bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of Secondary Sewage Effluent with a Peat‐Sand Filter Bed
Authors: Nichols Dale S. , Boelter Don H.
Published: July 2010

A peat‐sand filter bed was constructed to provide additional treatment of the secondary sewage effluent from a campground located on the shore of North Star Lake, within the Chippewa National Forest in north‐central Minnesota. This effluent contained an average of 30.9 mg/liter total nitrogen, 8.63 mg/liter total phosphorus, and 122,000 fecal coliforms/100 ml. An average of 6.8 cm/week was applied from late May through early October for 8 years. The peat‐sand filter bed accomplished almost complete removal of fecal coliform bacteria and P. About 90% of the waste‐water N was removed during the 2nd and 3rd years of operation, but this declined to about 50% by the 5th year, due to oxidation of the peat and release of N. The high Fe, Al, and ash content of the peat contributed to the filter's highly efficient removal of P. Microbial immobilization in the peat contributed to N and P removal during the first 2 or 3 years of waste water application. Rough‐stalked bluegrass (Poa trivialis L.) planted on the peat surface of the filter was very important in overall N and P removal. Nutrient uptake by the bluegrass increased each year and accounted for 45% of the P and virtually all of the N removed from the waste water in the 5th year of the study.
Relationship Between Land‐Use Practices and Fecal Bacteria in Soils
Authors: Faust Maria A.
Published: July 2010

Fecal and other bacteria populations in soils from pasture, cornfield, and forest sites were assessed at the Rhode River watershed. Total coliform (TC), fecal coliform (FC), total streptococci (TS), fecal streptococci (FS), and aerobic heterotrophic bacteria (TVC) numbers were determined seasonally. They were also determined with depth to 25 cm in soils from the pasture. Bacterial numbers per gram of pasture soil from the surface 1 cm were: 252‐1,603 TC, 10‐3% FC, 317‐2,270 TS, 163‐1,330 FS, and 1.6‐65.1 × 106 TVC. The numbers declined markedly with depth, except that TS and TVC numbers remained near the surface values. Fecal coliform numbers varied seasonally, from 22 to 396 MPN/g soil in fall and spring when cattle were grazing, and from 10 to 50 MPN/g soil in winter and summer when cattle were absent from the pasture. The cornfield and forest surface soils contained equally low FC numbers ranging from 3 to 27 MPN/g soil. Aerobic heterotrophic bacteria were similar in magnitude at all three land‐use sites. No readily discernable seasonal pattern was noted. The proportion of coliform bacteria differed with land use. In pasture soils 67% of isolates were confirmed as Escherichia coli, 22% were Enterobacter aerogenes, and 11% belonged to other species. In cornfield soils only 8% were E. Coli, 77% E. aerogenes, and 15% other species. In forest soils only E. coli were the dominant species. Thus, the pro‐ portion of E. coli was directly related to the degree of fecal pollution of the soils, and the proportion of E. aerogenes increased with remoteness of the soil from potential polluting agents.
Prediction of Water‐Extractable Phosphorus Content of Soil Following a Phosphorus Addition
Authors: Sharpley A. N.
Published: July 2010

The effect of time on the water‐extractable P content (PX) of surface soil (0–10 cm) following a P addition (PA) was investigated in the laboratory using 20 soils from 14 states. The soils were incubated with P equivalent to 0‐, 25‐, 50‐, and 100‐kg/ha additions and the water‐extractable P content and soluble P concentrations of runoff from the soils determined at frequent intervals. Water‐extractable P decreased in the first 2 weeks after P addition; following this PX remained fairly constant. Water‐extractable soil P content was linearly related to PA at any given time after the addition. The slope of this relationship decreased logarithmically with time after a P addition. In the first 2 weeks after P addition, the slope of the relationship between PX and PA could be predicted from percent clay content or P sorption capacity of the soil. Using these simple relationships, an improved prediction of the amount of soluble P available for transport in surface runoff from fallow soil can be made from limited extractable soil P data.
Environmental Effects of a Medium‐Fertility 12‐Month Pasture Program: II. Nitrogen
Authors: Owens L. B. , van Keuren R. W. , Edwards W. M.
Published: July 2010

Four small, medium fertility (56 kg/ha per year N) watersheds were used in a rotational summer‐grazing and winter‐feeding program to determine its effects on N levels in water. During a 5‐year study on sloping uplands in Ohio, the concentrations of NO3‐N and NH4‐N were determined in precipitation, surface runoff, subsurface flow, and sediment. Although the NO3‐N concentration was generally higher in the surface runoff from the summer‐grazing/winter‐feeding area than from the summer‐grazing‐only areas, it usually resulted in no significant impairment of water quality, except on a few occasions when the NO3‐N concentration exceeded 10 mg/liter. The N transported in the subsurface flow from the summer‐grazing only areas was approximately equal to that transported from the winter‐feeding area and to the amount of N received in the precipitation. Both surface runoff transport and sediment transport of N were much greater in the winter‐feeding area than in the summer‐grazing‐only areas because these latter areas yielded very little surface runoff and only a trace of soil loss. Reduction of vegetative cover and increased soil disturbance on the winter‐feeding area resulted in increased surface runoff and soil erosion and thus more N was transported. Surface and subsurface losses of N from the winter‐feeding area were nearly equal. A large percentage of N was transported by the large storms, which represented a small percentage of the total number of storms.
Prediction of Phosphorus Losses in Runoff from Southern Plains Watersheds
Authors: Sharpley A. N. , Smith S. J. , Menzel R. G.
Published: July 2010

The concentrations of soluble and particulate (sediment) P in runoff from several cropland and grassland watersheds across the Southern Plains were predicted from relationships obtained from simulated rainfall‐runoff studies. Soluble P was predicted from the water‐extractable P content of surface soil (0–1 cm) collected in March each year, using a general P‐extraction coefficient covering all the soils found at the watersheds studied. For individual soils the P‐extraction coefficient was related to the depth of interaction between surface soil and runoff. Particulate P concentration was predicted from the total P content of surface soil collected in March each year, using P‐enrichment ratios calculated from sediment discharge. Predictions of mean annual soluble and particulate P concentrations were good over a wide range in concentrations (50–500 and 200–5,100 µg P/liter, respectively), fertilizer and watershed management practices, soil types, and vegetative covers. The results obtained indicate that relationships used in the CREAMS model can provide accurate predictions of mean annual P concentrations.
Heavy Applications of Liquid‐Digested Sludge on Three Ultisols: I. Effects on Soil Chemistry
Authors: Robertson W. K. , Lutrick M. C. , Yuan T. L.
Published: July 2010

The quantities of municipal wastes are so large that croplands have been considered as possible sinks for their disposal. In this study large amounts of liquid‐digested sludge were applied to the soil. The accumulation and distribution of its constituents in the soil profile were studied.

The sludge contained 2.6 and 3.0% dry matter and very little Cd and other toxic metals. Liquid sludge equivalent to 0, 87, 174, 241, 288, and 335 metric tons/ha of dry matter was applied to each of three Paleudults (Orangeburg fine sand loam [fsl], Lucy fsl, and Troup fsl) over a 6‐year period. Soil samples, to a depth of 150 cm, were obtained 1 year after the last sludge application to determine nutrient and organic matter movement.

Sludge applications increased soil organic matter to a depth of 90 cm in Orangeburg fsl and Troup fsl, but had no consistent effect on Lucy fsl. About 50% of the applied organic matter was oxidized, forming acids that lowered the soil pH.

Double acid extraction of Orangeburg fsl indicated that Ca, Mg, and to some extent K, moved below the 90‐cm depth of the soil profile. Lesser amounts leached from the 90‐ to 120‐cm layer, and no detectable amounts leached from the 120‐ to 150‐cm layer. Extractable Fe and Al increased to the 90‐cm depth. Extractable Cu remained in the top 30 cm and Zn in the top 90 cm of the profile.

Similar results were found in a 5N HCl digest except that P was significantly increased by sludge application and accumulated largely in the surface soil.
Influence of Soil Temperature and Soil Moisture on Degradation and Metabolism of Carbofuran in Soils
Authors: Ou L.‐T. , Gancarz D. H. , Wheeler W. B. , Rao P. S. C. , Davidson J. M.
Published: July 2010

This study was conducted to determine the effects of soil moisture and soil temperature on mineralization rate and the solvent‐extractable 14C‐activity disappearance rate of 14C‐carbofuran (2,3‐dihydro‐2, 2‐dimethyl‐7‐benzofuranyl‐N‐methylcarbamate) and the formation of nonextractable 14C‐activity in six U.S. soils, to evaluate the difference between the two rates, and to statistically correlate these rates with key soil factors.

Both mineralization rate and solvent‐extractable 14C‐activity disappearance rate approximated to first‐order kinetics. The solvent‐extractable 14C‐activity disappearance rates were much higher than the mineralization rates. The difference was reflected in the formation of nonextractable 14C‐activity in soils. As high as 94.5% of 14C‐activity became nonextractable at the end of 28 days of incubation. Four metabolites, 3‐hydroxycarbofuran, 3‐ketocarbofuran, carbofuran phenol, and 3‐ketocarbofuran phenol were detected in the solvent extracts. 14C‐activity associated with these metabolites in the extracts were generally <5% of the 14C‐carbofuran applied, so that the difference between the solvent‐extractable parent‐chemical disappearance rate and the solvent‐extractable 14C‐activity disappearance rate was insignificant. In general an increase in temperatures from 15 to 27°C had a greater influence on solvent‐extractable 14C‐activity disappearance rate than did an increase from 27 to 35°C, and the temperature for maximum rate was between 27 to 35°C. Logarithmic k1 values of solvent‐extractable 14C‐activity appeared to be inversely correlated with logarithmic soil‐water tension (Ψ). No statistical correlation with key soil factors was observed for either the solvent‐extractable 14C‐activity disappearance rate or minralization rate.
Disposition of Fertilizer Nitrate Applied to Sorghum‐Sudangrass in the Southern Plains
Authors: Smith S. J. , Dillow D. W. , Young L. B.
Published: July 2010

Results are reported for a 3‐year field‐plot study on the fate of fertilizer 15N associated with sorghum‐sudangrass (Sorghum sudanense) production. The fertilizer was applied under dryland conditions at a 112‐kg N/ha annual rate to eight area soils representative of five soil orders. On a seasonal average, slightly more than half the fertilizer was taken up by the plants (tops + roots), and about a third was incorporated in the soil organic matter. Very little (<5%) remained an inorganic leachable form, and about 7% was unaccounted. The unaccounted is considered to represent denitrification, since soil profile sampling during and after the cropping season showed no evidence of fertilizer‐N leaching below the root zone. Preplant soil nitrate was a better indicator of total soil N availability the first 2 years, whereas the mineralization potential was better the third year. From an environmental standpoint, use of the N fertilizer at the described rate and prevailing farming conditions appeared to pose no potential pollution problems.
Chemical Water Quality of Runoff From Grazing Land in Nebraska: I. Influence of Grazing Livestock
Authors: Schepers J. S. , Francis D. D.
Published: July 2010

The chemical quality of runoff water from a 32.5‐ha cow‐calf pasture area at the Roman L. Hruska U.S. Meat Animal Research Center near Clay Center, Nebr., was determined over a 3‐year period. Runoff events from the grazed pasture were separated into those occurring while livestock were grazing and those occurring when no livestock were present. Grazing livestock increased by 52% the total solids concentration, but only increased total organic carbon and chemical oxygen demand concentrations by 11 and 7%, respectively, and decreased by 19% the total Kjeldahl nitrogen concentration. Concentrations of NH4‐N, NO3‐N, total P, soluble P, and Cl− were 6, 45, 37, 48, and 78% greater, respectively, when livestock were grazing. Runoff from an ungrazed control area within the pasture contained chemical concentrations that ranged from 1.94 to 10.8 times greater than those from an adjacent pasture under ungrazed conditions. We attributed these elevated concentrations to wildlife activity and decomposition of plant material.
Effect of Sewage Sludge on Trace Element Mobility in Soils
Authors: Gerritse R. G. , Vriesema R. , Dalenberg J. W. , de Roos H. P.
Published: July 2010

Adsorption of Be, F, B, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Tc, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Pb, Bi, and P was measured in a sandy soil and a sandy loam soil at concentration levels closely corresponding to those to be expected for field conditions. Mobilities of the elements in the soils were calculated from the adsorption data. Of the trace elements studied, F, B, and Tc were found to be very mobile in both the sandy and sandy loam soils. Manganese, Sr, and Sb were highly mobile only in the sandy soil, and Mo in the sandy loam soil. In general, sludge solutions appeared to increase the mobility of elements in a soil. This is due to a combination of complexation by dissolved organic compounds, high background concentrations, and high ionic strengths of the soil solutions. The relative effects of these factors vary strongly among elements.

Equations were derived predicting the rates of accumulation in soils and accompanying increases in the soil solutions of trace elements added with sewage sludge.

When adsorption was related to soil organic matter content, for many trace elements the strength of adsorption was found to depend only on pH, increasing with increasing pH.
Acid Rain, Air Pollution, and Tree Growth in Southeastern New York
Authors: Puckett L. J.
Published: July 2010

Whether dendroecological analyses could be used to detect changes in the relationship of tree growth to climate that might have resulted from chronic exposure to components of the acid rain‐air pollution complex was determined. Tree‐ring indices of white pine (Pinus strobus L.), eastern hemlock (Tsuga canadensis (L.) Cart.), pitch pine (Pinus rigida Mill.), and chestnut oak (Quercus prinus L.) were regressed against orthogonally transformed values of temperature and precipitation in order to derive a response‐function relationship. Results of the regression analyses for three time periods, 1901–1920, 1926–1945, and 1954–1973 suggest that the relationship of tree growth to climate has been altered. Statistical tests of the temperature and precipitation data suggest that this change was nonclimatic. Temporally, the shift in growth response appears to correspond with the suspected increase in acid rain and air pollution in the Shawangunk Mountain area of southeastern New York in the early 1950's. This change could be the result of physiological stress induced by components of the acid rain‐air pollution complex, causing climatic conditions to be more limiting to tree growth.
Effects of Injection and Surface Applications of Liquid Swine Manure on Corn Yield and Soil Composition
Authors: Sutton A. L. , Nelson D. W. , Hoff J. D. , Mayrose V. B.
Published: July 2010

A 3‐year field experiment was conducted to study the agronomic effects of methods and rates of liquid swine manure application to Brookston‐Crosby silt loam soil (fine, mixed mesic Aeric Ochraqualfs) cropped to corn (Zea mays L.). Swine manure (5.2–6.6% dry matter) from an anaerobic pit was applied to soil annually at 90, 135, and 180 t/ha by injection (30 cm below soil surface) and broadcast (surface) methods. These three rates provided averages of 428, 643, and 857 kg N/ha; 133, 200, and 266 kg P/ha; and 155, 232, and 310 kg K/ha per year; respectively. Check and inorganic fertilizer (168 kg N/ha, 56 kg P/ha, and 112 kg K/ha) treatments were also studied.

The injection method of liquid manure application increased corn grain yield an average of 2,130 kg/ha each year, compared with the broadcast method at similar rates of application. Injection of swine manure was associated with higher corn‐leaf N levels the first year; corn‐leaf N, P, and K levels the second year; and corn‐leaf N and K the third year of the study when compared with corn leaves from the broadcast method. Rate of manure application had little influence on corn‐leaf analyses, and inconsistent effects on corn yield.

Nutrient loadings of the soil from liquid manure applications were in excess of crop requirements, as evidenced by nutrient accumulations, particularly P and K, in the soil. Increases in soil nutrient levels at different depths in the profile reflected the initial placement of the manure by application methods (broadcast vs. injection). Volatile losses of NH3‐N from surface‐applied liquid manure were reflected in lower corn yield response, lower corn‐leaf N content, and lower soil NH4+ and NO3− levels when comparing these parameters with the injection treatment. Application of liquid swine manure by injection at the 90 t/ha rate increased corn grain yield 14% above that from the inorganic fertilizer treatment.
Agriculture and Water Quality in the Canadian Great Lakes Basin: III. Phosphorus
Authors: Miller M. H. , Robinson J. B. , Coote D. R. , Spires A. C. , Draper D. W.
Published: July 2010

A major objective of the International Joint Commission Pollution from Land Use Activities Reference Group (PLUARG) was to determine the P contribution to the Great Lakes from the various agricultural activities in the basin.

In Canada, two approaches were used. The total agricultural contribution was estimated by relating measured P loads at the outlets of 10 representative agricultural watersheds to land characteristics and agricultural activities in the watersheds. In the second approach the P contribution from four sources—runoff from cropland, livestock operations and unimproved land, and erosion of farm streambanks—was estimated from detailed studies of each source.

Percent clay in the surface soil and proportion of the area in rowcrop accounted for 85% of the variability in total P unit‐area loads from the agricultural watersheds. Dissolved reactive P unit‐area loads were related to clay content of surface soil and the P added to soils in the watershed (R2 = 0.90).

The total P load to the Great Lakes from the more than 300 subbasins of the agricultural portion of the Canadian Great Lakes Basin was estimated to be 3,000 t year−1. The source studies indicated that about 70% of this load was attributable to cropland runoff, 20% to livestock operations, and 10% to a combination of runoff from unimproved land and streambank erosion.
Agriculture and Water Quality in the Canadian Great Lakes Basin: IV. Nitrogen
Authors: Neilsen G. H. , Culley J. L. B. , Cameron D. R.
Published: July 2010

Eleven agricultural watersheds in southern Ontario were sampled approximately 3,000 times during the years 1975–1977 for Total Kjeldahl N (TKN) and NO3‐N as part of the Canadian activities of the Pollution from Land Use Activities Reference Group (PLUARG).

Only 12% of runoff samples had NO3‐N concentrations below 0.3 mg L−1, while 3% of the samples exceeded the 10‐mg L−1 Ontario drinking water standard. Two‐year‐average total N stream loadings ranged from 3.5 to 29.2 kg N watershed‐ha−1. The NO3‐N loads averaged 75% of total N loads over all 11 watersheds. Both NO3‐N and total N unit‐area loads were significantly correlated with total N addition to the watershed, and with percent of watershed under cultivation, in row‐crops and corn (Zea mays L.), or tile‐drained. The TKN loads were positively correlated with watershed surface‐soil clay content and with extent of soils with high surface runoff potential.

Remedial measures to reduce stream N loading should only be considered for watersheds where stream N loading much exceeds inputs of N from precipitation. In these watersheds, improved fertilizer N efficiency in corn production may provide the greatest potential for reduced stream N loading. Proper location of manure storage sites is most important to minimize N pollution from livestock activities. About 70% of both stream NO3‐N and total N loading occurred from January to April during the spring runoff season. Agronomic practices that reduce either postharvest teachable soil N or erosion during spring runoff merit future research.
Precision and Accuracy of Visual Foliar Injury Assessments
Authors: Gumpertz Marcia L. , Tingey David T. , Hogsett W. E.
Published: July 2010

This study compared three measures of foliar injury: (i) mean percent leaf area injured of all leaves on the plant, (ii) mean percent leaf area injured of the three most injured leaves, and (iii) the proportion of injured leaves to total number of leaves. For the first measure, the variation caused by reader biases and day‐to‐day variations were compared with the innate plant‐to‐plant variation.

Bean (Phaseolus vulgaris ‘Pinto’), pea (Pisum sativum ‘Little Marvel’), radish (Rhaphanus sativus ‘Cherry Belle’), and spinach (Spinacia oleracea ‘Northland’) plants were exposed to either 3 µL L−1 SO2 or 0.3 µL L−1 ozone for 2 h. Three leaf readers visually assessed the percent injury on every leaf of each plant while a fourth reader used a transparent grid to make an unbiased assessment for each plant.

The mean leaf area injured of the three most injured leaves was highly correlated with all leaves on the plant only if the three most injured leaves were <100% injured. The proportion of leaves injured was not highly correlated with percent leaf area injured of all leaves on the plant for any species in this study. The largest source of variation in visual assessments was plant‐to‐plant variation, which ranged from 44 to 97% of the total variance, followed by variation among readers (0–32% of the variance). Except for radish exposed to ozone, the day‐to‐day variation accounted for <18% of the total. Reader bias in assessment of ozone injury was significant but could be adjusted for each reader by a simple linear regression (R2 = 0.89–0.91) of the visual assessments against the grid assessments.
Atmospheric Dispersion of Ammonia During Application of Anhydrous Ammonia Fertilizer
Authors: Denmead O. T. , Freney J. R. , Simpson J. R.
Published: July 2010

There is a need to develop techniques for the prediction of the aerial spread of hazardous chemicals released in agricultural operations. The dispersion of ammonia (NH3) gas during soil injection of anhydrous NH3 is one such example. In previous work we established that after injection NH3 escaped from the soil to the atmosphere at a rate that decreased exponentially with time; in our study the whole process took about 2 h. In this paper we combine the dynamics of the emission process with existing micrometeorological theory for atmospheric dispersion from line sources, to predict NH3 concentrations in the air at the downwind edge of the field. The predictions are compared with concentrations measured during an injection operation.

Although the total NH3 emission during the operation was only 1.2 kg/ha, NH3 concentrations up to 213 µg/m3 were recorded at the downwind edge in the early stages of injection. Wind speed and atmospheric stability had large influences on NH3 dispersion. In light winds and stable conditions NH3 concentrations > 100 µg/m3 were recorded when the applicator was > 200 m upwind, and some NH3 enrichment still occurred when it was 600 m upwind.

The model underestimates NH3 concentrations when the treated width is <30 m, but predicts them very well at greater distances in both stable and unstable conditions. The model is used to predict NH3 concentrations downwind of the applicator for a range of wind speeds and emission strengths.

The approach should prove useful not only for estimating NH3 pollution hazards but also for predicting dispersion in related agricultural operations where a time‐dependent decay and/or a line‐source analogy are appropriate.
Chemical Characteristics of Wet and Dry Atmospheric Fallout in Northern California
Authors: Mc Coll John G. , Monette Larry K. , Bush Douglas S.
Published: July 2010

Wet and dry atmospheric fallout were monitored on an event basis at eight locations during the wet season, November 1978–May 1979. Nine different ionic species, plus conductivity and volume, were determined. Wet fallout was commonly acid (pH < 5.6) at all sites, although there was considerable variation between sites, and temporal variation within sites. At most sites H+ was highly correlated with NO3− but not with SO42−, and NO3−/SO42− equivalent ratios exceeded 1.0, indicating that HNO3 was predominant and H2SO4 secondary. Dry fallout comprises a large proportion of total atmospheric fallout.
Wastewater Treatment by Soils: Role of Particle‐Size Distribution
Authors: Tare Vinod , Bokil S. D.
Published: July 2010

This investigation evaluated the important parameters required to achieve an acceptable infiltration rate with adequate water quality improvement in a soil wastewater treatment system. Locally available sand and Kanpur silt (Entisol) were used in this evaluation. The particle‐size distribution of soil was found to be an important parameter in improving the infiltration rate and water quality. An expression, based on retardant kinetics for biochemical oxygen demand (BOD), is proposed for chemical oxygen demand (COD) removal in soils as a function of soil depth. Also, an empirical relationship is developed that shows how the overall reduction in COD with soil depth varies with the time since the wasetwater application was initiated. The overall COD reduction rate increases for the first several days following the initiation of the wastewater application, and thereafter it decreases. This indicates that wastewater should not be continuously applied to soils. There should be alternating wet periods (wastewater application) and dry periods (no wastewater application). A significant reduction in NH3‐N, total N, total P, and total coliforms also resulted because of particle‐size distribution.
Decomposition of Acrylamide in Soils
Authors: Abdelmagid H. M. , Tabatabai M. A.
Published: July 2010

Acrylamide is a potential ground‐water contaminant and is a known neurotoxin to man. Thus, information about its fate in soil is desired. The fate of N in acrylamide added to five soils was studied by performing analyses for NH3, NH4+, NO2−, and NO3− after incubation of acrylamide‐treated soils for various times. The results showed that acrylamide‐N is readily hydrolyzed in field‐moist and air‐dried soils under aerobic and waterlogged conditions and that acrylamide‐N is converted to NO2− and NO3− under aerobic conditions. The percentage of acrylamide‐N recovered as inorganic N increased with increasing temperature (10–30°C) and incubation time (2–21 d). After 3 d of incubation at 30°C under aerobic conditions, the percentage of acrylamide‐N recovered as inorganic N ranged from 11% in Clarion soil to 76% in Canisteo soil. The corresponding recovery values after 14 d of incubation were 74% and 94%, respectively. Generally, the results with field‐moist soils were similar to those obtained with air‐dried soils. The recovery of acrylamide‐N after 21 d of incubation under waterlogged conditions at 20°C ranged from 76% in Harps soil to 93% in one sandy (Chelsea) soil. Expressed as percentage of acrylamide‐N added, the NH+‐N produced in Clarion, Fayette, Harps, and Canisteo soils after 7 d of incubation under waterlogged conditions ranged from 18% in Clarion soil to 38% in Canisteo soil. The corresponding vlaues after 21 d of incubation were 81% and 90%, respectively. Significant amounts of NH3 were volatilized from sandy and calcareous soils treated with acrylamide.
A Proposal for Estimation of Soil Leaching and Leaching Constants for Use in Assessment Models
Authors: Baes C. F. , Sharp R. D.
Published: July 2010

A model to predict annual‐average, order‐of‐magnitude leaching constants for solutes in agricultural soils is given. The leaching constants, specific by geographic location and solute, are for use in exposure, dose, or risk assessment models to account for removal from the root zone via leaching in a manner analogous to radiological decay. The model presented here relates annual‐average water infiltration (Vw) with soil bulk density (ϱ) and porosity (θ) and the distribution coefficient (Kd) for the solute. Annual infiltration is determined from site‐specific estimates of total precipitation (P), irrigation (I), and evapotranspiration (E). A review, discussion, and determination of generic default model input parameters is included. The parameters ϱ and θ vary within a factor of three, and are lognormally distributed with estimated geometric mean values of 1.35 g cm−3 and 0.48 cm3 cm−3, respectively. Geographic distributions of U.S. county‐averaged P, I, and E were determined from historical weather station records, the 1974 Agricultural Census, and an evapotranspiration model, respectively. Variability in site‐specific annual‐average estimates of these parameters is expected to be within a factor of three, also. The most variable and unpredictable parameter is Kd, which may range from one to many orders of magnitude, depending on solute and soil characteristics, including pH. Estimated distributions of Kd for 27 elements in soils 4.5 ≤ pH ≤ 9.0, and correlations between Kd and pH for Cu, Zn, Cd, and Pb are also included. Finally, eight comparisons of model predictions with leaching constants, determined directly from observed data, are made for Pu, Sr, and Tc. In all comparisons, except one study of Pu, the model predicted leaching constants within an order of magnitude of observed values. For Pu the model underpredicted, and for Sr and Tc the model overpredicted leaching rates.
The Role of Delaware River Freshwater Tidal Wetlands in the Retention of Nutrients and Heavy Metals
Authors: Simpson Robert L. , Good Ralph E. , Walker Raymond , Frasco Barry R.
Published: July 2010

Tidal cycle budgets for June, July, August, September, and November 1979 showed that inorganic N was imported to the wetland from the Delaware River early in the growing season and exported late in the growing season. Nitrate and organic nitrogen were imported following macrophyte dieback. Reactive P was never lost from the marsh, and was actually imported on three dates. Total P was imported in July, September, and November, but otherwise exported. The metal present in the lowest concentration, Cd, was always exported; Ni, Cu, and Zn were imported on all but one date. Lead was imported late in the growing season and following macrophyte dieback. Nonpoint‐source inputs of Pb exceeded inputs from tidal waters.

The vegetation played a major role in the retention of N, P, Cu, Pb, and Ni entering the wetland through the growing season. The litter retained significant quantities of all heavy metals following macrophyte dieback, but it serves only as a temporary storage vehicle because rates of decomposition are high. The soil showed no definite seasonal pattern of nutrient or heavy metal retention. Elevated Pb levels occurred at sites near storm drains reflecting rapid sedimentation and retention of this metal as storm waters entered the wetland. It is concluded that freshwater tidal wetlands play an important seasonal role in reducing nutrient and heavy metal loading in the upper Delware River estuary.
Fecal Coliform Release Patterns from Fecal Material of Cattle
Authors: Thelin Richard , Gifford Gerald F.
Published: July 2010

The study examined the magnitude of a release of indicator bacteria (fecal coliform) from bovine fecal deposits that were rained on by a rainfall simulator at a rate of 6.1 ± 0.3 cm/h for 15 min, as affected by duration of rainfall and age of fecal deposits. Standard fecal deposits were placed on a platform and rained on with the runoff water being sampled at 5, 10, and 15 min. Samples were then examined by the most probable number (MPN) method for the presence of fecal coliforms.

Results indicate the potential for bacterial pollution from bovine fecal deposits. An equilibrium in the concentration of fecal coliforms being released from the fecal deposit was reached within 10 min. Fecal deposits < 5 d of age released fecal coliforms on the order of millions/100 mL of water. Concentrations declined to 40,000/100 mL at 30 d of not‐rained on age. The decline followed a typical bacterial death curve.
Sewage Sludge Components Extractable With Nonaqueous Solvents
Authors: Strachan S. D. , Nelson D. W. , Sommers L. E.
Published: July 2010

Organic components in sewage sludges were extracted with nonaqueous solvents (hexane and methanol) and characterized by chromatography, infrared spectroscopy, and mass spectrometry. On the average, nonaqueous solvent soluble compounds represented 10.6% of sludge dry weight (24.8% of ash‐free dry weight) and contained 36% of the total organic C in sludge. Major compounds in nonaqueous solvent extracts included two different waxes, one phenolic fatty acid ester, and a glyceride fatty acid. Significant amounts of dibutyl phthalate, di(2‐ethylhexyl)phthalate, and butyl benzyl phthalate were also present in sludges. The presence of fats, waxes, and oils was expected; however, the presence of phthalate esters in sludges has apparently not been previously reported. The types of phthalate esters in sludge suggest that they are derived from industrial inputs to the municipal sewage treatment system. Polychlorinated biphenyls, polybrominated biphenyls, or chlorinated hydrocarbons were not detected in any of the sludges examined.
Evaluating the Release of Soluble Components From Sediment
Authors: Avnimelech Y. , Yamamoto M. , Menzel R. G.
Published: July 2010

The evaluation of soluble components exchange between sediments and the pore or overlying water is essential for the quantitative description of sediment‐water systems. Lake and farm pond sediments differing in degree of nutrient enrichment were equilibrated with varying amounts of water. The extraction of soluble components is described as a function of a linear distribution of the soluble components between the solid and liquid phases and through mass‐balance considerations. The sizes of potentially available nutrient pools and the distribution coefficients were calculated for NH4+, organic N, and C. Ortho‐P release appeared to depend upon solubility consideration and did not follow the above‐mentioned model.
Spatial Distribution of Pesticide Residues in a Former Apple Orchard
Authors: Veneman P. L. M. , Murray J. R. , Baker J. H.
Published: July 2010

During the period 1900–1950, considerable amounts of Pb arsenate pesticides were used in apple orchards. Many of these orchards are not in fruit production any longer and are used for home gardening, pasture, or forage and vegetable cropping. This paper examines the spatial distribution of inorganic pesticide residues in an abandoned orchard in central Massachusetts.

Maximum Pb and As concentration in surface soils sampled in a grid‐like pattern, were 870 µg g−1 and 120 µg g−1, respectively. Areas high in contaminants were either former tree sites or low spots where spray residues collected. A transect through the approximate location of a former tree site showed Pb and As concentrations under the dripline of 1400 µg g−1 and 330 µg g−1, respectively, and lower values of 170 µg g−1 and 50 µg g−1 outside the periphery of the crown. Lead, arsenic, and zinc concentrations decreased with increasing depth, with maximum concentrations in the upper 5 cm. No evidence of significant leaching of Pb, As, Zn, or Cu was observed below the 20‐cm depth. The rather insoluble Pb orthoarsenate appeared to be the predominant species for the Pb and As residues.
Volatile Sulfur Compounds From a Redox‐controlled‐cattle‐manure Slurry
Authors: Beard W. E. , Guenzi W. D.
Published: July 2010

Volatile S compounds have been implicated as contributors to the odor problem from cattle‐feedlots. This study was designed to evaluate the effects of oxidation‐reduction potentials (Eh) on the type and amount of volatile S compounds released from cattle manure. The laboratory experiment utilized a manure slurry controlled at pH 7, 30°C, and at preselected Eh levels. The Eh of the slurry was initially controlled at +300 mV, and subsequently decreased in increments of 100 mV/week through −200 mV. Effluent gases from the incubation flask were trapped, and the S gases analyzed by gas chromatography. Carbonyl sulfide (COS) and carbon disulfide (CS2) production was low (≤0.07 µg/g manure/d) at all redox levels. Dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) were highest at 0 mV, while hydrogen sulfide (H2S) and methanethiol (MeSH) were greatest at −100 mV. The total amount of S volatilized from the manure slurry as each compound was: H2S, 155 µg; MeSH, 135 µg; DMS, 83 µg; DMDS, 27 µg; COS, 8 µg; and CS2, 3 µg; representing about 1.7% of the total manure S.
Fate of Nitrogen and Phosphorus in a Waste‐water Retention Reservoir Containing Aquatic Macrophytes
Authors: Reddy K. R.
Published: July 2010

Potential use of retention/detention reservoirs stocked with vascular aquatic macrophytes was evaluated, using a microcosm reservoir for reducing the N and P levels of agricultural drainage effluents (waste water). The treatments evaluated were reservoirs stocked with (i) pennywort (Hydrocotyle umbellata L.), (ii) water hyacinth (Eichhornia crassipes [Mart] Solms), (iii) cattails (Typha latifolia L.) and elodea (Egeria densa P), and (iv) control (no macrophytes). Labeled 15N was used to differentiate preferential uptake of 15NH4+ and 15NO3−, and to follow the fate of added 15NH4+ and 15NO3−.

Results showed that 34 to 40% of the added inorganic 15N (15NH4+ + 15NO3−) was removed through plant uptake, while 45 to 52% of the added 15N was unaccounted for, presumably lost through NH3 volatilization and nitrification‐denitrification processes. In the control reservoir, algal biomass removed 4.4% of added 15N, while 41% of the added 15N was not accounted. Pennywort and cattail‐elodea systems were found to be most effective, with about 50% inorganic N removal in a 4‐day detention period. All aquatic macrophytes preferred 15NH4+ over 15NO3−, but the difference in uptake was not significant, except for pennywort and cattails, which removed 84 and 92% of the added 15NH4+ as compared to 16 and 8% of the added 15NO3−, respectively. About 25 to 29 d were required by the systems with macrophytes to remove 50% of the wastewater P. Plant removal of P was in the range of 3 to 65% of added P, while 7 to 87% of the added P was lost through precipitation and adsorption reactions.
The Impact of Sulfur Dioxide on Plant Sexual Reproduction: In Vivo and In Vitro Effects Compared
Authors: Du Bay Denis T. , Murdy William H.
Published: July 2010

In Lepidium virginicum L., exposure of pollen to 0.6 ppm sulfur dioxide (SO2) for 4 h reduced pollen germination in vitro 94% from the control, whereas exposure to 0.6 ppm SO2 for 2, 4, and 8 h during flowering reduced pollen germination in vivo 50% from the control, but did not affect seed set. An interaction between SO2 and water may have caused the inhibition of pollen germination in a liquid culture medium, as well as on the moist surface of an intact stigma. However, the results suggest that the use of pollen germination and pollen tube elongation in vitro to assess the direct effects of SO2 on plant sexual reproduction in vivo is not valid.
Carbon Dioxide and Global Temperature: What the Data Show
Authors: Idso Sherwood B.
Published: July 2010

Analyses of data from a number of sources indicate that (i) there was a gradual increase in global atmospheric CO2 concentration from about 1860 to 1945, (ii) there has been a much more rapid rate of increase in atmospheric CO2 concentration from 1945 to the present, (iii) the most recent trend of global surface air temperature during this period of rapid CO2 increase has been downwards, which is in contradiction to the predictions of the most sophisticated general circulational models of the atmosphere in use today, (iv) this downward trend in surface air temperature has been most pronounced in northern latitudes, which is also in contrast to the model predictions, and (v) the downward temperature trend has been greater in summer than in winter, which is again in contradiction to the models. It is thus concluded that the theoretical numerical models of the atmosphere are grossly in error in their predictions of future CO2 effects on world climate, as is also suggested by several recent empirical studies. Consequently, since increasing global population requires more and more food, and since elevated CO2 concentrations have been documented to enhance crop productivity by increasing rates of photosynthesis, and water use efficiency by decreasing rates of transpiration, it is further concluded that increased levels of atmospheric CO2 may actually be beneficial to our future well‐being.
Behavior of Chromium in Soils. VI. Interactions Between Oxidation‐Reduction and Organic Complexation
Authors: James Bruce R. , Bartlett Richmond J.
Published: July 2010

Initial oxidation rates of different forms of Cr(III) added to an Aquic Udorthent soil, and the maximum Cr(VI) levels observed, decreased in the order: freshly‐precipitated Cr(OH)3 > Cr‐citrate > aged Cr(OH)3 in citrate > aged Cr(OH)3. The oxidation of Cr(III) in tannery sewage sludge and in tannery effluent added to a Typic Eutrochrept soil also was studied as a function of time and loading rate. Amounts of Cr(VI) formed increased with Cr(III) added from 0.025 to 6.2 mmol/100 g soil (29 to 7,200 kg/ha) for sewage sludge Cr(III), and from 0.1 to 1.8 mmol/100 g soil (103 to 2,100 kg/ha) for the tannery effluent Cr(III). Levels of water‐soluble Cr(VI) increased for a month in most of the treatments, despite the presence of reducing agents in the soil and in the wastes. Adding citric acid to the soil along with the tannery wastes increased the amount of Cr(VI) formed at each treatment level, and decreased the Cr(III) loading rate required for observation of oxidation. Mutual facilitation of Cr(III) oxidation by chelation and of further chelation by oxidation was postulated as a possible mechanism for the continuous formation of Cr(VI) in a soil.

The reduction of soluble Cr(VI) in unlimed (pH 5.3) and limed (pH 6.5) samples of an Ultic Hapludalf resulted in the formation of soluble organic complexes of Cr(III) if citric acid was added with the Cr(VI). During a 9‐d incubation period, more reduction of Cr(VI) occurred in unlimed than in limed samples, but higher levels of soluble Cr(III)‐chelate were measured in the limed treatments. Increasing the ratio of citrate to Cr(VI) increased the rate of reduction of the Cr(VI) in the Aquic Udorthent. Soluble Cr(III)‐chelate formed, and the length of time the Cr(III) remained soluble also increased with the citrate/Cr ratio.
Response of Spruce and Birch Foliage to Leaching by Acidic Mists
Authors: Scherbatskoy Timothy , Klein Richard M.
Published: July 2010

Seedlings of yellow birch (Betula alleghaniensis Britt.) and white spruce (Picea glauca (Moench) Voss) were exposed to mists consisting of distilled water at pH 5.7, or sulfuric acid in distilled water at pH 4.3 or 2.8. Misting treatments, 4 h each, were applied once, twice, or three times, separated by 72 h. Leaf tissue chlorophyll concentrations were determined, and foliar leachate was analyzed for K+, Ca2+, NO3−, H2PO4−, total carbohydrate, total protein, and total amino acids. Decreased leaching of carbohydrate, protein, K+, and H2PO4− occurred with increasing number of mistings, indicating that these substances were not readily resupplied to leaching sites. Protein leaching was reduced by misting at pH 2.8. Leaching of amino acids, K+, and Ca2+ increased with decreasing mist pH, and leachate pH was higher than the pH of applied mists, suggesting that cation exchange plays a role in foliar leaching by acidic solutions. Amino acid leaching from birch increased with increasing number of mistings at pH 2.8. There was no strong effect on chlorophyll concentrations, and leaching of NO3− and H2PO4− did not vary with mist pH.
Water Quality From Water‐Harvesting Systems
Authors: Frasier Gary W.
Published: July 2010

Water harvesting is a technique used to supply animal and domestic drinking water in areas where more conventional methods cannot supply sufficient water. The water collected by a water‐harvesting system has the potential of being contaminated by deterioration by‐products of the materials used in constructing the system, from dust that is deposited on the catchment surface, or from impurities trapped in the rain. During a 3‐y period, runoff water samples were collected for water quality analyses from 10 types of catchment treatments on operational and experimental water‐harvesting systems in Arizona. Atomic absorption spectrophotometry techniques were used to determine the concentrations of Al, As, Cd, Ca, Cr, Co, Cu, Fe, Pb, Mg, Hg, K, Na, V, and Zn in each water sample. There was no evidence that deterioration of the catchment treatments would cause a contamination of the runoff water. With the exception of As, most samples had significantly lower concentrations of these constituents than the maximum standards for animal or domestic drinking water supplies.

Arsenic was the only chemical consistently found in the water samples at potentially hazardous concentrations for domestic drinking water supplies. Excessive As concentrations were not associated with any specific type of catchment treatment. The logarithm of As concentration in the runoff was positively correlated with the logarithm of the time since the previous rain, and negatively correlated with the logarithm of the total rainfall quantity. Apparently, As was deposited on the catchment surface as dryfall dust, and/or was washed from the atmosphere by the rainfall.
Municipal Sewage Sludge Compost‐Amended Soils: Some Spatiotemporal Treatment Effects
Authors: Darmody R. G. , Foss J. E. , Mc Intosh M. , Wolf D. C.
Published: July 2010

Amending soils with composted sewage sludge can be a useful way to both dispose of sewage sludge and improve the chemical and physical properties of soils. Composted, municipal sewage sludge was added to a Chester silt loam (fine‐loamy, mixed, mesic Typic Hapludult) in a tree nursery at rates of 0,150, and 300 dry t/ha. Soils were sampled to a depth of 150 cm, in 25‐cm increments each year for the 3 y after compost addition, and analyzed for pH and extractable Ca, Mg, K, P, Cu, and Zn. Surface soil pH values and levels of Ca, K, P, Cu, Zn, and organic C increased, while bulk density values decreased with increased compost application. Surface soil levels of extractable K and P increased over 3 y after addition, while the other elements remained stable. Soil Mg content was not significantly changed by compost additions.

With the exception of K, the extractable elements added by compost were found to be mobile. In the 300 t/ha plots, Ca was significantly increased to a depth of 50 cm and pH, P, Cu, and Zn was significantly increased to 75 cm. Depth of significant increase was less in the 150 t/ha plots. All the elements that increased at depth, except Cu, showed a gradual decline in concentration from the surface. In the 300 t/ha plots, Cu concentration gave a maximum in the B horizon.