bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic Induction Methods Applied to an Abandoned Manure Handling Site to Determine Nutrient Buildup
Authors: Eigenberg Roger A. , Nienaber John A. 
Published: June 2010

ABSTRACTMovement of nutrients from livestock manure handling sites has the potential to negatively impact the environment. This study was conducted using electromagnetic induction (EMI) measurements to develop apparent soil electrical conductivity (ECa) maps to identify regions of nutrient buildup beneath an abandoned compost site. A trailer‐mounted EM‐38 coupled with a global positioning satellite system was towed across an area used for composting of feedlot manure. The resulting ECa maps were compared with known locations of compost rows confirming the alignment of row locations with high ECa regions. The identified rows were cored and compared with the region between the rows. The identified rows with a compost history demonstrated significant (P < 0.05) increases in soluble salts (1.6 times greater), NO3 (6.0 times greater), and Cl (2.0 times greater) compared with the area between the rows at a 1.5‐m depth. Image processing techniques were used to display yearly changes that were associated with nutrient movement and transformations in the soil beneath the site. Correlations between EMI measurements and soil core analyses for NO3–N, Cl, and EC provided ancillary support for the EMI methods. The use of EMI for mapping of sites having a history of livestock waste application was effective in delineating high nutrient buildup areas and for observing spatial ECa changes over time.
Nitrogen Management Considerations for Landspreading Municipal Solid Waste Compost
Authors: Wolkowski Richard P. 
Published: June 2010

ABSTRACTMany municipalities have examined composting as an alternative to landfilling for the management of organic solid waste materials. Ultimately these materials will be land‐applied and therefore some knowledge of nutrient availability will be necessary to optimize crop yield and minimize environmental risk. Field studies were conducted in 1993 and 1994 on a silt loam and a loamy sand soil in Wisconsin to determine the effect of municipal solid waste compost (MSWC) on corn (Zea mays L.) yield, plant nutrient concentration, and soil nitrate N content. Municipal solid waste composts with ages of 7, 36, and 270 d were applied at rates of 22.5, 45, and 90 Mg ha−1 to small plots. Rates of commercial nitrogen (N) fertilizer, ranging from 0 to 179 kg N ha−1, were applied to separate plots to determine the N availability from the MSWC. Treatments were applied in the spring and incorporated before planting corn. The 270‐d MSWC increased corn whole‐plant dry matter and grain yield at each location in both years above the 7‐ and 36‐d MSWC. Rate of MSWC only affected grain yield at the loamy sand site in 1994. Municipal solid waste compost had minimal effect on the levels of plant nutrients in the whole‐plant tissue measured at physiological maturity. Nitrate N measured in the top 90 cm of soil was higher throughout the growing season in treatments receiving recommended N fertilizer when compared with any of the MSWC treatments. It was estimated that 6 to 17% of the total N in the 270‐d MSWC became available in the first year. The land‐application of mature MSWC at the tested rates would be an agronomically and environmentally admissible practice.
Cadmium Availability from Granulated and Bulk‐Blended Phosphate‐Potassium Fertilizers
Authors: Chien S. H. , Carmona G. , Prochnow L. I. , Austin E. R. 
Published: June 2010

ABSTRACTRecent field experiments have shown that high chloride (Cl) in irrigation waters can increase soil cadmium (Cd) uptake by crops because of the formation of soluble ion‐pair complexes of Cd with Cl in soil solution. The present study was aimed at testing a hypothesis that KCl in granulated PK fertilizers may enhance Cd uptake by crops from Cd‐containing P fertilizers because of close contact between Cd and Cl in the same granules. Less effect would be expected if the same granular PK fertilizers were bulk‐blended because of separation of Cd and Cl in different granules. A single superphosphate (SSP) containing 32 mg Cd kg−1 was granulated by the compaction process with KCl at a P to K ratio = 1:1. Granular KCl was also bulk‐blended with granular SSP or Cd‐free monocalcium phosphate (MCP) at the same P to K ratio. An acid Ultisol (pH 5.2) was treated with PK fertilizers at 400 mg kg−1 each for P and K. Upland rice (Oryza sativa L.) and soybean [Glycine max (L.) Merr.] were grown to maturity, and signalgrass (Brachiaria decumbens Stapf.) was cut four times during the study. The results showed that the agronomic effectiveness in increasing crop yield was the same with SSP and MCP whether granulated or bulk‐blended with KCl. Concentrations of Cd in plant tissue samples of all crops were much lower for MCP than for SSP. In all the plant tissue samples, except grain samples of upland rice, Cd concentrations obtained with granulated (SSP + KCl) were significantly higher than that with bulk‐blended (SSP) + (KCl).
Determination of Polyacrylamide in Soil Waters by Size Exclusion Chromatography
Authors: Lu Jianhang , Wu Laosheng , Gan Jianying 
Published: June 2010

ABSTRACTDetermination of polyacrylamide (PAM) concentration in soil waters is important in improving the efficiency of PAM application and understanding the environmental fate of applied PAM. In this study, concentrations of anionic PAM with high molecular weight in soil waters containing salts and dissolved organic matter (DOM) were determined quantitatively by size exclusion chromatography (SEC) with ultraviolet (UV) absorbance detection. Polyacrylamide was separated from interferential salts and DOM on a polymeric gel column eluted with an aqueous solution of 0.05 M KH2PO4 and then detected at a short UV wavelength of 195 nm. Analysis of PAM concentrations in soil sorption supernatants, soil leachates, and water samples from irrigation furrow streams showed that SEC is an effective approach for quantifying low concentrations (0–10 mg L−1) of PAM in waters containing soil DOM and salts. The method has a lower detection limit of 0.02 μg and a linear response range of 0.2 to 80 mg L−1 Precision studies gave coefficients of variation of <1.96% (n = 4) for >10 mg L−1 PAM and <12% (n = 3) for 0.2 to 3 mg L−1 PAM.
Enhancing Phytoextraction
Authors: Schmidt Ulrich 
Published: June 2010

ABSTRACTFor heavy metal–contaminated agricultural land, low‐cost, plant‐based phytoextraction measures can be a key element for a new land management strategy. When agents are applied into the soil, the solubility of heavy metals and their subsequent accumulation by plants can be increased, and, therefore, phytoextraction enhanced. An overview is given of the state of the art of enhancing heavy metal solubility in soils, increasing the heavy metal accumulation of several high‐biomass‐yielding and metal‐tolerant plants, and the effect of these measures on the risk of heavy metal leaching. Several organic as well as inorganic agents can effectively and specifically increase solubility and, therefore, accumulation of heavy metals by several plant species. Crops like willow (Salix viminalis L.), Indian mustard [Brassica juncea (L.) Czern.], corn (Zea mays L.), and sunflower (Helianthus annuus L.) show high tolerance to heavy metals and are, therefore, to a certain extent able to use the surpluses that originate from soil manipulation. More than 100‐fold increases of lead concentrations in the biomass of crops were reported, when ethylenediaminetetraacetic acid (EDTA) was applied to contaminated soils. Uranium concentrations could be strongly increased when citric acid was applied. Cadmium and zinc concentrations could be enhanced by inorganic agents like elemental sulfur or ammonium sulfate. However, leaching of heavy metals due to increased mobility in soils cannot be excluded. Thus, implementation on the field scale must consider measures to minimize leaching. So, the application of more than 1 g EDTA kg−1 becomes inefficient as lead concentration in crops is not enhanced and leaching rate increases. Moreover, for large‐scale applications, agricultural measures as placement of agents, dosage splitting, the kind and amount of agents applied, and the soil properties are important factors governing plant growth, heavy metal concentrations, and leaching rates. Effective prevention of leaching, breeding of new plant material, and use of the contaminated biomass (e.g., as biofuels) will be crucial for the acceptance and the economic breakthrough of enhanced phytoextraction.
Contribution of Particulate Phosphorus to Runoff Phosphorus Bioavailability
Authors: Uusitalo Risto , Turtola Eila , Puustinen Markku , Paasonen‐Kivekäs Maija , Uusi‐Kämppä Jaana 
Published: June 2010

ABSTRACTRunoff P associated with eroded soil is partly solubilized in receiving waters and contributes to eutrophication, but the significance of particulate phosphorus (PP) in the eutrophying P load is debatable. We assessed losses of bioavailable P fractions in field runoff from fine‐textured soils (Cryaquepts). Surface runoff at four sites and drainflow at two of them was sampled. In addition to dissolved molybdate‐reactive phosphorus (DRP) losses, two estimates of bioavailable PP losses were made: (i) desorbable PP, assessed by anion exchange resin‐extraction (AER‐PP) and (ii) redox‐sensitive PP, assessed by extraction with bicarbonate and dithionite (BD‐PP). Annual losses of BD‐PP and AER‐PP were derived from the relationships (R2= 0.77–0.96) between PP and these P forms. Losses of BD‐PP in surface runoff (94–1340 g ha−1) were typically threefold to fivefold those of DRP (29–510 kg ha−1) or AER‐PP (13–270 g ha−1). Where monitored, drainflow P losses were substantial, at one of the sites even far greater than those via the surface pathway. Typical runoff DRP concentration at the site with the highest Olsen‐P status (69–82 mg kg−1) was about 10‐fold that at the site with the lowest Olsen P (31–45 mg kg−1), whereas the difference in AER‐PP per mass unit of sediment was only threefold, and that of BD‐PP 2.5‐fold. Bioavailable P losses were greatly influenced by PP runoff, especially so on soils with a moderate P status that produced runoff with a relatively low DRP concentration.
Prediction of Trace Element Mobility in Contaminated Soils by Sequential Extraction
Authors: Pueyo M. , Sastre J. , Hernández E. , Vidal M. , López‐Sánchez J. F. , Rauret G. 
Published: June 2010

ABSTRACTThe modified three‐step sequential extraction procedure proposed by the Community Bureau of Reference (or Bureau Communautaire de Référence, BCR) was used to predict trace element mobility in soils affected by an accidental spill comprising arsenopyrite‐ and heavy metal–enriched sludge particles and acid waste waters. The procedure was used to obtain the distribution of both the major (Al, Ca, Fe, Mg, and Mn) and trace elements (As, Bi, Cd, Cu, Pb, Tl, and Zn) in 13 soils of contrasting properties with various levels of contamination and in the sludge itself. The distributions of the major elements enabled us to confirm the main soil fractions solubilized in each of the three steps, and, in turn, to detect the presence of pyritic sludge particles by the high Fe extractability obtained in the third step. Cadmium was identified as being the most mobile of the elements, having the highest extractability in the first step, followed by Zn and Cu. Lead, Tl, Bi, and As were shown to be poorly mobile or nonmobile. In the case of some of the trace elements, the residual fractions decreased at higher levels of contamination, which was attributed to the anthropogenic contributions to the polluted samples. Comparison with soil–plant transfer factors, calculated in plants growing in the affected area, indicated that a relative sequence of trace element mobility was well predicted from data of the first step.
Temperature and Microbial Activity Effects on Trace Element Leaching from Metalliferous Peats
Authors: Qureshi Shabnam , Richards Brian K. , McBride Murray B. , Baveye Philippe , Steenhuis Tammo S. 
Published: June 2010

ABSTRACTDue to geochemical processes, peat soils often have elevated concentrations of trace elements, which are gradually released following drainage for agriculture. Our objectives were to use incubation temperatures to vary microbial activity in two metalliferous peats (M7 acidic peat and M3 neutral peat) from the Elba, New York region, and to use periodic leaching to assess the extent of trace element release from these soils. Dried soils were mixed with glass beads to maintain aeration, moistened, and incubated at 4, 16, 28, and 37°C in 10‐cm‐diameter × 8‐cm‐tall columns. Five incubation–leaching cycles were performed, each consisting of 7.3 d of incubation (28 d for the final cycle) followed by 16 h of leaching with synthetic acid rain at 2.5 mm h−1 Microbial activity was determined initially and after the final leaching by measuring C mineralization following glucose stimulation. Cumulative respiration results were ranked 28 > 16 > 4 > 37°C, with M7 acidic peat respiration values greater than M3 neutral peat at each temperature. Initial leachate pH levels were between 2 and 4, with acidification less pronounced and shorter‐lived for the M3 peat. Leachate S, dissolved organic carbon (DOC), NO3–N, and trace elements declined with successive leachings (rebounding slightly in the final M3 leachate), with concentrations typically greater in the M7 leachate. Elemental losses followed the same general ranking (28 > 16 > 4 > 37°C); losses at 28°C were 15 to 22% for As, Cd, Ni, and Zn from the M7 peat; losses from M3 were comparable only for Cu (1%) and Ni (19%). The correlation of respiration with S, DOC, and trace elements losses indicates that microbial processes mediated the release of trace elements in both peat soils. Neutral M3 peat pH levels limited losses of most analytes.
Effect of Rainfall Simulator and Plot Scale on Overland Flow and Phosphorus Transport
Authors: Sharpley Andrew , Kleinman Peter 
Published: June 2010

ABSTRACTRainfall simulation experiments are widely used to study erosion and contaminant transport in overland flow. We investigated the use of two rainfall simulators designed to rain on 2‐m‐long (2‐m2) and 10.7‐m‐long (32.6‐m2) plots to estimate overland flow and phosphorus (P) transport in comparison with watershed‐scale data. Simulated rainfall (75 mm h−1) generated more overland flow from 2‐m‐long (20 L m2) than from 10.7‐m‐long (10 L m2) plots established in grass, no‐till corn (Zea mays L.), and recently tilled fields, because a relatively greater area of the smaller plots became saturated (>75% of area) during rainfall compared with large plots (<75% area). Although average concentrations of dissolved reactive phosphorus (DRP) in overland flow were greater from 2‐m‐long (0.50 mg L−1) than 10.7‐m‐long (0.35 mg L−1) plots, the relationship between DRP and Mehlich‐3 soil P (as defined by regression slope) was similar for both plots and for published watershed data (0.0022 for grassed, 0.0036 for no‐till, and 0.0112 for tilled sites). Conversely, sediment, particulate phosphorus (PP), and total phosphorus (TP) concentrations and selective transport of soil fines (<2 μm) were significantly lower from 2‐ than 10.7‐m‐long plots. However, slopes of the logarithmic regression between P enrichment ratio and sediment discharge were similar (0.281–0.301) for 2‐ and 10.7‐m‐long plots, and published watershed data. While concentrations and loads of P change with plot scales, processes governing DRP and PP transport in overland flow are consistent, supporting the limited use of small plots and rainfall simulators to assess the relationship between soil P and overland flow P as a function of soil type and management.
Cotton Defoliant Runoff as a Function of Active Ingredient and Tillage
Authors: Potter Thomas L. , Truman Clint C. , Bosch David D. , Bednarz Craig W. 
Published: June 2010

ABSTRACTCotton (Gossypium hirsutum L.) defoliant runoff was recently identified as an ecological risk. However, assessments are not supported by field studies. Runoff potential of three defoliant active ingredients, dimethipin (2,3‐dihydro‐5,6‐dimethyl‐1,4‐dithiin 1,1,4,4‐tetraoxide), thidiazuron (N‐phenyl‐N‐1,2,3‐thidiazol‐5‐yl‐urea), and tribufos (S,S,S‐tributyl phosphorotrithioate) was investigated by rainfall simulation on strip (ST) and conventionally tilled (CT) cotton in south central Georgia. Simulated rainfall timing relative to defoliant application (1 h after) represented an extreme worst‐case scenario; however, weather records indicate that it was not unrealistic for the region. Thidiazuron and tribufos losses were 12 to 15% of applied. Only 2 to 5% of the more water soluble dimethipin was lost. Although ST erosion rates were less, loss of tribufos, a strongly sorbing compound, was not affected. Higher sediment–water partition coefficients (kd) were measured in ST samples. This likely explains why no tillage related differences in loss rates were observed, but it is unknown whether this result can be generalized. The study was conducted in the first year following establishment of tillage treatments at the study site. As soil conditions stabilize, ST impacts may change. Data provide an estimate of the maximum amount of the defoliants that will run off during a single postapplication storm event. Use of these values in place of the default value in runoff simulation models used in pesticide risk assessments will likely improve risk estimate accuracy and enhance evaluation of comparative risk among these active ingredients.
Contrasting Physiological Responses of Dwarf Sea‐Lavender and Marguerite to Simulated Sea Aerosol Deposition
Authors: Sánchez‐Blanco M. J. , Rodríguez P. , Morales M. A. , Torrecillas A. 
Published: June 2010

ABSTRACTPlants of two wild native species from littoral areas, marguerite [Argyranthemum coronopifolium (Willd.) C.J. Humphries] and dwarf sea‐lavender [Limonium pectinatum (Aiton) O. Kuntze], grown in an unheated plastic greenhouse, were sprayed 2 to 3 min per day over a 7‐d period with different aqueous solutions containing (i) an anionic surfactant (S1); (ii) a solution simulating the composition of sea aerosol (S2); (iii) a solution simulating sea aerosol with anionic surfactant (S3), and (iv) deionized water alone (control). The plant resistance to sea aerosol and the ability to recover from treatments were studied. By the end of the spraying period, marguerite showed a significant reduction in growth compared with control. However, most of the growth parameters were significantly unaffected in dwarf sea‐lavender when plants were treated with sea aerosol containing surfactant. Measurements of water relations variables in marguerite showed a slight decrease in leaf turgor potential after spraying with sea aerosol containing surfactant. The surfactant enhanced the foliar absorption of salt in marguerite plants, inducing reductions in leaf stomatal conductance and causing such damage in the photosynthetic apparatus that the level of net photosynthesis decreased and had not recovered by the end of the experiment. The treatments had no effect on leaf stomatal conductance and photosynthesis rate in dwarf sea‐lavender plants. The response of the species studied to sea aerosol was related to the degree of salinity tolerance. Although both species are wild native plants from littoral areas, marguerite is not salt tolerant and was the most sensitive to the sea aerosol treatments, while dwarf sea‐lavender, a halophyte species, was more efficient at decreasing the toxic salt content of the tissues as its growth and ornamental characteristics were not affected.
Infiltration and Adsorption of Dissolved Atrazine and Atrazine Metabolites in Buffalograss Filter Strips
Authors: Krutz L. J. , Senseman S. A. , Dozier M. C. , Hoffman D. W. , Tierney D. P. 
Published: June 2010

ABSTRACTVegetated filter strips (VFS) potentially reduce the off‐site movement of herbicides from adjacent agricultural fields by increasing herbicide mass infiltrated (Minf) and mass adsorbed (Mas) compared with bare field soil. However, there are conflicting reports in the literature concerning the contribution of Mas to the VFS herbicide trapping efficiency (TE). Moreover, no study has evaluated TE among atrazine (6‐chloro‐N‐ethyl‐N′‐isopropyl‐[1,3,5]triazine‐2,4‐diamine) and atrazine metabolites. This study was conducted to compare TE, Minf, and Mas among atrazine, diaminoatrazine (DA, 6‐chloro‐[1,3,5]triazine‐2,4‐diamine), deisopropylatrazine (DIA, 6‐chloro‐N‐ethyl‐[1,3,5]triazine‐2,4‐diamine), desethylatrazine (DEA, 6‐chloro‐N‐isopropyl‐[1,3,5]triazine‐2,4‐diamine), and hydroxyatrazine (HA, 6‐hydroxy‐N‐ethyl‐N′‐isopropyl‐[1,3,5]triazine‐2,4‐diamine) in a buffalograss VFS. Runoff was applied as a point source upslope of a 1‐ × 3‐m microwatershed plot at a rate of 750 L h−1 The point source was fortified at 0.1 μg mL−1 atrazine, DA, DIA, DEA, and HA. After crossing the length of the plot, water samples were collected at 5‐min intervals. Water samples were extracted by solid phase extraction and analyzed by high performance liquid chromatography (HPLC) photodiode array detection. During the 60‐min simulation, TE was significantly greater for atrazine (22.2%) compared with atrazine metabolites (19.0%). Approximately 67 and 33% of the TE was attributed to Minf and Mas, respectively. These results demonstrate that herbicide adsorption to the VFS grass, grass thatch, and/or soil surface is an important retention mechanism, especially under saturated conditions. Values for Mas were significantly higher for atrazine compared with atrazine's metabolites. The Mas data indicate that atrazine was preferentially retained by the VFS grass, grass thatch, and/or soil surface compared with atrazine's metabolites.
Modeling Macropore Flow Effects on Pesticide Leaching
Authors: Roulier Stéphanie , Jarvis Nicholas 
Published: June 2010

ABSTRACTMacropore flow is a key factor determining pesticide fate, but models accounting for this process need parameters that cannot be easily measured. This study was conducted to investigate the use of inverse techniques to estimate parameters controlling macropore flow and pesticide fate in the dual‐permeability model MACRO. Undisturbed columns were sampled at three landscape positions (hilltop, slope, hollow) with contrasting texture and organic carbon content. Transient leaching experiments were performed for an anionic tracer and the herbicide MCPA (4‐chloro‐2methylphenoxy acetic acid) during a 4‐mo period, first under natural rainfall, and then under controlled irrigation in the laboratory. The tracer breakthrough for the finer‐textured soil from the hilltop showed strong evidence of macropore flow, resulting in a rapid leaching of MCPA, while leaching was minimal from the organic‐rich hollow soil, since macropore flow was weaker and adsorption stronger. The MACRO model was linked to the inverse modeling program SUFI (Sequential Uncertainty Fitting) to enable calibration of nine key model parameters. Based on calculated model efficiencies, MACRO–SUFI gave generally good predictions of water movement and tracer and pesticide transport, although some errors were attributed to difficulties in simulating the effects of soil moisture on degradation and the timing of water outflows. Even after calibration, significant uncertainties remained for some key parameters controlling macropore flow. Nevertheless, the parameter estimates were significantly different between landscape positions and could also be related to basic soil properties. The posterior uncertainty ranges could probably be reduced with a more exhaustive sampling of the parameter space and improved experimental designs.