Bioresource and Agricultural Engineering Commons^™

Complete Genome Sequence Of Thauera Aminoaromatica Strain Mz1t, Ke Jiang, John Sanseverino, Archana Chauhan, Susan Lucas, Alex Copeland, Alla Lapidus, Tijana Glavina Del Rio, Eileen Dalin, Hope Tice, David Bruce, Lynne Goodwin, Sam Pitluck, David Sims, Thomas Brettin, John C. Detter, Cliff Han, Y.J. Chang, Frank Larimer, Miriam Land, Loren Hauser, Nikos C. Kyrpides, Natalia Mikhailova, Scott Moser, Patricia Jegier, Dan Close, Jennifer M. Debruyn, Ying Wang, Alice C. Layton, Michael S. Allen, Gary S. Sayler

United States Department of Energy: Publications

Thauera aminoaromatica strain MZ1T, an isolate belonging to genus Thauera, of the family Rhodocyclaceae and the class the Betaproteobacteria, has been characterized for its ability to produce abundant exopolysaccharide and degrade various aromatic compounds with nitrate as an electron acceptor. These properties, if fully understood at the genome-sequence level, can aid in environmental processing of organic matter in anaerobic cycles by short-circuiting a central anaerobic metabolite, acetate, from microbiological conversion to methane, a critical greenhouse gas. Strain MZ1T is the first strain from the genus Thauera with a completely sequenced genome. The 4,496,212 bp chromosome and 78,374 bp plasmid …

The Crystal Structure Of The Extracellular 11-Heme Cytochromeundareveals A Conserved 10-Heme Motif And Defined Binding Site For Soluble Iron Chelates, Marcus J. Edwards, Andrea Hall, Liang Shi, James K. Fredrickson, John M. Zachara, Julea N. Butt, David J. Richardson, Thomas A. Clarke

United States Department of Energy: Publications

Members of the genus Shewanella translocate decaor undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/ egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between …

Three-Dimensional Bayesian Geostatistical Aquifer Characterization At The Hanford 300 Area Using Tracer Test Data, Xingyuan Chen, Haruko Murakami, Melanie S. Hahn, Glenn E. Hammond, Mark Rockhold, John M. Zachara, Yoram Rubin

United States Department of Energy: Publications

Tracer tests performed under natural or forced gradient flow conditions can provide useful information for characterizing subsurface properties, through monitoring, modeling, and interpretation of the tracer plume migration in an aquifer. Nonreactive tracer experiments were conducted at the Hanford 300 Area, along with constant-rate injection tests and electromagnetic borehole flow meter tests. A Bayesian data assimilation technique, the method of anchored distributions (MAD) (Rubin et al., 2010), was applied to assimilate the experimental tracer test data with the other types of data and to infer the three-dimensional heterogeneous structure of the hydraulic conductivity in the saturated zone of the Hanford …

Analysis Of Phase Separation In High Performance Pbte–Pbs Thermoelectric Materials, Steven N. Girard, Klaus Schmidt-Rohr, Thomas C. Chasapis, Euripides Hatzikraniotis, B. Njegic, E. M. Levin, A. Rawal, Konstantinos M. Paraskevopoulos, Mercouri G. Kanatzidis

United States Department of Energy: Publications

Phase immiscibility in PbTe–based thermoelectric materials is an effective means of top-down synthesis of nanostructured composites exhibiting low lattice thermal conductivities. PbTe_{1− x} S_x thermoelectric materials can be synthesized as metastable solid solution alloys through rapid quenching. Subsequent post-annealing induces phase separation at the nanometer scale, producing nanostructures that increase phonon scattering and reduce lattice thermal conductivity. However, there has yet to be any study investigating in detail the local chemical structure of both the solid solution and nanostructured variants of this material system. Herein, quenched and annealed (i.e., solid solution and phase-separated) samples of PbTe–PbS are analyzed …

Nanoscale Structure And Structural Relaxation In Zr50cu45al5 Bulk Metallic Glass, Jinwoo Hwang, Z. H. Melgarejo, Y. E. Kalay, I. Kalay, Matthew J. Kramer, D. S. Stone, P. M. Voyles

United States Department of Energy: Publications

Hybrid reverse Monte Carlo simulations of the structure of Zr₅₀Cu₄₅Al₅ bulk metallic glass incorporating medium-range structure from fluctuation electron microscopy data and short-range structure from an embedded atom potential produce structures with significant fractions of icosahedral- and crystal-like atomic clusters. Similar clusters group together into nanometer-scale regions, and relaxation transforms crystal-like clusters into icosahedral clusters. A model refined against only the potential does not agree with the fluctuation microscopy data and contains few crystal-like clusters.

Enhancement Of Thermopower Of Tags-85 High-Performance Thermoelectric Material By Doping With The Rare Earth Dy, E. M. Levin, S. L. Bud’Ko, K. Schmidt-Rohr

United States Department of Energy: Publications

Enhancement of thermopower is achieved by doping the narrow-band semiconductor Ag_6.52Sb_6.52Ge_36.96Te₅₀ (acronym TAGS-85), one of the best p -type thermoelectric materials, with 1 or 2% of the rare earth dysprosium (Dy). Evidence for the incorporation of Dy into the lattice is provided by X-ray diffraction and increased orientation-dependent local fields detected by ¹²⁵Te NMR spectroscopy. Since Dy has a stable electronic configuration, the enhancement cannot be attributed to 4f -electron states formed near the Fermi level. It is likely that the enhancement is due to a small reduction in the carrier …

Incorporating A Completely Renormalized Coupled Cluster Approach Into A Composite Method For Thermodynamic Properties And Reaction Paths, Sean A. Nedd, Nathan J. Deyonker, Angela K. Wilson, Mark S. Gordon, Piotr Piecuch

United States Department of Energy: Publications

The correlation consistent composite approach (ccCA), using the S4 complete basis set two-point extrapolation scheme (ccCA-S4), has been modified to incorporate the left-eigenstate completely renormalized coupled cluster method, including singles, doubles, and non-iterative triples (CR-CC(2,3)) as the highest level component. The new ccCA-CC(2,3) method predicts thermodynamic properties with an accuracy that is similar to that of the original ccCA-S4 method. At the same time, the inclusion of the single-reference CR-CC(2,3) approach provides a ccCA scheme that can correctly treat reaction pathways that contain certain classes of multi-reference species such as diradicals, which would normally need to be treated by more …

Experimental And Theoretical Electronic Structure Of Eurh2as2, A. D. Palczewski, R. S. Dhaka, Y. Lee, Yogesh Singh, D. C. Johnston, B. N. Harmon, Adam Kaminski

United States Department of Energy: Publications

The Fermi surfaces (FS’s) and band dispersions of EuRh₂As₂ have been investigated using angle-resolved photoemission spectroscopy. The results in the high-temperature paramagnetic state are in good agreement with the full-potential linearized augmented-plane-wave calculations, especially in the context of the shape of the two-dimensional FS’s and band dispersion around the Γ (0,0) and X (π,π) points. Interesting changes in band folding are predicted by the theoretical calculations below the magnetic transition temperature T_N ≈ 47 K. However, by comparing the FS’s measured at 60 and 40 K, we did not observe any signature of this transition at …

Magnetic And Structural Transitions In The Iron-Chalcogenide High-Tc Superconductor: K0.8fe1.76se2.00, W. N. Rowan-Weetaluktuk, D. H. Ryan, J. M. Cadogan, R. Hu, S. L. Bud’Ko, Paul C. Canfield

United States Department of Energy: Publications

⁵⁷Fe Mössbauer spectroscopy was used to study single-crystals of K_0.8Fe_1.76Se_2.00 from 6K to 673 K. At 6 K, the hyperfine field (B_hf) is canted away from the c-axis by 18±3°. The temperature dependence of B_hf follows a spin wave model with a spin excitation gap of 9±1 meV. A sudden increase in the line width and a corresponding drop in (1/2)eQV_zz at T_N = 532 K are indications of strong coupling between the magnetic and structural transitions.

Evaluation Of Niobium As Candidate Electrode Material For Dc High Voltage Photoelectron Guns, M. Bastaninejad, Md. Abdullah Mohamed, A. A. Elmustafa, P. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, R. Mammei, K. Surles-Law, P. Williams

United States Department of Energy: Publications

The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field …

Saturated–Unsaturated Flow In A Compressible Leaky-Unconfined Aquifer, Phoolendra Mishra, Velimir Vesselinov, Kristopher Kuhlman

United States Department of Energy: Publications

An analytical solution is developed for three-dimensional flow towards a partially penetrating largediameter well in an unconfined aquifer bounded below by a leaky aquitard of finite or semi-infinite extent. The analytical solution is derived using Laplace and Hankel transforms, then inverted numerically. Existing solutions for flow in leaky unconfined aquifers neglect the unsaturated zone following an assumption of instantaneous drainage due to Neuman. We extend the theory of leakage in unconfined aquifers by (1) including water flow and storage in the unsaturated zone above the water table, and (2) allowing the finite-diameter pumping well to partially penetrate the aquifer. The …

Comparison Of 2-Way Versus Metered 3-Way Boom Shut-Off Valves For Automatic Section Control On Agricultural Sprayers, Ajay Sharda, Joe D. Luck, John P. Fulton, Timothy P. Mcdonald, Scott A. Shearer, Daniel K. Mullenix

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Modern spray rate controllers along with technologies such as automatic section control (ASC) provide benefits such as overlap reduction on agricultural sprayers. However, product (liquid) dynamics within the boom plumbing affect off-rate errors and application uniformity during rate changes and ASC actuation. Therefore, this study was conducted to compare nozzle flow stability and uniformity across the boom when using two different boom shut-off valves (2-way and metered 3-way) on an 18.3-m sprayer boom. Pressure transducers were mounted at 1) the boom manifold, 2) randomly at 12 nozzle bodies across the spray boom, and 3) upstream and downstream of the flow …

Field Performance Evaluation Of A Ventilation System: A Swine Case Study, Jay D. Harmon, Michael C. Brumm, Larry D. Jacobson, Stephen H. Pohl, David R. Stender, Richard R. Stowell

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building and how they work as a system. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep‐pit swine finishing building with two 1,000‐head rooms. Exhaust fans connected to the manure pit and wall fans were operated at various stages as a negative‐pressure ventilation …

Evaluation Of A Rhodamine-Wt Dye/Glycerin Mixture As A Tracer For Testing Direct Injection Systems For Agricultural Sprayers, Joe D. Luck, Scott A. Shearer, Brian D. Luck, Fred A. Payne

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to provide valuable insight regarding the use of Rhodamine WT (red) dye as a tracer for evaluating injected concentrations. More specifically, the effects of mixing the dye with glycerin to simulate the viscosity of a pesticide (e.g., glyphosate) or injecting the dye/glycerin mixture into deionized (DI) versus tap water on developing appropriate calibration equations were evaluated. Test results indicated that mixing the dye in a solution of glycerin and DI water significantly affected absorbance measurements compared to the dye mixed solely in DI water. The error in estimating absorbance was 7.4% between the two …

Trapping Phosphorus In Runoff With A Phosphorus Removal Structure, Chad J. Penn, Joshua M. Mcgrath, Elliott Rounds, Garey A. Fox, Derek M. Heeren

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reduction of phosphorus (P) inputs to surface waters may decrease eutrophication. Some researchers have proposed fi ltering dissolved P in runoff with P-sorptive byproducts in structures placed in hydrologically active areas with high soil P concentrations. Th e objectives of this study were to construct and monitor a P removal structure in a suburban watershed and test the ability of empirically developed fl ow-through equations to predict structure performance. Steel slag was used as the P sorption material in the P removal structure. Water samples were collected before and after the structure using automatic samples and analyzed for total dissolved …

A Submersible Magnetic Stirrer For Use In Measuring Photosynthesis In A Biofloc Technology Production System, Bartholomew W. Green, E. Gregory O'Neal

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Measuring photosynthesis or primary productivity in biofloc technology production systems is challenging because the biofloc must be maintained in suspension constantly. Photosynthesis can be measured in external incubators designed to keep the biofloc suspended in the biochemical oxygen demand (BOD) bottle, but primary productivity must be measured in the biofloc technology production system culture unit. Therefore, a submersible device is required to keep the biofloc suspended in the BOD bottle. This report details a submersible, air-powered magnetic stirrer that we designed, fabricated from off-the-shelf materials, and tested in biofloc technology production system tanks.

2012 Nebraska Water Monitoring Programs Report, Marty Link, Mike Archer

Nebraska Department of Environmental Quality: Reports

The following Nebraska Department of Environmental Quality staff have contributed to this report with their photos, maps, numbers, words, and editing. Their efforts are greatly appreciated and gratefully acknowledged here: Mike Archer, Ken Bazata, Dave Bubb, Ryan Chapman, Jason Garber, Patrick Hartman, Tom Heatherly, Dave Ihrie, Dan Inman, Greg Michl, Will Myers, Patrick O’Brien (NARD), Brad Routt, and Dave Schumacher.

Sparse Pseudospectral Approximation Method, Paul G. Constantine, Michael Eldred, Eric Phipps

United States Department of Energy: Publications

Multivariate global polynomial approximations – such as polynomial chaos or stochastic collocation methods – are now in widespread use for sensitivity analysis and uncertainty quantification. The pseudospectral variety of these methods uses a numerical integration rule to approximate the Fourier-type coefficients of a truncated expansion in orthogonal polynomials. For problems in more than two or three dimensions, a sparse grid numerical integration rule offers accuracy with a smaller node set compared to tensor product approximation. However, when using a sparse rule to approximately integrate these coefficients, one often finds unacceptable errors in the coefficients associated with higher degree polynomials.

By …

Raman/Rayleigh Scattering And Co-Lif Measurements In Laminar And Turbulent Jet Flames Of Dimethyl Ether, Frederik Fuest, Robert S. Barlow, Jyh-Yuan Chen, Andreas Dreizler

United States Department of Energy: Publications

To reduce the impact of combustion of fossil fuels on air quality and climate change, dimethyl ether (DME) is a promising alternative diesel fuel candidate. Technical combustion processes, including formation of pollutants, are influenced by turbulence–chemistry interaction. Therefore, accurate prediction by computational combustion models of combustion systems burning DME must account for multiple scalars and scalar gradients. The testing of such models requires detailed experiments. Here a study is presented on the feasibility of simultaneous species and temperature measurements in turbulent dimethyl ether flames, using line-imaged Raman/Rayleigh scattering of the major species H₂, O₂, N_{2 …}

Application Of Pdf Mixing Models To Premixed Flames With Differential Diffusion, Edward Richardson, Jacqueline Chen

United States Department of Energy: Publications

Differential diffusion alters the balance of reaction and diffusion in turbulent premixed combustion, affecting the performance and emissions of combustion devices. Modelling combustion devices with Probability or Filtered Density Function (PDF or FDF) methods provides an exact treatment for the change in composition due to chemical reaction, while molecular mixing has to be modelled. Previous PDF molecular mixing models do not account for differential diffusion in a manner which satisfies realizability requirements. A new approach for treating differential diffusion, which ensures realizability, is proposed for pairwise-exchange mixing models in general, and applied in the Interaction by Exchange with the Mean …

Pore-Scale Characterization Of Biogeochemical Controls On Iron And Uranium Speciation Under Flow Conditions, Carolyn I. Pearce, Michael J. Wilkins, Changyong Zhang, Steve M. Heald, James K. Fredrickson, John M. Zachara

United States Department of Energy: Publications

Etched silicon microfluidic pore network models (micromodels) with controlled chemical and redox gradients, mineralogy, and microbiology under continuous flow conditions are used for the incremental development of complex microenvironments that simulate subsurface conditions. We demonstrate the colonization of micromodel pore spaces by an anaerobic Fe(III)-reducing bacterial species (Geobacter sulfurreducens) and the enzymatic reduction of a bioavailable Fe(III) phase within this environment. Using both Xray microprobe and X-ray absorption spectroscopy, we investigate the combined effects of the precipitated Fe(III) phases and the microbial population on uranium biogeochemistry under flow conditions. Precipitated Fe(III) phases within the micromodel were most effectively …

Quantitative 3-D Elemental Mapping By La-Icp-Ms Of A Basaltic Clast From The Hanford 300 Area, Washington, Usa, Sheng Peng, Qinhong Hu, Robert Ewing, Chongxuan Liu, John M. Zachara

United States Department of Energy: Publications

Laser ablation with inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to measure elemental concentrations at the 100-μm scale in a 3-dimensional manner within a basaltic clast sample collected from the Hanford 300 Area in south-central Washington State, United States. A calibration method was developed to quantify the LAICP- MS signal response using a constant-sum mass fraction of eight major elements; the method produced reasonable concentration measurements for both major and trace elements when compared to a standard basalt sample with known concentrations. 3-Dimensional maps (stacked 2-D contour layers, each representing 2100 μm × 2100 μm) show …

Molecular Underpinnings Of Fe(Iii) Oxide Reduction By Shewanella Oneidensis Mr-1, Liang Shi, Kevin Rosso, Tomas Clarke, David Richardson, John M. Zachara, James K. Fredrickson

United States Department of Energy: Publications

In the absence of O₂ and other electron acceptors, the Gram-negative bacterium Shewanella oneidensis MR-1 can use ferric [Fe(III)] (oxy) (hydr) oxideminerals as the terminal electron acceptors for an aerobic respiration. At circumneutral pH and in the absence of strong complexing ligands, Fe(III) oxides are relatively insoluble and thus are external to the bacterial cells. S. oneidensis MR-1 and related strains of metal-reducing Shewanella have evolved machinery (i.e.,metal-reducing or Mtr pathway) for transferring electrons from the inner-membrane, through the periplasmanda cross the outer-membrane to the surface of extracellular Fe(III) oxides. The protein components identified to date for the Mtr …

The ‘Porin–Cytochrome’ Model For Microbe-To-Mineral Electron Transfer, David Richardson, Julea Butt, James K. Fredrickson, John M. Zachara, Liang Shi, Marcus Edwards, Gaye White, Nanakow Baiden, Andrew Gates, Sophie Marritt, Thomas Clarke

United States Department of Energy: Publications

Many species of bacteria can couple anaerobic growth to the respiratory reduction of insoluble minerals containing Fe(III) or Mn(III/IV). It has been suggested that in Shewanella species electrons cross the outer membrane to extracellular substrates via ‘porin–cytochrome’ electron transport modules. The molecular structure of an outer-membrane extracellular-facing deca-haem terminus for such a module has recently been resolved. It is debated how, once outside the cells, electrons are transferred from outer-membrane cytochromes to insoluble electron sinks. This may occur directly or by assemblies of cytochromes, perhaps functioning as ‘nanowires’, or via electron shuttles. Here we review recent work in this field …

Methane And Carbon Dioxide Production From Simulated Anaerobic Degradation Of Cattle Carcasses, Qi Yuan, Samuel Saunders, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Approximately 2.2 million cattle carcasses require disposal annually in the United States. Land burial is a convenient disposal method that has been widely used in animal production for disposal of both daily mortalities as well as during catastrophic mortality events. To date, greenhouse gas production after mortality burial has not been quantified, and this study represents the first attempt to quantify greenhouse gas emissions from land burial of animal carcasses. In this study, anaerobic decomposition of both homogenized and unhomogenized cattle carcass material was investigated using bench-scale reactors. Maximum yields of methane and carbon dioxide were 0.33 and 0.09 m …

Fabrication And Characterization Of Dna-Loaded Zein Nanospheres, Mary C. Regier, Jessica D. Taylor, Tyler Borcyk, Yiqi Yang, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background: Particulates incorporating DNA are promising vehicles for gene delivery, with the ability to protect DNA and provide for controlled, localized, and sustained release and transfection. Zein, a hydrophobic protein from corn, is biocompatible and has properties that make it a promising candidate material for particulate delivery, including its ability to form nanospheres through coacervation and its insolubility under physiological conditions, making it capable of sustained release of encapsulated compounds. Due to the promise of this natural biomaterial for drug delivery, the objective of this study was to formulate zein nanospheres encapsulating DNA as the therapeutic compound, and to …

Runoff Nutrient Loads As Affected By Residue Cover, Manure Application Rate, And Flow Rate, Chance Thayer, John E. Gilley, Lisa M. Durso, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Manure is applied to cropland areas with varying surface cover to meet single‐year or multiple‐year crop nutrient requirements. The objectives of this field study were to: (1) examine runoff water quality characteristics following land application of manure to sites with and without wheat residue, (2) compare the water quality impacts of land application of manure to meet 0‐, 1‐, 2‐, 4‐, and 8‐year P‐based requirements for corn, and (3) evaluate the effects of varying runoff rates on runoff nutrient loads. Three 30‐min simulated rainfall events, separated by 24 h intervals, were applied at an intensity of 70 mm h^{‐1 …}

Quantification And Heterogeneity Of Infiltration And Transport In Alluvial Floodplains, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Peter Q. Storm, Brian E. Haggard, Todd Halihan, Ronald B. Miller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In order to protect drinking water systems and aquatic ecosystems, all critical nutrient source areas and transport mechanisms need to be characterized. It is hypothesized that hydrologic heterogeneities (e.g., macropores and gravel outcrops) in the subsurface of floodplains play an integral role in impacting flow and contaminant transport between the soil surface and shallow alluvial aquifers which are intricately connected to streams. Infiltration is often assumed to be uniform at the field scale, but this neglects the high spatial variability common in anisotropic, heterogeneous alluvial floodplain soils. In the Ozark ecoregion, for example, the erosion of carbonate bedrock (primarily limestone) …

Berm Method For Quantification Of Infiltration And Leaching At The Plot Scale In High Conductivity Soils, Derek M. Heeren, Garey A. Fox, Daniel E. Storm

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Measuring infiltration and leaching at the plot scale is difficult, especially for high hydraulic conductivity soils. Infiltration rate has been indirectly calculated at the plot scale by comparing surface runoff to rainfall. Direct measurement of infiltration and leaching beyond the point scale is typically limited to locations where land forming has been performed, e.g. infiltration ponds and fields with basin irrigation. The standard method for field measurement of infiltration is a double ring infiltrometer, which is limited in size (typically 30 cm diameter). In this research, a new method is proposed that uses a temporary berm constructed of a water …

Field Scale Modeling To Estimate Phosphorus And Sediment Load Reductions Using A Newly Developed Graphical User Interface For Soil And Water Assessment Tool, Aaron R. Mittelstet, Erin R. Daly, Daniel E. Storm, Michael J. White, Greg A. Kloxin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Streams throughout the North Canadian River watershed in northwest Oklahoma, USA have elevated levels of nutrients and sediment. Soil and Water Assessment Tool (SWAT) was used to identify areas that likely contributed disproportionate amounts of Phosphorus (P) and sediment to Lake Overholser, the receiving reservoir at the watershed outlet. These sites were then targeted by the Oklahoma Conservation Commission (OCC) to implement conservation practices, such as conservation tillage and pasture planting as part of a US Environmental Protection Agency Section 319(h) project. Conservation practices were implemented on 238 fields. The objective of this project was to evaluate conservation practice effectiveness …