bluuebunny/crossref_metadata_2025 huggingface dataset:
Saline Cooling Tower Water for Irrigation in Minnesota: II. Drainage Water Composition, Leaching Fraction, and Effect on Aquifer Quality
Authors: Engel R. E. , Malzer G. L. , Bergsrud F. G.
Published: July 2010

Saline cooling tower water (CTW) from the Sherburne County electrical power plant in Minnesota is being considered as an irrigation water source on surrounding croplands. Since the soils are coarse‐textured and this region receives an average 66 cm rainfall annually, salt will leach into the underlying aquifer. This study was undertaken to determine composition of drainage waters, leaching fractions (LF), and quality of the underlying aquifer (10–12 m) as affected by irrigation with CTW at two rates under three cropping systems.

In a 3‐yr field study (1979–1981), alfalfa (Medicago sativa L.), corn (Zea mays L.), and fallow plots were irrigated at rates that replaced net water deficits (I1) and twice the net water deficits (I2) in the cropped areas. The soil at this site was a Hubbard loamy sand (Udorthentic Haploboroll). Lysimeters, 57 cm in diam, were buried 150 cm below the plots to monitor the composition of the drainage waters and to determine the LF. Wells were installed in all plots to monitor deep movement of the CTW salts into the aquifer.

Application of CTW increased the concentration of Ca and SO4 in the drainage waters. These ions together comprised 70–75% of the total ion equivalents measured. Salt concentrations were generally higher under alfalfa than corn and fallow, reflecting its higher water requirement. Drainage waters were undersaturated with respect to gypsum; thus, SO4, added from the irrigation water stayed in solution. The LF under the I2 rate averaged 0.58. The LF under the alfalfa and corn (I1 rate) averaged 0.34 and 0.38, respectively. The LFs under the I1 rate were higher than anticipated. Apparently, even when irrigation was scheduled at a rate consistent with satisfactory crop growth, a considerable amount of water—and in turn salts—were lost from the soil profile due to heavy, erratic precipitation.

Salt concentrations in the aquifer increased greatly over the 3 yr. Sulfate concentrations peaked at 6.4 mmol L−1 in 1981, over 20 times greater than background levels and higher than U.S. Environmental Protection Agency drinking water standards.
Effect of Feedlot Runoff on a Southern Illinois Forested Watershed
Authors: Pinkowski R. H. , Rolfe G. L. , Arnold L. E.
Published: July 2010

Beef (Bos taurus) feedlot runoff was applied to an oak‐hickory (Quercus‐Carya) forested watershed to evaluate the effectiveness of the forest in removing and utilizing the added nutrients. Application followed the normal precipitation pattern and was, thus, variable in intensity throughout the year. Feedlot effluent additions averaged 261.1 m3 ha−1 over the 4‐yr study period. High percentages of total nutrient additions were retained by the watershed, but drainage water quality declined over the study period. An average of 99.8% of the added K, 99.4% of the PO4−3‐P, 99.2% of the Na, and 98.4% of the Ca and Mg were retained by the watershed. Nitrate‐N was the only nutrient showing a net loss, averaging 276% of the added NO3−‐N.

In the watershed runoff, NO3−‐N increased from a baseline mean of 0.83 mg L−1 to a treatment mean of 12.27 mg L−1. Phosphate‐P also increased from a baseline mean of 0.02 mg L−1 to a treatment mean of 0.88 mg L−1. Soil physical and chemical properties also changed as a result of the feedlot runoff input. Soil exchangeable cations and anions in the top 7.5 cm increased and bulk density decreased from 1.15 mg M−3 to 1.03 mg M−3. Maximum soil changes occurred within 30 m of the effluent discharge point.

Both tree and herbaceous plant species composition of the watershed also changed during the study period. Plant species composition became more similar to moist‐site communities and plant numbers decreased overall. Species characteristic of dry sites decreased in growth rate, while moist site species increased in growth.

Results of the experiment indicate that (i) a gravity flow system is an efficient and economical means of dispersing feedlot runoff through a forested watershed, (ii) feedlot effluent can be utilized as a nutrient supplement, and (iii) the vegetation of the oak‐hickory forest was an effective biological filter.
Boron Toxicity Characteristics of Four Northern California Endemic Tree Species
Authors: Glaubig B. A. , Bingham F. T.
Published: July 2010

A greenhouse study was undertaken to determine the characteristics of soil B toxicity for four tree species endemic to The Geysers area in northern California: digger pine (Pinus sabiniana Dougl. ex D. Don), California laurel (or, California bay) [Umbellularia californica (Hoo. & Arn. Nutt.)], madrone (Arbutus menziesii Pursh), and bigleaf maple (Acer macrophyllum Pursh). Significant exponential relationships were found between soil B concentration and relative growth, and between tissue B concentration and relative growth for the four species. Significant linear relationships were found between both soil and tissue B concentration and foliar damage for the four species. Foliar damages over 25% of the leaf or needle area on digger pine, California laurel, madrone, and bigleaf maple, respectively, occurred at saturated soil extract concentrations (mmol B/L) of 1.2, 0.4, 0.5, and 0.08. Twenty‐five percent foliar damage was associated with leaf or needle tissue concentrations (mmol B/kg) of 115, 100, 50, and 30 for the digger pine, California laurel, madrone, and bigleaf maple, respectively. Growth decrements of 25% occurred at saturated soil extract concentrations (mmol B/L) of 1.6, 0.3, 0.2, 0.5 for the digger pine, California laurel, madrone, and bigleaf maple, respectively. Twenty‐five percent growth decrements were associated with leaf or needle tissue concentrations (mmol B/kg) of 140, 100, 20, and 7 for the digger pine, California laurel, madrone, and bigleaf maple, respectively. By comparison with two agronomic crops—cotton (Gossypium hirsutum L.) and cowpea (Vigna unguiculata L.)—the four tree species were placed into one of six B tolerance classes.
Transport of Escherichia coli Through Intact and Disturbed Soil Columns
Authors: Smith M. S. , Thomas G. W. , White R. E. , Ritonga D.
Published: July 2010

The transport of antibiotic resistant Escherichia coli through several soils was evaluated. Up to 96% of the bacteria irrigated onto the surface of 280 mm deep intact columns were recovered in the effluent. Soil structure appeared to be related to the extent of transport. Columns prepared from mixed, repacked soil were much more effective bacterial filters than the intact soils. As rate of water input increased, the fraction of E. coli recovered in the effluent increased. The observed behavior of E. coli and the Cl− solution in which they were suspended suggests that flow through soil macropores, which bypasses the adsorptive or retentive capacities of the soil matrix, is a common phenomenon. In waste disposal systems dependent on purification in the soil profile, this could significantly increase the probability of groundwater contamination.
Persistence and Fate of 2,4‐D Butoxyethanol Ester in Artificial Ponds
Authors: Birmingham Brendan C. , Colman Brian
Published: July 2010

A granular formulation of the butoxyethanol ester of 2,4‐dichlorophenoxyacetic acid (2,4‐D) was applied at a rate of 23 kg a.i. ha−1 to outdoor, artificial, polythene‐lined ponds infested with Eurasian watermilfoil (Myriophyllum spicatum L.). Water temperature dropped from 25°C at time of treatment to 0°C after 56 d and the ponds were frozen over for the rest of the study. Samples of plant material, pond water, and sediment were taken over a 180‐d period, extracted, and analyzed by gas chromatography to determine residue concentrations of ester and 2,4‐D. Ester levels in water were low and dropped to < 1.0 µg L−1 within 15 d. Ester concentration in sediment 7 d post application was 1.7 µg g dry wt−1, but dropped to 0.1 µg g dry wt−1 after 42 d. 2,4‐Dichlorophenoxyacetic acid residues in water declined to 1.0 mg L−1 after 85 d and to 0.2 mg L−1 after 178 d. Residues in plant material dropped to 10 µg g dry wt−1 after 70 d; sediment residues were negligible after 50 d. Residues of 2,4‐dichlorophenol or 2,4‐dichloroanisole were not detected in any samples. Despite the low temperature prevailing in the latter half of the study, a relatively rapid rate of 2,4‐D breakdown was maintained both in pond water and sediment.
Identification of Phospholipids in Soils and Sewage Sludges by High‐Performance Liquid Chromatography
Authors: Stott D. E. , Tabatabai M. A.
Published: July 2010

A method was developed for identification of phospholipids in soils and sewage sludges. This method involves extraction of the phospholipids from soils or sewage sludges with a chloroform‐methanol mixture and analysis of an aliquot of the extract (10 µL) with a high‐performance liquid chromatograph coupled with a normal‐phase silica‐gel analytical column. The eluent used was a mixture of acetonitrile‐methanol‐phosphoric acid (vol/vol/vol, 260:12:3). Absorbance at 205 nm was used as a means of detection. The following phospholipids were identified in soil and sewage sludge samples: phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), and phosphatidyl serine (PS). The identities of the peaks were verified by standard additions technique and by two‐dimensional thin‐layer chromatography.

The concentration of lipid P in soils and sewage sludges ranged from 0.50 to 2.38 and from 38.2 to 330 mg kg−1, respectively. The amounts of PE and PC present in six soils ranged from 5.4 to 16 µg P kg−1 (avg = 10.1) and from 3.6 to 48 (avg = 20.9), respectively. The corresponding ranges for these phospholipids in six sewage sludge samples were 3.5 to 13 mg kg−1 (avg = 6.1) and 0 to 6.8 (avg = 3.6). The other phospholipids were not detected in most of the soil and sewage sludge samples studied.
Trace Metal Accumulations in Tissues of Goats Fed Silage Produced on Sewage Sludge‐Amended Soil
Authors: Bray B. J. , Dowdy R. H. , Goodrich R. D. , Pamp D. E.
Published: July 2010

Studies were conducted to document the impact of sewage sludge‐fertilized corn (Zea mays L.) on the feed and food chain under controlled experimental conditions that eliminated any direct ingestion of sewage sludge by animals. Accumulations of trace metals were measured in various tissues of dairy goats (Capra hircus) consuming corn silage that contained up to 5.3 mg Cd/kg and 113 mg Zn/kg, for 3 consecutive years.

The Cd concentrations in goat livers increased as the amount of silage‐borne Cd increased and reached a high concentration of 2.94 mg/kg. Kidney Cd concentrations were approximately 10 times greater than those observed in liver, ranging from 3 mg/kg for animals fed control corn silage to 22 mg/kg for those consuming silage grown on soil amended with the highest rate of sewage sludge. However, this concentration is an order of magnitude less than the critical level suggested for induction of renal dysfunction.

Kidney Zn ranged from 76.6 to 91.8 mg/kg with animals fed control silage having less Zn than animals fed sludge‐fertilized corn silage. Concentrations of Zn in livers did not differ among treatments. Copper concentrations in livers and kidneys were significantly lower (approximately 2 mg/kg) in animals receiving sludge‐fertilized silage than in animals fed control silage. The reduced Cu absorption may have been caused by a Cd and/or Zn metabolic interference.

The elemental concentrations of 12 other metals and minerals in goat liver and kidney were not affected by treatment. Similarly, elemental concentrations in heart and muscle were not affected by treatment.
Element Accumulation and Release by Macrophytes in a Wetland Stream
Authors: Peverly John H.
Published: July 2010

Aquatic macrophyte growth and element accumulation was measured seasonally for 1 yr in Oak Orchard Creek, NY, and compared with stream element loads. The stream flows from drained and cultivated wetland soils upstream into undisturbed wetlands downstream. The stream was calcareous and near saturation with CO2 most of the time. It was enriched with dissolved N, P, and K in both water and sediments, especially just below the cultivated area.

Plant biomass was greatest at the lower end of the wetlands in July, ranging up to about 600 g dry wt m−2 and consisting mostly of elodea (Elodea canadensis Michx.) and curlyleaf pondweed (Potamogeton crispus L.). Maximum net biomass accumulation rate was about 0.06 mg C m−2 s−1 for sago pondweed (Potamogeton pectinatis L.).

Element concentrations in plant tissues were above limiting levels and showed no definite relationship to season or species, although instream emergent plants showed a fall decrease in major nutrients (N, P, and K). Tissue nutrient concentrations were related to position in the stream, increasing as the nutrient concentrations increased in the water.

Maximum nutrient load contained by the plants occurred in July, which corresponded to the maximum standing crop. Potential contributions of major nutrients to the creek from plant senescence that occurred instream ranged from 10 to 100% in summer and fall. However, this contribution is 1 to 2% of total annual stream nutrient load.
Lettuce and Broccoli Response and Soil Properties Resulting from Tannery Waste Applications
Authors: Hemphill Delbert D. , Volk V. V. , Sheets P. J. , Wickliff C.
Published: July 2010

Broccoli (Brassica oleracea L. var. italica) and lettuce (Lactuca sativa L.) were grown on Willamette sil (Pachic Ultic Argixerolls) amended 1 and 2 yr earlier with chrome tannery wastes at rates up to 192 Mg ha−1 to determine nutrient and trace element availability. Soils were sampled at 0‐ to 15‐ and 15‐ to 30‐cm depths just before seeding the crops. Tannery waste increased soil pH, N, extractable Ca, B, and total Cr content and reduced soil extractable Mg and Fe content. Waste application had essentially no effect on soil K, P, S, Zn, Mn, Cu, Ni, Pb, Cd, and Mo content. The N concentration of lettuce grown on waste‐amended soil was higher than that of lettuce grown on untreated soils. Tannery waste did not consistently affect plant tissue concentrations of other nutrient or trace elements, including Cr. Yields of both crops increased when grown on tannery waste‐amended soil and were approximately equal to the yields obtained when commercial N fertilizer was applied at 112 kg N ha−1. This suggests that significant quantities of waste organic N were mineralized and made available. With proper safeguards, tannery waste may be an effective and safe crop fertilizer, and disposal on agricultural land may be an acceptable alternative to landfilling or trenching.
Release of Nutrients and Metals Following Oxidation of Freshwater and Saline Sediment
Authors: DeLaune R. D. , Smith C. J.
Published: July 2010

Mississippi River deltaic sediments were collected from freshwater and adjacent saline environments along Louisiana's Gulf Coast to evaluate chemical changes that may develop when bottom sediment from different salinity regimes with contrasting levels of reduced S are exposed to anoxic environment. Chemical transformations of the dredged sediments were influenced by changes in the sediment‐water pH and oxidation‐reduction status. Sediment pH decreased as the redox potential (Eh) was increased in both the freshwater and saline sediment. Both sediments had near‐neutral pH when maintained under anoxic conditions and the minimum pH developed under oxic conditions was 5.1 and 3.0 for the freshwater and saline sediment, respectively. The acidity developed in the saline sediment resulted in the release of the potentially toxic metals Pb, Cu, Ni, Cr, Cd, and Sb into solution. There was also an increase in the solution concentration of Fe, Mn, Al, and Se. The solution concentration of these elements was inversely proportional Eh (P ≤ 0.05). The freshwater sediment when exposed to oxic conditions showed no increase in the solution concentrations of these elements. Results suggest that the concentration of reduced S in anoxic dredged sediment along other areas of the Gulf Coast should be closely evaluated in relation to potential acidity before subjected to upland disposal.
Sediment and Nutrient Export in Runoff from Burned and Harvested Pine Watersheds in the South Carolina Piedmont
Authors: Van Lear D. H. , Douglass J. E. , Cox S. K. , Augspurger M. K.
Published: July 2010

Soil and nutrient export in ephemeral flow were studied over a 3‐yr period following clearcutting three loblolly pine (Pinus taeda L.) watersheds (0.60–1.24 ha). Two preharvest, low‐intensity prescribed fires had no effect on flow or water quality. Harvesting after the third prescribed fire significantly increased sediment concentration and export, but increases were minor compared with sediment export reported for mechanical site preparation. Nutrient concentrations varied among watershed locations because of differences in surface soil depth, but were generally unaffected by harvest. Because harvest increased runoff, nutrient export (concentration × flow) was generally increased. Results of this study show that loblolly pine stands in the erosive Piedmont physiographic region can be harvested following a series of low‐intensity prescribed fires with minimal soil loss or degradation of water quality.
Yields and Leaf Elemental Composition of Cotton Grown on Sludge‐Amended Soil
Authors: Watson J. E. , Pepper I. L. , Unger M. , Fuller W. H.
Published: July 2010

A 3‐yr field study was conducted to determine the effects of land application of anaerobically digested, air‐dried sewage sludge on growth of upland cotton (Gossypium hirsutum L.). Cotton lint yields obtained with sludge rates from 20 to 80 Mg/ha were comparable with those obtained by area farmers employing conventional fertilizer practices. Rates of 80 Mg/ha had no significant effect on lint yields, although lint/seed ratios tended to decrease with increased sludge rate for all years. After 3 yr of sludge application, the leaf and seed concentrations of Cd, Zn, Ni, and Cu were not significantly different from those on the fertilized check plots. Leaf concentrations of Cd were higher than seed concentrations, but the reverse trend was true for Zn, indicating that Zn may not be directly useable as a model for Cd behavior in cotton.
Mineral Content of Sphagnum Mosses in Belgian Bog Ecosystems
Authors: Lembrechts J. F. M. , Vanderborght O. L. J.
Published: July 2010

The concentrations of 11 elements (Na, K, Ca, Mg, Al, Fe, P, Cu, Mn, Pb, and Zn) were determined in nine Sphagnum species, collected in minerotrophic and ombrotrophic bogs in northern (“De Antwerpse Kempen”) and eastern (“Les Hautes Fagnes”) Belgium. The concentrations of all elements, except Ca, Zn, and Mn, were positively related to the moistness of the habitat. Differences in the behavior of the individual elements are explained by differences in origin, physical properties, and biological importance. The Ca and Cu levels were lower in “Les Hautes Fagnes” due to differences in air pollution (Cu) or trophic status of the sampling sites (Ca). The concentrations of all elements, except Ca, Mg, and Mn, exceeded those of Sphagnum from Canada and Scandinavia, probably indicating a higher trophic status or a higher industrial and agricultural pollution level in the areas investigated.
Reaction of Fertilizer and Liquid Manure Phosphorus with Soil Aggregates and Sediment Phosphorus Enrichment
Authors: Bhatnagar V. K. , Miller M. H. , Ketcheson J. W.
Published: July 2010

Phosphorus enrichment ratios (PER) were estimated for sediment from six runoff events from plots that had been under one of three management systems for at least 5 yr: no‐till (NT), no‐till manured (NTM), and fall plowed manured (FPM). Sodium bicarbonate‐extractable P enrichment ratios (Ext‐PER) in sediment were 2.15, 1.30, and 1.10 for NT, NTM, and FPM treatments, respectively. The higher Ext‐PER on the NT treatment could not be explained solely by a higher clay enrichment.

A laboratory experiment was conducted to test three hypotheses developed to explain the difference in Ext‐PER values. Phosphorus in the form of either inorganic salt (KH2PO4) or liquid poultry manure (chicken, Gallus gallus domesticus) was added to soil at rates up to 400 mg P kg−1. Soils were passed through 7‐d wetting and drying cycles for 235 d and sampled periodically. Most of the added P from both the manure and inorganic P treatment was associated with the clay fraction. The proportion of P that was desorbable increased as the amount of P added increased. This may, in part, explain the lower Ext‐PER on the manured plots, which had a greater amount of P added. Manure increased water stability of soil aggregates. In addition, the Ext‐P concentration in water‐stable aggregates from the manure treatment increased with increasing aggregate size, whereas the inorganic P source had no effect. Manure did not alter the size distribution of dry‐sieved aggregates, but Ext‐P was increased to a greater extent in the larger aggregates, indicating that there was a preferential sorption of manure P by larger‐sized aggregates. This conclusion was supported by results from a small field trial. The preferential sorption of P from liquid manure by larger, more stable aggregates may result in a lower Ext‐PER in sediment from manured fields.
Effect of Some Coal Gasification and Tar Sand Process Waters on the Viability of Indicator Bacteria of Fecal Contamination
Authors: Adams J. C.
Published: July 2010

This research was undertaken to determine if a spill of either coal gasification or tar sand process waters could have detrimental effects on the numbers of indicator bacteria in receiving waters. The objectives were (i) to determine the effect of mixing process waters with “natural” waters on the numbers of fecal coliforms and fecal streptococci after storage of these mixtures at 4 and 20°C, (ii) to determine if the growth phase at the time of exposure was important to the survival of Escherichia coli, and (iii) to determine the importance of pH in the toxicity of a process water. Addition of 10% (vol/vol) of one coal gasification water to river water resulted in approximately 90% reduction in numbers of fecal coliforms within 5 h of storage at 4°C, whereas there was a 65% reduction during this time when storage was at 20°C. An additional coal gasification water and two tar sand process waters were not toxic to fecal coliforms. Survival of fecal streptococci was not adversely affected in any of the waters. Stationary phase cells of E. coli were killed within 5 h of exposure to a 10% concentration of Hanna IV B‐1 coal gasification water, whereas lag and exponential phase cells were unaffected during this exposure time. Further, after 24 h of exposure, 40% of the lag phase cells were viable, while live cells from the other two phases of growth were reduced by 99.9%. There was a 12% reduction in viable cells of E. coli after 120 h of exposure to a 10% concentration of Hanna IV B‐1 process water adjusted to pH 7.0. In contrast, during this same time period there was a 5 log reduction in viable cells that were exposed to the process water (pH 8.6), which had not been neutralized.
Sediment, Season, and Salinity Effects on Phosphorus Concentrations in an Estuary
Authors: Kunishi H. M. , Glotfelty D. E.
Published: July 2010

A 4‐yr study was made to better understand nonpoint‐source inputs of P into the Wye River—a shallow, well‐mixed estuary of the Chesapeake Bay. Water and sediment samples were taken periodically from along the length of the river and from the main freshwater tributary. Phosphorus forms and concentrations in solution were measured and P sorption isotherms were determined from sediment samples.

Molybdate‐reactive P concentrations were highest during the summer in the uppermost reaches of the river under tidal influence and decreased with increasing salinity downstream. Molybdate‐reactive P concentrations in the river thus appeared to depend on the season and to indicate that increasing temperatures promote P release from sediment and P mineralization by benthic and other marine organisms. In addition, molybdate‐reactive P in the river was released from sediment when fresh water from a tributary diluted the divalent cation concentration of the brackish water. Best‐management farm practices to reduce the loss of P by runoff would not be expected to markedly lower the concentration of molybdate‐reactive P in the river.
Effect of Sewage Sludge on Microbial Activity in an Old, Abandoned Minesoil
Authors: Stroo H. F. , Jencks E. M.
Published: July 2010

The effect of lime, fertilizer, and sewage sludge (50 and 100 kg ha−1) upon microbial activity and growth of sparsely distributed tall fescue (Festuca arundinaceae Schreb.) on an old, acidic, infertile sandy loam (Typic Udispolents; loamy‐skeletal, mixed, acid, mesic) minesoil was evaluated. Respiration rate and activities of amylase, urease, and phosphatase were used as indices of microbial activity. When compared with the control, lime significantly increased respiration rate, had no affect upon amylase and urease activities, and significantly reduced phosphatase activity. Fertilizer significantly increased respiration rate and amylase activity, but significantly decreased urease activity. Phosphatase activity was not affected by fertilizer applications. Lime plus fertilizer significantly increased respiration rate and amylase activity, had no affect upon phosphatase activity, while it drastically reduced urease activity. Sludge at both rates of application in conjunction with lime and fertilizer (S1LF, S2LF) are only compared with the lime‐fertilizer treatment. Both S1LF and S2LF significantly increased respiration rate and urease activity; S2LF was significantly more effective than S1LF. Amylase activity was significantly increased by both S1LF and S2LF, although there was no difference between the two treatments. The S1LF had no affect upon phosphatase activity, whereas S2LF caused a significant activity increase. All treatments produced significant increases in tall fescue yield. Fertilizer was significantly more effective than lime. The fertilizer and the lime‐fertilizer treatments were about equally effective. Both S1LF and S2LF produced yields that were significantly greater than the lime‐fertilizer treatment. The S2LF had a significantly greater effect upon yield than did S1LF.
Lead Distribution and Fluxes in a High‐Elevation Forest in Northern Vermont
Authors: Friedland A. J. , Johnson A. H.
Published: July 2010

High‐elevation forests receive large amounts of atmospheric lead (Pb) and accumulate it in the forest floor. In order to determine Pb partitioning in a montane, coniferous forest, we analyzed forest floor and mineral soil (Haplorthods and Fragiorthods), and vegetation parts (leaves, twigs, bark, wood) for their Pb content. Soil and stream water were sampled to estimate Pb flux. Mean Pb concentration in trees, in mg kg−1, was root bark (33.0), twigs (28.3), bark (23.0) > root wood (10.4) > foliage (3). wood (3). Total Pb in above‐ground biomass (trees + shrubs + herbs) was 0.89 kg ha−1. Lead in the organic horizon (forest floor) was 20 kg ha−1 while Pb in the mineral horizon (E + B) was 63 kg ha−1.

Monitoring of soil water for one year yielded volume‐weighted mean Pb concentrations of 3.7, 1.8, 1.1, and 1.0 µg L−1 at 3‐, 12‐, 25‐, and 40‐cm depth, respectively. Stream Pb concentration averaged 0.6 µg L−1. We estimated annual Pb input of > 700 g ha−1 yr−1. Estimated output from the forest in stream water was < 12 g ha−1 yr−1. Annual accumulation in the forest floor is approximately 3% of the current forest floor Pb amount. At current accumulation rates, forest floor Pb amount will double in 30 to 40 yr. At current leaching rates, mean residence time of Pb in the forest floor is approximately 500 yr. The ratio of Pb input to output for the forest is 60:1.
Potentials of Cassava Peels as a Soil Amendment: II. Field Evaluation
Authors: Agbim N. N.
Published: July 2010

The effect of cassava (Manihot esculenta Crantz) peels (CP), applied in different proportions with poultry droppings (PD) (chicken, Gallus gallus domesticus), on the growth of a root crop variously named cocoyam, taro, dasheen, and eddo [Colocasia esculenta (L.) Schott] was evaluated in the field over a 4‐yr period, which included 1 yr of fallow. The treatments 100% CP‐0% PD; 75% CP‐25% PD; 50% CP‐50% PD; 25% CP‐75% PD; and 0% CP‐100% PD were each applied at the rates of 0, 10, 25, and 50 Mg ha−1. At 10 Mg ha−1 the CP‐PD mixtures increased yield by 559, 328, and 311%, respectively, for the 1979, 1980, and 1982 croppings, thus emphasizing the value of the amendment. Significant increases in yield (P < 0.01) were obtained each year for each increment in rate. The mean yields (Mg ha−1) of 2.20, 5.09, and 2.40, respectively, for 1979, 1980, and 1982 demonstrate the residual benefit from these wastes after their incorporation into the soil. After 2 yr, treatment had no sustained effect on residual soil N. Residual (extractable) soil P increased from 11 mg kg−1 with 100% CP to 89 mg kg−1 with 75% CP‐25% PD, thus showing the relatively low and high potentials, respectively, of CP and PD for increasing soil P. Since the availability of PD is considerably less than CP, a 75% CP‐25% PD mixture at 25 Mg ha−1 was deemed appropriate for most efficient utilization of the wastes. At 10 Mg ha−1 of CP, total yield over 3 yr was also increased by 139%. With treatments containing PD, the corresponding yield increases were in the range 275 to 568%. Thus, while CP was a good soil amendment, there was need to incorporate PD with it to maximize yield.
Growth and Heavy Metal Accumulation in Pine Seedlings Grown with Sewage Sludge
Authors: Berry C. R.
Published: July 2010

Loblolly pine seedlings were grown in microplots amended with 34 or 68 Mg ha−1 of one of five sewage sludges; (i) old sludge from Athens, GA, (ii) fresh sludge from Athens, GA, and sludges of undetermined age (ii) from Aikens, SC, (iv) from Newberry, FL, and (v) from Chicago, IL. Newberry sludge and fresh Athens sludge supported growth comparable to the inorganic fertilizer control. Seedlings grown with Chicago sludge grew well at the 68 Mg ha−1 rate (23.6 cm in height, 4.2 cm in root collar diameter and weighing 8.3 g) but were not as large as those grown with fertilizer (22.8 cm in height, 5.3 cm in root collar diameter and weighing 12.2 g). Seedlings grown with old Athens or Aiken sludge did not grow well and most of them were not of plantable size (i.e. 15 cm in height and 3.5 mm in root collar diameter). Pisolithus tinctorius did not form ectomycorrhizae on seedlings grown with the sludges as well as on seedlings grown with fertilizer (in most cases < 23% of short roots compared to 63% for controls). Thelephora terrestris formed ectomycorrhizae as readily on seedlings grown with the sludges as those grown with fertilizer when inoculation with the fungus was artificial; natural ectomycorrhizae, however, did not form as readily with some sludges as with fertilizer. When grown with Chicago sludge, roots, stems, and needles of seedlings had significantly more cadmium (two‐ to fourfold) than seedlings grown with other sludges. Poor growth of seedlings grown in old Athens sludge is assumed to be due to deficiencies of macronutrients, since fresh Athens sludge supported good growth. With Aiken sludge and to a lesser degree, Chicago sludge, toxicity of heavy metals is considered to be a possible factor contributing to poor seedling growth.
Using CREAMS and Economic Modeling to Evaluate Conservation Practices: An Application
Authors: Crowder Bradley M. , Pionke Harry B. , Epp Donald J. , Young C. Edwin
Published: July 2010

Economic modeling of the impacts of soil loss from agricultural activities traditionally has been based on the Universal Soil Loss Equation (USLE). Most studies have not considered the effects of agricultural production on N, P, and pesticides in runoff. This study, involving a representative Pennsylvania dairy farm, uses the CREAMS model (Chemicals, Runoff, and Erosion from Agricultural Management Systems) to estimate surface runoff losses of soil, plant nutrients, and pesticides. The CREAMS is a continuous simulation model that allows the user to compare the effectiveness of management practices for reducing these losses in a consistent and comprehensive tices for reducing these losses in a consistent and comprehensive manner. The usefulness of the CREAMS simulation model is demonstrated for analysis of agricultural cropping activities and their impacts on losses of chemicals and soil in runoff. Linear programming was used to simulate the impacts of farm‐level water pollution restrictions on farm income. The findings suggest that nonpoint source pollution can be reduced without necessarily reducing farm income. Farm income levels could be maintained by adopting conservation tillage practices or by changing crop rotation. Conservation tillage was found to be the most effective method for maintaining income when water pollution restrictions were imposed. Two years of corn (Zea mays) followed by 3 yr of alfalfa (Medicago sativa) was a profitable and effective rotation for controlling runoff losses. Continuous corn, at the other extreme, caused substantial losses of income when restrictions were imposed.
Effect of Temperature Control on the Composting Process
Authors: Sikora L. J. , Sowers M. A.
Published: July 2010

Aeration is a method for controlling temperature in composting of organic materials so that microbial activity can be optimized. To determine the conditions for optimum composting, two studies were conducted using a self‐heating laboratory composter in which aeration at two constant rates was evaluated and aeration at constant rate vs. aeration in response to temperature was evaluated. A mixture of raw, limed sewage sludge and woodchips (v/v, 1:1.8) was composted and CO2‐C and wet and dry weight losses were recorded. Numbers of thermophilic bacteria, fungi, and actinomycete were determined in the mixture before and after composting. Comparison of composting at rapid constant aeration rates of 900 and 1800 m3 h−1 Mg−1 indicated no difference in losses of CO2‐C, NH3‐N and moisture in composting runs of 12 and 14 d. Single peak temperatures between 60 and 68°C were recorded. In comparing constant aeration with that of temperature response, twice as much moisture was lost and 2.5 times as much CO2‐C evolved from the latter where temperatures were not allowed to exceed 55°C. Because both dry weight and N losses were increased similarly in the temperature response system, the final total N content of the compost was near that of the compost resulting from the constant aeration system. The total number of thermophilic microorganisms was greater in the final compost from the temperature response study, but more significantly, the population of fungi was substantially larger than in the compost from the constant aeration study. Control of composting by adjusting aeration in response to temperature as opposed to composting by constant aeration resulted in a drier, more stabilized compost for agricultural or horticultural use.
Toxaphene, Methyl Parathion, and Fenvalerate Disappearance from Cotton Foliage in the Mid‐South
Authors: Willis G. H. , Mc Dowell L. L. , Southwick L. M. , Smith S.
Published: July 2010

Insecticide foliar‐persistence data are needed for the development and refinement of predictive models concerning pesticide loss from agricultural ecosystems. Toxaphene (chlorinated camphene), methyl parathion [O,O‐dimethyl O‐(p‐nitrophenyl) phosphorothioate], and fenvalerate [(RS)‐α‐cyano‐3‐phenoxybenzyl (RS)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate] were field‐applied by ground equipment to mature cotton (Gossypium hirsutum L.) in northern Mississippi at rates of 2.30, 1.15, and 0.11 kg ha−1, respectively. Pesticide loads on the plants were measured periodically for 146 h following application. Air temperature, windspeed, and relative humidity were also measured during the study. About 92, 76, and 66% of the applied toxaphene, methyl parathion, and fenvalerate, respectively, were intercepted by the cotton plants. The calculated 50% disappearance times for toxaphene, methyl parathion, and fenvalerate were 17.6, 2.4, and 79.4 h, respectively.
Fate of Di‐2‐(ethylhexyl)phthalate in Three Sludge‐amended New Mexico Soils
Authors: Fairbanks B. C. , O'Connor G. A. , Smith S. E.
Published: July 2010

Di‐3‐(ethylhexyl)phthalate (DEHP) is toxic organic of concern limiting the reuse of sewage sludge on agricultural lands. The degradation, volatilization, and adsorption of DEHP‐14C were monitored in three calcareous soils from New Mexico amended or unamended with sewage sludge. Evolution of 14CO2 was the only mechanism of loss of DEPH from these soils. No volatilization of parent compound or organic metabolites was detected. The effects of sewage sludge on DEHP degradation varied with soil, DEHP concentration, and sludge incubation time. As a result, 50% disappearance time varied from 8 to 72 d, depending on treatment interactions. After 146 d, 76 to 93% of the DEHP‐14C was evolved as CO2. In general, DEHP persistence was reduced by previous exposure of the soil to sludge, but was increased or unaffected by fresh additions of sludge. Increasing DEHP concentration from 2 to 20 mg kg−1 soil increased DEHP persistence. Degradation of DEHP was greater in two sandy loams (Typic Haplargids and Petrocalcic Paleustolls) than in a clay soil (Typic Torrifluvents). Preliminary data suggest extensive adsorption of DEHP by all soils with no effect of sewage sludge additions.
Herbicide Residues from Winter Wheat Plots: Effect of Tillage and Crop Management
Authors: Brown David F. , Mc Cool Donald K. , Papendick Robert I. , Mc Donough Leslie M.
Published: July 2010

Data on the magnitude and persistence of residues of metribuzin (4‐amino‐6‐t‐butyl‐3‐(methylthio‐1,2,4‐triazine‐5‐(4H)‐one and bromoxynil octanoate (2,6‐dibromo‐4‐cyanophenyl octanoate) in soils and runoff water from winter wheat (Triticum aestivum L.) fields were collected on plots managed with different tillage and crop rotation systems during three seasons from 1978 to 1982. On steeply‐sloped runoff plots, the greatest runoff, erosion, and losses of herbicides occurred on plots that were planted in winter wheat after summer fallow and were tilled conventionally. The lowest erosion and herbicide losses were observed on plots directly seeded in winter wheat stubble without tillage, whereas the relative effectiveness of the other systems depended on the year, the volume of runoff, and the type of runoff events. Wheat residue from the previous crop was more effective than pea (Pisum sativum L.) residue in reducing erosion and herbicide losses, mainly because of the greater quantities of wheat residues produced. Compared to runoff of herbicides under summer conditions in the southeastern USA, runoff of herbicides under winter conditions in Eastern Washington was greatly extended, and there was very little movement or degradation of the herbicides while the ground was frozen. The half‐life of metribuzin in soil was 102 to 112 d (k = 0.0069 × 0.0062 d−1), but insufficient data were obtained to calculate the half‐life of bromoxynil octanoate. The disappearance of bromoxynil octanoate and bromoxynil (2,6‐dibromo‐4‐cyanophenol) from soil plots was rapid; only traces of bromoxynil octanoate or bromoxynil were present after 72 d under winter conditions. Small amounts of metribuzin and desaminodiketo metribuzin (DADK) moved down as far as 21 cm in the soil. Less than 0.060 µmol kg−1 of metribuzin and less than 0.015 µmol kg−1 DADK remained in the top 7 cm of soil 192 d after application of 0.43 to 0.56 kg ha−1 of metribuzin.
Self‐Sealing of Earthen Liquid Manure Storage Ponds: I. A Case Study
Authors: Miller M. H. , Robinson J. B. , Gillham R. W.
Published: July 2010

A monitoring system was established on an unlined, earthen storage pond near Kitchener, ON prior to the addition of liquid manure from a 4500‐head beef (Bos taurus) feeding operation. The bottom of the pond, which had a surface area when full of 2 ha, was a coarse textured sand. This material, with some gravel layers, extended below the water table, which was initially at 13.7 m below the ground surface. A platform, at which soil moisture measurement and groundwater sampling tubes were installed, was constructed within the pond. Additional groundwater sampling tubes were installed at several points surrounding the pond. Moisture content of the soil immediately below the pond reached saturation when liquid manure was first added but began to decrease within 2 weeks and reached a steady state at a water potential of about −0.03 MPa within 90 d. The infiltration rate at this time was estimated to be less than 10−8 m s−1, a value considered to indicate that the bottom was effectively sealed. There was a rapid increase in Cl content of the groundwater within 2 weeks of manure addition but the concentration declined to initial values within 12 weeks. There was no evidence of elevated Cl concentrations in groundwater outside the boundaries of the pond. The NO3‐N content of groundwater below the pond decreased to non‐detectable values very shortly after addition of manure but returned to background values within 12 weeks except in the upper portions of the groundwater. A similar depression of NO3‐N was observed at one sampling position within a few meters of the pond but not at more distant points. It was concluded that the NO3‐N depression was due primarily to denitrification in the groundwater as it passed below the pond. It is concluded that, with some limitations, unlined earthen manure ponds are environmentally acceptable, even in sandy material.
Self‐Sealing of Earthen Liquid Manure Storage Ponds: II. Rate and Mechanism of Sealing
Authors: Rowsell J. G. , Miller M. H. , Groenevelt P. H.
Published: July 2010

A laboratory study was conducted to determine the degree and rate of sealing of the soil surface where liquid beef (Bos taurus) manure with solids content of 50 g kg−1 was infiltrated into cores of a sandy loam, a loam, and a clay soil under hydraulic heads of 1 and 5 m. A second experiment explored the mechanism of sealing. The infiltration rate was expressed in the logarithmic form of the Kostiakov equation: log q = A + b log t where q = infiltration rate (m s−1) and t = time (s). In this relation A represents the log of the initial infiltration rate (at 1.0 s) and b is the rate of change in rate with time on a logarithmic scale. The infiltration rate decreased rapidly with time and reached a value of 10−8 m s−1 or less within 30 d on all soils at 1‐m hydraulic head. This rate is considered to indicate an essentially impermeable system. At a 5‐m head the infiltration rate reached 10−8 m s−1 within 10 d on the clay soil but required periods > 30 d on the other two soils. A physical blocking of pores was the major mechanism of sealing. The rate of reduction of infiltration into the loam soil was similar for sterilized manure indicating that in this study biological activity was not a factor. Infiltration of a salt solution having similar cationic constituents as the manure remained constant over time indicating that dispersion of soil particles was not a factor.
Groundwater Quality Changes Resulting from a Surface Bromide Application to a Pasture
Authors: Owens L. B. , Van Keuren R. W. , Edwards W. M.
Published: July 2010

Potassium bromide was applied at a rate of 168 kg Br−/ha to two 1.1‐ha pasture watersheds in east‐central Ohio to study the impacts on groundwater quality of a one‐time application of a soluble constituent. The watersheds had well‐drained residual silt loam soils and average slopes of about 20%. A nearly impermeable clay layer under the watersheds created a perched aquifer from which groundwater samples could be taken at developed springs. Three monolith, grassed lysimeters having soil profiles similar to the watersheds also received the Br−1 treatment. The lysimeters, which were 8 m2 in surface area and had a depth of 2.4 m, had shorter leaching pathways than the watersheds and showed peak Br−1 concentrations in percolation (24.0 mg/L maximum peak) occurring 52–78 weeks following the Br−1 application. The Br−1 concentration in the groundwater from the watersheds had lower peaks (9.2 mg/L maximum peak) but occurred 84 to 104 weeks after the Br−1 application. Because of variable leaching pathway lengths, including pathways much longer than those in the lysimeters, the watershed groundwater Br−1 applications had shown no meaningful decrease by 2 yrs after the Br−1 application. A one‐time application of a soluble, nondegradable chemical constituent can have a multi‐year influence on groundwater quality.
Comparative Toxicology of Laboratory Organisms for Assessing Hazardous Waste Sites
Authors: Miller W. E. , Peterson S. A. , Greene J. C. , Callahan C. A.
Published: July 2010

Multi‐media/multi‐trophic level bioassays have been proposed to determine the extent and severity of environmental contamination at hazardous waste sites. Comparative toxicological profiles for algae (Selenastrum capricornutum), daphnia (Daphnia magna), earthworms (Eisenia foetida), microbes (Photobacterium fisherii, mixed sewage microorganisms) and plants; wheat “Stephens,” (Triticum aestivum), lettuce, butter crunch, (Lactuca sativa L.), radish, “Cherry Belle,” (Raphanus sativa L.), red clover, “Kenland,” (Trifolium pratense L.) and cucumber, “Spartan Valor,” (Cucumis sativa L.) are presented for selected heavy metals, herbicides and insecticides. Specific chemical EC50 values are presented for each test organism. Differences in standard deviations were compared between each individual test organism, as well as for the chemical subgroup assayed. Algae and daphnia are the most sensitive test organisms to heavy metals and insecticides followed in order of decreasing sensitivity by Microtox (Photobacterium fisherii), DO depletion rate, seed germination and earthworms. Higher plants were most sensitive to 2,4‐D, (2,4‐Dichlorophenoxy acetic acid) followed by algae, Microtox, daphnia and earthworms. Differences in toxicity of 2,4‐D chemical formulations and commercial sources of insecticides were observed with algae and daphnia tests.
Wood Residue and Fertilizer Amendment of Bentonite Mine Spoils: I. Spoil and General Vegetation Responses
Authors: Smith J. A. , Schuman G. E. , De Puit E. J. , Sedbrook T. A.
Published: July 2010

Bentonite mine spoils in the northern Great Plains are difficult to rehabilitate and manage because of extreme saline‐sodic conditions and high percentage of 2:1 expanding clays. Wood residue and N fertilizer amendments have been shown to promote vegetation establishment on bentonite mine spoils. This study was conducted to determine wood residue and N fertilizer levels necessary to revegetate these mine spoils. Treatments included 0, 45, 90, and 135 Mg ha−1 of dry ponderosa pine wood residue and N fertilizer rates of 0, 2.5, 5.0, and 7.5 kg N Mg−1 of residue. A uniform P fertilization rate of 90 kg P ha−1 was used across all treatments. The greatest increase in seeded plant density, canopy cover and aboveground biomass occurred at 90‐Mg ha−1 wood residue fertilized at 2.5 kg N Mg−1 of residue. Spoils amended at these levels exhibited a mean first‐year plant density of 59 seedlings m−2, second‐year plant canopy cover of 67% and second‐year plant biomass (dry weight) of 2060 kg ha−1 compared to the zero wood residue treatment which had a plant density of 14 seedlings m−2, 8% plant canopy cover, and 80‐kg ha−1 plant biomass.