bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavior of Cinosulfuron in Paddy Surface Waters, Sediments, and Ground Water
Authors: Ferrero A. , Vidotto F. , Gennari M. , Nègre M. 
Published: June 2010

ABSTRACTCinosulfuron (3‐(4,6‐dimethoxy‐1,3,5‐triazin‐2‐yl)‐1‐[2‐(2‐methoxyethoxy)‐phenylsulfonyl]‐urea) is a sulfonylurea herbicide used to control a wide range of broadleaf weeds in rice (Oryza sativa L.). A 2‐yr field study was conducted in northwest Italy to determine the effect of cinosulfuron on surface and subsoil waters in rice paddies. Cinosulfuron was applied at 70 g a.i. ha−1 on 35 ha of flooded rice. After the treatment, the change in herbicide concentration over time was studied by analyzing water and sediment samples in a test paddy field (2.16 ha, located in the treated area), water in a spring and a pond (both located near the test paddy), two wells (up‐ and downhill to the treated area), and two piezometers (along the test paddy levee). To better understand some of the field study results, cinosulfuron degradation was also evaluated in the laboratory in solutions buffered to different pH values. Two weeks after the treatment, the cinosulfuron concentration in the paddy water decreased by about 60%. No cinosulfuron was detected at about 2.5 mo after the treatment. The concentration in the sediment gradually increased after the treatment, reaching the highest value (13.53 μg kg−1) 3 wk later. The maximum cinosulfuron content in the spring and pond were 0.91 and 0.29 μg L−1, respectively, and these were detected 60 to 90 days after treatment (DAT). The water collected in the piezometers reached the highest concentration (0.99 μg L−1) 29 DAT. Cinosulfuron was never detected in the wells. In the degradation study at different pH values, cinosulfuron degraded rapidly at low pH values.
Bioavailability of Biosolids Molybdenum to Corn
Authors: O'Connor G.A. , Granato T.C. , Dowdy R.H. 
Published: June 2010

ABSTRACTThis study was part of a larger effort to generate field data appropriate to the assessment of biosolids molybdenum (Mo) risk to ruminants. Corn (Zea mays L.) is an important component of cattle diet, and is a logical crop for biosolids amendment owing to its high N requirement. Paired soil and corn stover samples archived from two unique field experiments were analyzed to quantify the relationship (uptake coefficient, UC) between stover Mo and soil Mo load. Both studies used biosolids with total Mo concentrations typical of modern materials. Data from long‐term (continuous corn) plots in Fulton County, IL confirm expected low Mo accumulation by corn stover, even at very high biosolids loads and soil Mo loads estimated to be near 18 kg Mo ha−1 Uptake slopes were actually negative, but USEPA protocol would assign UC values of 0.001. Data from plots in Minnesota also suggested essentially no correlations between stover Mo and soil Mo loads for continuous corn. However, greater Mo accumulation in corn grown following soybean [Glycine max (L.) Merr.] suggests the possibility of enhanced Mo bioavailability to corn in corn–soybean rotations. Nevertheless, molybdenosis risk to cattle consuming corn stover produced on biosolids‐amended land is small as stover Mo concentrations were always low and stover Cu to Mo ratios exceeded 2:1, which avoids molybdenosis problems.
Modeling Pollutant Release from a Surface Source during Rainfall Runoff
Authors: Walter M. Todd , Parlange J.‐Y. , Walter M. F. , Xin X. , Scott C. A. 
Published: June 2010

ABSTRACTThough runoff from manure spread fields is recognized as an important mode of nonpoint‐source pollution, there are no models that mechanistically describe transport from a field‐spread manure–type source. A mechanistic, physically based model for pollutant release from a surface source, such as field‐spread manure, was hypothesized, laboratory tested, and field‐applied. The primary objective of this study was to demonstrate the potential applicability of a mechanistic model to pollutant release from surface sources. The laboratory investigation used stable sources and a conservative “pollutant” (KCl) so that the dynamic effects of source dissolution and chemical transformations could be ignored and transport processes isolated. The field investigation used runoff and soluble reactive phosphorus (SP) data collected from a dairy‐manure‐spread field in the Cannonsville watershed in the Catskills region of New York State. The model predictions corroborated well with observations of runoff and pollutant delivery in both the laboratory and the field. “Pollutant” release from surface sources was generally predicted within 11% of laboratory KCl measurements and field SP observations. Laboratory flume runoff predictions with 15 and 26% errors for 25 and 15 mm h−1 simulated rainfall intensity experiments, respectively, represented root mean square errors of less than 0.2 mL s−1 A 26% error was calculated for overland flow predictions in the field, which translated into approximately a 39 mL s−1 error. Results suggest that the hypothesized model satisfactorily represents the primary mechanisms in pollutant release from surface sources.
Artificial Recharge of Humic Ground Water
Authors: Alborzfar M. , Villumsen A. , Grøn C. 
Published: June 2010

ABSTRACTThe purpose of this study was to investigate the efficiency of soil in removing natural organic matter from humic ground waters using artificial recharge. The study site, in western Denmark, was a 10 000 m2 football field of which 2000 m2 served as an infiltration field. The impact of the artificial recharge was studied by monitoring the water level and the quality of the underlying shallow aquifer. The humic ground water contained mainly humic acids with an organic carbon (OC) concentration of 100 to 200 mg C L−1. A total of 5000 m3 of humic ground water were sprinkled onto the infiltration field at an average rate of 4.25 mm h−1. This resulted in a rise in the water table of the shallow aquifer. The organic matter concentration of the water in the shallow aquifer, however, remained below 2.7 mg C L−1. The organic matter concentration of the pore water in the unsaturated zone was measured at the end of the experiment. The organic matter concentration of the pore water decreased from 105 mg C L−1 at 0.5 m to 20 mg C L−1 at 2.5 m under the infiltration field indicating that the soil removed the organic matter from the humic ground water. From these results we conclude that artificial recharge is a possible method for humic ground water treatment.
Fate of Atrazine in Sandy Soil Cropped with Sorghum
Authors: Mbuya O.S. , Nkedi‐Kizza P. , Boote K.J. 
Published: June 2010

ABSTRACTA field study was conducted to determine the fate of atrazine (6‐chloro‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐triazine‐2,4‐diamine) within the root zone (0 to 90 cm) of a sandy soil cropped with sorghum [Sorghum bicolor (L.) Moench] in Gainesville, Florida. Atrazine was uniformly applied at a rate of 1.12 kg a.i. ha−1 to a sorghum crop under moderate irrigation, optimum irrigation, and no irrigation (rainfed), 2 d after crop emergence. Bromide as a tracer for water movement was applied to the soil as NaBr at a rate of 45 kg Br− ha−1, 3 d before atrazine application. Soil water content, atrazine, and Br− concentrations were determined as a function of time using soil samples taken from the root zone. Atrazine sorption coefficients and degradation rates were determined by depth for the entire root zone in the laboratory. Atrazine was strongly adsorbed within the upper 30 cm of soil and most of the atrazine recovered from the soil during the growing season was in that depth. The estimated half‐life for atrazine was 32 d in topsoil to 83 d in subsoil. Atrazine concentration within the root zone decreased from 0.44 kg a.i. ha−1 2 days after application (DAA) to 0.1 kg a.i. ha−1 26 DAA. Negligible amounts of atrazine (≈5 μg kg−1) were detected below the 60‐cm soil depth by 64 DAA. Most of the decrease in atrazine concentration in the root zone over time was attributed to degradation. In contrast, all applied bromide had leached past the 60‐cm soil depth during the same time interval.
Seasonal Hypoxia in the Bottom Water off the Mississippi River Delta
Authors: Rowe Gilbert T. 
Published: June 2010

ABSTRACTHypoxia (oxygen concentration less than 2 mg L−1 or 62.5 mmol m−3) occurs on the Louisiana continental shelf during summer when the consumption of oxygen by sediment and water column respiration exceed resupply by photosynthesis and mixing. Biological processes that consume or produce oxygen have been summarized in a budget that can be used to quantify the degree to which consumption in deep water and in the sediments exceeds net production and thus the time it takes to reach hypoxic conditions following the spring onset of stratification. The net consumption rate by the sea floor biota (sediment oxygen consumption, SOC) is inversely related to oxygen concentration and directly related to temperature. Photosynthesis is of potential importance throughout the deep water column and on the sea floor when light is adequate. A non‐steady state, time‐dependent numerical simulation model is used to compare biological and physical processes with shipboard measurements and continuous near‐bottom records. The simulations illustrate possible variations in oxygen concentration on time scales of hours to months, and these in general match much of the variability in the direct observations at time scales of days to weeks. The frequently observed unremitting anoxia lasting weeks at some locations is not produced in the present simulations. A possible explanation is the chemical oxidation in the water column of reduced metabolic end‐products produced in the sediments by anaerobic metabolism. Direct measurements of biological processes could lead to better understanding of how extrinsic forcing functions can best be managed to improve water quality.
Additives to Reduce Ammonia and Odor Emissions from Livestock Wastes: A Review
Authors: McCrory D.F. , Hobbs P.J. 
Published: June 2010

ABSTRACTThis paper reviews the use of additives to reduce odor and ammonia (NH3) emissions from livestock wastes. Reduction of NH3 volatilization has been shown to be possible, particularly with acidifying and adsorbent additives, and potential exists to develop further practical and cost‐effective additives in this area. Masking, disinfecting, and oxidizing agents can provide short‐term control of malodor, but as the capacity of these additives is finite, they require frequent reapplication. Microbial‐based digestive additives may offer a solution to this problem as they are regenerative, but they appear to have been developed without a thorough understanding of microbiological processes occurring in livestock wastes. Currently, their use to reduce odor or NH3 emissions cannot be recommend. If the potential of these types of additives is to be realized, research needs to shift from simply evaluating these unknown products to investigating known strains of bacteria or enzymes with known modes of action. To protect the farmers' interest, standard independent test procedures are required to evaluate efficacy. Such tests should be simple and quantify the capacity of the additive to perform as claimed. The principle use of additives needs to be identified and addressed during their development. Producers may not use effective additives in one area if they further compound other problems that they perceived to be more important. There is the potential to use additives to treat other problems associated with livestock wastes, particularly to improve handling properties, reduce pollution potential to watercourses, and reduce pathogenic bacteria. Further work is required in these areas.
Greenhouse Gases in Non‐Oxygenated and Artificially Oxygenated Eutrophied Lakes during Winter Stratification
Authors: Huttunen Jari T. , Hammar Taina , Alm Jukka , Silvola Jouko , Martikainen Pertti J. 
Published: June 2010

ABSTRACTConcentrations of dissolved methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) were measured in the water columns of non‐oxygenated and artificially oxygenated, ice‐covered eutrophied lakes in the mid‐boreal zone in Finland during late winter 1997 and 1999. Sampling was conducted during winter stratification, the critical period for oxygen (O2) deficiency in seasonally ice‐covered, thermally stratified lakes. Oxygen concentrations were maintained at least at a moderate level throughout the oxygenated water columns, whereas the non‐oxygenated columns suffered anoxic hypolimnia. The mean concentrations of dissolved CH4 exceeding the atmospheric equilibrium were greater in the non‐oxygenated water columns (20.6–154 μM) than in the oxygenated ones (0.01–1.41 μM). In contrast, the mean excess CO2 concentrations varied less between the non‐oxygenated and oxygenated sites (0.28–0.47 and 0.25–0.31 mM, respectively). Oxygenated water columns had greater mean excess concentrations of N2O (0.018–0.032 μM) than the non‐oxygenated ones (0.005–0.024 μM). If the accumulated greenhouse gas stores in the water columns during winter are assumed to be released to the atmosphere during the spring overturn, the global warming potentials (GWP, time horizon 100 yr) of these potential emissions at the non‐oxygenated, eutrophic study sites ranged from 177 to 654 g CO2 equivalent (CO2–e) m−2 compared with 144 to 173 g CO2–e m−2 at the oxygenated sites. The increase in the accumulation of CH4 was the main reason for the higher GWP of the non‐oxygenated sites. Anthropogenic eutrophication of lake ecosystems can generate increased CH4 emissions due to associated O2 depletion of their sediment and water column.
Removal of Herbicides from Liquid Media by Fungi Isolated from a Contaminated Soil
Authors: Bordjiba Ouahiba , Steiman Régine , Kadri Malika , Semadi Ammar , Guiraud Pascale 
Published: June 2010

ABSTRACTFungi were isolated from soil samples corresponding to pesticide‐contaminated soil (CS) and noncontaminated soil (NCS) in the Annaba vicinity (Algeria) and identified. The number of isolates obtained from CS and NCS were 263 and 288, respectively. The most frequent species (Aspergillus fumigatus, A. niger, A. terreus, Absidia corymbifera, and Rhizopus microsporus var microsporus) were not sensitive to the pesticides. The growth of the genus Trichoderma was inhibited by the pesticides, while genera Absidia and Fusarium were stimulated. The 53 species isolated were assayed for their ability to remove metribuzin from liquid medium. Only Botrytis cinerea from NCS and Sordaria superba and Absidia fusca from CS removed more than 50% of the compound after 5 d. Metamitron was very resistant. Among the 21 species tested, only Alternaria solani (from NCS), Drechslera australiensis (from CS and NCS), and Absidia fusca (from CS) reduced the concentration in the medium more than 10% (10–16%). Twelve species were grown with linuron, seven of them were inefficient in removing this compound. The two strains of Sordaria macrospora yielded 22 to 25% depletion, while Botrytis cinerea depleted linuron almost completely. Among the 31 species assayed for their ability to eliminate metobromuron, Botrytis cinerea (from CS and NCS) depleted almost completely the chemical from the medium. Rhizopus oryzae and Absidia fusca from CS removed 40 and 47% of the compound, respectively. No systematic relationships were observed between the soil contamination and herbicide elimination capacities of soil fungi. Absidia fusca and Botrytis cinerea were particularly interesting for bioremediation purposes because they were able to transform efficiently three of the four compounds assayed.
Hardwood Seedling Root and Nutrient Parameters for a Model of Nutrient Uptake
Authors: Kelly J.M. , Scarbrough J.D. , Mays P.A. 
Published: June 2010

ABSTRACTUse of mechanistic models is an increasingly accepted way to evaluate complex processes. The Barber‐Cushman model provides a means to simulate nutrient uptake once information on root system characteristics, nutrient uptake, and soil nutrient supply are developed. Objectives of this study were to determine during a growing season: (i) root growth for 1‐yr‐old black cherry (Prunus serotinaEhrh.), northern red oak (Quercus rubraL.), and red maple (Acer rubrumL.) seedlings; (ii) net plant increase in N, P, K, Ca, and Mg; (iii) soil solution and solid phase nutrient concentrations; and (iv) the influence of root growth and soil nutrient supply changes on nutrient uptake using the Barber‐Cushman model. Seedlings were grown in pots containing A horizon soil from two forest sites. Measurements were made on five occasions during the growing season. Root growth averaged 41.5 cm d−1for red maple compared with 28.0 and 16.7 cm d−1for cherry and oak, respectively. Seventy‐five percent of root growth occurred at the end of the growing season. Total plant N showed the greatest change (25–58%) due to soil source. Model simulations underestimated observed uptake by 31 to 99%. A clear relationship between soil solution nutrient concentration and plant uptake, an important assumption of the model, was not observed. Results indicate care will need to be exercised in the development and use of root growth and nutrient supply values in mechanistic models.
Fractionation and Mobility of Copper, Lead, and Zinc in Soil Profiles in the Vicinity of a Copper Smelter
Authors: Kabala Cezary , Singh Bal Ram 
Published: June 2010

ABSTRACTFour soil profiles located near a copper smelter in Poland were investigated for the distribution and chemical fractions of Cu, Pb, and Zn and their mobility in relation to soil properties. Contamination with heavy metals was primarily restricted to surface horizons and the extent of contamination was 7‐ to 115‐fold for Cu, 30‐fold for Pb, and 6‐fold for Zn as compared with subsurface horizons. In the less‐contaminated fine‐textured soil, the metals were distributed in the order: residual >> Fe–Mn oxides occluded > organically complexed > exchangeable and specifically adsorbed, while the order for sandy soils was: residual > organically complexed > Fe–Mn oxides occluded > exchangeable and specifically adsorbed. The contaminated surface horizons of these profiles showed no consistent pattern of metal distribution. However, the common features of highly contaminated soils were very low percentage of residual fraction and the dominance of the NH4OAc extractable fraction. The sum of mobile metal fractions was generally <10% in subsurface horizons, while in the contaminated surface horizons these fractions made up 50% of the total metal contents. Soil properties contributed more to the relative distribution of the metal fractions in the studied profiles than did the distance and direction to the source of pollution. The amounts of metal extracted by 0.01 M CaCl2 accounted for only a small part of the same metals extracted by NH4OAc. The mobility indexes of metals correlated positively and significantly with the total content of metals and negatively with the clay content.
On the Interaction Mechanisms of Atrazine and Hydroxyatrazine with Humic Substances
Authors: Martin‐Neto Ladislau , Traghetta Dinis Gomes , Vaz Carlos M.P. , Crestana Silvio , Sposito Garrison 
Published: June 2010

ABSTRACTAtrazine (6‐chloro‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐triazine‐2,4‐diamine) is retained against leaching losses in soils principally by sorption to organic matter, but the mechanism of sorption has been a matter of controversy. Conflicting evidence exists for proton transfer, electron transfer, and hydrophobic interactions between atrazine and soil humus, but no data are conclusive. In this paper we add to the database by investigating the role of (i) hydroxyatrazine (6‐hydroxy‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐triazine‐2,4‐diamine) and (ii) hydrophobicity in the sorption of atrazine by Brazilian soil humic substances. We demonstrate, apparently for the first time, that hydroxyatrazine readily forms electron‐transfer complexes with humic substances. These complexes probably are the cause of the well‐known strong adsorption by humic acids and they may be the undetected cause of apparent electron‐transfer complexes between soil organic matter and atrazine, whose transformation to the hydroxy form is facile. We also present evidence that supports the important contribution of hydrophobic interactions to the pH‐dependent sorption of atrazine by humic substances.
Particulate Phosphorus and Sediment in Surface Runoff and Drainflow from Clayey Soils
Authors: Uusitalo Risto , Turtola Eila , Kauppila Tommi , Lilja Taina 
Published: June 2010

ABSTRACTRecent work has shown that a significant portion of the total loss of phosphorus (P) from agricultural soils may occur via subsurface drainflow. The aim of this study was to compare the concentrations of different P forms in surface and subsurface runoff, and to assess the potential algal availability of particulate phosphorus (PP) in runoff waters. The material consisted of 91 water‐sample pairs (surface runoff vs. subsurface drainage waters) from two artificially drained clayey soils (a Typic Cryaquept and an Aeric Cryaquept) and was analyzed for total suspended solids (TSS), total phosphorus (TP), dissolved molybdate‐reactive phophorus (DRP), and anion exchange resin–extractable phosphorus (AER‐P). On the basis of these determinations, we calculated the concentrations of PP, desorbable particulate phosphorus (PPi), and particulate unavailable (nondesorbable) phosphorus (PUP). Some water samples and the soils were also analyzed for137Cs activity and particle‐size distribution. The major P fraction in the waters studied was PP and, on average, only 7% of it was desorbable by AER. However, a mean of 47% of potentially bioavailable P (AER‐P) consisted of PPi. The suspended soil material carried by drainflow contained as much PPi (47–79 mg kg−1) as did the surface runoff sediment (45–82 mg kg−1). The runoff sediments were enriched in clay‐sized particles and137Cs by a factor of about two relative to the surface soils. Our results show that desorbable PP derived from topsoil may be as important a contributor to potentially algal‐available P as DRP in both surface and subsurface runoff from clayey soils.
Stabilization of Composted Organic Matter after Application to a Humus‐Free Sandy Mining Soil
Authors: Leifeld Jens , Siebert Stefanie , Kögel‐Knabner Ingrid 
Published: June 2010

ABSTRACTThe use of mining substrates for recultivation purposes is limited due to their low organic matter (OM) contents. In a 1‐yr laboratory experiment we evaluated the stabilization of biowaste compost added to a humus‐free sandy mining soil to examine the suitability of compost amendment for the formation of stable soil organic matter (SOM). The stabilization process was characterized by measuring enrichment of OM and nitrogen in particle size fractions obtained after dispersion with different amounts of energy (ultrasonication and shaking in water), carbon mineralization, and amount of dissolved organic carbon (DOC). During the experiment, 17.1% of the organic carbon (OC) was mineralized. Organic carbon enrichment in the <20‐μm particle size fraction at the beginning of the experiment was in the range of natural soils with similar texture. Within 12 mo, a distinct OC redistribution from coarse into fine fractions was found with both dispersion methods. The accumulation of OC was more pronounced for the size separates obtained by ultrasonication, where the carbon distribution between 0.45‐ to 20‐μm particle size fractions increased from 30% at the beginning to 71% at the end of the experiment. Dissolved organic carbon contents ranged between 50 and 68 g kg−1 OC and decreased during the incubation. In conclusion, the exponential decrease of carbon mineralization and the OC enrichment in the fine particle size fractions both indicated a distinct OM stabilization in the mining soil.