bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant Uptake of Cadmium from Acid‐extracted Anaerobically Digested Sewage Sludge
Authors: Logan Terry J. , Feltz Robert E. 
Published: July 2010

AbstractApproximately 80% of the Cd in an anaerobically digested sewage sludge (initially containing 11.6 mmol Cd kg−1) was removed by acid extraction and dewatering. The acid extracted sludge was treated by (i) neutralization to pH 5.9 with Ca(OH)2, (ii) addition of monocalcium phosphate (MCP) followed by Ca(OH)2 neutralization to pH 5.9, and, (iii) addition of rock phosphate (RP) followed by Ca(OH)2 neutralization to pH 5.9. The three treated sludges and the non acid‐extracted sludge (aerated prior to application to soil) were applied to Spinks loamy sand (sandy, mixed, mesic, Psammentic Hapludalfs) at rates equivalent to 18.7 and 37.4 µmol Cd kg−1. Swiss chard (Beta vulgaris) was grown in the greenhouse for 56 d. Cadmium, Fe, Ca, and P were measured in saturation extracts of treated soil at 0, 4,18, 39, and 60 d after sludge addition. These data indicated that hydroxyapatite was stable throughout the study in the soil receiving MCP treated sludge but not in other soil treatments. Cadmium concentration in saturation extracts of the soil with MCP sludge decreased below the detection limit of 1.8 × 10−10 mol L−1 by day 4 at the 37.4 µmol Cd kg−1 application rate, while Cd concentrations in saturation extracts of the other sludge treatments were much higher throughout the study. Chard yields were higher in the control than in any of the sludge treatments, and the difference was attributed to greater N availability in the control. Cadmium concentration in Swiss chard tissue at harvest was significantly lower from the MCP sludge than from the other sludges. Cadmium concentration in chard tissue was also higher from the aerated sludge (11.9 mmol Cd kg−1) than from the three acid‐extracted sludges (2.58–3.29 mmol Cd kg−1). No significant difference in the Cd concentration of chard was obtained for the 18.7 and 37.4 µmol Cd kg−1 rates of the MCP sludge, while Cd concentrations in chard increased linearly with Cd applied by the other sludges.
Environmental Effects on Metsulfuron and Chlorsulfuron Bioactivity in Soil
Authors: Anderson R. L. 
Published: July 2010

AbstractMetsulfuron {2‐[[[[(4‐methoxy‐6‐methyl‐1,3,5‐triazin‐2‐71)amino] carbonyl]amino]sulfonyl]benzoic acid}, a sulfonylurea herbicide, is persistent in soil and may injure susceptible crops. To elucidate potential carryover situations, the effect of environment and soil factors on metsulfuron bioactivity was examined in a Platner loam (fine, montmorillonitic, mesic, Aricidic Paleustolls) and a Valent sand (mixed, mesic Ustic Torripsamments) soil with a corn (Zea mays L.) root bioassay. Increasing soil temperature from 8 to 24°C in the loam soil reduced the duration of metsulfuron bioactivity by 49%. The temperature effect on metsulfuron bioactivity in the sand was less pronounced, as the 16°C increase resulted in only 20% reduction of duration of bioactivity. The effect of soil water content on metsulfuron bioactivity was soil and temperature related. Increasing soil water increased metsulfuron degradation in the sand at 24°C, but not at 16°C, while in the loam, metsulfuron degradation was not affected by soil water level at either temperature. Incorporating metsulfuron in soil reduced the duration of bioactivity, while the presence of growing wheat (Triticum aestivum L.) plants in metsuifuron‐treated soil did not affect the duration of bioactivity. Metsulfuron retained on surface straw residue was washed off by simulated rainfall, but duration of metsulfuron bioactivity was increased by this straw residue retention. Chlorsulfuron {2‐chloro‐N‐[[(4‐methoxy‐6‐methyl‐1,3,5‐triazin‐2‐yl) amino]carbonyl]benzenesulfonamide}, another sulfonylurea herbicide, persisted slightly longer than metsulfuron at the same rate in both soils when incubated at 16°C with identical soil water levels.
Crop Response to Soil Applications of Phosphogypsum
Authors: Mays D. A. , Mortvedt J. J. 
Published: July 2010

AbstractPhosphogypsum (PG), a by‐product of the phosphate industry, was incorporated with soil to determine effects of land disposal on crop growth and uptake of cadmium (Cd) and radium (Ra). Application rates of PG were 0, 22, and 112 Mg ha−1. Soil was cropped sequentially with corn (Zea mays L.), wheat (Triticum aestivum L.), and soybeans [Glycine max (L.) Merr.] over a 1–5‐yr period. Yields of corn were decreased at the high PG rate, apparently because of a physiological calcium‐magnesium (Ca‐Mg) imbalance, but yields of wheat and soybeans were not affected by PG application. Concentrations of nutrient elements and Cd in the grain of each crop were not affected by PG application; the Cd concentration of Pg was 0.23 mg kg−1. Radiological assay of grain samples showed no increase in 226Ra radioactivity in any of the three crops due to PG application; PG contained 925 Bq kg−1 (25 nCi kg−1) of radioactivity. Analyses of soil after soybean harvest showed that the level of radioactivity in the surface 15‐cm layer increased from 35 Bq kg−1 in the control treatment to 73 Bq kg−1 at the high PG rate; the radioactivity level in the subsurface layer was not affected. These results suggest that PG may be applied to agricultural soils at relatively high disposal rates without increasing levels of Cd or radioactivity in corn, wheat, or soybean grain. Applications of By‐product PG at recommended rates of 500 to 1000 kg ha−1 as a source of Ca or S for crops would result in lower levels of Cd and radioactivity than those reported here.
Effects of Fertilizer, Pig Manure, and Sewage Sludge on Timothy and Soils
Authors: Warman P. R. 
Published: July 2010

AbstractResearch determined the effect of fertilizer, sewage sludge and pig (Sus scrofa domesticus) manure on timothy (Phleum pratense L.) yield, tissue composition, and soil fertility from 1979 to 1982. Field plots in Quebec on sandy loam and clay loam soils compared 0 fertilizer and annual applications (1979–1981) of two rates of fertilizer (F1,F2 = 110‐50‐85, 220‐50‐85 kg ha−1 N‐P2O5‐K2O), pig manure (PM1,PM2 = 75 150 wet Mg ha−1) or aerobically digested sewage sludge (SS1,SS2 = 150 300 wet Mg ha−1). The F2, PM2, and SS2 amendments produced similar yields and plant uptake of nutrients all 3 yr. Although nutrient uptake by timothy was generally higher on the clay loam, due to higher soil fertility and less leaching losses, the percent recovery of the applied nutrients (excluding N and Mn) was similar at both sites. Based on the K:(Ca + Mg) content and regardless of the treatment applied, a potential grass tetany problem exists in the timothy grown in the clay loam. No metal contamination was found in the soil or timothy following the application of any amendment. Only four soil chemical properties, of 11 measured, were influenced by the treatments on either soil. The PM2 treatment increased NO−3‐N, Bray P2 and extractable K; the SS2 treatment increased Bray P2 and DTPA Cu. The author, therefore, recommends the application of any of these amendments to timothy at either of the two rates.
Reducing Aspergillus Species Infection of Peanut Seed Using Resistant Genotypes
Authors: Mixon A. C. 
Published: July 2010

AbstractStudies were conducted to determine the potential of reducing aflatoxin contamination using recently released peanut (Arachis hypogaea L.) genotypes found to be resistant to seed invasion by aflatoxin‐producing strains of Aspergillus Link ex Fr. flavus and A. parasiticus Speare. Under certain environmental conditions these fungi metabolize aflatoxins which are highly potent carcinogens when ingested by animals. Resistant lines (GFA‐1, GFA‐2, AR‐1, AR‐2, AR‐3, and AR‐4) were evaluated for resistance to seed invasion and colonization of intact, dry seed by the Aspergillus species. When rehydrated and inoculated seed were incubated under favorable conditions, all the resistant peanut lines were more resistant than commercial peanut cultivars, “Florunner” and ‘Sunbelt Runner’, in successive years of evaluating. Pod yields of GFA‐1 and GFA‐2 pod yields approached those of the commercial cultivars. AH the resistant genotypes could reduce contamination of seed immediately following harvest or in short term storage when environmental conditions are conducive to A. flavus and A. parasiticus infection.
Potassium Losses in Runoff and Drainage Waters from Cropped, Large‐scale Lysimeters
Authors: Jones Robert L. , Hinesly Thomas D. 
Published: July 2010

AbstractLosses of total recoverable potassium (K) were measured in runoff and percolate waters from field lysimeter plots of Blount silt loam (fine, illitic, mesic Aeric Ochraqualfs) from May 1972 through April 1974. Six plots were irrigated annually with digested sewage sludge, while another six plots which had been treated with a complete fertilizer were irrigated with well water. Each year all plots were fertilized with KCl in amounts that supplied 269 kg K ha−1 prior to the preparation of a seedbed for corn (Zea mays L.). For the 2 yr of record, combined K losses in runoff and drainage waters from sludge‐treated plots averaged 41.9 and 8.2 kg ha−1, respectively. For the same years, losses from plots irrigated with well water averaged 23.3 and 10.5 kg K ha−1 in runoff and drainage waters, respectively. The differences between treatments within each year were not significant, but they were significant between years within treatment. Large K losses occurred in runoff during heavy summer rains and in winter when rapid snow melt and rain events took place. Consistently higher K losses were observed in drainage waters during late winter and spring periods for both years. Median concentrations of total recoverable K in runoff and drainage waters from sludge‐treated plots were, respectively, 7.5 and 4.8 mg L−1 in the first year and 7.8 and 2.4 mg L−1 during the second year. Respective data for water‐irrigated lysimeters were 6.0 and 2.9 mg K L−1 in 1972 through 1973 and 7.5 and 1.8 mg K L−1 in 1973 through 1974. Potassium losses were small when compared to amounts supplied as constituents of sludge and fertilizer and to soil levels of total native and acid‐extractable K. In the drier year, 1973 through 1974, total K losses in runoff and drainage from plots receiving conventional fertilizers were similar to weights of K removed in grain.
Response of Soybean to Low Concentrations of Ozone: II. Effects on Growth, Biomass Allocation, and Flowering
Authors: Amundson Robert G. , Raba Richard M. , Schoettle Anna W. , Reich Peter B. 
Published: July 2010

AbstractSoybean plants were subjected to ozone (O3) and water stress to determine whether the two stresses interact to alter growth. Potted soybean (Glycine max [L.] Merrill cv. Hodgson) plants were exposed to O3 for 6.8 h daily in four controlled environment chambers. The air supply to the chambers was filtered, and constant amounts of O3 were added: 0.01, 0.05, 0.09, or 0.13 µL L−1. Within each O3 treatment, half of the plants were watered daily and half had water withheld 2 or 3 d per week. At 2‐week intervals plants were harvested and divided into leaves, stems, and roots. Exposure to increasing concentrations of O3 resulted in a linear decline in growth, but did not influence the allocation of biomass to roots, stems, and leaves. Ozone also delayed the onset of flowering. Weekly water stress periods of 2 or 3 d duration significantly inhibited the growth of soybean but did not alter the allocation of biomass or delay the onset of flowering. Water stress acted to close stomates and reduce the effective O3 dose which resulted in a reduced percent reduction in growth that could be attributed to O3 stress.
Metals in Low‐elevation, Southern Appalachian Forest Floor and Soil
Authors: Berish C. W. , Ragsdale H. L. 
Published: July 2010

AbstractLitter and humus, and surficial (0–5 cm) and deeper (25–30 cm) mineral soil were collected from two, 90‐yr‐old forests to measure readily‐available, potentially‐available, and total‐pool quantities of metals in low elevation, southern Appalachian soils. Soils of the two forested watersheds are either in the Evard or Tate series, a fine‐loamy, mesic family of Typic Hapludults. Concentrations of Ca, K, Mg, Mn, Cd, Co, Cu, Pb, and Zn in soils were determined by three extraction methods (water soluble, weak acid, and total dissolution). Total soil Ca, K, Mg, and Mn pools were two or more orders of magnitude greater than trace metal pools. Total soil metal pools at both depths followed a trend of K ≫ Ca ≥ Mg > Mn ≫ Zn > Cu ≫ Pb ≥ Co ≫ Cd. Fractions of the total metal pools that were readily and potentially available generally decreased with depth.Litter and humus trace metal concentrations of two low elevation watersheds in the Coweeta Basin contain lower concentrations of Cu, Zn, and Pb than commonly reported for the northeastern USA. Aerial deposition of Cd, Co, and Pb was indicated by the surficial forest floor enrichment in those elements compared to the mineral soil. The largest trace metal pool in forest floor litter and humus was for lead, and was presumably from long‐range transport, deposition and subsequent retention on humic materials. Metals measurement in the relatively pristine organic forest floor and mineral soil at Coweeta will be useful for future evaluations of trace metal impacts on southern Appalachian forest ecosystems.
Analysis of Time‐dependent Chemical Processes in Soils
Authors: Skopp J. 
Published: July 2010

AbstractAnalysis of time‐dependent processes in soils has been the subject of recent interest. Examples of such interest include the demonstration of nonequilibrium conditions during transport, slow release of plant nutrients, and a fundamental interest in reaction mechanisms. No unified approach to these problems exists in the literature. The present study was undertaken to provide uniformity in terminology and a methodology for solving a variety of problems. The interrelationship of chemical kinetics and transport processes is examined. Particular attention is paid to potential ambiguities and alternative interpretations of concentration histories. A variety of rate law formulations are presented. Microscopic and macroscopic approaches to transport process are described. The implications of these descriptions of transport upon chemical reactions are discussed, it is concluded that reaction kinetics and transport may be readily confounded. Furthermore, different kinetic mechanisms may result in concentration histories that are not distinguishable experimentally.
Nitrogen Mineralization of Sewage Sludges in Soils
Authors: Garau M. A. , Felipó M. T. , de Villa M. C. Ruiz 
Published: July 2010

AbstractIn order to profit from recycling sewage sludge through the soil‐plant system, it is necessary to know the amount of mineralizable organic‐N from sludge. The purpose of this study was to determine N‐mineralization of two sewage sludges in two different soils, comparing leached and nonleached incubation procedures. The cumulative N mineralized during successive incubation periods increased linearly with incubation time and sludge incorporation rate. The mineralization process was more influenced by soil type than by rate and kind of sludge applied. The amount of mineralized‐N was higher for the leaching procedure. This cumulative‐N expressed as the percentage of applied organic‐N was inversely dependent on sewage sludge rate added for the leached procedure and is independent of the rate for the nonleached. The N‐mineralization rate was 0.0202 ± 0.0011 and 0.0650 ± 0.0068 d−1, respectively, for leached and nonleached procedures. The potentially mineralizable N increased with the sludge rate applied and was higher for aerobic sludge and neutral soil. In general, the leached method gave twofold higher vlaues than the nonleached method. The net percentage of potentially mineralizable N vs. organic‐N added was 43.0 ± 7.8 and 27.7 ± 4.0, respectively, for leached and nonleached procedures.
pH Buffering in Forest Soil Organic Horizons: Relevance to Acid Precipitation
Authors: James Bruce R. , Riha Susan J. 
Published: July 2010

AbstractSamples of organic surface horizons (Oi, Oe, Oa) from New York State forest soils were equilibrated with 0 to 20 cmol HNO3 kg−1 soil in the laboratory by a batch technique designed to simulate reactions of acid precipitation with forest floors. Each organic horizon retained a constant percentage of added H+ (67–96%) regardless of quantity added, and buffer capacities of the samples ranged from 18 to 36 cmol (H+) kg−1 (pH unit)−1, an order of magnitude higher than those measured in underlying mineral horizons. Calcium was the dominant cation in unacidified equilibrium solutions, and its concentration changed the most in response to acidification of the soils. Aluminum contributed <1% to total cationic charge in solution and Fe concentration decreased upon addition of up to at least 5 cmol (H+) kg−1. From 38 to 79% of H+ removed by the soils was not balanced by increases in soluble Ca, Mg, K, Mn, Fe, Zn, Al, and Cu, and buffering by soluble organic and inorganic constituents accounted for 8 to 58% of H+ removal. Protonation of anions of weak organic acids in solution and solid phases probably accounted for this H+ removal without increasing cation concentrations. Because of H+ removal by forest floor organic horizons and the dominance of Ca in equilibrium solutions, potential impacts of acid precipitation on aluminum solubility of underlying mineral horizons of forest soils will be due more to Ca(NO3)2 and CaSO4 in leaching water, rather than to direct effects of HNO3 and H2SO4.
Chemical Quality of Suspended Sediment from Watersheds Subjected to Surface Coal Mining
Authors: Dick W. A. , Bonta J. V. , Haghiri F. 
Published: July 2010

AbstractThe chemical quality of suspended sediment in surface water runoff, which is changed as a result of surface coal mining activities, may influence water quality and have effects where the sediment is deposited downstream from the mine site. Suspended sediment samples were collected from three small watersheds in east‐central Ohio prior to, during, and after surface mining and reclamation. The chemical quality of the suspended sediment was determined by measuring Ca, Mg, Fe, Al, Mn, Ni, Pb, Cd, Cu, Zn, Sr, P (following pretreatment of the sample with 30% H2O2 and extraction with 0.3 MHCl), acetate‐soluble SO2−4, pH, organic C, and Hg. Differences in concentrations of parameters were observed among the three watersheds and were related to the composition of the overburden material. At Watersheds C06 and M09, the concentrations of the chemical parameters in suspended sediment samples, collected after reclamation had been completed, were not significantly (P = 0.05) different than concentrations measured prior to surface mining. An exception was the concentration of organic C, which was lower during the postreclamation period. The concentrations of Mg, Fe, and Al were significantly greater at Watershed J11 during the postreclamation period compared to the premine period while P, organic C, Mn, and Pb concentrations were significantly lower. Concentrations of parameters in suspended sediment samples collected concurrently at the inlet and outlet of the sediment ponds at Watersheds C06 and M09 were not significantly (P = 0.05) different. However, due to settling of the larger and heavier sediment particles, a trend toward increased concentration of parameters in sediment samples collected at the pond outlet compared to the pond inlet occurred at both Watersheds C06 and M09.
Effect of Sludge Additions on Nitrogen Removal in Soil Columns Flooded with Secondary Effluent
Authors: Lance J. C. 
Published: July 2010

AbstractMixing sewage sludge with the surface layer of soil in columns was tested as a way to increase N removal in soil columns flooded with secondary effluent containing 18 mg/L total N. Dry sludge was mixed in the top 5 cm of two columns at an application rate equivalent to 50 Mg/ha. The infiltration rates of the two columns were 30 and 60 cm/d. The infiltration rates were the same before and after addition of sludge. Nitrogen (total) removed by the 30 cm/d column was increased from about 22 to about 55% by adding sludge. The same amount of sludge added to the 60 cm/d column decreased N removal for several cycles before N removal stabilized at 34% or at about double the rate measured before sludge was added. Sludge decomposition in the soil columns apparently provided a steady source of organic C for denitrifying bacteria. Nitrogen removal at the 30 cm/d infiltration rate was sufficient to maintain the average total N content in the water from the column outlet at 8 mg/L. These results show that mixing sludge with soil in ground‐water recharge basins could allow increased application rates of sewage water and thereby reduced costs. Utilization of some sludge without contaminating the groundwater would be an added benefit.
Phosphorus Solubility in Sludge‐amended Calcareous Soils
Authors: O'Connor G. A. , Knudtsen K. L. , Connell G. A. 
Published: July 2010

AbstractSludge additions to calcareous soils in New Mexico increased water soluble and NaHCO3‐extractable P as well as plant uptake of P, whereas inorganic fertilizer P has often been ineffectual. This paper describes attempts to explain sludge effects in terms of increased solubility of secondary Ca‐P solid phases (e.g., tricalcium and octacalcium phosphate) in amended calcareous soils. Both greenhouse and field data, representing several croppings of amended soils were examined. Ancillary effects, primarily slight pH reductions, associated with sludge additions to the soils were apparently responsible for increased P solubility in amended soils.
Environmental Radiation Exposure Rate in Louisiana
Authors: Beck James N. , Keeley Dean F. , Meriwether John R. , Thompson Ronald H. 
Published: July 2010

AbstractThe environmental radiation exposure rate has been measured using thermolumineseent dosimetry at 26 monitoring stations in Louisiana over a period of 2 yr. Sets of LiF dosimeters that are essentially tissue equivalent in their energy response characteristics were left at each station for 90 d, replaced, and the exposure they received determined. The chips were exposed to a standard source three times during the 2‐yr period to assure their accuracy. On at least two occasions during the study period, samples of soil were taken at each station. These samples were dried, ground, sieved for uniformity, and analyzed by gamma ray spectroscopy. The specific activity of 40K, 137Cs, and some of the decay products of U and Th were determined. The average exposure rate for all stations was found to be 19.6 ± 2.8 µC kg−1 yr−1 (76 ± 11 mR yr−1). The range in values, from 15.0 to 25.5 µC kg−1 yr−1 is generally explained by the variation of the 40K specific activity in the natural soil bodies where the stations are located. The 40K specific activity ranges from 100 to 900 Bq kg−1 across the state. The other activities are also related to soil type, but none vary as dramatically as 40K. The results obtained agree with other more limited surveys and provide a large, reliable baseline to which future studies can be referred when assessing changes in environmental radiation levels.