bluuebunny/crossref_metadata_2025 huggingface dataset:
Fertilizer Nitrogen Distribution Under Irrigation Between Soil, Plant, and Aquifer
Authors: Gerwing J. R. , Caldwell A. C. , Goodroad L. L.
Published: July 2010

A field experiment was established on a Sverdrup sandy loam in Central Minnesota to evaluate the effects of amounts and timing of nitrogen (N) fertilizer applications on N uptake by irrigated corn (Zea mays L.) and the movement of N into the aquifer 4.5 m below the soil surface. Nitrogen was applied as urea at rates of 179 and 269 kg N/ha in one application at planting or in split applications through the season. Soil solution analysis showed NO3 moving below the rooting zone in all plots with much higher concentrations below the one‐time fertilizer applications. Split applications of N had only minimal effect on the concentration of NO3‐N in the aquifer but one‐time applications increased the concentration by 7 and 10 ppm. The use of 13N showed that splitting the 179‐kg rate increased the N in the plant derived from fertilizer from 33.1 to 54.5%, and increased the recovery of fertilizer N by the plant from 30.4 to 52.1%, even though whole plant yields were not affected. Nearly one‐fourth of the applied N remained in the upper 45‐cm soil layer at harvest regardless of treatment. No accumulation of NO3 was found in the soil profile or underlying material to a depth of 3.0 m.
Nutrient Chemistry in Herbicide‐treated Ponds of Differing Fertility
Authors: Peverly John H. , Johnson Robert L.
Published: July 2010

Ponds 0.04 ha in bottom area and 1.2 m uniform depth with similar densities of the submerged aquatic plant Elodea canadensis Michx. but with different previous nutrient additions were treated with 1 mg/liter diquat (6,7‐dihydrodipyrido [1,2‐a:2′,1′‐c] pyrazinediium ion) on 17 Nov. 1972. This was done to simulate normal weedkill conditions and to measure subsequent carryover effects of past nutrient inputs. Before treatment and for 1 year thereafter, soluble P, particulate P, NO3−, NO2−, NH4+, K+, and chlorophyll a were measured in treated and similar control ponds. After herbicide treatment soluble P concentrations rose dramatically within 24 hours but were reduced to control levels of 10 to 20 µg/liter within 3 weeks. All P forms in the fertilized treated pond remained low until the following June, when particulate and organic P increased to 100 to 300 µg/liter as a result of mineralization processes. Chlorophyll a rose soon after to about 200 µg/liter and NH2+‐N to 100 µg/liter. There were no other differences between control or treated ponds in NH4+ or NO3− concentrations, but both increased several fold each fall in all ponds. Definite carryover effects of previous nutrient inputs were demonstrated in the herbicidetreated ponds, but not in untreated ponds. The compartment in the pond which stored these nutrients and then released them upon herbicide treatment was the rooted macrophytes.
Effects of Soil‐applied Sewage Sludge on Concentrations of Elements in Earthworms
Authors: Helmke P. A. , Robarge W. P. , Korotev R. L. , Schomberg P. J.
Published: July 2010

Samples of earthworms (Aporrectodea tuberculata [Annelida: Lumbricidae]) and their casts collected from field plots were analyzed by neutron activation analysis to evaluate the suitability of using earthworms to monitor the bioavailability of elements in soils, and to determine the effects of land application of sewage sludge on the concentrations of trace elements in earthworms. Culture of earthworms on soils treated with radioactive tracers shows that earthworms accumulate Cd, Co, Hg, and Zn, but not Hf, Sc, and Tb. The results for the earthworms from the field plots are corrected for the effects of contamination by uneliminated casts with the use of interelement ratios. The concentrations of Hg and Cr in the casts increase with increasing rates of sludge application, but the constant concentrations of these elements in the earthworms show that these elements are not bioavailable. The concentrations of Cd, Cu, and Zn in the earthworms increase, while those of Se decrease with increasing rates of sludge application. The very high concentrations of Cd in the earthworms, ranging from about 10 ppm in the control samples to over 100 ppm in the affected samples, show that earthworms efficiently accumulate Cd.
Metabolic Fate of Atrazine in the Spartina alterniflora‐Detritus—Uca pugnax Food Chain
Authors: Mc Enerney J. T. , Davis D. E.
Published: July 2010

Leaves from Spartina alterniflora Loisee (smooth cordgrass) plants grown with their roots in solutions containing 14C ring‐labeled atrazine were converted to detritus in model ecosystems that simulated the salt marsh environment. Percentages of radioactivity in chloroform‐soluble, water‐soluble, and insoluble materials in the leaves were 55, 38, and 7, respectively. Twenty days later these values for detritus were 9, 78, and 13, respectively. Thus, there was a decline in the percentage of radioactivity in the chloroform fraction which contains atrazine and nontoxic metabolites and a concurrent increase in the water‐soluble fraction that contains only nontoxic metabolites.

An important detritivore in the salt marsh, the mud fiddler crab, when fed detritus labeled with atrazine further decreased the percentage of the chloroform‐soluble atrazine or atrazine metabolites. Radioactivity originally present in either atrazine or atrazine metabolites fed to mud fiddler crabs was concentrated in the water‐soluble extract from the crabs, suggesting that either selective absorption through the gut or metabolism of the chloroform‐soluble form(s) to water‐soluble material by the fiddler crabs or the crabs' enteric flora. Atrazine and atrazine metabolite concentrations were reduced from lower (detritus) to higher trophic levels (mud fiddler crabs) in the simulated salt marsh ecosystem.
An Evaluation of Alternative Simulated Treatments of Septic Tank Effluent
Authors: Stewart L. W. , Carlile B. L. , Cassel D. K.
Published: July 2010

Six modified soil columns (180 by 15 cm) with an upper unsaturated zone and a lower saturated zone were dosed twice daily for 220 days with 1.65 cm of septic tank effluent via a cinderblock cube. Examined were: (i) the performance of the cinderblock material as a means of introducing effluent into two soils having different textures, (ii) the treatment capability of the two soils under unsaturated flow to purify septic tank effluent, and (iii) denitrification in a saturated zone containing either a Histic epipedon‐sand mixture (9% OM) or gravel only.

Water as simulated rainfall totaling 4.3 cm was added in five increments to the soil overlying the cinderblock cubes during the first 45 days of dosing. Severe biological clogging occurred after 50 days in the cinderblock material embedded in the loamy sand columns. This resulted in continuously ponded effluent inside the cinderblock cubes. Continuous ponding did not develop in the cubes placed in the sand columns.

At a distance 95 cm below the cinderblock cube, conversion of total nitrogen to NO3 in sand columns ranged from 83 to 100% and the PO4‐P content of the percolating effluent averaged < 1 mg/liter. Column effluent samples analyzed for fecal coliform were all negative. Soil samples revealed no penetration of fecal coliforms below 30 cm in either the loamy sand or sand columns. In the saturated zone containing the Histic epipedon‐sand mixture, NO3 was reduced by 93% at 42 days, but only 22% at 95 days. Chemical oxygen demand in the column effluent gradually declined from 188 mg/liter at 42 days to 85 mg/liter at 220 days. No significant denitrification occurred in the saturated zones containing gravel only.
Commercial Production of Wheat Grain Irrigated with Municipal Waste Water and Pump Water
Authors: Day A. D. , McFadyen J. A. , Tucker T. C. , Cluff C. B.
Published: July 2010

Experiments were conducted in southern Arizona to study the effects of irrigating wheat (Triticum aestivum L.) with a mixture of pump water and waste water and with pump water alone on wheat growth, grain yield, grain quality, soil properties, and irrigation water quality.

In small plot research, wheat irrigated with the pump water‐waste water mixture produced taller plants, more heads per unit area, heavier seeds, higher grain yields, and higher straw yields than did wheat grown with only pump water. When large fields were compared, wheat grown with the pump water‐waste water mixture had taller plants, more lodging, lower grain volume‐weights, and higher grain yields than did wheat produced with pump water.

The pH and exchangeable sodium of soil irrigated with pump water alone or the pump water‐waste water mixture were similar. Soluble salts and nitrate‐nitrogen were higher in soils irrigated with pump water than they were in soils irrigated with the pump water‐waste water mixture. Extractable phosphorus was higher in soils irrigated with the pump water‐waste water mixture than in soils irrigated with pump water.

Total soluble salts and nitrate‐nitrogen were higher in pump water than they were in the pump water‐waste water mixture; however, the pump water‐waste water mixture had higher levels of total nitrogen and phosphorus than did pump water. The higher grain yields obtained when wheat was irrigated with the pump water‐waste water mixture than were produced when wheat was grown with pump water alone probably resulted from lower concentrations of soluble salts in the pump water‐waste water mixture than were present in pump water.
The Use of Zonal Centrifugation in Delineating Trace Element Distributions in Sewage Sludges from the Dayton, Ohio, Area
Authors: Bergman Steven C. , Ritter Charles J. , Zamierowski Edward E. , Cothern C. Richard
Published: July 2010

Density gradient zonal cenfrifugation, using tetrabromoethane‐ethanol solutions as density gradients, was used to fractionate two sewage sludges. The distributions of Cd, Cu, Pb, Ni, and Zn in the sludge fractions were determined using atomic absorption spectrophotometry. Trace element concentrations are related to density in a simple pattern. Seventy‐five weight percent of the total trace elements in the sludges are contained in low‐density (1.60 to Z.10 g/cm3), organic‐rich fractions. A small portion of the total trace elements in sludge is also associated with minerals such as sulfides and sulfates in high‐density fractions.

Because organic‐rich fractions of sludge contain the highest absolute amount of trace elements, it is concluded that most of the trace elements are located in organic compounds in the sludges studied. Furthermore, it is suggested that particular organic compounds, within a limited density range, contain the greatest concentrations of trace elements.
Effects of Hypolimnetic Aeration on Nitrogen Transformations in Simulated Lake Sediment‐Water Systems
Authors: Chen R. L. , Keeney D. R. , Sikora L. J.
Published: July 2010

Mechanical aeration of the anoxic hypolimnion of small, eutrophic, thermally stratified lakes and impoundments has been proposed as a temporary water quality improvement technique. We hypothesized that proper manipulation of this technique could lead to significant N loss through nitrification‐denitrification. This hypothesis was examined by using simulated sediment‐water and batch incubation systems, and the use of 15N.

Aeration of an NH4‐enriched hypolimnion should lead to disappearance of ammonium and formation of nitrate. If the sediment had a high oxygen demand, nitrate should rapidly disappear once aeration was discontinued. Nitrate should also disappear, although more slowly, during aeration due to reactions at the sediment‐water interface and in the surficial sediment. The amount of N removed from the sediments by nitrification‐denitrification would vary widely, depending on the lake, but would not be as large as predicted from nonlabeled N mass balances due to assimilatory nitrate reduction (immobilization).

The results of this work indicate that nitrification is rapid, even at 10°C, when the hypolimnion is aerated, and that denitrification and nitrate immobilization is equally rapid when aeration is stopped and the hypolimnion again becomes anaerobic. However, at least in Cox Hollow Lake sediments, a considerable amount of nitrate (up to about 60%) is immobilized rather than denitrified. Thus, the net loss of N from the lake system is much less than would be predicted from strictly inorganic N mass balance calculations, and hypolimnion aeration does not offer much promise as a method for removing N from lakes.
Nitrogen Transformations and Microbial Population Dynamics in Soil Amended with Fermentation Residue
Authors: Volz M. G. , Heichel G. H.
Published: July 2010

To evaluate the fate of N in an agricultural soil treated with an N‐rich industrial byproduct, fermentation residue was applied to Yalesville fine, sandy loam at a loading rate of 75 dry metric tons/ha, or 2,130 and 1,780 kg N/ha during 1975 and 1976, respectively. Treated and control plots were planted to soybeans (Glycine max L. Merr.) each year. The treated plots yielded 4,350 kg/ha of soybean grain compared with 3,600 kg/ha for the controls in 1975, and 4,100 kg/ha compared with 3,700 kg/ha in 1976. Yield enhancements attributable to fermentation residue application were significant (P = 0.05) each year despite the severe repression of nodulation on treated plants compared with controls.

During the growing season, NO3−‐N accumulations >80 µg/g oven dry soil were observed in the top 5 cm of treated soil, compared with accumulations of 15 µg/g or less in the control. Further, elevated NO3−‐N levels were observed in the top 91 cm of treated soil throughout the fallow and growing seasons, when compared with control plots, suggesting that some of the applied N may have been transported to the water table as NO3−.

Populations of five physiological groups of microorganisms closely mirrored soil levels of NO3−‐N and NH4+‐N in both experiments. Denitrifying bacteria reached population densities of 3.0 × 109/g oven dry treated soil compared with a maximum of 6.8 × 105/g for control soil during the growing season. Enhanced N transforming activity by microorganisms in soil receiving fermentation residue compared with the control soil was supported by the elevated populations of NH4+ and NO2− oxidizing bacteria, and NO3− reducing‐, denitrifying‐, and heterotrophic aerobic bacteria observed throughout the fallow and growing seasons. Although application of fermentation residue significantly increased soybean yields, the limited recovery of added N by the crop and the likelihood of substantial N losses suggest a reassessment of application rates or efforts to stabilize N applied to soils from fermentation residues.
Soil Temperature and Sewage Sludge Effects on Metals in Crop Tissue and Soils
Authors: Sheaffer C. C. , Decker A. M. , Chaney R. L. , Douglass L. W.
Published: July 2010

Effects of soil temperature and sewage sludge application on plant and soil Zn, Cu, Cd, Ni, and Pb levels, soil pH, and soil organic matter were determined in a field experiment in which corn (Zea mays L.) was grown for 2 years in a sandy Typic Hapludult soil amended with 0, 56, and 112 metric tons/ha of sewage sludge at the start of the experiment. Soil temperature regimes of 16, 27, 35°C, and ambient (x̄ = 22°C) were applied to sludge treatments from May to October each year. Following removal of corn at the conclusion of the 1975 growing season, oats (Avena sativa L.), wheat (Triticum aestivum L.), rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), and arrowleaf clover (Trifolium vesiculosum Savi) were grown until the following spring.

Sewage sludge application resulted in significant increases in soil organic matter, pH, and DTPA extractable Zn, Cu, Cd, and Ni. Soil heating to 35°C significantly reduced soil pH for all sludge rates compared to 16°C and ambient (22°C) temperatures by the conclusion the experiment. This decrease was greatest for plots amended with 112 metric tons/ha sewage sludge and least for the check plots. Soil temperature had no effect on levels of soil organic matter or DTPA extractable metals. Extractable Zn, Cu, and Ni levels increased from the start to the conclusion of the experiment.

Concentrations of Zn, Cu, Ni, and Cd were increased in corn, legume, and small grain tissue by sludge treatments. Corn seedling Zn and Cu concentrations exceeded that in ear leaves, stover, and grain; lowest metal concentrations were found in the corn grain. Increasing soil temperature did not consistently affect Cu, Ni, Cd, or Pb concentrations in corn tissue. Zinc concentrations in corn tissue generally increased as soil temperature rose, but exceptions did exist. No residual soil temperature effects were observed on metal concentrations in legumes or small grains.
Denitrification in Freshwater Wetland Soil
Authors: Bartlett M. S. , Brown L. C. , Hanes N. B. , Nickerson N. H.
Published: July 2010

The application of secondary treated waste water to fresh water wetlands has received recent attention as a tertiary treatment method. The fate of nitrate nitrogen in such applications is of concern because of the potential for leaching into ground and surface water supplies. Nitrate removal in wetland soil‐water suspensions was studied using a Warburg Respirometer. All important pathways of nitrate reduction were accounted for using a nitrogen mass balance. The data indicate that 90 to 95% of the nitrate added to wetland soil‐water suspensions is reduced to nitrogenous gases, with little or no transfer of nitrate to ammonia nitrogen or organic nitrogen fractions.
Disposal of Septic Tank Effluent in Mound and Sand Filter‐Trench Systems on a Clay Soil
Authors: Simons A. P. , Magdoff F. R.
Published: July 2010

Small‐scale mound systems and conventional sand filter‐trench systems for disposal of septic tank effluent were established on a clay soil. During a wet year (1976), major differences in soil moisture patterns were observed between the two systems. Unsaturated flow of effluent occurred through the gravel/sand interface of the mound systems, although a slight pressure‐head buildup occurred at the bottom of the mound fill. Conventional sand filter‐trench systems were under water throughout most of the 1976 monitoring season. However, when the dry conditions of 1977 allowed the water table to drop below 1.2 m, unsaturated conditions occurred below the gravel/sand interface of both the mound and sand filter systems. Water tension patterns below the gravel/sand interface indicated development of the early stages of clogging (but not permanent ponding) in the mounds, while those within the sand filter‐trench system indicated the development of a restricting layer. Rejuvenation of the mound infiltrative surface occurred during the warm and dry 1977 spring and early summer.

Temperatures below the gravel/sand interface dropped to about −3°C during the winter in the mound systems, but stayed just above freezing in the sand filters. A lack of snow accumulation on top of the mounds probably allowed the subzero temperatures.
Incidence of Salmonellae in Feedlot Manure
Authors: Clinton N. A. , Weaver R. W. , Zibilske L. M. , Hidalgo R. J.
Published: July 2010

Manure from cattle in 11 major feefllots in Texas was sampled during summer and winter months to determine the presence of salmonellae. Both moist and dry samples of manure were collected. Of the 505 pens from which manure was sampled, 49 were positive for salmonellae. Only 2 of the 49 isolations were made from dry manure samples. One feedlot contained salmonellae in 44% of its pens. But no salmonellae were isolated from the manure in two of the feedlots. The frequency of isolating salmonellae from different feedlots varied with the season of the year but the overall frequency was similar for both seasons. Ten salmonella serotypes were isolated with the two most common being Salmonella typhimurium and Salmonella anatum. These results indicate that manure in feedlots may have an important role in the epidemiology of salmonellae.
Effects of Phosphorus Fertilizer and Lime on the As, Cr, Pb, and V Content of Soils and Plants
Authors: Goodroad L. L. , Caldwell A. C.
Published: July 2010

The occurrence in fertilizer materials of small quantities of chemical elements not essential to plants suggests that the soil may become contaminated with these elements due to the use of fertilizers. Two experimental sites: a Nicollet clay loam fertilized with 0, 1,111, 2,222, 4,444, and 8,888 kg/ha of concentrated superphosphate (CSP) and 20.2 metric tons of lime, and a Port Byron silt loam fertilized for 19 years with 99, 73, 82, and 352 kg/ha annually of CSP, calcium metaphosphate, phosphoric acid, and southern rock phosphate, respectively, were sampled to determine if significant amounts of arsenic (As), chromium (Cr), lead (Pb), or vanadium (V) had been added from use of these fertilizer materials. There was no indication of increased As, Cr, Pb, or V from the addition of P fertilizers to either the Nicollet or Port Byron soils. The addition of lime increased the Cr content of the Nicollet soil by approximately 3 ppm, but there was no increase in As, Pb, or V. There was no increase in As, Cr, Pb, or V from addition of CSP in soil samples from below the Ap horizon to a depth of 47.5 cm. Soil samples from a representative Nicollet soil suggest that higher As, Cr, Pb, and V concentrations in the A and B horizons are due to leaching of CaCO3 into the C horizon. Corn (Zea mays L.) plant growth and grain yields were similar for all CSP and lime treatments. The results of this study indicate that the use of P fertilizers at the rates presently applied would not add substantially to the natural levels of As, Cr, Pb, and V in the soil.
Nitrate Leaching from Sewage‐irrigated Perennials as Affected by Cutting Management
Authors: Hook J. E. , Burton T. M.
Published: July 2010

A field study was conducted on two waste water‐treated sites to evaluate the effectiveness of various cutting treatments for controlling nitrogen (N) leaching. Secondary municipal sewage effluent was applied at 7.5 cm/week during the growing season to Kentucky bluegrass (Poa praetensis L.), which received treatments of no cutting, biweekly mowing, and triannual hay harvest. Effluent was also applied at rates of 0, 5.0, and 10.0 cm/week to indigenous vegetation in an abandoned field which received treatments of no cutting, once, and twice‐annual harvests. Soil‐water was sampled with porous‐cup samplers. The N concentration in the 120‐ to 150‐cm depth was taken as a measure of N which escaped the root zone and which would leach to the ground water. Recharge volume was calculated from irrigation, rainfall, and potential evapotranspiration.

Soil‐water from the 150‐cm depth in the Kentucky bluegrass consistently contained < 10 mg/liter of mineral N. Mineral N concentration of soil‐water did not differ significantly among the cutting managements. Even though no vegetation was removed from the no‐cutting and the mowed plots, they were as effective as the harvested plots in controlling N leaching past the 150‐cm depth in the 2‐year study.

For the oldfield vegetation, there was no significant difference in mineral N concentration in soil‐water at the 120‐cm depth between the 5.0‐ and 10.0‐cm/week irrigation rates. The mineral N concentration at 120 cm under both irrigation rates was affected by time of year and by cutting treatments. The twice‐annual harvest controlled N leaching more effectively than not cutting. The once‐annual harvest was more effective than not cutting for the 10‐cm/week rate but not for the 5.0‐cm/week rate. During the late summer and fall mineral N in the leachate increased to > 10 mg N/liter for the no cutting but not for the harvested oldfields. For reliable control of N leaching, removal of the N in harvested biomass was recommended.
Suspended Sediment‐Phosphorus Relationships for the Inflow and Outflow of a Flood Detention Reservoir
Authors: Schreiber J. D. , Rausch D. L.
Published: July 2010

Callahan Reservoir, located in an agricultural area near Columbia, Missouri, was studied for 3 years to determine the inflow and outflow suspended sediment phosphorus (P) and the solution P relationships. During the study, the mean inflow solution ortho‐P concentration was 0.085 mg/liter as compared with 0.041 mg/liter for the outflow. Concentrations of ortho‐P were highest in both the inflow and outflow during the fall and winter. As yearly suspended sediment concentrations decreased in both the inflow and outflow, due to lower runoff and sediment yields, solution ortho‐P (mg/liter), as well as sediment total, inorganic, organic, and exchangeable P concentrations (µg/g), increased. Similarly, as a result of coarse sediment deposition within the reservoir during individual storm events, outflow sediments were enriched in clay and had higher concentrations (µg/g) of total, inorganic, organic, and exchangeable P than inflow sediments. However, because of sediment deposition within the reservoir, outflow volume concentrations (mg/liter) of sediment total P decreased fourfold as compared with inflow sediments.
Applying Liquid Dairy Waste to Silt Loam Soils Cropped to Corn and Alfalfa‐Orchard Grass
Authors: Sutton A. L. , Nelson D. W. , Moeller N. J. , Hill D. L.
Published: July 2010

Three‐year and 2‐year field experiments were conducted to study the effects on crop yield and soil and plant composition of applying dairy slurry to Kokomo silt loam cropped to corn (Zea mays L.) and Crosby silt loam fallowed and subsequently planted to alfalfa (Medicago sativa)‐orchard grass (Dactylis glomerata), respectively. Anaerobic dairy slurry (6.4 to 9.1% dry matter) was applied at rates 112, 224, and 336 metric tons/ha, providing an average of 304, 609, and 914 kg N/ha; 60, 121, and 181 kg P/ha; 293, 587, and 880 kg K/ha; and 61, 121, and 181 kg Na/ha, respectively, per year. A check treatment was also included.

Maximum corn grain and silage production was obtained with the 224‐metric ton slurry rate. Plant composition was not affected by waste applications except total N levels in corn leaves increased with increasing waste rates during the second year. Except for NH4+‐N, the concentrations of soil constituents measured (NO3−‐N, P, K, Na, EC) were increased by waste applications, especially with the 224‐ and 336‐metric ton rates, compared to the check. Similarly, as compared to the check, all soil constituents measured were increased by waste applications on the fallow soil. One year of alfalfa‐orchard grass cropping, however, reduced the levels of all measured soil components except P and K to concentrations similar to or lower than the initial values. Alfalfa‐orchard grass growth was variable, but the 112‐metric ton application rate appeared to support maximum yields. In general, the concentrations of P and K in forage tissue tended to increase with increasing waste application rate. Under the climatic conditions of this study, annual dairy slurry applications of <224 metric tons/ha to soil cropped with corn and 112 metric tons/ha to fallow soil subsequently planted with alfalfa‐orchard grass had no detrimental effects on the chemical composition of two silt loam soils or on plant composition.
Retorted Oil Shale Effects on Soil Microbiological Characteristics
Authors: Hersman L. E. , Klein D. A.
Published: July 2010

The effects of retorted oil shale additions on the microbiological characteristics of surface soils were investigated in a laboratory study to evaluate possible effects of mixing of soils and retorted shales which might occur as a part of revegetation programs in areas disturbed by oil shale processing. Soils were mixed with retorted oil shale at 5, 10, and 25% addition levels, and compared with normal soil and retorted shale over a 2.5‐mo period, with evaluation of microbiological parameters carried out at 2‐week intervals. With retorted shale present at up to 10% by weight, no negative effects on oxygen uptake or on actinomycete and bacterial populations were noted, while significant reductions of nitrogen fixation rates, as measured by acetylene reduction, and of dehydrogenase activity, fungal populations, radioactive glucose mineralization, and ATP concentrations occurred, with nitrogen fixation being most affected by shale material. These studies suggest that nonsymbiotic nitrogen fixation in surface soils may be especially sensitive to the presence of retorted oil shale. It would appear necessary to assure that sufficient surface soil is used to cover retorted oil shales to allow development and functioning of a diverse vegetation‐microbiological community in such a way that physical mixing or movement of water‐soluble retorted oil shale constituents into this surface soil layer would be minimized.
Effects of Tillage and Fertilization on Persistence of Crude Oil Contamination in an Alaskan Soil
Authors: Mitchell W. W. , Loynachan T. E. , Mc Kendrick J. D.
Published: July 2010

The persistence of Prudhoe Bay crude oil was evaluated with cereal plantings over a 4‐year period on field plots at Palmer, Alaska, oiled at 10 and 20 liters/m2 with tillage and fertilization as treatments. Following the field study soil was removed for greenhouse evaluations and analyses.

Tilling aided water infiltration on the oiled plots in the field. Oiled plots without tillage or fertilization produced negligible growth during the first three growing seasons and very poor growth (< 10% coverage) in the fourth year. In the first year, only the 10‐liter tilled plots provided tangible growth, about one‐tenth that of the unoiled plots. The 20‐liter plots required both treatments to produce growth in the second and third years, while either treatment sufficed for the 10‐liter plots, with growth still much reduced from the controls. Oil decomposition was sufficiently advanced in the fourth year to permit over 75% coverage on the tilled 10‐liter plots, about 50% coverage on the tilled and fertilized 20‐liter plots, and about 25 to 40% coverage on the tilled, unfertilized 20‐liter and on the fertilized, untilled 10‐liter plots. Annual weeds were mostly unsuccessful in invading the oiled plots until the fourth year.

Greenhouse studies with oiled, fertilized soil removed from the field in the fourth year showed that tillage benefited growth of barley and bromegrass in the surface layer but was detrimental to growth in the 10‐ to 15‐cm layer. Laboratory analyses corroborated the greater contamination of the deeper layers from the tilled plots. Field moisture levels were highly negatively correlated with residual oil contents, thus emphasizing the droughty effects of oil contamination. Residual oil contents of 13.5% completely inhibited germination of barley and brome, while levels under 7.5% allowed germination but reduced shoot heights. Decreasing levels of residual oil with increasing depth of tilled soil did not result in significantly greater plant growth. Beneficial degradation of oil may be retarded at depths in the soil, thus prolonging its phytotoxic effects. Tillage is best delayed to allow volatilization and some weathering to occur.
Contamination of Great Smoky Mountains Trout Streams by Exposed Anakeesta Formations
Authors: Bacon J. R. , Maas R. P.
Published: July 2010

Anakeesta formations, prevalent geologic deposits in the Great Smoky Mountains National Park (GSMNP), when exposed to air and water release an acid and heavy metal containing leachate into several GSMNP streams, rendering them virtually lifeless. Anakeesta pyrite affecting Beech Flats Creek was exposed during the construction of U.S. Highway 441, while exposures affecting Alum Cave Creek and Walker Prong are naturally occurring.

The road cut on U.S. 441 at Beech Flats Creek acts as point source of various contaminants. The acidity increases 100‐fold (pH 6.7 to 4.7) in the several hundred meters where the stream flows through a road cut fill area. Manganese and zinc were the main metallic ions introduced at the road cut. The zinc increased from 6 to nearly 200 ppb and the manganese increased from an undetectable level to over 250 ppb. Seasonal variations below the road show a high concentration near 500 ppb in the summer to a low concentration near 100 ppb in the winter for both manganese and zinc. Both manganese and zinc showed the dilution effect expected going downstream away from the road cut. Alum Cave Creek and Walker Prong showed much lower levels of manganese and zinc and no point source could be located.

The results of the present study should prove useful to National Park personnel in making management decisions. This is especially important in view of several proposed new roads in the Great Smoky Mountains National Park.
Preferential Clay Mineral Erosion from Watersheds in the Maumee River Basin
Authors: Rhoton F. E. , Smeck N. E. , Wilding L. P.
Published: July 2010

Runoff sediments and soil surface horizons from five small watersheds were characterized for clay mineralogy, particle size distribution, cation exchange capacity, and amorphous and free iron oxide content. The objective was to determine if preferential transport of clay minerals from these watersheds was occurring.

Clay mineralogical analysis indicated runoff sediments contained higher concentrations of illite and expandables with lower concentrations of vermiculite and quartz relative to watershed soils. The differences were attributed to preferential transport of fine clays from the soil surface.

Runoff sediments contained an average of 18.4% more clay than soil surface horizons. Additionally, the total clay fraction of sediments contained an average of 10.1% more fine clay. Cation exchange capacity increased from 41 meq/100 g for soil clay fractions to 46 meq/100 g for sediment clay fractions due to the increased fine clay content. Both amorphous and free iron oxide contents were lower in the clay fractions of runoff sediments than in the clay fractions of soil Ap horizons.
Measuring Air Pollutant Uptake by Plants: Nitrogen Dioxide
Authors: Rogers Hugo H. , Jeffries Harvey E. , Witherspoon Augustus M.
Published: July 2010

Direct kinetic determinations of the uptake of nitrogen dioxide (NO2) by selected plant species under various conditions were made using continuous stirred tank reactor (CSTR) techniques. Second‐order rate constants with respect to exposure concentration and leaf area were obtained for corn [Zea mays (L.) ‘Pioneer Brand 3369A’], soybean [Glycine max (L.) Merr. ‘Davis’], loblolly pine (Pinus taeda L.), and white oak (Quercus alba L.). Mean rate constants in units of 10−3 dm−2 min−1 were: corn, 9.3; soybean, 13.6; loblolly pine, 13.7; and white oak, 2.8. On a mass basis, rates would be 3.5, 5.1, 5.2, and 1.1 × 10−2 µg dm−2 min−1 pphm−1 (pphm = parts per hundred million), respectively. Uptake rate constants remained the same over 5‐hour exposure periods within the exposure concentration range of 0 to 58 pphm. The NO2 uptake increased as the level of photosynthetically active radiation (PAR) increased. This effect of light was linearly correlated with the inverse of total diffusive resistance. Varying the level of tissue nitrogen (N) did not influence NO2 uptake even though the leaves were smaller and chlorotic at the lower levels of tissue N. Photolysis of NO2 occurred in controlled environment rooms under artificial light; the mean k1 for photolysis was 0.03 min−1.
Nitrate Production from Chemically Treated Sewage Sludges in Soil
Authors: Beauchamp E. G. , Soon Y. K. , Moyer J. R.
Published: July 2010

Chemicals such as Ca(OH)2, Al2(SO4)3, and FeCl, are used to precipitate and prevent phosphorus from escaping in effluents from sewage plants in Ontario. Since such chemicals affect the characteristics of anaerobically digested sludges, incubation experiments were conducted to determine if the nitrate production in soil treated with these sludges was also affected.

Nitrate production of six anaerobically digested sewage sludges differed considerably when incubated with soil but not in a manner related to the chemical treatment of the sewage. Reduced nitrate production from whole sludge from one source was possibly attributable to relatively high lipid and petroleum hydrocarbon contents. With the exception of this sludge, 17 to 30% of the sludge N was nitrified in 16 weeks under laboratory conditions. Nitrate production lag periods of 2 weeks or more were observed with whole sludges. The lag period, if present, when reconstituted sludges (ammonium and soluble organic N removed) were incubated with soil was < 1 week with the exception of the one sludge which probably had high lipid and petroleum hydrocarbon contents. Incubation of reconstituted sludges in soil resulted in 29 to 32% nitrification of the organic N during the first 16 weeks. Nitrate production was relatively rapid in the early part of the 49‐week incubation period but slowed substantially later.
The Effects of Fluometuron on a Salt Marsh Ecosystem
Authors: Allen J. D. , Davis D. E.
Published: July 2010

A salt march on Sapelo Island, Georgia, dominated by a mono‐specific stand of spartina (Spartina alterniflora Loisel) was treated with fluometuron [1,1‐dimethyl‐3‐(α,α,α‐trifluoro‐m‐tolyl)urea]. Treatments were: spraying once each year with 90,000 ppm; spraying 30 times (twice each day for 5 consecutive days in 3 consecutive months) with 1,000, 100, 10, 1, or 0 ppm; or flooding 30 times (frequency as described above) with 100 or 0 ppm. One‐half of each plot was re‐treated in the same manner the second year while the other half was left untreated. Effects on spartina, periwinkle snails (Littorina irrorata Say), and horse mussels (Gukensia demissus Dillwyn) were measured 4 mo after the first treatment. Only spraying once with 90,000 ppm fluometuron or 30 times with 1,000 ppm significantly reduced fresh weight, dry weight, or number of shoots of spartina and re‐treatment the second year at the same rates did not increase the effect. The spartina on the plots treated the first year but not retreated the second year recovered completely. One year after the last of 30 sprayings with 1,000 ppm or 1 spraying with 90,000 ppm, there were significant levels of fluometuron residue in the spartina harvested from these plots.

Flooding 30 times with 100 ppm of fluometuron did not significantly decrease the total fresh or dry weight of spartina, but did cause visible injury symptoms and did decrease the number of shoots. Flooding 30 times with 100 ppm was nearly as toxic as spraying 30 times with 1,000 ppm. Neither flooding nor spraying adversely affected the number or weight of snails. The snails were not confined to the plots but fluometuron residues in them reflected the treatment rates so migration into or out of plots must have been minimal. Flooding with 100 ppm fluometuron did not adversely affect the mussels.
Kinetic Behavior of Phosphate Sorption by Acid, Sandy Soil
Authors: Fiskell J. G. A. , Mansell R. S. , Selim H. M. , Martin F. G.
Published: July 2010

The time dependency of phosphate sorption‐desorption in fertilized soil is particularly important to the efficiency with which plant roots absorb applied phosphorus from the soil solution. In this study, phosphorus sorption by two acid, sandy soils was measured with time using a laboratory batch technique for a range of initial phosphorus concentrations in solution. A comparison of experimental data with results calculated using a two‐site sorption‐desorption model showed that for contactimes > 1 hour the observed phosphorus sorption in both these sandy soils could be described by assuming rapid and slow reversible reactions to occur simultaneously at two separate types of sorption sites. However, for shorter contact times (< 1 hour) the 2‐site model did not describe the P sorption adequately. The orders of the forward reactions at the rapid and slow sorption sites were fractional and first‐order, respectively, with regard to the P concentration in solution. For a given soil, one set of rate coefficient values was sufficient to describe the solution phase concentration of P for several different initial concentrations.
Loss of Fluometuron in Runoff Water
Authors: Wiese A. F. , Savage K. E. , Chandler J. M. , Liu L. C. , Jeffery L. S. , Weber J. B. , La Fleur K. S.
Published: July 2010

The amount of fluometuron [1,1‐dimethyl‐3‐(α,α,α‐trifluoro‐m‐tolyl)urea] in runoff water under different environmental conditions was determined in the southern U.S. and Puerto Rico. In Mississippi, Puerto Rico, and Texas, runoff water was collected from soil sprayed with 4.4 kg/ha of fluometuron each year for 3 years. Tests were conducted in Tennessee for 2 years and in North and South Carolina for 1 year. Water samples were collected in 4‐ by 10‐m plots, and 1 m downslope. Initial runoff was produced with sprinkler irrigation immediately after herbicide application at all locations except Tennessee and South Carolina which relied on rainfall. Later in the season, water was sampled from two additional runoff events of either irrigation or rainfall. A total of 32 runoff events were sampled at the 6 locations. The level of fluometuron in water caught 1 m downslope from treated areas during the first runoff averaged 0.30 ppm and was highest (0.87 ppm) in Puerto Rico. Fluometuron concentration in subsequent events was much lower than in the first runoff events. Average loss of fluometuron in 1 cm of runoff was <1% of applied fluometuron. Only 2% of applied fluometuron was lost in the situation producing the highest concentration in runoff water. Level of fluometuron in runoff water was directly related to slope. Results of this study indicate that fluometuron concentrations in runoff from treated fields are such that nontarget species should not be adversely affected.
Microbial Mobilization of Calcium and Magnesium in Waterlogged Soils
Authors: Silverman M. P. , Munoz E. F.
Published: July 2010

Microbial mobilization of Ca and Mg was studied in 12 California soils amended with 0.5% glucose solution and incubated in air and anaerobically for 2 weeks under waterlogged conditions in the laboratory. Incubation in air resulted in a decrease of 1 to 2 units in the pH of soil solutions relative to control soils incubated without glucose. This was accompanied by 2.4‐ to 29.4‐fold increases in the Ca content and 0.7‐ to 41‐fold increases in the Mg content of soil solutions. A similar decrease in pH was observed under anaerobic incubation as well as 2.7‐ to 15.3‐fold increases in the Ca content and 1.5‐ to 47‐fold increases in the Mg content of soil solutions.

The rates of Ca and Mg release differed in soils incubated in air or under anaerobic incubation. In air the quantities of Ca and Mg in soil solutions increased for the first 3 to 10 days, then decreased. Under anaerobic incubation Ca and Mg concentrations either reached maximal values in 7 to 10 days with no subsequent decrease, or continued to increase for the duration of the experiments. The changes under anaerobic and air incubation conditions may be attributed to microbial production of a variety of organic metabolites from glucose which may be responsible for the release of Ca and Mg from exchange sites and other mineral reservoirs. These metabolic products probably are relatively stable under anaerobic incubation but become susceptible to subsequent biodegradation in the presence of air.
Characteristics of Wheat Grown with Sewage Sludge Placed at Different Soil Depths
Authors: Kirkham M. B.
Published: July 2010

This study was done to determine the effect on plant growth and elemental uptake when sludge was applied in a layer below the surface rather than on the surface. Sludge was placed at different depths in columns of a clay loam soil (Udertic Paleustolls). Winter wheat (Triticum aestivum L. em. Thell. ‘Ponca’) was grown in the columns.

When sludge was placed at the 0‐ to 2‐cm depth (surface application), dry weight of shoots was 2.4 times more than when sludge was placed at the 18‐ to 20‐cm depth. Root growth was prolific in the vicinity of sludge layers at the 18‐ to 20‐cm depth, but total root weight in columns was about the same with sludge placed at either depth. Soil water content was lower in columns with better plant growth, probably because of greater transpiration. Dilute‐acid (0.05N HCl + 0.25N H2SO4) extractable concentrations of heavy metals (Zn, Cu, Cd) in soil were lower when sludge was at the 18‐ to 20‐cm depth than when sludge was at the 0‐ to 2‐cm depth. Concentrations of Cu and Cd were highest in shoots of plants in columns with surface‐applied sludge. Highest concentrations of Cu and Cd in the roots occurred when sludge was at the 18‐ to 20‐cm depth rather than at the surface. Relatively small concentrations of Cu and Cd in roots were transferred to the shoots. The results showed that for maximum dry matter production, sludge should be surface‐applied. For minimal transfer of heavy metals from roots to shoots, sludge should be layered below the surface of the soil.
Elemental Composition of Barley and Ryegrass Grown on Acid Soils Amended with Scrubber Sludge
Authors: Walker W. J. , Dowdy R. H.
Published: July 2010

A greenhouse study assessed barley (Hordeum vulgare L.) and ryegrass (Secale cereale L.) growth on two acid soils amended with scrubber sludge from a coal‐fired, power‐generating plant. The scrubber sludge was the residue from flue gas desulfurization, which included unburned airborne particulates (fly ash). The feasibility of using this material as a soil amendment was investigated since both the source, low‐sulfur western coal, and the process by which this material was generated differ markedly from fly ashes used in many reported studies. Of particular interest were the effects of scrubber sludge applications on boron and selenium concentrations of barley and ryegrass.

Soils used were a coarse sand, Typic Hapludalf (pH = 4.8), and a silt loam, Udorthentic Haploboroll (pH = 5.7). Scrubber sludge application rates ranged from 0 to 100 g sludge/kg soil. Dry matter production for 6 weeks of growth was depressed for barley and ryegrass when applications exceeded 12.5 g sludge/kg soil. Soil pH increased from 4.8 to 7.2 in the coarse sand and from 5.7 to 7.6 in the silt loam by applications of 100 g sludge/kg soil.

Yield reductions for barley and ryegrass were attributed to high concentrations of tissue B, which ranged from 12 µg/g on control treatments to 150 and 2,000 µg/g on soils receiving 6.25 and 100 g sludge/kg soil, respectively. Tissue Se increased with added sludge, while Mn and Zn contents decreased, without reaching toxic or deficiency levels, respectively. Tissue Cd, Cu, P, and Pb levels fluctuated from soil to soil and crop to crop without approaching deficiency or toxicity levels.
Effects of Nitrogen Dioxide on Algae
Authors: Wodzinski Richard S. , Alexander Martin
Published: July 2010

Photosynthetic activity of Anabaena flos‐aquae in a soil suspension at an initial pH of 4.9 was almost totally eliminated after 3 days of exposure to 5.0 ppm (µl/liter) NO2, at which time the pH had fallen to 3.9. In contrast, A. flos‐aquae in soil suspensions at an initial pH of 6.0 was not inhibited after 3 days by 5.0 ppm NO2, but the activity was reduced by half in the presence of 15.0 ppm NO2; the pH was 6.5 and 5.8, respectively, in the NO2‐treated samples on day 3. Photosynthesis by the green algae Chlamydomonas reinhardtii and Ankistrodesmus falcatus in soil suspensions at an initial pH of approx 4.2 was not appreciably affected by 15.0 ppm of NO2 after 3 days, at which time the pH had fallen below 4.0. The high levels of NO2 and low pH values required for toxicity suggest that blue‐green and green algae probably will not be affected directly by NO2 in polluted air.