Journal of Environmental Quality 31:1761-1767 (2002)
© 2002 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
EXECUTIVE SUMMARIES
This Issue in Journal of Environmental Quality
 |
Soil Quality in New Zealand
|
|---|
Over the last decade a number of political and legislative measures have been introduced to encourage and enforce sustainable soil management in New Zealand. Lilburne et al. describe the legislative measures and outline the scientific response to the needs of regulatory agencies responsible for maintaining environmental quality. The research recommended a set of indicators to assess soil quality, along with target ranges defining acceptable values. They also discuss the communication of results to end-users, including the development of a computerized assessment tool. The link between the policy and science communities in New Zealand has become stronger since the political changes, although greater collaboration is still required.
L. Lilburne
(LilburneL{at}LandcareResearch.co.nz)
Soil Quality in New Zealand: Policy and the Science Response. J. Environ. Qual. 31:1768–1773.
|
A Dynamic Gas Flux Chamber
|
|---|
Dynamic chambers are commonly used to measure the emission of many trace gases and chemicals from soil. However, chamber technique can alter measured efflux for several reasons, such as the pressure difference created between outside and inside the chamber and the change of environmental properties (e.g., soil temperature and wind profile near the soil surface). Reichman and Rolston present an aerodynamic (flow through) chamber that was designed to accurately measure the surface flux of trace gases. Performance test results show: (i) a uniform distribution of air velocity within the chamber at the soil surface; (ii) steady state flux was attained within 5 min when the outlet air suction was 20 L/min or higher; (iii) the presence of the chamber did not affect the measured flux for outlet suction rates of 20 L/min, except that the chamber caused some cooling of surface soil; and (iv) the chamber measures soil efflux accurately when pressure deficit within the chamber with respect to ambient atmosphere ranges between 0.46 and 0.79 Pa.
R. Reichman
(raichman{at}iibr.gov.il)
Design and Performance of a Dynamic Gas Flux Chamber. J. Environ. Qual. 31:1774–1781.
|
Remove Ammonia with a Biofilter
|
|---|
Ammonia (NH3) removal efficiencies were evaluated when hydrogen sulfide (H2S) and NH3 in binary mixture gases were supplied to a ceramic biofilter seeded with earthworm casts. When NH3 was singly supplied to the biofilter, NH3 removal was maintained at almost 100% until inlet NH3 concentration was increased to 600 µL L-1 and space velocity to 330 h-1, at which the elimination capacity of NH3 was 148 g N m-3 h-1. When H2S was supplied simultaneously, however, the accumulation of toxic sulfide ions showed dual effects on NH3 removal efficiencies: First, no effects were observed at inlet H2S loading below 60 g S m-3 h-1; however, inhibition by H2S at higher loading was observed above 60 g S m-3 h-1. On the other hand, H2S gas supplied simultaneously with NH3 and was adsorbed only a little by the biofilter in the first period of operation and was not removed later.
K.-S. Cho
(kscho{at}ewha.ac.kr)
Hydrogen Sulfide Effects on Ammonia Removal by a Biofilter Seeded with Earthworm Casts. J. Environ. Qual. 31:1782–1788.
|
Canola and Broccoli as Alternative Crops
|
|---|
Selenium, boron, and salinity contamination of agricultural drainage water is potentially hazardous for water reuse strategies in central California. Banuelos examined the feasibility of using such high-value cash crops as canola and broccoli as recipients for Se-laden drainage water under field conditions. He reports that after two years, yields were economically satisfactory for the grower under high saline and B conditions. Up to 18% of the applied Se was extracted by the plants and an additional 16% was presumed lost in the soil by other processes, for example, volatilization and transformation of Se to insoluble forms of Se. Although soluble levels of Se did not increase in the soil, careful salt management, especially of excessive soluble B, will be essential for maintaining soil productivity with long-term use of drainage water.
G.S. Bañuelos
(gbanuelos{at}fresno.ars.usda.gov)
Irrigation of Broccoli and Canola with Boron- and Selenium-Laden Effluent. J. Environ. Qual. 31:1802–1808.
|
Jet Fuel Components Degrade in Soil
|
|---|
The main airport of Oslo (Norway) is situated on the Gardermoen delta where sedimentary layers may provide preferential flow paths for water-soluble contaminants. A field experiment was conducted to study transport and degradation of two aromatic jet fuel components (toluene and o-xylene) in unsaturated soil. The delta structure did provide a preferential flow path leading to a horizontal displacement of the plumes. However, the degradation potential for toluene and o-xylene in the soil was very high and almost all of the injected hydrocarbons were subject to aerobic biodegradation before reaching the saturated zone. Overall, first-order degradation coefficients were calculated to be in the range of 0.19 to 0.21 d-1 for toluene and 0.10 to 0.11 d-1 for o-xylene.
A.K. Søvik
(anne.sovik{at}jordforsk.no)
Transport and Degradation of Toluene and o-Xylene in an Unsaturated Soil with Dipping Sedimentary Layers. J. Environ. Qual. 31:1809–1823.
|
Biodegradation during Contaminant Transport
|
|---|
The level of microbial activity at a contaminated site, as well as the biodegradation potential, is influenced by numerous factors including the type and quantity of microorganisms and their deposition in the subsurface environment. Miscible-displacement experiments were conducted to investigate the interaction between microbial growth and cell elution, and their impact on resultant microbial distribution between the aqueous and solid phases in a sandy, low-organic-C-content, porous medium. For conditions yielding a considerable amount of microbial growth, the majority of the biomass was associated with the aqueous phase (68–90%). Conversely, under minimal-growth conditions, most cells (approximately 60–70%) were attached to particle surfaces. Results suggest the increase in aqueous-phase cells observed for the experiments exhibiting the greatest growth is associated with the production of new cells, and that under appropriate conditions, aqueous-phase biomass can contribute significantly to contaminant biodegradation.
M.L. Brusseau
(brusseau{at}ag.arizona.edu)
Biodegradation during Contaminant Transport in Porous Media: V. The Influence of Growth and Cell Elution on Microbial Distribution. J. Environ. Qual. 31:1824–1830.
|
Optimize Chromium(Vl) Removal from Soil
|
|---|
Soil contamination with chromium(VI) is widespread, including at many small Cr plating businesses. Simulating indigenous bacteria to transform Cr(VI) to Cr(III) may provide a low-cost remediation method, but the activity must be sustainable year-round to prevent ground water contamination. Batch studies at 10°C found C addition promoted Cr(VI) biotransformation, and aerobic conditions with added ammonia were most favorable at high Cr(VI) concentrations. Anaerobic sulfate reduction resulted in sulfides that formed unextractable complexes with Cr and may therefore yield the most stable Cr sequestration in soil. Bioactivity was partially successful in Cr(VI) transformation, regardless of the presence of nitrate, ferric iron, or sulfate as competitive electron acceptors under anaerobic conditions, indicating biostimulation could be successful under a wide range of site conditions.
A.R. Bielefeldt
(Angela.Bielefeldt{at}colorado.edu)
Low-Temperature Chromium(VI) Biotransformation in Soil with Varying Electron Acceptors. J. Environ. Qual. 31:1831–1841.
|
A Novel Bioremediation Technology
|
|---|
A novel bioremediation technology is reported that uses a combination of abiological surfactant soil washing followed by polycyclic aromatic hydrocarbon (PAH) biological oxidation in soil washwater using a white rot fungus (Phanerochaete chrysosporium Burdsall in Burdsall & Eslyn) in a rotating biological contactor (RBC) reactor. Total removal efficiency for any of nine PAHs in an 11-month aged soil was greater than 90% using a combination of surfactant soil washing and P. chrysosporium oxidation of PAHs in soil washwater in an RBC reactor when used in batch operation, and greater than 76% when used in continuous operation. This combined technology permits (i) a rapid abiological cleanup of soil for compliance with relevant soil quality standards and (ii) PAH biological removal in soil washwater for compliance with aqueous discharge standards.
J.P. Obbard
(chejpo{at}nus.edu.sg)
Polycyclic Aromatic Hydrocarbon Removal from Soil by Surfactant Solubilization and Phanerochaete chrysosporium Oxidation. J. Environ. Qual. 31:1842–1847.
|
Soil Quality at a National Scale
|
|---|
Soil quality was measured at 222 sites in 12 soil orders and 9 land-use categories in New Zealand. Topsoil (0–100 mm) properties measured were: total C and N, potentially mineralizable N, pH, Olsen P, cation exchange capacity, bulk density, total porosity, macroporosity, total available water, and readily available water. Soil order and land-use categories explained 55 to 76% of the variance in soil properties. Total C contents of pastures were comparable with indigenous forest soils, but pastures were less acidic and with higher N and P contents. Plantation forests had characteristics similar to indigenous forests on comparable soils. Cropland soils comprised <1% of the national land cover and generally had high inorganic fertility, low organic matter, and evidence of compaction.
G. Sparling
(SparlingG{at}LandcareResearch.co.nz)
Soil Quality at a National Scale in New Zealand. J. Environ. Qual. 31:1848–1857.
|
Water Table and Nitrogen Fertilization Management
|
|---|
Nitrate (NO3) pollution of water resources has become a widely recognized risk in intensively managed agricultural ecosystems. Water and N fertilizer are the two most important factors affecting crop production and NO3 movement to surface and ground water. Strategies to reduce NO3 pollution should therefore seek to prevent accumulation of NO3 in the soil profile. Water table management is a practice that has been shown to offer better quality while enhancing or maintaining crop performance. The NO-3–N concentrations in the soil profile and drain discharge were less under subirrigation than under free drainage for nearly all sampling dates. Corn yield was not affected by water table during normal growing seasons, but was affected by N fertilization rate in 1996 and 1997.
C. Hamel
(hamel{at}nrs.mcgill.ca)
Environmental and Agronomic Implications of Water Table and Nitrogen Fertilization Management. J. Environ. Qual. 31:1858–1867.
|
Nitrogen and Phosphorus Leach from Container Forest Nurseries
|
|---|
Knowledge about impacts of forest nurseries is needed in environmental management work and in life cycle analyses of wood products. The amounts of N and P leached through container trays into the ground were determined in actual seedling production. The annual leaching of N through container medium into ground was the same order of magnitude as the mean losses of N from Finnish agricultural fields; P leached in greater amounts. The total N and P load could increase substantially because of nutrients fertigated outside container trays. Evaluation of production systems and methods could help nurseries to develop growing practices that decrease the nutrient load of the environment.
M.-L. Juntunen
(marja-liisa.juntunen{at}metla.fi)
Leaching of Nitrogen and Phosphorus during Production of Forest Seedlings in Containers. J. Environ. Qual. 31:1868–1874.
|
Excess Cadmium Likely in Agricultural Soils of the Netherlands
|
|---|
Regression models for Cd concentration in crops were used to derive critical threshold concentrations for Cd in soil from food quality standards for Cd in crops. These critical threshold concentrations in soil vary in space, because uptake of Cd by crops depends on the pH, soil organic matter content, and clay content of soil. The probability that actual Cd concentration exceeds these critical threshold concentrations was approximated by Monte Carlo simulation. The cumulative distribution functions of Cd in soil and the basic soil properties were estimated by a geostatistical method that can make use of prior knowledge of the spatial pattern of these soil properties. The estimated probability for grassland is negligible, even in areas with high Cd concentrations in soil. For arable soils, however, these probabilities commonly are larger than 5% when sugarbeet or wheat is taken as a reference crop, and locally exceed 50%.
D.J. Brus
(d.j.brus{at}alterra.wag-ur.nl)
Mapping the Probability of Exceeding Critical Thresholds for Cadmium Concentrations in Soils in the Netherlands. J. Environ. Qual. 31:1875–1884.
|
Organic Complexes of Cadmium in Compost
|
|---|
Amending soils with composted municipal solid waste (MSW) adds significant amounts of organic trace metals complexes, with important consequences for bioavailability and mobility in the soil environment. Kaschl et al. report on the complexation of Cd by different organic ligands extracted, separated, and purified from MSW compost. Partially soluble and strongly humified ligands demonstrated the highest capacity to sequester Cd. In addition, Cd was strongly bound by soluble ligands containing N functional groups. Hence, these two types of ligands are considered to be the most relevant for organic complexation of Cd by compost-derived ligands in the soil solution after compost addition.
Y. Chen
(yonachen{at}agri.huji.ac.il)
Cadmium Binding by Fractions of Dissolved Organic Matter and Humic Substances from Municipal Solid Waste Compost. J. Environ. Qual. 31:1885–1892.
|
Extract Lead with High Biomass Plants
|
|---|
Cabbage, mung bean, and wheat were grown in Pb-contaminated soils. Application of EDTA (3.0 mmol of EDTA/kg soil) to soil significantly increased the concentration of Pb in the shoots and roots of all plants. Results of the sequential chemical extraction of soil samples showed Pb concentrations in the carbonate–specifically adsorbed and Fe–Mn oxide phases were significantly decreased after EDTA treatment. The application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one and two dose application methods. This approach could help minimize the amount of chelate applied in the field and reduce the potential risk of soluble Pb movement into ground water.
X.-D. Li
(cexdli{at}polyu.edu.hk)
Lead Phytoextraction from Contaminated Soil with High-Biomass Plant Species. J. Environ. Qual. 31:1893–1900.
|
Strong pH-Control of Heavy Metal Release in Soils
|
|---|
Soil pH is known to strongly control the sorption–desorption of heavy metal ions in soils, but it is not known if this also holds for the kinetics of heavy metal release. Sukreeyapongse et al. performed laboratory release experiments to quantify the pH-dependent release kinetics of Cd, Cu, and Pb from natural or sludge-amended Kandiustults and Hapludalfs. With two exceptions, relative release rates (release rate/total content of metal in soil) plotted vs. steady state pH followed the same curves for each metal. These curves could be described by a rate expression of the form: Relative release rate = k[H+]a, with specific a (empirical constant) and k (rate constant) parameters for each metal demonstrating that metal release in these systems can be explained by proton-induced desorption and dissolution reactions. With decreasing pH, pronounced increases in release rates were observed in the sequence Cd > Pb > Cu.
H.C.B. Hansen
(haha{at}kvl.dk)
pH-Dependent Release of Cadmium, Copper, and Lead from Natural and Sludge-Amended Soils. J. Environ. Qual. 31:1901–1909.
|
Spatial Variation of 137Cs in Small Catchments
|
|---|
Surface contamination by bomb-derived and Chernobyl-derived 137Cs has been subject to changes due to physical decay and lateral transport of contaminated soil particles, which have resulted in an ongoing transfer of radionuclides from terrestrial ecosystems to surface water, river bed sediments, and floodplains. By means of a simple sediment budget model and universal kriging, van der Perk et al. were able to separate the spatial patterns of 137Cs resulting from soil erosion and deposition from other sources of variation in 137Cs in a small hilly catchment of Slovakia. The remaining spatial pattern reveals initial fallout pattern of Chernobyl-derived 137Cs and the effect of floodplain deposition. The spatially uncorrelated variation is considerable and is largely attributed to short-range 137Cs redistribution during fallout.
M. van der Perk
(m.vanderperk{at}geog.uu.nl)
Assessment of Spatial Variation of Cesium-137 in Small Catchments. J. Environ. Qual. 31:1930–1939.
|
Bioavailable Phosphorus Content in Runoff
|
|---|
Bioavailable phosphorus (BAP) in runoff is one of the key elements in controlling eutrophication. In this study, laboratory runoff experiments were conducted in soil boxes to determine BAP content in runoff from 10 mostly calcerous soils from the Minnesota River basin under simulated storms. The BAP levels of runoff, estimated with iron oxide–impregnated paper, were well predicted by Mehlich-III P, Olsen P, equilibrium phosphorus concentration (EPC), and P sorption index based on sorptivity of the soils, but the correlation coefficients between these parameters and runoff BAP were generally lower than those for runoff SRP. Findings from this research provide reference tools to develop simple and rapid methods to estimate BAP levels in agricultural runoff.
P.L. Brezonik
(brezo001{at}umn.edu)
Estimating Runoff Phosphorus Losses from Calcareous Soils in the Minnesota River Basin. J. Environ. Qual. 31:1918–1929.
|
Nitrate in Streams Relate to Morphological Features
|
|---|
Variability of nutrient concentrations within watersheds must be better understood to establish nutrient guidelines that are applicable and to discern which areas or landscape positions within the watershed are vulnerable to nutrient losses. Work was conducted to determine the relationship between N and P concentrations in stream base flow and watershed morphological features such as number of streams per square kilometer. Franklin et al. found higher concentrations of nitrate were more likely in stream sections with many streams per square kilometer when compared with stream sections with fewer streams per square kilometer. Results indicate an innate variability of nutrient concentrations within streams exists and suggest decision makers should consider location within the watershed when making nutrient management guidelines and decisions.
D.H. Franklin
(dfrankln{at}arches.uga.edu)
Distribution of Inorganic Nitrogen and Phosphorus Concentrations in Stream Flow of Two Southern Piedmont Watersheds. J. Environ. Qual. 31:1910–1917.
|
Rapid Chemical Movement to Tile Drains
|
|---|
Subsurface drainage systems are used to study chemical movement in soils. Fortin et al. report bromide, atrazine, and metolachlor were first detected in drainage water at the same time and followed an event-driven behavior throughout a monitored period. Fall tillage using either moldboard plow or chisel plow had little impact on pesticides behavior to tile drain, but affected bromide concentration peaks and total water leachate volume. Rapid chemical movement to tile drains suggests preferential flow is important and unaffected by tillage practices.
J. Fortin
(josee.fortin{at}sga.ulaval.ca)
Preferential Bromide and Pesticide Movement to Tile Drains under Different Cropping Practices. J. Environ. Qual. 31:1940–1952.
|
Sorption and Desorption of Organic Contaminants
|
|---|
Ran et al. examine the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a peat soil, and two subsamples of the soil treated by base + acid and acid alone were used as the sorbents. The contents of black C particles were quantified using a chemical extraction method, and petrographical examinations revealed the presence of condensed soil organic matter in peat. Results show the sorption and desorption isotherms are generally nonlinear and the apparent sorption–desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent–sorbate systems indicates black C is likely responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat.
Y. Ran
(yran{at}gig.ac.cn)
The Role of Condensed Organic Matter in the Nonlinear Sorption of Hydrophobic Organic Contaminants by a Peat and Sediments. J. Environ. Qual. 31:1953–1962.
|
Retention Equation Describes Soil Column Chromatography
|
|---|
A general log-linear retention equation between capacity factor and volumetric methanol fraction has been developed to describe the mobilities of nonionic organic chemicals in soil column chromatography (SCC). The linear solvation energy relationship (LSER) was employed to analyze the retention from molecular interactions. The most important factor determining the transportation was found to be the solute hydrophobic partition in soils, and the second important factor was the solute hydrogen-bond basicity. The experimental data from two reference soils and 121 analytes can be accurately explained by the retention equation.
F. Xu
(fengxu64{at}hotmail.com)
Retention Equations of Nonionic Organic Chemicals in Soil Column Chromatography with Methanol–Water Eluents. J. Environ. Qual. 31:1972–1979.
|
Year-Round Forage Systems for Dairy Manure Effluent Sprayfields
|
|---|
Increasing nitrate levels in the historic Suwannee River in northern Florida have been partially linked to the increasing number and size of dairies in the river's basin. Woodard et al. compare two forage systems for N removal in a dairy sprayfield at three effluent N rates and present nitrate leaching patterns over four 12-month cycles. A bermudagrass (perennial)–rye system was far superior to a system of sequentially planted annual forages (corn–forage sorghum–rye) for recovering N and preventing nitrate leaching. In the latter, the period between harvest of one forage and canopy closure of the next was highly prone to nitrate leaching. The inclusion of a perennial grass component with high N removal capability into year-round forage systems may decrease the risk of nitrate contamination of ground water.
K.R. Woodard
(krw{at}gnv.ifas.ufl.edu)
Nitrogen Removal and Nitrate Leaching for Forage Systems Receiving Dairy Effluent. J. Environ. Qual. 31:1980–1992.
|
Sugar Maple Monitors Soil Changes
|
|---|
Five dolomitic lime treatments were applied to a sugar maple experimental plot, on a single tree basis, at the Lake Clair Watershed, Quebec, Canada. Four years after the treatment, the average sugar maple xylem concentration of Mg and the Ca to Mn and Mg to Mn ratios were strongly affected by the liming treatment. The latter ratios were found to be the strongest predictors of humus (and to a lesser extent of the upper B horizon) chemistry. The significant effects of liming rate on those variables, combined with the absence of significant temporal trends, demonstrated changes in wood chemistry caused by liming were smoothed and homogenized at least in the last 20 growth rings of trees. This finding precludes the use of sugar maple to monitor temporal soil changes associated with acidic deposition, at least for the relatively mobile elements studied, although wood chemistry is representative of actual soil conditions for the elements mentioned above.
D. Houle
(houle.Daniel{at}uqam.ca)
Soil and Tree-Ring Chemistry Response to Liming in a Sugar Maple Stand. J. Environ. Qual. 31:1993–2000.
|
A-Bomb 90Sr Remains in Hiroshima Trees
|
|---|
Information on past environmental pollution can sometimes be obtained through chemical analysis of tree rings. Kagawa et al. report on a peak of 90Sr specific activity at the 1945 ring of Japanese cedar [Cryptomeria japonica (L. f.) D. Don] sampled in the "black rain" contaminated area in Hiroshima. Alkali earth metals such as Sr have relatively immobile characteristics in wood compared to alkali metals such as Cs, thus reducing translocation of 90Sr to neighboring tree rings and enabling reconstruction. Tree-ring 90Sr analysis helped distinguish between residual 90Sr activity, from the Hiroshima atomic bomb and atmospheric nuclear testing, indicating the possibility of assessing previous local 90Sr pollution through tree-ring analysis.
A. Kagawa
(akagawa{at}ffpri.affrc.go.jp)
Tree-Ring Strontium-90 and Cesium-137 as Potential Indicators of Radioactive Pollution. J. Environ. Qual. 31:2001–2007.
|
Can Carbon Dioxide Protect Plants from Ozone Stress?
|
|---|
Elevated carbon dioxide (CO2) has been shown to protect plants from ozone (O3) stress, but this interaction has been tested for only a few crops An O3–tolerant line and an O3–sensitive line of snap bean (Phaseolus vulgaris L.) were exposed throughout a season to mixtures of CO2 and O3 to determine if CO2 can protect snap bean from O3 stress. Elevated CO2 protected the O3–tolerant line but did not protect the O3–sensitive line from yield suppression caused by O3. The results show that the effects of CO2 + O3 mixtures cannot be predicted by knowing effects of the individual gases.
A.S. Heagle
(asheagle{at}unitylncsu.edu)
Growth and Yield Responses of Snap Bean to Mixtures of Carbon Dioxide and Ozone. J. Environ. Qual. 31:2008–2014.
|
Golf Course Operation Influences Streams
|
|---|
Interest in golf has risen dramatically in North America in recent years. This trend has led to the construction of numerous new courses in Canada, including many on the Precambrian Shield. Golf course development and operation may have impacts on streams and lakes in this region because they are intensively managed and represent a major land use change. Winter et al. evaluated the influence of golf course operation on benthic macroinvertebrate communities in Precambrian Shield streams using rapid bioassessment and the reference condition approach. Marked differences in three of six golf course streams relative to the forested reference streams suggest golf course land management practices can be associated with significant differences in macroinvertebrate community structure.
J.G. Winter
(WinterJe{at}ene.gov.on.ca)
Impacts of Golf Courses on Macroinvertebrate Community Structure in Precambrian Shield Streams. J. Environ. Qual. 31:2015–2025.
|
Phosphorus Source Affects Phosphorus Runoff
|
|---|
The application of phosphorus to agricultural soils can exacerbate runoff P losses and accelerate eutrophication of surface waters. Kleinman et al. demonstrate how the solubility of P in manure and mineral fertilizer, and the method by which nutrient sources are applied to soil, interact to affect the loss of P in runoff over the near term.
P.J.A. Kleinman
(pjk9{at}psu.edu)
Effect of Mineral and Manure Phosphorus Sources on Runoff Phosphorus. J. Environ. Qual. 31:2026–2033.
|
Acid–Base Accounting Helps Predict Post-Mining Water Quality
|
|---|
Mining regulations require assessing the overburden quality of rocks and their potential impacts on surface and ground water. Acid–base accounting (ABA) is an analytical procedure that provides values to help evaluate the maximum potential acidity (MPA) and neutralization potential (NP) of overburden rocks before coal mining. To predict the post-mining water quality, the MPA and NP are compared. Acid mine drainage is predicted when the NP to MPA ratio is <1, a ratio of >2 is predicted to produce alkaline water, while acid or alkaline water can occur between 1 and 2. Skousen et al. collected overburden and water quality data from 56 sites in western Virginia and found post-mining water quality was accurately predicted in 50 of 52 sites based on overburden characterization by ABA. Four of the 56 sites had high NP to MPA ratios but produced acidic water for reasons other than overburden quality. Acid–base accounting is a good tool to assess overburden quality before surface mining. Regulatory agencies should use the NP to MPA ratios calculated from ABA in surface mine permitting decisions.
J. Skousen
(jskousen{at}wvu.edu)
Acid–Base Accounting to Predict Post-Mining Drainage Quality on Surface Mines. J. Environ. Qual. 31:2034–2044.
|
Volatilization of Dimethylselenide from Soils
|
|---|
The volatilization of dimethylselenide (DMSe) from seleniferous soils and sediments is a process that contributes to the natural decontamination of these environments. However, factors such as degradation, addition of organic amendments, moisture content, and depth to surface can significantly influence total DMSe emissions to the atmosphere. Dungan et al. examined the impact of the above-mentioned factors on the transport of DMSe through packed soil columns. Results suggest the biodegradation of DMSe plays a significant role in reducing emissions. Increasing our understanding of the factors that influence the gaseous diffusion of DMSe should help in determining the feasibility of using selenium volatilization as a remediation technique.
R.S. Dungan
(Rdungan{at}ussl.ars.usda.gov)
Volatilization and Degradation of Soil-Applied Dimethylselenide. J. Environ. Qual. 31:2045–2050.
|
Nitrogen and Phosphorus Available in Poultry Litter
|
|---|
Poultry litter applications to land have been based on N concentration in litter, resulting in application of P in excess of plant requirements, which may cause degradation of water quality. Preusch et al. report the effect of litter source and composting of poultry litter on N mineralization and availability of P in two soil types found in the Chesapeake Bay watershed. Litter source had a large impact on N mineralization rates of fresh but not composted poultry litter. Composting yielded a more predictable and reliable source of mineralizable N than fresh litter. However, composting did not consistently reduce P, and P was as available in composted as in fresh poultry litter. Research indicates application of composted poultry litter based on N requirements of crops may result in significant P inputs, which can negatively impact the environment.
T.J. Tworkoski
(ttworkos{at}afrs.ars.usda.gov)
Nitrogen and Phosphorus Availability in Composted and Uncomposted Poultry Litter. J. Environ. Qual. 31:2051–2057.
|
Phosphorus Characteristics of Dairy Feces
|
|---|
An important approach to reduce P surplus on animal farms and improve water quality is to optimize P feeding and minimize excessive P in rations. Dou et al. show that decreasing P concentrations in lactating cow diets not only lowered the excretion of acid digest total P in feces, but more importantly reduced the amount and proportion of fecal P that is water soluble and thus most susceptible to loss in the environment. Excess P in diets was excreted in feces as water-soluble forms. The P measured in water extract of feces is highly responsive to changes in diet P concentrations and hence can be indicative of dietary P status. A fecal P indicator concept is proposed and discussed.
Z. Dou
(dou{at}cahp.vet.upenn.edu)
Phosphorus Characteristics of Dairy Feces Affected by Diets. J. Environ. Qual. 31:2058–2065.
|
Swine Microbial Communities Influence Odors
|
|---|
Our poor understanding of the microbial ecology of anaerobic, outdoor swine manure storage systems has hindered our ability to establish links between microbial communities and malodor emissions. Merrill and Halverson used lipid profiling to characterize microbial communities in phototrophic lagoon and basin systems and measured the manure concentration of various organic malodor indicator compounds. Results show that fatty acid methyl ester (FAME) profiling can be used to differentiate among various types of storage systems and to detect dynamic seasonal changes in some of the systems' microbial communities. Seasonal changes in FAME profiles correlated with several organic malodor indicator compound concentrations, suggesting FAME profiles could be used as a diagnostic tool for predicting odor emission potential of a swine manure storage system.
L.J. Halverson
(larryh{at}iastate.edu)
Seasonal Variation in Microbial Communities and Organic Malodor Indicator Compound Concentrations in Various Types of Swine Manure Storage Systems. J. Environ. Qual. 31:2074–2085.
|
Sandy Soils Amended with Paper Mill Residuals
|
|---|
Foley and Cooperband investigated annual additions of raw paper residuals (PMR), paper mill residuals composted with bark (PMRB), and paper mill residuals composted alone (PMRC) to sandy soils and effects on total soil carbon (C) and plant-available water (PAW). All amended treatments increased total soil C relative to the nonamended control following applications in 1998 and 1999. All PMR treatments increased PAW by 5 to 45% relative to the control and reduced the amount of irrigation water required for potato production by 4 to 30%. There was a clear trend of greater reduction in irrigation requirements (amount and frequency) with more C added. The PMRB amended to sandy soils may sustain elevated PAW and reduce irrigation requirements beyond one year.
L. Cooperband
(lrcooperband{at}facstaff.wisc.edu)
Paper Mill Residuals and Compost Effects on Soil Carbon and Physical Properties. J. Environ. Qual. 31:2086–2095.
|
Selenium Removed by Muskgrass in Wetland Microcosms
|
|---|
Earlier field studies suggested the macroalga muskgrass (Chara canescens Desv. & Lois) plays an important role in the removal of selenium (Se) from agricultural drainage water. Lin et al. evaluated the efficiency of Se removal from drainage water by muskgrass-vegetated wetland microcosms and determined the extent to which muskgrass removed Se through phytoextraction and biovolatilization. Results show microcosms containing muskgrass reduced daily mass Se input in inflow drainage water by 72.1% compared with a reduction of 50.6% for the unvegetated control microcosm. Overall, 1.9% of total mass Se input accumulated in muskgrass tissues and 0.5% was removed via biological volatilization.
Z.-Q. Lin
(zlin{at}nature.berkeley.edu)
Evaluation of the Macroalga, Muskgrass, for the Phytoremediation of Selenium-Contaminated Agricultural Drainage Water by Microcosms. J. Environ. Qual. 31:2104–2110.
|
Size and Age Do Matter
|
|---|
Recent research of Knuteson et al. has focused on development of constructed wetlands to assimilate pesticide-contaminated water. For improved aesthetics, these wetlands have been established with ornamental plant species. The effectiveness of a plant species for phytoremediation depends in part on its tolerance for the contaminant, which may vary depending on plant age and size. Knuteson et al. examined the influence of plant age and size on uptake, distribution, and toxicity of the herbicide simazine in the ornamental wetland plants parrot feather [Myriophyllum aquaticum (Vell.) Verdc.] and canna (Canna x hybrida L. ‘Yellow King Humbert’). Four-week-old (larger) parrot feather and canna plants were more tolerant of simazine than two-week-old plants. The two-week-old plants of both species had higher tissue burdens of simazine than four-week-old plants. Simazine was primarily accumulated in the leaves of both parrot feather and canna. Simazine uptake was correlated with water uptake in both species. Results suggest plants in a constructed wetland designed for simazine assimilation would be more vulnerable to simazine toxicity shortly after emergence; however, once the simazine dissipates, plants may recover fully.
S.L. Knuteson
(sknutes{at}clemson.edu)
Influence of Plant Age and Size on Simazine Toxicity and Uptake. J. Environ. Qual. 31:2096–2103.
|
Earthworms, Bacteria Increase Bioavailability of Phosphorus from Fly Ash
|
|---|
Huge amounts of fly ash are generated from coal-fired plants throughout the world, resulting in acute disposal problems and environmental pollution. Among various efforts of using fly ash for productive purposes, its application in low fertile agricultural soils has shown promising results. However, despite good occurrence in total amount, bioavailability of most plant nutrients is rather low in fly ash. This causes a problem for using this material as a source of plant nutrition. Bhattacharya and Chattopadhyay show bioavailability of P in fly ash can be improved substantially by adoption of vermicomposting technology. Introduction of epigeic earthworms in different combinations of fly ash and organic matter tended to encourage bioavailability of P through effects of organic matter and actions of phosphate solubilizing bacteria on release of P to more available forms.
G.N. Chattopadhyay
(gunindranath_c{at}hotmail.com)
Increasing Bioavailability of Phosphorus from Fly Ash through Vermicomposting. J. Environ. Qual. 31:2116–2119.
|
Control Swine Slurry Bacteria
|
|---|
Ten commercially available manure odor control agents were evaluated in bench-scale laboratory microcosms for their ability to inhibit or kill Escherichia coli, a commonly used indicator of fecal pollution and potential pathogen. At manufacturer recommended rates, none of the agents reduced viable populations of E. coli in pure cultures or in swine manure slurry. However, at 10-fold higher than recommended rates, EnviroPur rapidly reduced viable populations of E. coli. Results suggest that at manufacturer recommended rates, the odor-controlling agents would not be effective at suppressing E. coli in stored swine manure slurry, but further evaluation at a commercial scale is warranted.
E. Topp
(toppe{at}em.agr.ca)
Evaluation of Commercial Odor Control Agents for Suppressing Escherichia coli in Swine Manure Slurry. J. Environ. Qual. 31:2120–2123.
TOP
Soil Quality in New...
A Dynamic Gas Flux...