bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation of Pyridine Derivatives in Soil
Authors: Sims Gerald K. , Sommers Lee E.
Published: July 2010

The fate of pyridine and 25 substituted pyridines in soil (Aeric Ochraqualfs) was examined by measuring the quantity remaining and the inorganic N released as a result of degradation of the pyridine ring for a period of 64 d. Each compound was added to soil at 2 mmol kg−1. Compounds studied included pyridine substituted with one or two hydroxyl, carboxyl, chlorine, amine, or methyl groups. During the 64‐d incubation period, extractability of pyridine derivatives with 2 M KCl + 0.01 M HC1 decreased from an average of 88 ± 8.8% to essentially 0 for all compounds except aminopyridines. From 36 to 94% of added aminopyridines was recovered after 64 d of incubation. Degradation of the majority of pyridine derivatives was confirmed by accumulation of N in amounts equivalent to 61 to 80% of the decrease in extractable pyridines at 64 d of incubation. Degradation of unsubstituted pyridine occurred within 8 d, whereas most hydroxypyridines were degraded within 32 to 64 d. Pyridinecarboxylic acids appear to be the most labile group of pyridine derivatives and were dissipated from soil in 4 to 16 d. Most chloropyridines persisted in soil and became weakly associated with some insoluble soil component. However, 4‐chloropyridine degraded in 16 d. Aminopyridines resisted degradation in soil while methylpyridines were degraded in 8 to 32 d. Degradability of the compounds generally followed the order pyridinecarboxylic acids > pyridine = mono‐hydroxypyridines > methylpyridines > aminopyridines and chloropyridines. This trend was consistent with previous results on biodegradability of the compounds in soil suspension cultures.
The Solubility Relationships of Calcium and Magnesium Minerals in Processed Oil Shales
Authors: Reddy K. J. , Lindsay W. L.
Published: July 2010

One of the major problems occurring with the oil shale industry is the production of large amounts of solid wastes (spent shale). The high alkalinity of these waste materials often presents problems for successful management practices to minimize overall pollution impact on the environment. The objective of this study was to determine solubility of calcium and magnesium minerals to explain high alkalinity of spent shales. Two oil shales, one processed by Los Alamos National Laboratory (LANL) and another processed by Lurgi Ruhrgas (Lurgi) were examined in this study. The x‐ray diffraction analysis was used to identify different mineral phases of spent oil shales. The results indicate that processing oil shales at high temperature destroyed carbonate minerals and formed silicate minerals including wollastonite (αCaSiO3), clinoenstatite (MgSiO3), or diopside (CaMg(SiO3)2). These minerals buffered pH above 11.00 and controlled Ca2+ and Mg2+ activities in solution. The experimental findings in this study further suggest that oxides or hydroxides of Ca and Mg produced initially from processing oil shales did not persist after moisture was allowed to contact the spent shale.
Decomposition of Potato Processing Wastes in Soil
Authors: Smith J. H.
Published: July 2010

Solid filtered or centrifuged potato processing wastes were obtained from three potato processors in Idaho. The waste samples were dried and ground to pass a 2‐mm sieve and added to soils at rates of 0, 2.5, 10, and 25 g/kg. The 100‐g samples of Portneuf silt loam soil containing the waste material was incubated at 26 °C and decomposition of the added wastes was determined by measuring CO2 evolution in a flowing air stream passing over the soil in the incubation flask. Each increment of added organic waste material increased the amount of carbon evolved during the 12‐week incubation. The waste materials contained 6.8, 20.4, or 65.5 g N/kg waste. However, these differences in N did not change the amount of CO2 evolved at the 12‐week incubation, although the evolution curves were shaped somewhat differently during the 12 weeks. Regression analyses of the cumulative carbon resulted in highly significant R2 values being obtained for each potato processing waste material. Decomposition of the solid waste materials ranged from 24 to 92% depending upon the source and application rate. The rapid decomposition of the solid wastes verified field research indicating that potato wastes have not more than 1 yr residual fertilizer value. The organic waste is not likely to accumulate in the field.
Intrusion of Reclaimed Uranium Mill Tailings by Prairie Dogs and Ground Squirrels
Authors: Shuman Rob , Whicker F. Ward
Published: July 2010

The potential for intrusion of soil‐covered uranium mill tailings was investigated with respect to two sciurids, the whitetail prairie dog (Cynomys leucurus) and the Wyoming ground squirrel (Spermophilus elegans). At a study site in Wyoming, measurements of gross alpha radioactivity on mound surfaces of artificially‐introduced prairie dogs were made to reveal any tailings penetration through 0.5 m of soil‐cover. Also, the impact of prairie dog burrowing upon radon flux from the cover surface was investigated. Limited, short‐lived intrusion of the waste layer was noted, but no significant changes in radon flux were detected. Wyoming ground squirrels confined to soil‐ and soil/tailings‐filled barrels burrowed to less extreme depths when confronted by mill tailings. Additional work at an inactive railings pile in western Colorado revealed repeated intrusion through a shallow cover and subsequent transport of radioactive material to the ground surface by prairie dogs that had voluntarily invaded the site at least 10 yr prior to this study. Radon flux from burrow entrances was significantly greater than that from undisturbed ground at the Colorado site. Differences in burrowing and radionuclide release between the Wyoming and Colorado sites may have been due to railings characteristics such as pH and/or texture, or to other factors such as residence time of the animals.
Variations in Natural Nitrogen‐15 Abundance as an Aid in Manure‐nitrogen Studies
Authors: Selles F. , Karamanos R. E.
Published: July 2010

The fate of manure N in the soil‐plant system was studied in a growth chamber experiment with soil columns (Typic Haploborolls) using three rates of manure (equivalent to 0, 60, and 90 Mg ha−1) and two water regimes. Estimates of manure N contribution to various compartments of the system were derived using the changes in natural 15N abundance of the N sources in the system. These sources included manure‐derived inorganic N from manure amendments to the soil, inorganic N initially present in the soil and soil‐derived inorganic N. Calculations of the contribution of each source to soil, plant, and leachate were based on the principle of isotopic dilution. Complete recovery of manure and manure‐derived N in the systems studied were obtained and N balances were drawn for both uncropped and cropped treatments through a series of calculations. This was not possible in all cases when the contribution was calculated from the difference between manure amended and nonamended treatments. Although large propagated errors may be incorporated in the calculations based on the isotopic dilution principle, the proposed technique appears to be sensitive enough to semiquantitatively describe the fate of manure N in the soil‐plant system.
Soil Potential Ratings for Onsite Wastewater Disposal
Authors: Steele D. P. , Petersen G. W. , Fritton D. D.
Published: July 2010

The soil potential concept has been developed to provide more useful information in interpreting soil suitabilities for various uses. Soil potential rating systems have been applied to onsite wastewater disposal in several regions. However, true utility of this type of rating system will not be discernable until it has been widely applied to explore various approaches. A procedure was developed for generating soil potential ratings for onsite residential wastewater disposal. This procedure was used to rate every soil mapping unit (91) in Potter Township, Centre County, PA. These ratings were developed by selecting the most appropriate onsite disposal technology using the following seven properties: depth to bedrock, depth to fragipan, depth to seasonally high water table, soil percolation time, slope, surface stoniness, and landscape position. In order to determine the ratings, an appropriate disposal system had to be selected for each mapping unit. Whenever possible the selection of a system followed state regulations (54% of selections). Innovative designs were developed for all other cases. Costs of construction and maintenance (over the design life) were estimated for the best and worst case examples of each soil mapping unit. The dollar costs were indexed over a range of 0 to 106. These numbers were later grouped into five soil potential classes according to the frequency of index rating values and an error estimation. The ratings were compared with the performance of onsite systems on four of the rated soil mapping units. This comparison indicated that the ratings were appropriate, allowed the numerical rating of every soil mapping unit, and could be used as a land use planning tool.
Effect and Disposition of TNT in a Terrestrial Plant
Authors: Palazzo A. J. , Leggett D. C.
Published: July 2010

Little is known about the response of terrestrial plants to 2,4,6‐trinitrotoluene (TNT). To assess its effects, yellow nutsedge (Cyperus esculentus L.) was grown in hydroponic cultures containing TNT concentrations of 0, 5, 10, and 20 mg/L. The deleterious effects of TNT were rapid and occurred at solution concentrations of 5 mg/L and higher. Root growth was most affected, followed by leaves and rhizomes. Root weights were reduced about 95% when grown in the presence of TNT. Plant yields were 54 to 74% lower than the control. The TNT and its metabolites, 4‐amino‐2,6‐dinitrotoluene (4‐ADNT), and 2‐amino‐4,6‐dinitrotoluene (2‐ADNT) were found throughout the plants. Solutions were continually monitored to ensure that no metabolites were present in solution. Since TNT was the only compound taken up, the metabolites must have formed within the plant. Levels of 4‐ADNT exceeded those of 2‐ADNT and TNT itself ranging up to 2200 mg/kg in roots of plants grown in 20 mg/L of TNT. The greatest quantities of all three compounds were found in the rhizomes. Increasing solution TNT levels increased the concentrations and quantities of all three compounds in the plants.
Decomposition of Benzidine, α‐Naphthylamine, and p‐Toluidine in Soils
Authors: Graveel John G. , Sommers Lee E. , Nelson Darrell W.
Published: July 2010

Decomposition of 14C‐labeled benzidine, α‐naphthylamine, and p‐toluidine in soil was studied in laboratory experiments by monitoring CO2 production during a 308‐ to 365‐d incubation period. The importance of microbial activity in decomposition of all three aromatic amines was shown by decreased 14CO2 evolution in 60Co treated soils. After 365 d of incubation, 8.4 to 12% of added benzidine (54.3 µmol kg−1) was evolved as CO2 while 17 to 31% of added α‐naphthylamine (69.8 µmol kg−1) and 19 to 35% of added p‐toluidine (93.3 µmol kg−1) were evolved as CO2 in 308 d. Decomposition of benzidine, α‐naphthylamine, and p‐toluidine was greatest at a water potential of −0.033 MPa and decreased at both 0 and −0.5 MPa. Decomposition was enhanced by increasing the temperature from 12 to 30°C. The absolute amount of α‐naphthylamine and p‐toluidine decomposed increased while the percentage of added amine degraded decreased as application rate was increased from 1 to 1000 mg kg−1. For benzidine, both the amount and proportion decomposed increased with an increase in application rate. Decomposition of aromatic amines was not enhanced by the addition of decomposable substrates. Differences in decomposition of aromatic amines occurred among soils, but consistent relationships between decomposition of amines and soil properties were not observed. In batch equilibration studies, the Freundlich equation described aromatic amine sorption. Isotherms were nonlinear for benzidine and α‐naphthylamine and linear for p‐toluidine. Desorption of sorbed amines followed the order: benzidine < p‐toluidine < α‐naphthylamine and was inversely related to the extent of decomposition.
Nitrogen Transformations in a Poultry Manure Amended Soil: Temperature and Moisture Effects
Authors: Sims J. T.
Published: July 2010

Efficient agronomic management of poultry manure requires information on its contribution to the N budget of the soil‐crop system. Of primary importance in this regard is the timing of N mineralization from the organic fraction of the manure. As manure applications are frequently made year round, it is also essential to understand how environmental variations will alter the rate and extent of N mineralization. Consequently, a laboratory study was conducted for 150 d to measure the effects of temperature and moisture on net N mineralization from three poultry manures. Each manure sample was incorporated with an Evesboro loamy sand (mesic, coated typic Quartzipsamments) and changes in soil inorganic N (NH+4‐N and NO−3‐N) and pH were determined at 30, 90, and 150 d. Although variations were noted between manure types, most of the net mineralization (Nm) observed at 25 °C and 40 °C occurred within the first 90 d. Mineralization was reduced at 0 °C but, by the conclusion of the study, considerable accumulations of inorganic N (18–76 mg/kg) were detected at this temperature. Thirty to 60% of the organic N added to the soil in manures 1 and 3 was mineralized, when moisture was not limiting. Inconsistent mineralization patterns obtained with manure 2 were attributed to microbial immobilization of N. Accumulations of NH+4‐N under cold or dry conditions resulted in elevated soil pH levels. Conversely, considerable soil acidification occurred under warm, moist conditions due to rapid nitrification of NH+4‐N added in the manures.
Binding of Herbicides by Water‐soluble Organic Materials from Soil
Authors: Madhun Yousef A. , Young J. L. , Freed V. H.
Published: July 2010

The gel filtration method of Hummel and Dreyer (1962) has been used for the study of binding of herbicides by water‐soluble organic substances extracted from soil with distilled water. Evidence is offered for the binding of bromacil (5‐bromo‐3‐sec‐butyl‐6‐methyluracil), diuron [3‐(3,4‐dichlorophenyl)‐1,1,dimethylurea], chlorotoluron [3‐(3‐chloro‐4‐methylphenyl)‐1,1‐dimethylurea], simazine (2‐chloro‐4,6‐bis‐ethylamino‐s‐triazine), glyphosate [N‐(phosphonomethyl) glycine], and diquat (1,1‐ethylene‐2,2‐bipyridylium ion) by water soluble soil organic materials (WSSOM). Infrared and gel filtration data showed that the WSSOM consist of compounds with molecular masses in the range of 700 to 5000 daltons and resemble very closely the fulvic acids present in soil and surface waters. The amount of herbicide bound by WSSOM was determined from the elution diagram of the herbicide‐WSSOM complex. The results of this study point to the significance of WSSOM in relation to the fate and behavior of pesticides and pollutants in soil and water. The binding of these chemicals by WSSOM may figure important in the assessment of their mobility and transport in the environment.
Effect of Soil and Effluent Characteristics on Phosphorus Sorption in Dosed Columns
Authors: Nagpal N. K.
Published: July 2010

The effects of soil and effluent loading characteristics on long‐term P retention and movement in soil columns were investigated. Six soil columns, 0.120 to 0.160 m deep and 0.20 m diam, were obtained from < 2‐mm fraction of Rosewall gravelly sandy loam (Inceptisols) and Qualicum gravelly loamy sand (Inceptisols). The columns were subjected to an instantaneous daily dose, except on weedends and holidays, of three effluent treatments over a period of 609 d. The three effluent treatments varied in P concentration and hydraulic loading levels; low (7.8 mg P/L, 0.0158 m/d), moderate (15.7 mg P/L, 0.0158 m/d) and high (15.7 mg P/L, 0.0315 m/d). The soils in the columns were kept unsaturated during the experiment. Continued effluent loading resulted in P breakthrough and a decrease in P sorption by soils. In five of six columns, P sorption by soils reached equilibrium. Both pore volume at P breakthrugh (PVBT) and P sorption at equilibrium (PSEQ) appeared to be affected by preferential movement of effluent through macropores. Irrespective of the mode of effluent flow, an increase in effluent P concentration and hydraulic loading decreased PSEQ; the effect of hydraulic loading on PSEQ was, however, more pronounced. Doubling the P loading through an increase in effluent P concentration decreased PSEQ by 2 to 11%; however, a similar increase in P loading obtained by a twofold increase in hydraulic loading, decreased PSEQ by 12 and 34% in Rosewall and Qualicum soils, respectively. Strong influence of effluent flow rate on PVBT, masked the effect, if any, of soil type and effluent loading on PVBT. The implications of these results with respect to wastewater renovation capability of a septic tank drainfieid were discussed.
Kinetics of Metal Dissolution from Forest Soils by Soluble Organic Acids
Authors: Pohlman Andrew A. , Mc Coll John G.
Published: July 2010

Two kinetic models are presented that describe the dissolution of Al, Fe, Mn, and Mg from two forest soils by soluble organic acids. Dissolution of Al, Fe, and Mn occurred as a first‐order kinetic reaction. The rate was in the order Mn ≫ Al> Fe in di‐ and tricarboxylic acids, salicylic, p‐hydroxybenzoic, and tannic acids, and the order Mn ≫ Fe > Al in gallic acid and catechol. Complexing acids removed these metals faster than noncomplexing acids. The dissolution of Mn followed first‐order kinetics from Holland Variant soil and parabolic‐type kinetics from Shaver soils. Dissolution of Mn by parabolic‐type kinetics followed a similar ion exchange process as in NH4OAc leaching of Al, Fe, Mn, and Mg from both soils. The chemical structure, and the type and position of functional groups within a given organic chemical series, were important factors affecting the dissolution rates of Al, Fe, and Mn, but not for Mg. The di‐ and tricarboxylic acids containing β‐hydroxy functional groups and phenolic acids containing orthohydroxy groups dissolved Al and Fe about 3 to 6 times faster than similar organic compounds with other functional‐group combinations. The interaction between α‐carboxy and β‐hydroxy groups and these metals is thought to favor the formation of a stable chelated six‐members ring structure. Gallic acid was effective in dissolving Mn, and the mode of chelation appeared to be the two adjacent phenolic‐OH groups capable of forming a stable five‐membered ring structure. The rate of dissolution of Mn in gallic acid was about 3 to 6 times faster than in salicyclic or p‐hydroxybenzoic acids. Dissolution of Mg was assumed to be by H+ ion exchange and not by chelating action.
Removal of Paraquat, Diquat, and Amitrole from Aqueous Solution by Chemically Modified Peat
Authors: Mac Carthy Patrick , Djebbar K. E.
Published: July 2010

The presence of organic pesticides in aquatic systems has been reported for more than 40 yr. Various methods, such as sorption by clays, activated C, or synthetic resins, have been used to remove these pesticides from water. Certain pesticides, such as the cationic species paraquat (C12H14N2Ch2; 1,1′‐dimethyl‐4,4′‐bipyridinium dichloride), diquat (C12H12N2Br2; 6,7‐dihydrodipyrido[1,2‐a:2′,1′‐c]pyrazinediium dibromide), and the basic species amitrole (C2H4N4; 3‐amino‐s‐triazole), are sorbed by peat. However, the use of raw peat as a sorption medium for the removal of pesticides is hampered by the relative impermeability of peat, the leaching of organic matter from peat into the effluent, and by the disaggregation of peat at pH values greater than ca. 6.0. Treatment of peat with concentrated sulfuric acid at elevated temperatures yields a granular product that has an enhanced cation exchange capacity, that is resistant to leaching, and is permeable to water flow. The objective of this research was to evaluate the use of such chemically‐modified peat for removing paraquat, diquat, and amitrole from aqueous solution under a variety of experimental conditions. Using isotherm and column experiments, it was shown that the treated peat is very effective in removing these pesticides from aqueous solution. Treated peat has a capacity of about 1 mol (+) kg−1 for these three pesticides. The effects of pH, ionic strength, and flow rate on the efficiency of pesticide removal were found to be relatively small. Peats from two different localities behaved similarly in these experiments.
Permethrin Washoff from Cotton Plants by Simulated Rainfall
Authors: Willis G. H. , Mc Dowell L. L. , Smith S. , Southwick L. M.
Published: July 2010

Developing models for predicting amounts of pesticide transported in runoff and suspended sediment from agricultural land to aquatic. habitats has been hampered for foliarly‐applied pesticides by a lack of knowledge about the processes of pesticide washoff from plants by rainfall. A multiple‐intensity rainfall simulator was used to determine the effects of rain intensity and amount on permethrin [(3‐phenoxyphenyl) methyl (±)‐cis, trans‐3‐(2,2‐dichloroethenyl)‐2,2‐dimethylcyclopropanecarboxylate] concentrations and amounts washed from mature cotton (Gossypium hirsutum L.) plants. Permethrin concentration in plant washoff was independent of rain intensity when 25 mm of simulated rain was applied at 6.6, 13.0, 25.7, and 51.3 mm h−1 2 h after permethrin was applied at 0.224 kg ha−1. Concentrations were less when the same amount of simulated rain was applied at 106.4 mm h−1. Permethrin concentrations in plant washoff decreased rapidly during the early phases of washoff. About 35% of the permethrin load on the plants 2 h after application was washed off by 25 mm of rain; an additional 76 mm of rain removed only 11% more of the permethrin from the plants. Rainfall amount had greater influence than rainfall intensity on the amount of permethrin washed from the cotton plants. This information greatly simplifies modeling the movement of permethrin from the plant canopy to soil during natural storms when intensities vary greatly within storms and from storm to storm.
Evaluation of Nitrogen Availability Indexes for a Sludge Compost Amended Soil
Authors: O'Keefe Barry E. , Axley J. , Meisinger J. J.
Published: July 2010

Several N availability methods were evaluated on a sludge amended soil, since sludge applications are usually based on N availability and a soil N evaluation to optimize loading rates. Yearly amendments of composted, lime‐stabilized, raw sludge were applied, at 0, 56, 112, and 224 Mg ha−1, to an Elkton silt loam soil (Typic Ochraquults), in Beltsville, MD, as follows: whole plots (1975–1977), half plots (1978), and no plots (1979–1981). In 1978 and 1981, surface and subsurface soil samples were collected and maize (Zea mays L.) total N uptake was determined. The biological method (73‐week aerobic incubation [NT]) of assessing soil N availability revealed an initial rapid miner. alization phase (NE) over the first 28 weeks and a constant phase thereafter. The chemical methods were total soil N (TN), acid KMnO4 oxidizable N (P), autoclave extractable N (A), and 2 M KCl extractable NH+4‐N (K). Curvilinear regression analyses relaling maize N uptake to these N indexes gave the following R2 values: NE, 0.93; NT, 0.94; TN, 0.93; P, 0.92; A, 0.95; and K, 0.92. All methods were equally sensitive on sludge treated soils; however, the incubation procedure was best on untreated soil. Including second zone soil N and expressing the results on a root‐zone volume basis improved N uptake predictions with unfertilized controls, but was unnecessary for sludge treated plots. These results indicate that chemical N availability indexes can be used to assess soil N availability on sludge treated land; provided they are calibrated to local soil‐crop‐climate conditions.
Prediction of Available Zinc in Sewage Sludge‐amended Soils
Authors: Rappaport B. D. , Martens D. C. , Simpson T. W. , Reneau R. B.
Published: July 2010

A routine soil test would be helpful for management of agricultural soils amended with sewage sludge high in Zn. Fourteen field sites were selected in the Coastal Plain, Piedmont, and Ridge and Valley regions of Virginia to evaluate the suitability of the dilute HCl‐H2SO4 and DTPA soil extractants for prediction of Zn uptake by corn (Zea mays L.). Soil and corn tissue samples were collected from these sites where sewage sludge had been applied previously. Multiple regression analysis was used to assess the forms of soil Zn extracted by dilute HCl‐H2SO4 and DTPA. The exchangeable and specifically sorbed, organically bound and noncrystalline hydroxide and oxide bound Zn fractions were tested to develop equations. Dilute HCl‐H2SO4 extracts were related to the three Zn fractions (R2 = 0.98**), whereas organically bound Zn was the only Zn fraction related to DTPA‐extractable Zn (r = 0.96**). Earleaf Zn concentration correlated more closely with DTPA‐extractable Zn (r = 0.64*) than with dilute HCl‐H2SO4‐extractable Zn (r = 0.35). The earleaf Zn concentration was studied as a function of either DTPA‐ or dilute HCl‐H2SO4‐extractable Zn, exchangeable and specifically sorbed Zn, organically bound Zn, and noncrystalline hydroxide and oxide bound Zn. Inclusion of the above fractions in a multiple regression analysis did not improve the relationship between earleaf Zn concentration and dilute HCl‐H2SO4‐extractable Zn. A coefficient of multiple determination (R2 = 0.77**) was obtained between earleaf Zn concentration and a two variable regression equation comprised of DTPA‐extractable Zn and organically bound Zn. The negative regression coefficient for organically bound Zn indicated that a portion of this fraction, which was extracted by the DTPA, did not supply Zn to corn plants.
Chemical Composition of Vegetables Grown on an Agricultural Soil Amended with Sewage Sludges
Authors: Keefer R. F. , Singh R. N. , Horvath D. J.
Published: July 2010

Heavy metals were analyzed in edible and nonconsumable parts of radish (Raphanus sativus L. cv. White Icicle), carrots (Daucus carota cv. Chantenay), cabbage (Brassica oleracea var. capitata L. cv. Market Topper), green beans (Phaseolus vulgaris cv. Tenderette), sweet corn (Zea mays L. rugosa cv. Silver Queen), and tomatoes (Lycopersicon esculentum cv. West Virginia '63) grown on a sandy loam soil to which four sewage sludges were applied in the field at 90 and 180 Mg ha−1. Cadmium, Cr, and Pb concentrations in the edible parts of the vegetables from sludge treated plots were no more than 1.0 mg kg−1 above those from the untreated control plots. However, considerably more of these elements accumulated in radish tops, bean leaves, and corn leaves grown on a soil treated with two of the sludges. Nickel concentrations in vegetables from plots receiving two of the sludges were significantly higher than in the controls for both edible and nonconsumable parts of most of the vegetables grown. More Ni was absorbed by vegetables grown on a plot treated with sludge which was relatively low in total Ni (270 mg kg−1) than with a sludge which contained more than 47 times as much total Ni. Copper and Zn levels in vegetables grown on some sludge‐treated soils were elevated; however, these were not so high to cause alarm. The results emphasize the need for more information about sewage sludge than just total elemental analyses prior to application onto land on which vegetables will be grown.
A One‐dimensional Model of Chemical Diffusion and Sorption in Saturated Soil and Aquatic Systems
Authors: Corwin D. L.
Published: July 2010

A one‐dimensional model for chemical diffusion in saturated porous media systems is presented. The one‐dimensional diffusion model provides for adsorpfion‐desorption reactions either Freundlich or Langmuir, and both solid and liquid phase first‐order chemical degradation under isothermal, water‐saturated conditions. Finite‐difference solutions to the model which simulate the one‐dimensional diffusion of an inorganic/organic chemical from the sediment of an aquatic system into the overlying water are provided for a variety of initial and boundary conditions. Analogous applications to flow processes within a slructured soil can be made for the diffusion of an inorganic/organic chemical into and out of saturated planar soil aggregates. The initial and boundary conditions are designed to simulate a variety of aquatic situations: ponds, lakes, streams, rivers and oceans. Both explicit and implicit (i.e., Crank‐Nicolson) finite‐difference schemes are presented for four different saturated systems. The model provides a means of assessing the physicoehemical dynamics of chemical‐sediment‐water interactions and of assessing the pollution potential of chemicals to plants and animals as determined by their propensity to migrate to different compartments of the aquatic environment. The models can also determine the influence of diffusion processes within planar soil aggregates upon solute flow in saturated structured soils. Various simulations are presented for boron (B), diquat (1,1′‐ethylene‐2,2′‐dipyridilium dibromide), and bromacil (5‐bromo‐3‐sec‐butyl‐6‐methyluracil).
Proton and Metal Complexation by Water‐soluble Ligands Extracted from Anaerobically Digested Sewage Sludge
Authors: Baham John , Sposito Garrison
Published: July 2010

A water‐soluble extract (WSE) of an anaerobically‐digested sewage sludge containing 19.5 mol m−3 (19.5 mM) total soluble carbon (CTS) was acidified to pH 3 and titrated with NaOH to pH 11 in a 50 mol m−3 (50 mM) NaClO4 background at 25°C. Conditional protonation constants were determined from the formation function computed from the titration data. The common logarithms of the average protonation constants for functional groups titrated between pH 3 and 11 were 4.2, 7.2, and 9.6. Trace metal‐WSE complexes were chromatograpbed on a molecular size exclusion gel. Copper formed the more stable complexes with the ligands in the WSE when compared to Ni or Cd. Cadmium was present predominately as the free metal ion or in inorganic complexes. Adsorption of Cu by montmorillonite was significantly reduced in the presence of the WSE. Since most of the organic carbon present in the WSE remained in solution during the adsorption experiments, the primary factor controlling Cu solubility was concluded to be the formation of soluble organo‐Cu complexes. A “mixture model” was developed to simulate qualitatively the proton binding of the inorganic and organic components of the WSE. This model included organic and inorganic ligands whose relative concentrations were previously analytically determined for the WSE. The “mixture model” ligands were employed to model Ca and Cd speciation for gel filtration and adsorption experiments. The “mixture model” qualitatively explained the observed speciation in both experiments.
Crop Yield Response Predicted with Different Characterizations of the Same Ozone Treatments
Authors: Cure William W. , Sanders John S. , Heagle Allen S.
Published: July 2010

Data were obtained from three field experiments studying the effects of chronic doses of ozone (O3) on crop yield. All used open‐top exposure chambers. Two were of the same design with soybean [Glycine max (L.) Merr.] in 1977 and 1978 and the third was with peanut (Arachis hypogaea L.) in 1980. Exposures had been conducted for 7 h each day starting shortly after crop emergence and ending with maturity. Each experiment included a treatment level below ambient, two at ambient levels, one within and one outside of a chamber, and two to three treatments at levels above ambient established by adding different but constant amounts of O3 to ambient air. Three different characterizations of each O3 treatment were compared as independent variables in simple linear O3 dose‐yield response models. Ozone treatments were characterized as (i) the seasonal mean of the daily 7‐h means (“7‐h mean”), (ii) the seasonal mean of the daily maximum 1‐h mean concentrations (“1‐h mean”), and (iii) the seasonal maximum 1‐h mean concentration (1‐h max). The ratio of the 1‐h mean to 7‐h mean concentration in each treatment was very similar over the range of treatment levels in an experiment. Models of the same yield data developed with either seasonal mean could probably be used interchangeably by converting between concentration scales with a constant multiple. The relation between the 1‐h max concentration and either of the seasonal means changed with treatment level within an experiment and was different for similar treatments in different years. The range of yields predicted with models based on 1‐h max concentrations using the maximum and minimum ambient O3 concentrations in the 3 yr of these experiments was three to four times that obtained with either seasonal mean model.
Time‐dependent Leaching of Radium from Leaves and Soil
Authors: Simon Steven L. , Deming Elizabeth J.
Published: July 2010

The accumulation of Ra or other radionuclides in vegetation via root uptake depends on the availability and uptake rate from soil, in addition to the rate of loss from the leaves due to natural leaching processes. We conducted studies to determine the time‐dependent leachable fraction of 226Ra from soil as a function of time after soil spiking and the loss rate of internal 226Ra from leaves due to leaching by exposure to natural field conditions. The leachable fraction of Ra from spiked soil decreased exponentially over time to a value of 0.1% after approximately 28 d. The internal Ra activity in leaves decreased exponentially to 40% of the original activity after 1 yr of exposure to outdoor conditions in a semiarid environment. The relationship of these two phenomena to the accumulation of Ra in plants via root uptake is illustrated by the equilibrium solution of a first‐order differential equation.
Extractability and Plant Availability of Molybdenum from Inorganic and Sewage Sludge Sources
Authors: Pierzynski Gary M. , Jacobs Lee W.
Published: July 2010

A greenhouse experiment was conducted to evaluate the influence of soil pH on the plant uptake and extractability of Mo applied to a soil as an inorganic salt and as a Mo‐enriched sewage sludge. Molybdenum additions of 30, 60, and 120 mg/kg soil from Na2MoO4·2H2O and 20, 44, and 94 mg/kg soil from an anaerobically digested sewage sludge significantly increased Mo concentrations in corn (Zea mays L.), soybeans [Glycine max (L.) Merr.], and alfalfa (Medicago sativa L.) grown on a sandy loam soil. Increases in soil pH significantly increased Mo accumulation in the three crops from both Mo sources. Molybdenum extracted with Tamm's acid ammonium oxalate was not significantly influenced by soil pH, while Mo extracted from sludge treated soils with the ammonium bicarbonate‐DTPA (AB‐DTPA) extractant was significantly increased with increasing soil pH. Multiple regressions between Mo concentrations in the crops and extractable Mo and soil pH indicated that soil pH was a significant variable in 17 of 24 prediction equations. The AB‐DTPA extractant was more effective in predicting Mo concentrations in plant tissue than Tamm's acid ammonium oxalate with sludge Mo additions and is more effective with sludge source Mo as compared to inorganic source Mo. Whether AB‐DTPA will predict Mo uptake by plants grown on soils receiving Mo additions needs to be tested by field evaluation with a large number of soil types.
Characteristics of Air Exclusion Systems vs. Chambers for Field Air Pollution Studies
Authors: Olszyk David M. , Kats Gerrit , Dawson Philip J. , Bytnerowicz Andrzej , Wolf Joanne , Thompson C. Ray
Published: July 2010

An air exclusion system was designed, constructed, and tested to determine its effectiveness in studies of air pollutant effects on vegetation. The air exclusion system was shown to be an effective alternative to open‐top field chambers for controlled exposures of air pollutants to low growing plants. The system design included particulate and activated charcoal filters, pressure‐type blowers, a mixing manifold, and perforated inflatable ducts that were positioned between rows of plants. Tests with CO as a tracer gas indicated optimal system parameters for air exclusion including: air flow of at least 0.944 m3 s−1 within the ducts, three or four rows of holes on the side of each duct pointing 45° upward, 90° to the side, and 45° downward from the center of the duct, four ducts per system, and a hole size that provided an air velocity of 0.5 to 1.8 m s−1 over the plant canopy. Reductions of > 70% in ambient O3 concentrations could be achieved over the plant canopy at 0.25 m above the ground with the air exclusion system under optimum conditions (low ambient wind speed and high ambient ozone concentrations). This was comparable to the reductions achieved with either open‐top or closed‐top chambers. A gradient in ozone concentrations was obtained within a single system by delineating the ducts into three sections with different sized holes. Sulfur dioxide was added to a modified system to provide a gradient of 0, 0.03, 0.07, and 0.15 µL SO2 L−1 over a winter growing season. No large environmental differences were found between air exclusion systems and open‐top chambers vs. outside plots in the summer. In the fall and winter, open‐top chambers had higher air, leaf, and soil temperatures than air exclusion sytems or outside plots. Air speed over the plant canopy was higher with the air exclusion system than in open‐top chambers or outside plots.
Soil and Groundwater Salinity Along Drainage Ditches in Eastern North Dakota
Authors: Skarie R. L. , Richardson J. L. , Maianu A. , Clambey G. K.
Published: July 2010

The most severely affected saline soils in the Red River Valley of North Dakota are normally observed in linear patterns along shallow roadside drainage ditches. Although the affected areas tend to be small, taken as a group they represent a considerable loss of productivity. Research was conducted to study the relationship between soil salinity and groundwater hydrology adjacent to roadside drains. Data for groundwater depth, electrical conductivity, and chemistry indicated that significant seepage occurs from the ditches. During recharge periods, both depth and salinity of groundwater tended to increase with distance from the drain. Ratios of Ca2+ to Mg2+ and Na+ tended to decrease over the same distance. Maximum salinity of the soil surface was observed where groundwater was of intermediate depth and salinity for a given site. Soils near the drain were most saline at the surface, whereas soils beyond the influence of the ditch exhibited increasing salinity with depth. Seepage rates calculated from soil and groundwater parameters did not correlate with observed values of soil salinity for a given site. The degree of salinization appears more closely related to the frequency that surface water ponds in the drains. Pond permanence was inferred by wetland classification of the drains according to the plant species present.
Wastewater Renovation in a Slash Pine Plantation Subjected to Prescribed Burning
Authors: Red Jane T. , Nutter Wade L.
Published: July 2010

Two experimental areas were established in an underdrained 16‐yr‐old slash pine (Pinus elliottii Mor.) plantation land treatment system receiving 2.5 cm/week of secondarily treated domestic wastewater. One of the experimental areas was subjected to a prescribed burn as a forest management practice. A high degree of wastewater renovation was achieved and the prescribed burn had no significant effect on wastewater renovation. Forest floor storage of K, Ca, Mg, and P was significantly increased from pretreatment levels due to wastewater irrigation. Prescribed burning had no effect on forest floor nutrient storage. Soil concentrations of total and available P, Ca, Mg, and K increased significantly in the surface soil horizon due to wastewater irrigation. Additional increases in the surface soil horizon of total P, Ca, Mg, and K concentration occurred due to burning. Wastewater irrigation resulted in significant reductions in soil acidity and total‐Kjeldahl N concentration in the surface horizon. Prescribed burning altered species composition and density of the understory. No significant differences in overstory nutrient storage were observed due to treatment.
Effects of Sulfur Dioxide and Ambient Ozone on Winter Wheat and Lettuce
Authors: Olszyk David M. , Bytnerowicz Andrzej , Kats Gerrit , Dawson Philip J. , Wolf Joanne , Thompson C. Ray
Published: July 2010

Winter wheat (Triticum aestivum L. ‘Yecora Rojo’) and lettuce (Lactuca saliva L. ‘Empire’) were exposed in the field to SO2 or ambient O3 to determine the effects of these air pollutants on important winter grown crops. Plants were exposed with tubular air exclusion systems or in open‐top field chambers to ambient air, or filtered air plus 0, 0.03, 0.07 or 0.15 µL SO2 L−1. Exposures were continuous from 18 Jan. to 7 May 1984 for wheat and from 18 Jan. to 13 Mar. 1984 for lettuce. Harvests to evaluate early plant growth were made after 2 to 3 weeks of exposure for each crop; final harvests were made at the end of the exposures. Wheat yield was decreased with exposure to 0.15 µL SO2 L−1 in open‐top field chambers, but was not affected by SO2 exposure in air exclusion systems. Lettuce yield was decreased with exposure to 0.15 µL SO2L−1 in air exclusion systems, but was not affected by SO2 exposure in open‐top chambers. Neither wheat nor lettuce yield was reduced by ambient O3 in either air exclusion systems or open‐top chambers. The results from the two types of exposure systems could not becompared statistically due to differences in experimental design and soil topography. However, the differences in plant growth between the two systems were dramatic when compared to outside plots. Wheat and lettuce growth and yield was only slightly greater with air exclusion systems than in outside plots, but much greater in open‐top field chambers than in outside plots.
Comparison of Solid vs. Liquid Dairy Manure Applications on Corn Yield and Soil Composition
Authors: Sutton A. L. , Nelson D. W. , Kelly D. T. , Hill D. L.
Published: July 2010

A 6‐yr field experiment was conducted to determine the effects of liquid and solid dairy (Bos taurus) manure applications on a Crosby silt loam (Aerie Ochraqualfs) soil cropped to corn (Zea mays L.). Liquid manure at rates of 112, 224, and 336 Mg ha−1 and solid manure at rates of 34, 67, and 101 Mg ha−1 were spread annually for 5 yr. No manure was applied the 6th yr, but the soil was cropped to determine residual nutrient effects. Check and inorganic fertilizer treatments were also included in the study. Manure addition increased corn yields when compared to the check (no fertilizer). There were variable weather conditions and nutrient concentrations of the manure sources, and the manure application rates were relatively high. Corn yields were as great or greater from plots supplied with manure and manure slurries as those supplied with commercial fertilizer. Over the 5 yr of manure application, the 224 Mg ha−1 rate of liquid manure and the 67 Mg ha− rate of solid manure results in maximum corn yields that were 1% higher than commercial fertilizer. Accumulations of nutrients in the soil from high liquid manure application rates (224 and 336 Mg ha−1) increased corn yields during the residual cropping year. Corn leaf N and P concentrations tended to reflect N and P rates applied with the manures and the fertilizer treatment compared to the check, but not consistently each year. Source of manure had little affect on corn leaf composition. Soil P, K, and Na increased with each additional year of manure application and tended to increase with higher application rates. Extractable P accumulated in the upper profile of soil, whereas exchangeable K and Na increased at lower depths in the soil profile, especially with the highest manure application rates. Based on this study, both solid and liquid dairy manures are valuable sources of nutrients for corn production; however, they are less efficient than commercial fertilizers when comparing equivalent nutrient levels and when they are applied to the soil surface. Excessive application of either manure source causes potential for considerable groundwater pollution.
Injury and Yield Response of Cotton to Chronic Doses of Ozone and Sulfur Dioxide
Authors: Heagle Allen S. , Heck W. W. , Lesser V. M. , Rawlings J. O. , Mowry F. L.
Published: July 2010

Knowledge of relationships between chronic doses of O3 and crop yield is required to set air quality standards that protect agricultural interests and to determine the need to develop resistant cultivars of sensitive species. Open‐top field chamber studies have provided some information of this type for a few crop species including one western cullivar of cotton (Gossypium hirsutum L.). Our objectives were to measure relationships between chronic doses of O3 and yield of an eastern cotton cultivar and to determine whether these relationships could be affected by chronic doses of SO2. ‘Stoneville 213’ was exposed in open‐top field chambers to five doses of O3 (seasonal 7 h d−1 means from 0.026–0.104 µL L−1) and four doses of SO2 (seasonal 4 h d−1 means from 0.00–0.35 µL L−1), singly, and in all possible combinations. Exposures began when first foliar leaves were expanding and continued until final harvest. Stoneville 213 was sensitive to O3‐induced yield decrease and regression analyses provided models describing this relationship. Compared to cotton yield in charcoal‐filtered‐air chambers, the measured decrease of cotton yield at levels of O3 that occurred during the 1982 season at Raleigh, NC was 11%. Doses of SO2 at levels greater than those occurring regionally did not significantly affect cotton and did not significantly change cotton response to O3.
Characterization of Cadmium and Zinc in Four Soils Treated with Sewage Sludge
Authors: Mullins G. L. , Sommers L. E.
Published: July 2010

Cadmium and Zn were characterized in soils treated with 100 Mg ha−1 of an anaerobically digested sewage sludge from Chicago, IL. The four soils included a Chalmers silt loam (Typic Haplaquolls) (Indiana), Celina loam (Aquic Hapludalfs) (Michigan), Celina silt loam (Aquic Hapludalfs) (Ohio), and a Piano silt loam (Typic Aquidolls) (Wisconsin). The single application of sludge supplied 19 kg Cd ha−1 and 340 kg Zn ha−1. Four or five crops of barley (Hordeum vulgare L.) had been grown on each site prior to soil sampling. Soil solutions obtained by a centrifugation method contained Zn in the range of 1.4 to 10.5 µmol L−1 while Cd ranged from 18 to 135 nmol L−1. The addition of sludge increased the concentration of both metals in the soil solutions of all four soils. Evaluation of soil solution data with the computer program GEOCHEM showed that > 85% of the total soluble Cd and > 91% of the total soluble Zn existed as the free metal ion. Sludge addition increased the amount of Cd and Zn extracted by DTP A and 4 M HNO3. The relative increases in soil solution and extractable Cd and Zn were different in each of the four soils even though the same sludge was applied at the same rate. Diffusion coefficients measured with a cation exchange resin paper method (De), ranged from 1.8 × 10−11 to 1.7 × 10−9 cm2 s−1 for Zn and from 5.2 × 10−11 to 3.2 × 1O−10 cm2 s−1 for Cd. The application of sludge had little or no effect on the magnitude of De for either Cd or Zn as measured by the resin paper method, but the diffusion coefficients for Zn were inversely related to soil pH. Increases in the flux of Cd and Zn to plant roots in sludge‐treated soils will be a reflection of changes in soluble and extractable Cd and Zn.