activity.
      • Microbial deconjugation likely liberates estrogen conjugates to active free forms.
      • Composting poultry manure with aeration reduces aqueously extractable estrogenicity.

      Published: April 27, 2017

    • M. Raimonet, T. Cazier, V. Rocher and A. M. Laverman
      Nitrifying Kinetics and the Persistence of Nitrite in the Seine River, France

      Although a higher oxidation rate for nitrite than for ammonia generally prevents nitrite accumulation in oxic waters, nitrite concentrations in the Seine River (1–31 μM) exceed European norms. We investigated the kinetics of in situ ammonia- and nitrite-oxidizing communities in river water and wastewater treatment plant (WWTP) effluents to determine the role of pelagic nitrification in the origin and persistence of nitrite downstream of Paris. The main source of nitrite is the major Parisian WWTP, and its persistence, up to tens of kilometers downstream of the plant, is explained by low ammonia and nitrite oxidation rates and high river flow. Furthermore, similar nitrite and ammonia oxidation rates preclude a rapid consumption of both preexisting nitrite and nitrite produced by ammonia oxidation. (continued)

      Core Ideas:
      • Nitrite in the Seine River mostly originates from wastewater treatment plant effluents.
      • Nitrite persists in the river because of similar ammonia and nitrite oxidation rates.
      • Despite high nitrite concentrations, relatively low nitrite oxidation rates occur, possibly due to mixotrophy.

      Published: April 27, 2017

    • David E. Ruppert, Brian A. Needelman, Peter J.A. Kleinman, Martin C. Rabenhorst, Bahram Momen and David B. Wester
      Hydrology and Soil Manipulations of Iron-Rich Ditch Mesocosms Provide Little Evidence of Phosphorus Capture within the Profile

      Agricultural drainage ditches function as first-order streams and affect nutrient management. Soil mesocosms from a ditch featuring a vertical (increasing upward) gradient in iron (Fe) and phosphorus (P) were subjected to hydraulic and soil treatments. These manipulations mimicked aspects of dredging and controlled drainage and inspected the soil release and retention of P. Treatments did not remove P from simulated groundwater. (continued)

      Core Ideas:
      • Fe-based P capture occurs as Fe oxidizes upon emergence at the ditch surface.
      • At our site, P capture is not based on properties of in-place soil material.
      • Many common techniques assume P capture by in-place soil materials.
      • At our site, P capture appears to occur simultaneous to soil formation.

      Published: April 27, 2017


    • Mara Nothers, Nitzan Segev, Juergen Kreyling, Amgad Hjazin and Elli Groner
      Desert Vegetation Forty Years after an Oil Spill

      Deserts are the most frequent locations of terrestrial crude oil contaminations. Nevertheless, the long-term effects of petroleum hydrocarbons on desert ecosystems are still unknown, which makes risk assessment and decision making concerning remediation difficult. This study examined the long-term effects of petroleum hydrocarbons on perennial desert vegetation. The study site was a hyper-arid area in the south of Israel, which was contaminated by a crude oil spill in 1975. (continued)

      Core Ideas:
      • Long-term effects of an oil spill on plants in a hyper arid desert were studied.
      • An area that had been contaminated 40 yr ago was compared to reference areas.
      • The community composition of perennial plants was not altered.
      • Recruitment of Acacia, the only tree and keystone species, was diminished.

      Published: April 13, 2017


    • Charlotte E. Riggs, Randall K. Kolka, Edward A. Nater, Emma L. Witt, Trent R. Wickman, Laurel G. Woodruff and Jason T. Butcher
      Yellow Perch ( Perca flavescens ) Mercury Unaffected by Wildland Fires in Northern Minnesota

      Wildland fire can alter mercury (Hg) cycling on land and in adjacent aquatic environments. In addition to enhancing local atmospheric Hg redeposition, fire can influence terrestrial movement of Hg and other elements into lakes via runoff from burned upland soil. However, the impact of fire on water quality and the accumulation of Hg in fish remain equivocal. We investigated the effects of fire—specifically, a low-severity prescribed fire and moderate-severity wildfire—on young-of-the-year yellow perch (Perca flavescens) and lake chemistry in a small remote watershed in the Boundary Waters Canoe Area Wilderness in northeastern Minnesota. (continued)

      Core Ideas:
      • The study investigated wildland fire impact on fish mercury and lake chemistry.
      • A paired watershed approach was used in the investigation.
      • Wildland fire decreased upland organic soil carbon and mercury stocks.
      • There was no impact of wildland fire on fish mercury or lake productivity.
      • Lake chemistry and fish mercury varied with climate and lake water levels.

      Published: March 23, 2017


    • Nahal Hoghooghi, David E. Radcliffe, Mussie Y. Habteselassie and Jaehak Jeong
      Modeling the Effects of Onsite Wastewater Treatment Systems on Nitrate Loads Using SWAT in an Urban Watershed of Metropolitan Atlanta

      Onsite wastewater treatment systems (OWTSs) can be a source of nitrogen (N) pollution in both surface and ground waters. In metropolitan Atlanta, GA, >26% of homes are on OWTSs. In a previous article, we used the Soil Water Assessment Tool to model the effect of OWTSs on stream flow in the Big Haynes Creek Watershed in metropolitan Atlanta. The objective of this study was to estimate the effect of OWTSs, including failing systems, on nitrate as N (NO3–N) load in the same watershed. (continued)

      Core Ideas:
      • We examined the importance of OWTSs on stream NO3–N load in the urban watershed.
      • The SWAT model sufficiently predicted the effect of OWTSs on NO3–N load.
      • The NO3–N load was the main component of the total N load in the watershed.

      Published: April 27, 2017


    • Brian Dougherty, Myles Gray, Mark G. Johnson and Markus Kleber
      Can Biochar Covers Reduce Emissions from Manure Lagoons While Capturing Nutrients?

      The unique physical and chemical properties of biochars make them promising materials for odor, gas, and nutrient sorption. Floating covers made from organic materials (biocovers) are one option for reducing odor and gas emissions from livestock manure lagoons. This study evaluated the potential of floating biochar covers to reduce odor and gas emissions while simultaneously sorbing nutrients from liquid dairy manure. This new approach has the potential to mitigate multiple environmental problems. (continued)

      Core Ideas:
      • Biochar biocovers can reduce odor and gas emissions from livestock manure lagoons.
      • Floating biochar covers can passively capture nutrients from livestock manure.
      • Biochars exhibited a range of nutrient retention and emission reduction efficacies.

      Published: April 27, 2017

    • Henry Y. Sintim, Valtcho D. Zheljazkov, Michael E. Foley and Roque L. Evangelista
      Coal-Bed Methane Water: Effects on Soil Properties and Camelina Productivity

      Every year, the production of coal-bed natural gas in the Powder River Basin results in the discharge of large amounts of coal-bed methane water (CBMW) in Wyoming; however, no sustainable disposal methods for CBMW are currently available. A greenhouse study was conducted to evaluate the potential to use CBMW as a source of irrigation water for camelina [Camelina sativa (L.) Crantz]. We assessed the effects of three CBMW concentrations (0% [1:0], 50% [1:1], and 100% [0:1] tap water to CBMW) on selected soil properties, growth, seed oil, and fatty acid composition of three camelina cultivars: Blaine Creek, Ligena, and Pronghorn. The 100% CBMW reduced seed and estimated biofuel yields by 24 and 23%, respectively, but increased the oil content by 3%, relative to the control. (continued)

      Core Ideas:
      • Unsustainable disposal methods for coal-bed methane water (CBMW) is a major problem.
      • Irrigation with 100% CBMW reduced camelina yield and affected soil structure.
      • Irrigation with 1:1 tap water to CBMW had minimal effects on camelina and soil structure.
      • 1:1 tap water to CBMW could be used to irrigate camelina in the short term.
      • There was evidence of Na uptake, but it was at a low level (28 mg Na kg−1).

      Published: April 6, 2017

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