bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth Responses of 53 Open‐Pollinated Loblolly Pine Families to Ozone and Acid Rain
Authors: McLaughlin S. B. , Layton P. A. , Adams M. B. , Edwards N. T. , Hanson P. J. , O'Neill E. G. , Roy W. K.
Published: July 2010

Field exposures of 9950 containerized 12‐wk‐old loblolly pine (Pinus taeda L.) seedlings representing 53 commercially important, open‐pollinated families were conducted to evaluate individual and interactive effects of acid rain and O3 on growth response. A 36‐plot field research facility comprised of 33 open‐top chambers and three open plots was used to test effects of five O3 levels that included ambient (A) and seasonally integrated levels that were 0.53, 1.10, 1.58, or 2.15 times ambient. Individual effects of three levels of simulated acid rain (pH 3.3, 4.5, and 5.2) as well as their interaction with O3 at 0.53A, 1.58A, and 2.15A levels were also included. Exposure to ambient air reduced average growth in height (26%), diameter (5%), and volume (14%) compared with growth of seedlings exposed to a 47% lower dose in charcoal filtered (CF) air. Responses to increasing O3 above ambient levels varied widely between families, became increasingly inhibitory at the highest O3 levels, but did not significantly exceed growth reductions found in ambient air. Diameter growth was reduced in most families by all levels of O3 addition. Acid rain caused a general stimulation of height growth at ambient levels (pH 4.5), while both height and diameter growth were reduced at a mean pH of 3.3. Significant antagonism between rainfall acidity and O3 effects on height and biomass increment was detected with increasing pollutant concentrations. Ozone reduced root/shoot biomass in most families, while acid rain did not.
Sorption and Retention of Herbicides in Vertically Oriented Earthworm and Artificial Burrows
Authors: Stehouwer R. C. , Dick W. A. , Traina S. J.
Published: July 2010

In many temperate region no‐tillage agro‐ecosystems, the vertically oriented burrows of the nightcrawler earthworm (Lumbricus terrestris L.) function as preferential flow paths and may promote the rapid downward transport of surface‐applied chemicals. The burrows of nightcrawlers, however, are lined with a material that is enriched in organic C relative to the surrounding soil matrix that may affect transport of organic chemicals. Vie investigated the effect of this lining on the sorption and retention of four herbicides: atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N(2‐methoxy‐1‐methylethyl)acetamide], dicamba (3,6‐dichloro‐2‐methoxybenzoic acid), and primisulfuron [3‐[4,6‐bis(difluoromethoxy)‐pyrimidin‐2yl]‐1‐(2‐methoxy carbonylphenyl sulfonyl) urea]. Batch sorption isotherms were determined using burrow lining and bulk soil collected from seven depth intervals from 0 to 50 cm. Sorption of the more strongly sorbed herbicides (atrazine and metolachlor) was enhanced by a factor of up to three on burrow lining relative to bulk soil, while there was little or no enhancement of the weakly sorbed herbicides (dicamba and primisulfuron). Transport and retention of these herbicides was measured in intact burrows in undisturbed soil blocks. Concentrations of the two strongly sorbed herbicides decreased during flow through nightcrawler and artificial (unlined) burrows, with the largest decreases occurring in earthworm burrows. Concentrations of the two weakly sorbed herbicides decreased very little during flow through either type of burrow. Retained herbicide concentrations were higher in nightcrawler than in artificial burrow walls, and decreases in concentration from the surface to the second 1‐mm wall layer were greater in nightcrawler than in artificial burrow walls. These results indicate the material lining nightcrawler burrows may significantly retard herbicide transport during lateral flow into and out of burrows.
Herbicide Runoff from Ornamental Container Nurseries
Authors: Keese R. J. , Camper N. D. , Whitwell T. , Riley M. B. , Wilson P. C.
Published: July 2010

Runoff and pond water samples from a container nursery that recycles water for irrigation were tested for movement of herbicides from the site of application. Residues of oryzalin [4‐(dipropylamino)‐3,5‐dinitrobenzene‐sulfonamide], pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzamine]), and oxyfluorfen [2‐chloro‐1‐(3‐ethoxy‐4‐nitrophenoxy)‐4‐(trifluoromethyl)benzene], active ingredients in the granular formulations of Rout [2‐chloro‐1‐(3‐ethoxy‐4‐nitrophenoxy)‐4‐(trifluoromethyl)benzene+3,5‐dinitro‐N4,N4‐dipropylsulfanilamide] and OH‐2 (Ornamental Herbicide‐2), were evaluated. Herbicides were applied at labeled rates and followed by irrigation. Water samples were collected, herbicides were extracted by solid phase extraction and analyzed by reverse phase high pressure liquid chromatography with ultraviolet (UV) detection. Maximum herbicide residues were detected within the first 15 min of water runoff; oryzalin residues were the greatest of the three herbicides evaluated (4 mg L−1 water at 15 min) and showed rapid decreases thereafter. Herbicide residues detected in pond samples decreased over time until the detection limit was reached (2 wk following application). A microplot study was conducted to evaluate the effects of plastic, woven fabric or gravel bedcovers on herbicide movement. Plastic and fabric allowed greatest movement of oryzalin and pendimethalin, while gravel significantly retained and retarded movement of all three herbicides. Results indicate that bedcover composition plays a significant role in the movement of herbicide from the site of application. Release of active ingredient from granular formulations was evaluated; dinitroanilines (oryzalin and pendimethalin) release faster than oxyfluorfen. Oryzalin in Rout was the most rapidly released, is the most water soluble, and 71% of total active ingredient was accounted for after 3 wk.
Decreasing Phosphorus Solubility in Poultry Litter with Aluminum, Calcium, and Iron Amendments
Authors: Moore P. A. , Miller D. M.
Published: July 2010

Arkansas produces approximately one billion broilers (Gallus gallus domesticus) each year. Phosphorous runoff from fields receiving poultry fitter is believed to be one of the primary factors affecting water quality in northwest Arkansas. Poultry litter contains ≈20 g P kg−1, of which ≈2 g P kg−1 is water soluble. The objective of this study was to determine if soluble P levels could be reduced in poultry litter with Al, Ca, and/or Fe amendments. Poultry litter was amended with alum, sodium aluminate, quick lime, slaked lime, calcitic limestone, dolomitic limestone, gypsum, ferrous chloride, ferric chloride, ferrous sulfate, and ferric sulfate, and incubated in the dark at 25 °C for 1 wk. The Ca treatments were tested with and without CaF2 additions in an attempt to precipitate fluorapatite. At the end of the incubation period, the fitter was extracted with deionized water and water soluble P determined. Water soluble P levels in the poultry litter were reduced from >2,000 mg P kg−1 litter to <1 mg P kg−1 litter with the addition of alum, quick lime, slaked lime, ferrous chloride, ferric chloride, ferrous sulfate, and ferric sulfate under favorable pH conditions. Gypsum and sodium aluminate reduced water soluble P levels by 50 to 60%. Calcitic and dolomitic limestone were less effective. The results of this study suggest that treating litter prior to field application with some of these compounds could significantly reduce the amount of soluble P in runoff from litter‐amended pastures. Therefore, chemical additions to reduce soluble P in litter may be a best management practice in situations where eutrophication of adjacent water bodies due to P runoff has been identified. Preliminary calculations indicate that this practice may be economically feasible. More research is needed, however, to determine any beneficial and/or detrimental aspects of this practice.
Liming Value Determination of a Calcareous, Gypsiferous Waste for Acid Sulfate Soil
Authors: Offiah O. , Fanning D. S.
Published: July 2010

Reclamation of acid sulfate soils requires the use of liming materials. SWAN‐gypsum (secondary waste acid neutralization gypsum), a waste from a sulfuric acid, titanium oxide refining process, contains ≈10% CaCO3, as well as CASO4·2 H2O (gypsum) and Fe oxides. This material was tested via laboratory incubation studies in comparison to laboratory grade CaCO3 as a liming material for a silty clay material from a Typic Sulfaquept formed on dredged materials. A batch titration method (by shaking a set of soil samples amended with various levels of a potential liming material) was also tested. Closed, partially closed, and open systems were employed with the batch titration method. The ability of SWAN‐gypsum to raise soil pH was comparable to its CaCO3 content. The CaCO3 occurs as unreacted aragonite that is Fe oxide coated as a result of the acid neutralization process that produces the waste. Gypsum and Fe oxides, also present in the waste, were shown to have little or no liming value with the soil material employed. Batch titration (open system, 24 h shaking) gave neutralization results similar to those from regular incubation for 45 d. The pH values achieved with increasing levels of SWAN‐gypsum were lower with closed than with open systems at pH values above 6.6 (by 0.1 to 0.45 pH units, presumably due in part to differences in CO2 pressure), but higher with the closed system at lower pH values (by 0.2 to 2.3 pH units, perhaps due to oxidation of sulfides with the open system). At pHs below neutral following open hatch titration, pHs measured before drying the materials, were higher than those measured after drying and rewetting by 0.2 to 1.5 pH units, whereas they were slightly lower before drying, by up to 0.2 pH units, at pHs above neutral. Additional factors (e.g., physical properties and other possible effects of Fe oxides and CASO4·2 H2O) that need to be considered prior to field utilization of SWAN‐gypsum as a soil amendment are mentioned. The methods reported for testing the liming value of this waste should have value in testing the liming value of other potential acid neutralizing materials.
Simultaneous Extraction of Six Pesticides Using a Dual‐Column Extraction Procedure
Authors: Watts D. W. , Bogus E. R. , Hall J. K. , Mumma R. O.
Published: July 2010

A method was developed that allowed for the simultaneous extraction of six pesticides (three chloro‐s‐triazines, a substituted amide, an organic phosphate, and a benzoic acid derivative) from either soil or water samples. This method utilizes two types of solid‐phase extraction columns, one reverse phase, and one anion exchange column, connected in series to extract all six compounds from a single sample. After separate elution of the two columns, high pressure liquid chromatography was employed to analyze the benzoic acid derivative utilizing a C‐18 column and paired ion techniques with a detection limit of 6 µg L−1. A gas chromatograph, equipped with a N‐P detector, was used to analyze the remaining five compounds. The detectable limit for the chloro‐s‐triazines was 3 µg L−1 while the detection limit of the substituted amide was 6 µg L−1.
Allocation of Carbon in Plants under Stress: An Analysis of the ROPIS Experiments
Authors: Laurence J. A. , Amundson R. G. , Friend A. L. , Pell E. J. , Temple P. J.
Published: July 2010

This paper addresses common patterns of plant C allocation in response to stress. The ROPIS studies used species ranging from slow growing, long‐lived evergreen trees (red spruce [Picea rubens Sarg.] and ponderosa pine [Pinus ponderosa Dougl.]), to fast growing evergreen and deciduous trees (loblolly pine [Pinus taeda L.] and aspen [Populus tremulaides Michx.]) and annuals (radish [Raphanus sativus L.]). Several factors helped to explain the effects of ozone, the common stress in all ROPIS experiments, on allocation in these diverse species. Species with high relative growth rates readily changed allocation in response to stress. For example, radish and aspen allocated C to produce new leaves in response to ozone and allocated C to roots in response to water and N deficits. In contrast, red spruce had the lowest relative growth rate, and neither total plant biomass nor C allocation were affected by ozone after four growing seasons. However, partitioning of C to foliar starch reserves was reduced. Ponderosa pine and loblolly pine had intermediate relative growth rates. Ozone reduced total plant biomass and allocation to coarse roots in ponderosa pine, while total plant biomass but not allocation was reduced in loblolly pine. Radish, aspen, and ponderosa pine all maintain low foliar starch reserves and experienced ozone‐induced foliar senescence. In contrast, red spruce and loblolly pine maintain substantial foliar starch reserves, which were reduced by ozone. However, they did not experience ozone‐induced senescence. While fast growing species showed the greatest changes in allocation in response to stress, we do not suggest that rapidly growing plants are more sensitive to stress. We suggest they have a higher capacity to allocate C to compensate for the stress. Slower growing species rely more on C storage or multiple shoot growth periods within the growing season to respond to stresses that alter the pattern of C allocation in faster growing species.
Compensation as a Plant Response to Ozone and Associated Stresses: An Analysis of ROPIS Experiments
Authors: Pell E. J. , Temple P. J. , Friend A. L. , Mooney H. A. , Winner W. E.
Published: July 2010

This paper examines the role that compensation plays in determining plant response to stress. In addition to exploring the compensatory responses to individual stresses, multiple stresses that induce different compensatory strategies are considered. To do this we have utilized results of many experiments conducted by the Response of Plants to Interacting Stresses (ROPIS) project. Similarities and differences in compensatory responses of plants are considered as a function of growth habits viz. herbaceous annuals, and deciduous and evergreen perennials. The predominant way that plants compensate for stress is through shifts in C allocation, with shifts toward the roots occurring in response to stresses like drought and nutrient deficiencies. Photosynthetic poisons like ozone (O3) and sulfur dioxide (SO2) will induce shifts in favor of the shoot. Plant physiological strategies for coping with stress can also lead to shifts in shoot/root ratio; these include accelerated senescence of injured leaves in favor of production of new foliage, altered leaf area and rates of photosynthesis, and N and C allocation. At the biochemical level, the mechanisms for induction of compensatory shifts are not known; however, it is likely that hormonal changes lead to altered genetic expression of protein synthesis that modify metabolism within tissues or organelles. At the whole plant level, the role of sink strength appears to be important in determining the flow of C and N in stressed plants.
Changes in Infiltration and Drainage during Wastewater Irrigation of a Highly Permeable Soil
Authors: Cook F. J. , Kelliher F. M. , McMahon S. D.
Published: July 2010

The effects of wastewater irrigation on hydraulic properties of a highly permeable, volcanic‐ash soil are presented. Ponded infiltration rate, water content, and drainage were measured by the instantaneous profile technique in a 5‐m3, 2.3 m deep isolated soil monolith. This was done both before and after 32 mo of irrigation with secondary‐treated wastewater. Irrigation then continued for a further 4 mo. After 8 mo of no irrigation, a third set of measurements was made. Ponded infiltration rate decreased by 50% from 8.3 × 10−5 to 4.1 × 10−5 m s−1 after 32 mo of wastewater irrigation. A further decrease to 1.7 × 10−5 m s−1 was found 1 yr later. Three years of wastewater irrigation resulted in a 25‐mm decrease in the amount of water stored by the soil to a depth of 2.3 m after 20 d of drainage. This decrease was mainly at depths less than 1 m and may be due to restricted wetting of the soil. An identical decrease was found in the amount of water that drained from the soil during these 20 d. However, the water content at depth 0.1 m after 20 d of drainage was increased by 0.1 m3 m−3. This increase in water content and the concomitant decrease in infiltration rate appear to be caused by clogging of soil pores.
Mass Flow of a Volatile Organic Liquid Mixture in Soils
Authors: Gerstl Z. , Galin Ts. , Yaron B.
Published: July 2010

The flow of kerosene, a volatile organic liquid mixture (VOLM), was studied in loam and clay soils and in a medium sand. The kerosene residual capacity and conductivity were determined for all three media at different initial moisture contents and with kerosene of different compositions. The kerosene conductivity of the soil was found to be strongly influenced by the soil texture and initial moisture content as well as by the kerosene composition. The kerosene conductivity of the sand was two orders of magnitude greater than that of the soils and was unaffected by initial moisture contents as high as field capacity. The kerosene conductivity of the loam soil was similar in oven dry and air dry soils, but increased significantly in soils at 70% and full field capacity due to the Yuster effect. In the clay soil the kerosene conductivity of the air dry soil was four times that of the oven dry soil and increased somewhat in the soil at 70% field capacity. No kerosene flow was observed in the oven dry soil at full field capacity. The differences in kerosene conductivity in these soils and the effect of moisture content were attributed to the different pore‐size distributions of the soils. Changes in the composition of the kerosene due to volatilization of the light fractions resulted in increased viscosity of the residual kerosene. This increased viscosity affected the fluid properties of kerosene, which resulted in decreased kerosene conductivity in the sand and the soils.
Persistence of Metals in Soil and Selected Vertebrates in the Vicinity of the Palmerton Zinc Smelters
Authors: Storm G. L. , Fosmire G. J. , Bellis E. D.
Published: July 2010

Concentration of Cd, Pb, Zn, and Cu in soil and wildlife at the Palmerton zinc smelter site in eastern Pennsylvania were determined 6 yr after zinc smelting was terminated in 1980. Levels of the four metals were higher in litter (01 and 02 horizon) than in soil (A1 horizon), and the metals were at or near levels when the smelters were still in operation. Levels of metals in soil were highest at sites close to the smelters and decreased as distances from the smelters increased. The relation of decreasing amounts of metals in body tissues with increasing distance from the smelters also held true for amphibians and mammals. An exception to this relation was higher level of Cu in red‐backed salamanders (Plethodon cinereus) captured ≈17 km downwind than those captured ≈12 km downwind. Levels of Zn, Pb, and Cu in liver, kidney, and muscle tissue of white‐footed mice (Peromyscus leucopus) were not different (P > 0.05) which is reportedly considered an indication of environmental contamination. Levels of Cd in kidneys and liver of white‐tailed deer (Odocoileus virginianus) at Palmerton were five times higher than those for whitetailed deer collected 180 km southwest of Palmerton in southcentral Pennsylvania. The abnormal amounts of metals in the tissues of terrestrial vertebrates, and the absence or low abundance of wildlife at Palmerton indicated that ecological processes within 5 km of the smelters were markedly influenced 6 yr after zinc smelting was discontinued.
Morphological Characteristics of Reconstructed Prime Farmland Soils in Western Pennsylvania
Authors: Bell James C. , Cunningham Robert L. , Anthony Craig T.
Published: July 2010

The major soil horizons of prime farmlands disturbed by surface mining in the USA must be reconstructed during reclamation in accordance with current federal legislation. Consequently, the topsoil (Ap horizon) and subsoil (B and C horizons) are removed and stockpiled separately during overburden removal activities and are replaced over spoil during reclamation in an attempt to reconstruct the original soil profile and to help maintain soil productivity. This study was conducted to investigate the morphological, physical, and chemical properties of reconstructed mine soils and to identify characteristics of these soils that could limit crop growth. We described and sampled a total of 72, 1‐ to 2‐year‐old, reconstructed soil profiles at eight reclaimed surface mines throughout western Pennsylvania. Soil depth over spoil was generally >75 cm with an observed range of 5 cm to >2 m. Well‐expressed Ap horizons were observed in nearly all profiles. The structure of the reconstructed subsoils was drastically altered by mining to a structureless and massive condition. Excessively compacted shallow soil layers restricted downward penetration of plant roots within 47% of the soil profiles described. Reconstructed soil horizons that are likely to restrict plant growth included horizons composed of spoil, horizons with >50% rock fragments and excessively compacted soil layers. These restrictive soil horizons were found within 1 m of the surface for 57 of the 72 soil profiles described and within 50 cm for 51% of the soil profiles. Morphological investigations of reconstructed soils could be useful for evaluating reclamation success and soil productivity potential.
Adsorption and Desorption of Atrazine and Deethylatrazine by Low Organic Carbon Geologic Materials
Authors: Roy W. R. , Krapac I. G.
Published: July 2010

The adsorption and desorption of atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) and a primary metabolite, deethylatrazine (2‐amino‐4‐chloro‐6‐isopropylamino‐s‐triazine; DEA), by low organic C (≤ 3.3 g kg−1) materials were measured by batch‐equilibrium techniques. The adsorbents were samples of glacial outwash sand, till, and stream sediments. The adsorption of both atrazine and DEA conformed to linear isotherms. The adsorption of atrazine by most of the adsorbents yielded apparent Koc values that were in excess of those based on surface agricultural soils. Adsorption correlated with only the pH of the sand‐water suspensions. The desorption of atrazine was hysteretic under the conditions of the measurement. DEA had a lower affinity for the same adsorbents; the mean ratio of Kd values of DEA to those of atrazine was 0.37 ± 0.20. DEA adsorption did not correlate with organic C, surface area, clay content of the adsorbents, or with the pH of the suspensions. DEA adsorption, unlike atrazine, tended to be reversible. There was a linear relationship between the adsorption constants of atrazine and those of DEA.
Water Quality in the Shingle Creek Basin, Florida, before and after Wastewater Diversion
Authors: O'Dell Kim M.
Published: July 2010

Shingle Creek is a major inflow to Lake Tohopekaliga, Florida. Water quality and the trophic status of Lake Tohopekaliga are affected strongly by the water quality of Shingle Creek. This report documents 10 yr of water quality data in Shingle Creek at the lake outfall; for a pre‐ (October 1981–December 1986) and a post‐wastewater discharge (January 1987–September 1991) removal period. Nutrient budgets for the subbasins were calculated from an intensive research program (January 1983–December 1985) to document instream impacts attributable to wastewater, determine the role of the cypress swamp in the middle subbasin, and document relationships between water quality and land uses. Rapid urbanization converted forested uplands and agricultural lands to housing and commercial land use during the study. Stormwater runoff in Florida has been identified as a major pollution source. Treatment of stormwater pollution, through Best Management Practices (BMPs), has been regulated by the State of Florida in this area since 1982. By 1988, 84% of the urban landuse in the upper basin was subject to stormwater treatment prior to being discharged to the creek. Potential increases in urban derived nutrient inputs were offset by stormwater management, and alum treatment and diversion of municipal wastewater. Nitrogen loads, and P loads and variance decreased significantly during the 10‐yr period, despite rapid urbanization in the northern and central subbasins. Nutrient export from the subbasins was influenced by the dominant land use. The middle subbasin contains a swamp that contributed the greatest P and Cl− loads because of the increase in discharge to the swamp from sources other than the canal. The northern urban subbasin received the wastewater discharges and served as a net sink for N and P exported from the subbasin.
Study of Pesticide Occurrence in Two Closely Spaced Lakes in Northeastern Nebraska
Authors: Spalding Roy F. , Snow Daniel D. , Cassada David A. , Burbach Mark E.
Published: July 2010

Dissolved pesticide concentrations in 168 water samples collected from two closely‐spaced lakes between early May 1990 and mid‐June 1991 indicated large differences in impacts from watershed nonpoint source inputs. Pesticide levels in Maskenthine Lake, a small impoundment of 34 ha, increased in response to spring and early summer runoff events. Twelve pesticides [atrazine, 2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine; alachlor, 2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide; metolachlor, 2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide; cyanazine, 2‐[[4‐chloro‐6‐(ethylamino)‐s‐triazin‐2‐yl]amino]‐2‐methylpropionitrile; EPTC, S‐ethyl dipropylthiocarbamate; butylate, S‐ethyl diisobutylthiocarbamate; propachlor, 2‐chloro‐N‐(1‐methylethyl)‐N‐phenylacetamide; trifluralin, α,α,α‐trifluoro‐2, 6‐dinitro‐N,N‐dipropyl‐p‐toluidine; simazine, 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine; propazine, 2‐chloro‐4,6‐bis(isopropylamino)‐s‐triazine; fonofos, O‐ethyl S‐phenyl ethylphosphonodithioate; metribuzin, 4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one] and two atrazine metabolites, deethylatrazine, 2‐amino‐4‐chloro‐6‐isopropylamino‐s‐triazine (DEA) and deisopropylatrazine, 2‐amino‐4‐chloro‐6‐ethylamino‐s‐triazine (DIA) were detected. Atrazine, cyanazine, DEA and DIA levels were greater than 1 µg/L. Atrazine remained above the maximum contaminant level for potable water of 3 µg/L throughout the period of investigation. The pesticide response to spring and summer runoff events was much less pronounced at Willow Lake, a 284 ha impoundment. Ten of 12 pesticides and two atrazine metabolites in Maskenthine Lake were also detected in Willow Lake; however, concentrations did not exceed 1 µg/L. After the spring flush of pesticides in May and June, concentrations decreased until the following spring. Ratios of DEA to atrazine and DIA to atrazine remained relatively constant suggesting that appreciable amounts of biodegradates were not produced. Apparent half‐lives were calculated from observed concentration decreases that appeared to follow first‐order kinetics. Atrazine was the most persistent agrichemical (t1/2 = 193, t1/2 = 124) introduced in the spring runoff events. Extracted pesticide levels were higher hi bottom cores from Maskenthine Lake than from Willow Lake. Differences in pesticide levels in the two lakes were related to watershed slope, soil drainage capacity, landuse, and rainfall.
Quality of Runoff from Fescuegrass Plots Treated with Poultry Litter and Inorganic Fertilizer
Authors: Edwards D. R. , Daniel T. C.
Published: July 2010

Recent application of either organic or inorganic fertilizers can promote increased runoff concentrations of nutrients, organic matter, and/or suspended sofids. This experiment assessed the impacts of fertilizer treatment (control, poultry litter, and inorganic fertilizer) and simulated rainfalls (four events, one each at 7, 14, 36, and 68 d after application) on quality of runoff from fescuegrass (Festuca arundinacea Schreber) plots. Runoff was produced by simulated rainfall (50 mm h−1) and sampled at 0.08‐h intervals during runoff. Composite runoff samples from each plot were analyzed for NO3‐N, NH3‐N, total Kjeldahl (TKN), ortho‐P (PO4‐P), total P, chemical oxygen demand (COD), and total suspended solids (TSS). For the first simulated rainfall event, runoff concentrations of NO3‐N, NH3‐N, TKN, PO4‐P, and total P were highest from the plots that received inorganic fertilizer, while the highest concentrations of COD and TSS occurred in runoff from plots treated with poultry litter. Mean concentrations of NO3‐N, NH3‐N, TKN, PO4‐P, and total P in runoff from the litter‐treated plots during the second simulated rainfall were not significantly different than observed in runoff from the control plots. Runoff quality from the plots receiving poultry litter and inorganic fertilizer did not significantly differ from background (control) levels during the third simulated rainfall (with natural runoff occurring twice between the second and third simulated rainfalls). Runoff losses of parameters investigated were generally highest for the first simulated rainfall. Losses of N and P from the treated plots summed over all four simulated rainfalls were very small proportions of amounts applied (≈1.4 and 2.7%, respectively).
A White Clover System to Estimate Effects of Tropospheric Ozone on Plants
Authors: Heagle Allen S. , Miller Joseph E. , Sherrill Dorothy E.
Published: July 2010

An ozone‐sensitive (NC‐S) and an ozone‐resistant (NC‐R) clone of white clover (Trifolium repens L.) were tested to determine the feasibility of using them to indicate concentrations of tropospheric ozone (O3) and potential effects of O3 on plants. Plants of each clone were exposed daily in open‐top field chambers to O3 concentrations ranging from 0.5 to 1.5 times the ambient concentrations for three summer seasons near Raleigh, NC. Foliar injury, foliar chlorophyll, and forage production of both clones were related directly to the O3 concentration. Ozone routinely injured leaves, suppressed foliar chlorophyll, and decreased growth of NC‐S more than that of NC‐R. Forage production was highly variable over a wide range of weather conditions, but the relative forage production rate of both clones under such conditions was similar and the seasonal O3 response relationship between NC‐S and NC‐R was relatively stable. The level of response of NC‐S to O3 routinely increased from growth period to growth period suggesting an effect of previous exposure. More work is needed to calibrate the system over a wider range of ambient O3 levels and climatic conditions.
Uranium and Thorium Decay Series Radionuclides in Human and Animal Foodchains—A Review
Authors: Linsalata Paul
Published: July 2010

Human exposures along plant and animal pathways to isotopes of U, Th, Ra, Pb, and Po are reviewed. The range and variability of intakes among human populations resulting from dietary sources are presented. Also discussed are the sources of intake among farm animals reared for consumption. Under most circumstances, the soil‐plant‐human pathway is the predominant route of intake for humans and livestock. Radionuclide distributions within livestock and human tissues, and the transfer factors used to model intakes along various food chain pathways are summarized. Bone is the major site of deposition in livestock and humans. Where possible, summary data and conclusions from previous reviews are considered along with some notable gaps in the data base for natural series radionudides.
Radium‐226 and Calcium Uptake by Crops Grown in Mixtures of Sand and Clay Tailings from Phosphate Mining
Authors: Million J. B. , Sartain J. B. , Gonzalez R. X. , Carrier W. D.
Published: July 2010

Radium‐226 is a naturally occurring radionuclide found in reclaimed clay and sand tailings from phosphate mining. Field studies were conducted to investigate the effects of sand/clay ratio (SCR), Ca supplement, and organic amendments on the 226Ra concentration in turnip (Brassica rapa L.), banana pepper (Capsicum annum L.), cabbage (Brassica oleracea var. capitata), yellow squash (Cucurbita pepo L.), mustard [Brassica juncea (L.) Czern & Coss.] and alfalfa (Medicago sativa L.). For vegetables, treatment effects included SCR (2:1, 4:1, 6:1, and 8:1), phosphogypsum (PG) (0, 22, and 134 Mg ha−1), and peat (0, 100, 200 Mg ha−1). For alfalfa grown in a 1:1 SCR mixture, treatments included organic amendments (control, peat, sewage sludge, sawdust, composted sewage sludge, composted garbage and humate) applied at 44.8 Mg ha−1 (2.2 Mg ha−1 for humate). Plant 226Ra concentration tended to be higher in the 4:1 than in the 2:1 SCR mix but this depended on the crop and the season. Organic amendments and PG had no effect (p < 0.05) on the 226Ra concentration in vegetables and alfalfa. Mean 226Ra concentration in plant tissues ranged from 3.4 Bq kg−1 in banana pepper fruit to 31.1 Bq kg−1 in turnip leaf. Sand‐clay mixtures contained 289 to 592 Bq 226Ra kg−1. A quadratic relationship based on 631 observations was observed between 226Ra and Ca concentration in plant tissues. The 226Ra/Ca ratio in plant tissues ranged from 0.85 to 2.13 kBq 226Ra kg−1 Ca and decreased with increasing plant 226Ra. Results indicated that wide differences in plant 226Ca concentration were related more to differences in plant Ca levels than to soil factors.
Plant Cover and Water Balance in Gravel Admixtures at an Arid Waste‐Burial Site
Authors: Waugh W. J. , Thiede M. E. , Bates D. J. , Cadwell L. L. , Gee G. W. , Kemp C. J.
Published: July 2010

Isolation of radioactive waste buried in unsaturated zones will require long‐term control of recharge and erosion. Soil covers control recharge at arid sites by storing rainwater close enough to the surface to be removed by evapotranspiration. Surface layers of rock or gravel control erosion at sites with sparse vegetation, but can also alter plant habitat and cause recharge through interred waste. As an alternative, gravel mixed into the uppermost soil layer may control erosion over the long‐term better than surface gravel layers. We postulated that gravel admixtures also would not influence plant establishment or soil water balance in waste‐site covers. We measured the interactive effects of gravel admixture concentration, vegetation, and precipitation on soil water content and plant cover at the U.S. Department of Energy's Hanford Site in Washington state. Our results support the use of a combination of vegetation and gravel admixtures for erosion control. Vegetation seasonally depleted rootzone water storage to about 6.5 volume % regardless of precipitation amount or the presence of gravel admixture amendments. In contrast, yearly increases in soil water storage as deep as 225 cm in plots without vegetation may be a leading indicator of recharge. The composition and abundance of vegetation changed over time and in response to precipitation amount, but was not influenced by gravel amendments. Seeded wheatgrasses [Agropyron sibericum Wilde and Agropyron dasystachyum (Hook.) Scribn.] established only when irrigated with twice average precipitation (32 cm/yr), but persisted after the irrigation ceased. Cheatgrass (Bromus tectorum L.) and Russian thistle (Salsola kali L.) colonized areas that received both irrigation and ambient precipitation. Stands with wheatgrasses extracted water more rapidly and depleted soil water to lower levels than cheatgrass‐dominated stands. Increases in gravel cover and near‐surface gravel concentrations after 5 yr were evidence of the formation of a protective gravel veneer.
Acidic Fog and Temperature Effects on Stigmatic Receptivity in Two Birch Species
Authors: Hughes R. N. , Cox R. M.
Published: July 2010

Factorial assays were performed to determine the effects of simulated acid fog (SAF) and temperature on stigmatic receptivity in two birch species. Excised reproductive branches were sampled from representative individuals of mountain paper birch (Betula cordifolia Regel.) and paper birch (Betula papyrifera Marsh.) in populations adjacent to the Bay of Fundy, New Brunswick, Canada. Since 1979 these trees have exhibited branch dieback in association with abnormal foliar browning symptoms. This browning has been linked with acidity and nitrate deposited by fog, which is frequent in the area. In general, experimental results indicated that pollen germination increased with temperature, but pH effects were less obvious. Similarly, pollen tube growth responded positively to temperature and was little affected by fog acidity. ANOVA tests indicated a significant difference (P < 0.05) between species in their pollen germination response only at 12°C, and not at the other three temperatures tested. For pollen tube growth, significant differences between species (P < 0.05) were demonstrated at 12 and 22°C. A significant pH effect was demonstrated at 27°C for germination, while pH effects on tube growth were significant at 27 and 12°C (P < 0.01). A response surface regression analysis indicated that acidity significantly affected pollen germination in mountain paper birch (P < 0.001) but not in paper birch. Temperature was not a significant factor for in vivo pollen germination in either species. For pollen tube growth, however, temperature was more important than pH and produced highly significant effects in both species (P < 0.001). Acidity was also a significant factor in pollen tube growth for paper birch.
Phytotoxicity of a Chemical Weapon Simulant, Triethyl Phosphate
Authors: Sikora F. J. , Harper S. S. , Giordano P. M.
Published: July 2010

Triethyl phosphate (TEP) is proposed to be used as a chemical weapon simulant in missile testing at White Sands Missile Range in New Mexico. Studies were conducted to determine the phytotoxicity of TEP using sorghum‐sudangrass [Sorghum bicolor (L.) Moench], tomato (Lycopersicon lycopersicum Mill.), and glossy privet (Ligustrum lucidum Ait.) as test plants grown on Mimbres‐Glendale (MG) and Nickel‐Tencee (NT) soil associations obtained from White Sands Missile Range. Triethyl phosphate was applied to soil and foliar tissue at rates of 0, 4, 400, and 40 000 mg m−2 soil surface. Triethyl phosphate also was applied in a thickened formulation, as used in missile testing, at an application rate of 40 000 mg m−2 on both soil and foliar tissue. Toxicity was only observed at the highest application rate with pure and thickened TEP. The method of TEP application to soil or foliar tissue did not affect the dry matter weight of tomato or glossy privet growth. There were inconsistent effects of TEP application method on sorghum‐sudangrass dry matter weight, depending on soil type. Triethyl phosphate affected the test plants differently with resistance to TEP toxicity increasing in the order: tomato ≃ sorghum‐sudangrass on NT soil < sorghum‐sudangrass on MG soil < glossy privet. A seedling emergence study using sorghum‐sudangrass, tomato, and cucumber (Cucumis sativus L.) resulted in similar conclusions from the whole plant studies showing TEP toxicity only at the highest application rate of 40 000 mg m−2. There were indications from sorghum‐sudangrass growth and cucumber seedling emergence that TEP toxicity may be less on soil having a higher clay and organic matter content, which may have been due to TEP sorption in soil and decreased TEP bioavailability to plant roots. The absence of phytotoxicity symptoms indicated plants would not be harmed if application rates were at or below 400 mg TEP m−2.
The Effects of Zinc Fertilization on Cadmium Concentration in Wheat Grain
Authors: Oliver D. P. , Hannam R. , Tiller K. G. , Wilhelm N. S. , Merry R. H. , Cozens G. D.
Published: July 2010

Although the effect of Zn in soil on Cd uptake by plants has been studied extensively, there appears to be no consensus in the literature about the interactions. Furthermore, the majority of investigations have studied soils containing elevated concentrations of Cd or Zn as a result of pollution, e.g., the application of sewage sludge to the soil. The accumulation of Cd by wheat (Triticum aestivum L.) grain grown at nine sites across South Australia was investigated. Applications of low rates of Zn fertilizer (up to 5.0 kg Zn ha−1) were found to markedly decrease the Cd concentration in wheat grain grown in areas of marginal to severe Zn deficiency. No further significant decreases in Cd concentration in grain occurred at higher rates of applied Zn. Effectiveness of applied Zn on grain Cd concentration decreased with tune since application. Grain Cd concentrations decreased with fresh and residual applications of Zn fertilizer (up to 5.0 kg Zn ha−1). Soil tests may provide useful guides to situations where Cd concentrations in grain may be beneficially decreased by Zn applications.
Forms of Phosphorus in Sediments Eroded from Burnt Soils
Authors: Saá A. , Trasar‐Cepeda M. C. , Soto B. , Gil‐Sotres F. , Díaz‐Fierros F.
Published: July 2010

Wildland fires can increase erosion and nutrient loss in runoff by loss of vegetative cover and changes in soil structure and chemical composition. Thus, we investigated the effect of vegetation burning intensity on the loss of particulate P forms in eroded sediments by using a sequential fractionation method that distinguishes organic and inorganic P forms of different lability. Moderate burns, while not affecting P form distribution in the soil, led to high levels of inorganic P (largely Bic‐Pi, NaOH‐Pi, and HCl‐P) in eroded sediments, with phosphorus enrichment ratios ranging from 3.36 to 5.04. Severe burns modified P form distribution in the soil, and led to the almost complete disappearance of extractable organic P from the soil. Phosphorus form distribution in sediments eroded from the severely burnt plot was similar to that in the surface layer of the soil of that plot (0–2.5 cm). Within 10 mo of burning, and independently of burn intensity, sediments eroded from both the moderately and severely burnt plots had the same P form content and distribution as sediments eroded from control plots. As a consequence of burning, the annual total P losses due to removal of particulate matter in runoff increased from 1.42 kg ha−1 (control plot) to 4.35 kg ha−1 (moderately burnt plot) and 9.10 kg ha−1 (severely burnt plot). The results of the P fractionation reveal that burning leads to a 2‐ to 11‐fold increase in rapid‐turnover inorganic and organic P contents in eroded sediments. This implies greatly increased risks of eutrophication of receiving waters.
Comparison of Amendments and Management Practices for Long‐Term Reclamation of Abandoned Mine Lands
Authors: Pichtel J. R. , Dick W. A. , Sutton P.
Published: July 2010

Abandoned mine lands containing pyritic spoil may become toxic due to production of sulfuric acid and subsequent high levels of heavy metals. A field study was initiated to compare the long‐term (10 yr) effectiveness of digested municipal sewage sludge (224 Mg ha−1), powerplant fly ash (448 Mg ha−1), papermill sludge composted with either coarse or line wood bark (67, 90, and 112 Mg ha−1), and limed topsoil (20‐cm depth) in maintaining a grass‐legume mixture on toxic abandoned mine spoil (initial pH 3.4). Management of reclaimed plots included an additional one‐time application of N, P, and K according to soil test 1 yr after reclamation and annual cutting of vegetation that was either removed from the plot or left on the surface. Soil was sampled at depths of 0 to 10 and 10 to 20 cm, with the lower sample representing soil (except for the topsoil treatment) to which the amendments had not been mixed. These soil samples were analyzed for pH and plant nutrients. Dry matter production declined sharply after 3 yr and then recovered the last 2 yr due to favorable weather, although to only two‐thirds of the initial levels. The topsoil and sewage sludge amendments maintained overall highest yields and highest percent vegetative cover (93 and 91%, respectively). Amended spoil experienced a gradual pH increase over the study period with the topsoil amendment exhibiting the highest pH (7.0) and fly ash the lowest pH (5.1) after 10 yr. The topsoil and sewage sludge amendments generally maintained the highest soil K, Ca, and Mg concentrations, while the sewage sludge and fly ash amendments had the highest P concentrations. pH values and P, K, Ca, and concentrations in the 0‐ to 10‐cm soil horizon were higher than in the 10‐ to 20‐cm horizon. Management did not result in differences in plant uptake of nutrients and metals, but a one‐time addition of lime and fertilizer did increase vegetative yields. We conclude that the papermill sludge and sewage sludge amendments were roughly equivalent to limed topsoil for the successful long‐term reclamation of toxic mine spoil. The fly ash amendment was least successful due to its inability to provide pH and nutrient levels sufficient for the maintenance of good vegetative growth.
Earthworm Macropores and Preferential Transport in a Long‐Term Manure Applied Typic Hapludalf
Authors: Munyankusi E. , Gupta S. C. , Moncrief J. F. , Berry E. C.
Published: July 2010

Deep burrowing earthworm species have been found to be present in soils with a history of manure application. This study was designed to quantify the effects of long‐term application of liquid dairy manure and inorganic fertilizer on the distribution of earthworm macropores and in turn on the preferential transport of water and tracer through a typical soil of the karst area of the upper mid‐western USA. Large (≈ 30 cm diam. by 90 cm long) undisturbed soil columns were taken from plots where liquid dairy manure or inorganic fertilizers had been applied continuously for 8 yr. The number and size distribution of macropores in soil columns were nearly the same for both inorganic and manure treatments, however, visible surface macropores were continuous to much deeper depth in soil columns taken from manure than from the inorganic fertilizer plot. Identification of the earthworms a year later showed the presence of Apporectodea tuberculata, A. trapezoides, and Lumbricus rubellus, subsurface burrowers, as well as, L. terristris, a deeper burrowing species in the manure applied plot. Apporectodea tuberculata was the only species present in the inorganic fertilizer plot. Number of macropores and macroporosity varied with soil depth. The maximum macroporosity was <2.5% and it occurred at 2‐cm depth. The predominant macropore sizes were between 1‐ and 2‐mm radii for both treatments. During breakthrough experiments, Cl− appeared earlier in soil columns taken from the manure plot thereby indicating a greater continuity of macropores in the manure compared with the inorganic fertilizer treatment. Thearly appearance of Cl− in the manure treatment, however, was much slower than one would expect based on the number of macropores and their continuity estimated from the serial sectioning. This suggests that intrusive serial sectioning and image analysis techniques probably overestimate the continuity of macropores possibly due to vacuuming of the earthworm casts and other debris that plugs the macropore channels. Based on macropore size distribution with depth and related breakthrough curves, it is likely that most existing models of water and contaminant transport that simulate macropore flow, will not accurately predict the transport of water and contaminant because of their assumption that surface visible macropores are continuous to deeper soil depths. Data from this study showed that macropore size distribution could be described by a normal or log‐normal distribution function. These functions in combination with information on continuity and tortuosity of macropores may be sufficient, when used in some current macropore models, to adequately describe the conducting efficiency of macropores in soils.