bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Physical and Chemical Water Properties from Relationships with Watershed Soil Characteristics
Authors: Shirazi Mostafa A. , Boersma Larry , Johnson Colleen Burch , Haggerty Patricia K.
Published: June 2010

The Surface Waters component of the Environmental Monitoring and Assessment Program (EMAPSW) was developed by the USEPA to evaluate the extent and condition of lakes and streams over national and regional scales. Realistically, chemical or physical water properties (WPs) such as acidity or turbidity can be field‐sampled for only a small portion of all lakes and streams. However, soil characteristics (SCs) affect WPs and broad‐scale soil survey data have become available in the State Soil Geographic Data Base (STATSGO). We developed models relating observed WPs to SCs to extrapolate the sampled WPs to a region, potentially reducing extensive monitoring needs. Our study region consisted of 13 northeastern and Mid‐Atlantic states and contained 882 STATSGO soil map units. We used map units as the spatial component of WP analysis. The WPs were sampled in 721 randomly selected EMAPSW study sites. The watersheds of these sites represent 7.1% of the region's total area and spatially intersect 400 of its soil map units. Each intersected map unit was assigned the weighted average WPs from the corresponding watersheds. Conditional expectation models were used to extrapolate sampled WPs to 882 map units. The relative standard errors ranged from low for pH (0.8%), intermediate for total P (12.1%), and very high for chloride (54.8%). The high extrapolation errors indicate outlier conditions from natural, non‐soil, or anthropogenic sources.
Photodegradation of Selected Herbicides in Various Natural Waters and Soils under Environmental Conditions
Authors: Konstantinou Ioannis K. , Zarkadis Antonios K. , Albanis Triantafyllos A.
Published: June 2010

The photochemical degradation of herbicides belonging to different chemical groups has been investigated in different types of natural waters (ground, river, lake, marine) and distilled water as well as in soils with different texture and composition. Studied herbicides and chemical groups included atrazine, propazine, and prometryne (s‐triazines); propachlor and propanil (acetanilides); and molinate (thiocarbamate). The degradation kinetics were monitored under natural conditions of sunlight and temperature. Photodegradation experiments were performed in May through July 1998 at low concentrations in water samples (2–10 mg/L) and soil samples (5–20 mg/kg), which are close to usual field dosage. The photodegradation rates of all studied herbicides in different natural waters followed a pseudo–first order kinetics. The half‐lives of the selected herbicides varied from 26 to 73 calendar days in waters and from 12 to 40 d in soil surfaces, showing that the degradation process depends on the constitution of the irradiated media. The presence of humic substances in the lake, river, and marine water samples reduces degradation rates in comparison with the distilled and ground water. On the contrary, the degradation in soil is accelerated as the percentage of organic matter increases. Generally, the photodegradation process in soil is faster than in water. The major photodegradation products identified by using gas chromatography–mass spectrometry (GC–MS) techniques were the hydroxy and dealkylated derivatives for s‐triazines, the dechlorinated and hydroxy derivative for the anilides, and the keto‐derivative for the thiocarbamate, indicating a similar mode of degradation for each chemical category.
Biosolids Application in the Chihuahuan Desert: Effects on Runoff Water Quality
Authors: Rostagno César M. , Sosebee Ronald E.
Published: June 2010

Surface‐applied biosolids, the option most often used on rangelands, can increase the concentration of macronutrients and trace elements in the runoff water and can potentially produce eutrophication or contamination of surface waters. In this study, the effects of postapplication age of biosolids (18, 12, 6, and 0.5 mo) and rate of application (0, 7, 18, 34, and 90 Mg ha−1) on the quality of runoff water from shrubland and grassland soils were assessed. Between July and October 1996 simulated rainfall was applied to 0.50‐m2plots for 30 min at a rate of 160 mm h−1. All of the runoff water was collected. The concentration of NH+4–N, NO−3–N, PO3−4–P, total dissolved phosphorus (TDP), Cu, and Mn in the runoff water increased with rate of biosolids application and decreased with time of postapplication on the two soils. The highest PO3−4–P and NH+4–N concentrations, 4.96 and 97 mg L−1, respectively, were recorded in the grassland soil treated with 90 Mg ha−1of biosolids 0.5 mo postapplication. For the same soil, rate, and postapplication age of biosolids, Cu exceeded the upper limit (0.50 mg L−1) in drinking water for livestock. Ammonium N and PO3−4–P should be the main compounds considered when surface‐applying biosolids. Ammonium N at concentrations found in all biosolids‐treated plots may affect the quality of livestock drinking water by causing taste and smell problems. Orthophosphate can contribute to eutrophication if the runoff from biosolids‐treated areas enter surface waters.
Field‐Scale Preferential Transport of Water and Chloride Tracer by Depression‐Focused Recharge
Authors: Derby Nathan E. , Knighton Raymond E.
Published: June 2010

A tracer study was initiated in November 1993 to investigate depression‐focused recharge and to monitor solute movement through the vadose zone into the shallow ground water in southeastern North Dakota. Granular potassium chloride (KCl) was surface‐applied to two areas overlying subsurface drains and to one area instrumented with soil solution samplers, ground water monitoring wells, time domain reflectometry (TDR) probes, and temperature probes. One of the subsurface drain tracer plots was located on level ground while the other two sites were in small topographic depressions. Formation of ground water mounds beneath the depressions indicated that these areas are recharge sites. The applied Cl− tracer was found to move rapidly to the shallow ground water under the depressional areas after infiltration of spring snowmelt in 1994. Excessive rainfall events were also responsible for focused recharge and the rapid transport of the applied Cl− tracer. Water flow through partially frozen soil at the bottom of the depressions during thaw enhanced preferential movement of the tracer.
Nutrient Movement and Removal in a Switchgrass Biomass–Filter Strip System Treated with Dairy Manure
Authors: Sanderson Matt A. , Jones Ronald M. , McFarland Marshall J. , Stroup Jason , Reed Roderick L. , Muir James P.
Published: June 2010

Manure use on cropland has raised concern about nutrient contamination of surface and ground waters. Warm‐season perennial grasses may be useful in filter strips to trap manure nutrients and as biomass feedstock for nutrient removal. We explored the use of ‘Alamo’ switchgrass (Panicum virgatum L.) in a biomass production–filter strip system treated with dairy manure. We measured changes in extractable P in the soil, NO3–N in soil water, and changes in total reactive P and chemical oxygen demand (COD) of runoff water before and after a switchgrass filter strip. Five rates of dairy manure (target rates of 0, 50, 100, 150, and 200 kg N ha−1 from solid manure in 1995; 0, 75, 150, 300, and 600 kg N ha−1 from lagoon effluent in 1996 and 1997) were surface‐applied to field plots of switchgrass (5.2 by 16.4 m) with a 5.2‐ by 16.4‐m switchgrass filter strip below the manured area. Yield of switchgrass from the manured area increased linearly with increasing manure rate in each year. Soil water samples collected at 46 or 91 cm below the soil surface on 30 dates indicated <3 mg L−1 of NO3–N in all plots. Concentrations of total reactive P in surface runoff water were reduced an average of 47% for the 150 kg N rate and 76% for the 600 kg N rate in 1996 and 1997 after passing through the strip. Manure could effectively substitute for inorganic fertilizer in switchgrass biomass production with dual use of the switchgrass as a vegetative filter strip.
Rapid Methods to Determine Potentially Mineralizable Nitrogen in Broiler Litter
Authors: Qafoku O. S. , Cabrera M. L. , Windham W. R. , Hill N. S.
Published: June 2010

Although broiler (chicken,Gallus gallus domesticus) litter has long been used as a fertilizer, estimating the rate required to supply a desired amount of plant‐available N is still hampered by the lack of rapid methods to estimate potentially mineralizable nitrogen (PMN). Previous research has suggested that near infrared reflectance spectroscopy (NIRS) and certain poultry litter characteristics, such as water‐soluble organic nitrogen (WSON), may be useful for estimating PMN. The objectives of this study were to evaluate NIRS and WSON as tools to estimate PMN in broiler litter. Sixty sieved (2 mm) and freeze‐dried broiler litter samples were mixed with Cowarts sandy loam soil (fine‐loamy, kaolinitic, thermic Typic Kanhapludult) and incubated at 25°C for 112 d. Cumulative net N mineralized with time was fitted to a single‐pool exponential model to determine PMN for each broiler litter sample. The PMN values obtained were regressed against NIRS (780 to 2500 nm) and WSON measurements. We found strong relationships between measured‐ and NIRS‐predicted PMN, and between measured PMN and WSON. These results demonstrate the feasibility of using either of these two methods to estimate PMN in broiler litter. Future work should further test both methods for their ability to estimate mineralizable N in whole, moist broiler litter under field conditions.
Transport of Escherichia coli in Sand Columns with Constant and Changing Water Contents
Authors: Powelson David K. , Mills Aaron L.
Published: June 2010

Understanding how changes in volumetric water content (θ) affect bacterial adsorption could help reduce transport of pathogenic and indicator bacteria that may be present in infiltrating wastewater. Three flow regimes that simulated infiltration from a household septic system were evaluated: saturated, unsaturated with a constant volumetric water content θ (constant unsaturated flow), and unsaturated with cyclic changes in θ (variable unsaturated flow). Escherichia coli was suspended in artificial sewage (AS) and applied as step inputs to sand columns, with regular interruptions in input for variable unsaturated flow. A transport model was fit to the saturated and constant unsaturated flow breakthrough curves to determine retardation (R), the first‐order filtration coefficient (μ), and the maximum outflow relative concentration (Cmax). The total cells transported as a fraction of input (τ) in all three flow regimes was calculated. Constant unsaturated flow resulted in a significantly lower Cmax (0.633) in comparison with saturated flow (0.803, P ≤ 0.05), although unsaturated μ (0.0693 h−1) was not significantly different from saturated μ (0.0259 h−1). Constant unsaturated flow also resulted in a significantly smaller τ (0.617) than saturated (0.806) or variable unsaturated flow (0.734). In variable unsaturated flow, cell concentrations were out of phase with θ—as the column drained, cell concentrations in the outflow increased; and when a pulse of suspension was applied, cell concentrations decreased. Constant unsaturated flow is probably the best for removal of pathogenic bacteria because this regime resulted in lower maximum concentrations of E. coli and greater cell removal, in comparison with saturated and variable unsaturated flow.
Alfalfa Rapidly Remediates Excess Inorganic Nitrogen at a Fertilizer Spill Site
Authors: Russelle Michael P. , Lamb JoAnn F.S. , Montgomery Bruce R. , Elsenheimer Donald W. , Miller Bradley S. , Vance Carroll P.
Published: June 2010

By 1996, standard remediation techniques had significantly reduced the concentration of nitrate nitrogen (NO−3–N) in local ground water at the site of a 1989 anhydrous ammonia spill, but NO−3–N concentrations in portions of the site still exceeded the public drinking water standard. Our objective was to determine whether local soil and ground water quality could be improved with alfalfa (Medicago sativaL.). A 3‐yr study was conducted in replicated plots (24 by 30 m) located hydrologically upgradient of the ground water under the spill site. Three alfalfa entries [‘Agate’, Ineffective Agate (a non‐N2–fixing elite germplasm similar to Agate), and MWNC‐4 (an experimental germplasm)] were seeded in the spring of 1996. Corn (Zea maysL.) or wheat (Triticum aestivumL.) was seeded adjacent to the alfalfa each year. Crops were irrigated with N‐containing ground water to meet water demand. During the 3‐yr period, about 540 kg of inorganic N was removed from the aquifer through irrigation of 4.9 million L water. Cumulative N removal from the site over 3 yr was 972 kg N ha−1in Ineffective Agate alfalfa hay, compared with 287 kg N ha−1for the annual cereal grain. Soil solution NO−3concentrations were reduced to low and stable levels by alfalfa, but were more variable under the annual crops. Ground water quality improved, as evidenced by irrigation water N concentration. We do not know how much N was removed by the N2–fixing alfalfas, but it appears that either fixing or non‐N2–fixing alfalfa will effectively remove inorganic N from N‐affected sites.
Phosphate Release from Seasonally Flooded Soils
Authors: Young Eric O. , Ross Donald S.
Published: June 2010

Phosphorus derived from agricultural practices has been targeted as a leading cause of water quality degradation in Lake Champlain. Mobilization of P from seasonally flooded agricultural soils is a concern. Using 14 soils from a research farm in New York's Champlain Valley, we characterized the available P status, extractable Fe and Al, P sorption capacities, and soluble phosphate release in flooded laboratory microcosms. Quantities of NH4–acetate available P ranged from 3 to 100 mg kg−1 and fluoride‐extractable P from 10 to 211 mg kg−1 Flooding soils induced significant release of phosphate to the porewater over a 60‐ to 90‐d period in 13 of the 14 soils studied. Porewater phosphate increases ranged from 2.2 to 27.0 times the initial phosphate concentrations. However, floodwater phosphate increases were much lower, with a maximum of 3.6 times the initial concentration. Average porewater phosphate concentrations over the flooding period ranged from 0.046 to 7.0 mg L−1 and average floodwater P from 0.032 to 3.70 mg L−1 Ammonium‐acetate P and the degree of phosphorus saturation (DPS) were highly correlated with the average porewater and floodwater phosphate concentration. Average ratio of porewater to floodwater phosphate concentrations ranged from 1.0 to 3.3. Five soils that were lower in fluoride‐extractable P had increasing porewater phosphate accompanied by increasing porewater Fe2+ and decreasing floodwater phosphate. Results suggest that P solubility and mobility were a function of both the available P status and redox cycling.
Overview of Hypoxia around the World
Authors: Diaz Robert J.
Published: June 2010

No other environmental variable of such ecological importance to estuarine and coastal marine ecosystems around the world has changed so drastically, in such a short period of time, as dissolved oxygen. While hypoxic and anoxic environments have existed through geological time, their occurrence in shallow coastal and estuarine areas appears to be increasing, most likely accelerated by human activities. Several large systems, with historical data, that never reported hypoxia at the turn of the 19th century (e.g., Kattegat, the sea between Sweden and Denmark) now experience severe seasonal hypoxia. Synthesis of literature pertaining to benthic hypoxia and anoxia revealed that the oxygen budgets of many major coastal ecosystems have been adversely affected mainly through the process of eutrophication (the production of excess organic matter). It appears that many ecosystems that are now severely stressed by hypoxia may be near or at a threshold of change or collapse (loss of fisheries, loss of biodiversity, alteration of food webs).
Nitrogen Input to the Gulf of Mexico
Authors: Goolsby Donald A. , Battaglin William A. , Aulenbach Brent T. , Hooper Richard P.
Published: June 2010

Historical streamflow and concentration data were used in regression models to estimate the annual flux of nitrogen (N) to the Gulf of Mexico and to determine where the nitrogen originates within the Mississippi Basin. Results show that for 1980–1996 the mean annual total N flux to the Gulf of Mexico was 1568000 t yr−1 The flux was about 61% nitrate N, 37% organic N, and 2% ammonium N. The flux of nitrate N to the Gulf has approximately tripled in the last 30 years with most of the increase occurring between 1970 and 1983. The mean annual N flux has changed little since the early 1980s, but large year‐to‐year variations in N flux occur because of variations in precipitation. During wet years the N flux can increase by 50% or more due to flushing of nitrate N that has accumulated in the soils and unsaturated zones in the basin. The principal source areas of N are basins in southern Minnesota, Iowa, Illinois, Indiana, and Ohio that drain agricultural land. Basins in this region yield 1500 to more than 3100 kg N km−2 yr−1 to streams, several times the N yield of basins outside this region.
Effect on Water Resources from Upstream Water Diversion in the Ganges Basin
Authors: Adel Miah M.
Published: June 2010

Bangladesh faces at least 30 upstream water diversion constructions of which Farakka Barrage is the major one. The effects of Farakka Barrage on water resources, socioeconomy, and culture have been investigated downstream in the basins of the Ganges and its distributaries. A diversion of up to 60% of the Ganges water over 25 yr has caused (i) reduction of water in surface water resources, (ii) increased dependence on ground water, (iii) destruction of the breeding and raising grounds for 109 species of Gangetic fishes and other aquatic species and amphibians, (iv) increased malnutrition, (v) deficiency in soil organic matter content, (vi) change in the agricultural practices, (vii) eradication of inland navigable routes, (viii) outbreak of water‐borne diseases, (ix) loss of professions, and (x) obstruction to religious observances and pastimes. Further, arsenopyrites buried in the prebarrage water table have come in contact with air and formed water‐soluble compounds of arsenic. Inadequate recharging of ground water hinders the natural cleansing of arsenic, and threatens about 75000000 lives who are likely to use water contaminated with up to 2 mg/L of arsenic. Furthermore, the depletion of surface water resources has caused environmental heating and cooling effects. Apart from these effects, sudden releases of water by the barrage during the flood season cause devestating floods. In consideration of such a heavy toll for the areas downstream, strict international rules have to be laid down to preserve the riparian ecosystems.
Greenhouse Gas Emissions during Cattle Feedlot Manure Composting
Authors: Hao Xiying , Chang Chi , Larney Francis J. , Travis Greg R.
Published: June 2010

The emission of greenhouse gases (GHG) during feedlot manure composting reduces the agronomic value of the final compost and increases the greenhouse effect A study was conducted to determine whether GHG emissions are affected by composting method. Feedlot cattle manure was composted with two aeration methods—passive (no turning) and active (turned six times). Carbon lost in the forms of CO2 and CH4 was 73.8 and 6.3 kg C Mg−1 manure for the passive aeration treatment and 168.0 and 8.1 kg C Mg−1 manure for the active treatment. The N loss in the form of N2O was 0.11 and 0.19 kg N Mg−1 manure for the passive and active treatments. Fuel consumption to turn and maintain the windrow added a further 4.4 kg C Mg−1 manure for the active aeration treatment. Since CH4 and N2O are 21 and 310 times more harmful than CO2 in their global warming effect, the total GHG emission expressed as CO2–C equivalent was 240.2 and 401.4 kg C Mg−1 manure for passive and active aeration. The lower emission associated with the passive treatment was mainly due to the incomplete decomposition of manure and a lower gas diffusion rate. In addition, turning affected N transformation and transport in the windrow profile, which contributed to higher N2O emissions for the active aeration treatment. Gas diffusion is an important factor controlling GHG emissions. Higher GHG concentrations in compost windrows do not necessarily mean higher production or emission rates.
Solid‐State Nitrogen‐15 Nuclear Magnetic Resonance Analysis of Biologically Reduced 2,4,6‐Trinitrotoluene in a Soil Slurry Remediation
Authors: Knicker Heike , Achtnich Christof , Lenke Hiltrud
Published: June 2010

Soil contaminated with 2,4,6‐trinitrotoluene (TNT) and spiked with [14C]‐ and [15N3]‐TNT was subjected to an anaerobic–aerobic soil slurry treatment and subsequently analyzed by radiocounting and solid‐state 15N nuclear magnetic resonance (NMR) spectroscopy. This treatment led to a complete disappearance of extractable radioactivity originating from TNT and almost all of the radioactivity was recovered in the insoluble soil fraction. As revealed by solid‐state 15N NMR, a major fraction of partially reduced metabolites of TNT was immobilized into the soil during the early stage of the anaerobic treatment, although some of the compounds (i.e., aminodinitrotoluenes and azoxy compounds) were extractable by methanol. Considerable 15N intensity was assigned to condensation products of TNT metabolites. A smaller signal indicated the formation of azoxy N. This signal and the signal for nitro groups were not observed at the end of the anaerobic phase, revealing further reduction and/or transformation of their corresponding compounds. An increase of the relative proportion of the condensation products occurred with increasing anaerobic incubation. Aerobic incubation resulted in a further decrease of aromatic amines, presumably due to oxidative transformations or their involvement in further condensation reactions. The results of the study demonstrate that the anaerobic–aerobic soil slurry treatment represents an efficient strategy for immobilizing reduced TNT in soils.
Use of Diammonium Phosphate to Reduce Heavy Metal Solubility and Transport in Smelter‐Contaminated Soil
Authors: McGowen S.L. , Basta N.T. , Brown G.O.
Published: June 2010

Phosphate treatments can reduce metal dissolution and transport from contaminated soils. However, diammonium phosphate (DAP) has not been extensively tested as a chemical immobilization treatment. This study was conducted to evaluate DAP as a chemical immobilization treatment and to investigate potential solids controlling metal solubility in DAP‐amended soils. Soil contaminated with Cd, Pb, Zn, and As was collected from a former smelter site. The DAP treatments of 460, 920, and 2300 mg P kg−1and an untreated check were evaluated using solute transport experiments. Increasing DAP decreased total metal transported. Application of 2300 mg P kg−1was the most effective for immobilizing Cd, Pb, and Zn eluted from the contaminated soil. Metal elution curves fitted with a transport model showed that DAP treatment increased retardation (R) 2‐fold for Cd, 6‐fold for Zn, and 3.5‐fold for Pb. Distribution coefficients (Kd) increased with P application from 4.0 to 9.0 L kg−1for Cd, from 2.9 to 10.8 L kg−1for Pb, and from 2.5 to 17.1 L kg−1for Zn. IncreasedKdvalues with additional DAP treatment indicated reduced partitioning of sorbed and/or precipitated metal released to mobile metal phases and a concomitant decrease in the concentration of mobile heavy metal species. Activity‐ratio diagrams indicated that DAP decreased solution Cd, Pb, and Zn by forming metal–phosphate precipitates with low solubility products. These results suggest that DAP may have potential for protecting water resources from heavy metal contamination near smelting and mining sites.
Measurement and Modeling of Diclosulam Runoff under the Influence of Simulated Severe Rainfall
Authors: van Wesenbeeck I.J. , Peacock A.L. , Havens P.L.
Published: June 2010

A runoff study was conducted near Tifton, GA to measure the losses of water, sediment, and diclosulam (N‐(2,6‐dichlorophenyl)‐5‐ethoxy‐7‐fluoro‐[1,2,4]triazolo‐[1,5c]‐pyrimidine‐2‐sulfonamide), a new broadleaf herbicide, under a 50‐mm‐in‐3‐h simulated rainfall event on three separate 0.05‐ha plots. Results of a runoff study were used to validate the Pesticide Root Zone Model (PRZM, v. 3.12) using field‐measured soil, chemical, and weather inputs. The model‐predicted edge‐of‐field diclosulam loading was within 1% of the average observed diclosulam runoff from the field study; however, partitioning between phases was not as well predicted. The model was subsequently used with worst‐case agricultural practice inputs and a 41‐yr weather record from Dublin, GA to simulate edge‐of‐field runoff losses for the two most prevalent soils (Tifton and Bibb) in the southeastern U.S. peanut (Arachis hypogaea L.) market for 328 simulation years, and showed that the 90th percentile runoff amounts, expressed as percent of applied diclosulam, were 1.8, 0.6, and 5.2% for the runoff study plots and Tifton and Bibb soils, respectively. The runoff study and modeling indicated that more than 97% of the total diclosulam runoff was transported off the field by water, with <3% associated with the sediment. Diclosulam losses due to runoff can be further reduced by lower application rates, tillage and crop residue management practices that reduce edge‐of‐field runoff, and conservation practices such as vegetated filter strips.
Detailed Characterization of Solute Transport in a Heterogeneous Field Soil
Authors: Garrido Fernando , Ghodrati Masoud , Campbell Chris G. , Chendorain Michael
Published: June 2010

There is a necessity for improved physical understanding of solute transport processes in heterogeneous soil systems. In situ nondestructive techniques like time domain reflectometry (TDR) and fiber optic miniprobes (FOMPs) permit the collection of unique measurements of solute transport processes in soils for the purposes of model development and validation. This study examined the application of TDR and FOMPs to measure solute transport at various points laterally and at two depths in a heterogeneous clay‐loam soil. A miscible displacement experiment was performed at a constant irrigation flux to examine the applicability of these probes to field soils. In their first application to a field soil, the FOMPs were successfully calibrated and performed well in measuring solute breakthrough curves. Two flow regimes were identified in the soil profile, the first where lateral spreading of the solute occurred in the surface horizon, followed by convergence into preferential flow pathways in the second transport zone. The measured transport response was heterogeneous with at least two identifiable vertical flow phases. It was demonstrated using transfer function modeling and data from a corresponding laboratory study that the FOMPs were measuring the slower phase, while the TDR probes captured a composite of the fast and slow phases. The combination of these two techniques may be a means to separate solute transport phases in heterogeneous media and relate laboratory column results to field studies.
SOIL–SOILN Simulations of Water Drainage and Nitrate Nitrogen Transport from Soil Core Lysimeters
Authors: Jabro J.D. , Stout W.L. , Fales S.L. , Fox R.H.
Published: June 2010

Water resources protection from nitrate nitrogen (NO3–N) contamination is an important public concern and a major national environmental issue. The abilities of the SOIL–SOILN model to simulate water drainage and nitrate N fluxes from orchardgrass (Dactylis glomerata L.) were evaluated using data from a 3‐yr field experiment. The soil is classified as a Hagerstown silt loam soil (fine, mixed, semiactive, mesic Typic Hapludalf). Nitrate losses below the 1‐m depth from N‐fertilized grazed orchardgrass were measured with intact soil core lysimeters. Five N‐fertilizer treatments consisted of a control, urine application in the spring, urine application in the summer, urine application in the fall, and feces application in the summer. The SOIL–SOILN models were evaluated using water drainage and nitrate flux data for 1993–1994, 1994–1995, and 1995–1996. The N rate constants from a similar experiment with inorganic fertilizer and manure treatments under corn (Zea mays L.) were used to evaluate the SOILN model under orchardgrass sod. Results indicated that the SOIL model accurately simulated water drainage for all three years. The SOILN model adequately predicted nitrate losses for three urine treatments in each year and a control treatment in 1994–1995. However, it failed to produce accurate simulations for two control treatments in 1993–1994 and 1995–1996, and feces treatments in all three years. The inaccuracy in the simulation results for the control and feces treatments seems to be related to an inadequate modeling of N transformation processes. In general, the results demonstrate the potential of the SOILN model to predict NO3–N fluxes under pasture conditions using N transformation rate constants determined through the calibration process from corn fields on similar soils.
Influence of Fly Ash on Soil Physical Properties and Turfgrass Establishment
Authors: Adriano Domy C. , Weber John T.
Published: June 2010

A field study (1993–96) assessed the benefits of applying unusually high rates of coal fly ash as a soil amendment to enhance water retention of soils without adversely affecting growth and marketability of the turf species, centipedegrass [Eremochloa ophiuroides (Munro) Hack.]. A Latin Square plot design was employed that included 0 (control, no ash applied), 280, 560, and 1120 Mg ha−1 application rates of unweathered precipitator fly ash. The fly ash was spread evenly over each plot area, rototilled, and allowed to weather under natural conditions for 8 mo before seeding. High levels of soluble salts, indicated by the electrical conductivity (EC) of soil extracts, in tandem with an apparent phytotoxic effect from boron (B), apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil. However, plant height and rooting depth were not adversely affected, as were the dry matter (DM) yields throughout the study period. Ash treatment did not significantly influence water infiltration rate, bulk density, or temperature of the soil, but substantially improved water‐holding capacity (WHC) and plant‐available water (PAW). Enhanced water retention capacity improved the cohesion and handling property of harvested sod.
Hydrologic Behavior of Two Engineered Barriers following Extreme Wetting
Authors: Porro Indrek
Published: June 2010

Many engineered barriers are expected to function for hundreds of years or longer. Over the course of time, it is likely that some barriers will experience infiltration to the point of breakthrough. This study compares the recovery from breakthrough of two storage–evapotranspiration type engineered barriers. Replicates of test plots comprising thick soil and capillary–biobarrier covers were wetted to breakthrough in 1997. Test plots were kept cleared of vegetation to maximize hydrologic stress during recovery. Following cessation of drainage resulting from the wetting irrigations, water storage levels in all plots were at elevated levels compared with pre‐irrigation levels. As a result, infiltration of melting snow during the subsequent spring overloaded the storage capacity and produced drainage in all plots. Relatively rapid melting of accumulated snowfall produced the most significant infiltration events each year during the study. Capillary barriers yielded less total drainage than thick soil barriers. By limiting drainage, capillary barriers increased water storage in the upper portions of the test plots, which led to increased evaporation from the capillary barrier plots compared with thick soil plots. Increased evaporation in the capillary barrier plots allowed more water to infiltrate in the second season following the wetting tests without triggering drainage. All thick soil plots again yielded drainage in the second season. Within two years of intentionally induced breakthrough, evaporation alone (without transpiration) restored the capability of the capillary barrier covers to function as intended, although water storage in these covers remained at elevated levels.
Hydrologic Influence on Stability of Organic Phosphorus in Wetland Detritus
Authors: Pant H.K. , Reddy K.R.
Published: June 2010

Accretion of organic matter in wetlands provides long‐term storage for nutrients and other contaminants. Water‐table fluctuations and resulting alternate flooded and drained conditions may substantially alter the stability of stored materials including phosphorus (P). To study the effects of hydrologic fluctuation on P mobilization in wetlands, recently accreted detrial material (derived primarily from Typha spp.) was collected from the Everglades Nutrient Removal Project (ENRP), a constructed wetland used to treat agricultural drainage water in the northern Everglades. The detrital material was subjected to different periods of drawdown and consecutive reflooding under laboratory conditions. The 31P nuclear magnetic resonance (31P NMR) spectroscopy analysis revealed that sugar phosphate, glycerophosphate, polynucleotides, and phospholipids (glycerophosphoethanolamine and glycerophosphocholine) were the major forms of P in the detrital material. After 30 d of drawdown, polynucleotides were reduced to trace levels, whereas sugar phosphate, glycerophosphate, and phospholipids remained the major fractions of organic P. Microorganisms seemed to preferentially utilize nucleic acid P, perhaps to obtain associated nutrients including carbon and nitrogen. At the end of the 30‐d reflooding period, cumulative P flux from detritus to water column accounted for 3% of the total P (≤15 d of drawdown) and further decreased to 2% at 30 d of drawdown, but increased to 8% at 60 d of drawdown. The drawdown (≤30 d) not only reduced P flux to the water column, but also increased the humification and microbial immobilization of P. Excessive drawdown (60 d), however, triggered the release of P into the water column as the water content of detritus decreased from 95 to 11%.
Phosphorus Losses in Furrow Irrigation Runoff
Authors: Westermann D.T. , Bjorneberg D.L. , Aase J.K. , Robbins C.W.
Published: June 2010

Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff. We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse‐silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface‐irrigated with Snake River water. Water‐soluble P, Olsen P (inorganic and organic P), and iron‐oxide impregnated paper–extractable P (FeO‐Ps) were determined on a 0.03‐m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999. Dissolved reactive phosphorus (DRP) in a 0.45‐μm filtered runoff sample, and iron‐oxide impregnated paper–extractable P (FeO‐Pw), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4‐h irrigation on 18.3‐m field plots. The 1998 and 1999 data sets were combined because there were no significant differences. Flow‐weighted average runoff DRP and FeO‐Pwconcentrations increased linearly as all three soil P test concentrations increased. The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration. Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration. The average runoff total P concentration was 1.08 mg L−1at a soil Olsen P concentration of 10 mg kg−1Soil erosion control will be necessary to reduce P losses in surface irrigation runoff.
Factors Affecting Alkalinity Generation by Successive Alkalinity‐Producing Systems: Regression Analysis
Authors: Jage C.R. , Zipper C.E. , Noble R.
Published: June 2010

Use of successive alkalinity‐producing systems (SAPS) for treatment of acidic mine drainage (AMD) has grown in recent years. However, inconsistent performance has hampered widespread acceptance of this technology. This research was conducted to determine the influence of system design and influent AMD chemistry on net alkalinity generation by SAPS. Monthly observations were obtained from eight SAPS cells in southern West Virginia and southwestern Virginia. Analysis of these data revealed strong, positive correlations between net alkalinity generation and three variables: the natural log of limestone residence time, influent dissolved Fe concentration, and influent non‐Mn acidity. A statistical model was constructed to describe SAPS performance. Subsequent analysis of data obtained from five systems in western Pennsylvania (calibration data set) was used to reevaluate the model form, and the statistical model was adjusted using the combined data sets. Limestone residence time exhibited a strong, positive logarithmic correlation with net alkalinity generation, indicating net alkalinity generation occurs most rapidly within the first few hours of AMD–limestone contact and additional residence time yields diminishing gains in treatment. Influent Fe and non‐Mn acidity concentrations both show strong positive linear relationships with net alkalinity generation, reflecting the increased solubility of limestone under acidic conditions. These relationships were present in the original and the calibration data sets, separately, and in the statistical model derived from the combined data set. In the combined data set, these three factors accounted for 68% of the variability in SAPS systems performance.
Relationships between Biosolids Treatment Process and Soil Phosphorus Availability
Authors: Maguire R.O. , Sims J.T. , Dentel S.K. , Coale F.J. , Mah J.T.
Published: June 2010

Laws mandating phosphorus (P)‐based nutrient management plans have been passed in several U.S. Mid‐Atlantic states. Biosolids (sewage sludge) are frequently applied to agricultural land and in this study we evaluated how biosolids treatment processes and biosolids P tests were related to P behavior in biosolids‐amended soils. Eight biosolids generated by different treatment processes, with respect to digestion and iron (Fe), aluminum (Al), and lime addition, and a poultry litter (PL), were incubated with an Elkton silt loam (fine‐silty, mixed, active, mesic Typic Endoaquult) and a Suffolk sandy loam (fine‐loamy, siliceous, semiactive, thermic Typic Hapludult) for 51 d. The amended soils were analyzed at 1 and 51 d for water‐soluble phosphorus (WSP), iron‐oxide strip–extractable phosphorus (FeO‐P), Mehlich‐1 P and pH. The biosolids and PL were analyzed for P, Fe, and Al by USEPA 3050 acid–peroxide digestion and acid ammonium oxalate, Mehlich‐1, and Mehlich‐3 extractions. Biosolids and PL amendments increased extractable P in the Suffolk sandy loam to a greater extent than in the Elkton silt loam throughout the 51 d of the incubation. The trend of extractable WSP, FeO‐P, and Mehlich‐1 P generally followed the pattern: [soils amended with biosolids produced without the use of Fe or Al] > [PL and biosolids produced using Fe or Al and lime] > [biosolids produced using only Fe and Al salts]. Mehlich‐3 P and the molar ratio of P to [Al + Fe] by either the USEPA 3050 digestion or oxalate extraction of the biosolids were good predictors of changes in soil‐extractable P following biosolids but not PL amendment. Therefore, the testing of biosolids for P availability, rather than total P, is a more appropriate tool for predicting extractable P from the biosolids‐amended soils used in this study.
Biosolids Effects on Phosphorus Retention and Release in Some Sandy Florida Soils
Authors: Lu Peng , O'Connor George A.
Published: June 2010

The soil solid phase components most responsible for P sorption in Florida soils are Fe and Al oxides. Thus, we hypothesized that land application of biosolids would significantly increase a soil's P retention by increasing its content of P‐sorbing solids, especially when biosolids with high Fe and Al concentrations are applied to soils that sorb P poorly. Biosolids effects were quantified by a series of single‐point isotherms on soils from two field studies sampled for up to 4 yr after initial biosolids application. Biosolids additions had little effect on P retention in a soil with abundant oxalate‐extractable Fe and Al and a correspondingly large native P‐sorbing capacity. However, biosolids significantly increased P retention in a soil with low oxalate‐extractable Fe and Al content and low native P‐sorbing capacity. Biosolids effects on P retention lasted 1 to 3 yr after application, depending on biosolids source and rate of application, and generally mimicked persistence of increased extractable Fe and Al concentrations in the poorly P‐sorbing soil. Disappearance of added Fe and Al (and, hence, P retention capacity) from the surface horizons over time was relatively rapid, perhaps due to abundant organic acid production associated with biosolids degradation. Phosphorus in biosolids containing (or tailored to contain) abundant Fe and/or Al can be expected to behave as aslowly availableP source, and to be less subject to leaching losses than completely soluble P sources.
Tree Species for Recovering Nitrogen from Dairy‐Farm Effluent in New Zealand
Authors: Roygard Jon K.F. , Clothier Brent E. , Green Steve R. , Bolan Nanthi S.
Published: June 2010

Land treatment of dairy‐farm effluent is being widely adopted as an alternative to disposal into surface waters in New Zealand. This study investigated water balances and associated N leaching from short‐rotation forest (SRF) species irrigated with dairy‐farm effluent. Single trees were grown in lysimeters filled with Manawatu fine sandy loam (mixed mesic Dystric Eutrochrept). Dairy‐farm effluent was applied during two irrigation periods at 21.5 mm wk−1with a total loading equivalent to 870 kg N ha−1occurring over 17 mo. Following tree harvest in April 1997, measurements continued until August 1997 to monitor tree reestablishment. Cumulative N leached did not differ between lysimeters in which evergreen Sydney blue gum (Eucalyptus salignaSm.) and shining gum [Eucalyptus nitens(H. Deane & Maiden) Maiden] and deciduous kinu‐yanagi (Salix kinuyanagiKimura) were grown. Leachate N concentrations of all treatments were on average higher than the New Zealand drinking water standard of 11.3 mg N L−1TheE. nitensandS. kinuyanagitreatments leached 33 and 35 kg N ha−1yr−1in 1996 following application of 236 kg N ha−1during the first irrigation season. Leaf area was strongly correlated to evapotranspiration, drainage volume, and nitrogen leached. The majority of leaching in the tree treatments occurred after harvest. Reducing the leaching in the regrowth phase may be achieved through timing harvest in the spring when growth rates are higher and leaching potential is lower. Based on N uptake rates observed in this study and average pond discharge, a plantation of 5.4 ha would be required for N recovery on a typical dairy farm in New Zealand.
Effect of Flue Gas Desulfurization Residue on Plant Establishment and Soil and Leachate Quality
Authors: Punshon Tracy , Adriano Domy C. , Weber John T.
Published: June 2010

Effects on soil quality and crop establishment after incorporation of flue gas desulfurization by‐product (FGD) into soil as an amendment was assessed in a mesocosm study. Mesocosm units received applications equivalent to 0, 2.5, 5.0, 7.5, and 10% FGD residue [0, 25, 50, 75, and 100 tons acre−1]. Germination, biomass production, and elemental composition of corn (Zea mays L. var. Dekalb DK‐683), soybean [Glycine max (L.) Merr. var. Haskell Pupa 94], radish (Raphanus sativus L. var. Sparkler), and cotton (Gossypius hirsutus L. var. Deltapine 51) were determined. The quality of leachates and soil were also determined periodically. Flue gas desulfurization residue did not affect germination and all application rates stimulated aboveground biomass. Plants grown in FGD‐amended soil contained significantly elevated tissue concentrations of As, B, Se, and Mo. The FGD residue elevated surface soil pH from 5.5 (Control) to 8.1 (at 10% FGD). Leachate pH was unaffected by FGD, but salinity rose sharply with increasing application rates of FGD. Leachates contained higher concentrations of B, with small increases in Se and As. Flue gas desulfurization residue application caused an increase in total B, As, Mo, Se, and extractable Ca in the soil, but decreased Mn and Zn. Using FGD residues could have beneficial effects on crop establishment without detrimental effects on soil or leachate quality, at an optimum rate of approximately 2.5%. This material could alleviate surface acidity, and B and Mo deficiencies in plants.
Atmospheric Movements of Lindane (γ‐Hexachlorocyclohexane) from Canola Fields Planted with Treated Seed
Authors: Waite D.T. , Gurprasad N.P. , Sproull J.F. , Quiring D.V. , Kotylak M.W.
Published: June 2010

Lindane (γ‐hexachlorocyclohexane [γ‐HCH]) is used as an insecticide in many countries. Concentrations of γ‐HCH have been found in air, water, soil, snow, and tissue samples throughout the world and concerns have been raised for its potential effects on human and ecosystem health. In Canada, γ‐HCH is primarily used as a treatment on canola (Brassica napus L) seed with an estimated 455.3 Mg applied in 1997 and 510.4 Mg in 1998. The purpose of this study was to measure γ‐HCH volatilization from fields planted with treated canola seed. Atmospheric dry and wet deposition and soil samples were collected for two growing seasons (1997 and 1998) from a canola field planted with treated seed. Atmospheric concentrations as high as 16.1 and 7.4 ng m−3 were measured at 1 m above the canola field compared with maximum concentrations of 2.9 and 2.7 ng m−3 measured above a grass field located 2 km away (1997 and 1998, respectively). On the basis of measurements made in this study it was estimated that between 12 and 30% of the γ‐HCH applied as canola seed treatment may volatilize and be released to the atmosphere. This would create an atmospheric loading of 66.4 to 188.8 Mg for the 6‐wk period following planting, estimated from the quantity of seed sown on the Canadian prairies in 1998. Dry deposition rates and rain concentrations as high as 2203 ng m−2 d−1 and 170 ng L−1 were measured adjacent to the canola field.