bluuebunny/crossref_metadata_2025 huggingface dataset:
Declines of Organic Nutrient Pools in Tropical Semi‐Arid Soils under Subsistence Farming
Authors: da Silva Fraga Vânia , Salcedo Ignacio H.
Published: January 2014

Soils under subsistence farming in semi‐arid northeastern Brazil are showing progressive declines in soil fertility. In this study, we assessed the effects of subsistence farming on losses of organic nutrient pools in 10 independent sites that were distributed in five districts of two states. Each site had adjacent areas under dry forest and subsistence farming. Areas under each land use were separated in two groups that had different degrees of land degradation. Group assignment was based on land use history and visual observations of vegetation‐soil degradation and was further evaluated using137Cs activity to estimate erosion. Four combinations of land use degradation were defined: undisturbed (UDF) and disturbed (DDF) dry forest, and preserved (PC) and degraded (DC) cultivated land. Soils were sampled in the 0‐ to 7.5‐ and 7.5‐ to 15‐cm layers. The137Cs concentrations declined in the order UDF > DDF ≈ PC > DC. Soil C and N concentrations in DC (8.9 and 0.94 g kg−1soil, respectively) were half of those in UDF (17.8 and 1.51 g kg−1soil, respectively). The organic P (Po)/inorganic P (Pi) ratio was 1.47 in UDF and decreased to 0.82 in PC and DC. Carbon losses in DC were attributed to erosion (43%) and to mineralization (57%) processes. Differences between UDF and other land uses were greater in the 0 to 7.5 cm than in the 0‐ to 15‐cm layer. Carbon and N losses in low‐P status soils, in addition to limited water availability and unsuitable land management techniques, are likely to restrict the recovery of degraded soils by traditional bush fallow techniques.
Influence of Edaphic Factors on Sugar Maple Nutrition and Health on the Allegheny Plateau
Authors: Bailey S. W. , Horsley S. B. , Long R. P. , Hallett R. A.
Published: January 2014

Sugar maple (Acer saccharumMarsh.) decline has been a problem on the Allegheny Plateau for the last two decades. Previous work found that sugar maple is predisposed to decline by poor nutrition and incited to decline by severe insect defoliation. Nutritional diagnoses have been based on foliar chemistry; there is little information on soil attributes that influence susceptibility. We evaluated relationships among soil characteristics, foliar chemistry, and sugar maple decline for 43 stands on the Allegheny Plateau in New York and Pennsylvania using correlation and stepwise regression techniques. Foliar Ca and Mg concentrations correlated with soil exchangeable cations expressed on a concentration or site capital basis. Expression of base cation availability as a saturation value, or in ratio with Al, slightly improved the relationships, suggesting that antagonistic cations are important to sugar maple nutrition. The best predictions of foliar chemistry were made by regressions that considered soil chemistry across the depth of the B horizon, suggesting the importance of looking at more than one depth to assess nutrition. Landscape position and glacial history determined whether weathering products were effectively delivered to the rooting zone, resulting in the observed landscape gradients. All declining stands were on unglaciated upper landscape positions where soils had lower Ca and Mg levels compared with other landscape positions. Declining stands had <2% Ca saturation and <0.5% Mg saturation in the upper B and <4% Ca saturation and <0.6% Mg saturation in the lower B. These thresholds may be useful in predicting susceptibility to sugar maple decline.
Adsorption of Dissolved Organic Carbon and Nitrogen in Soils of a Weathering Chronosequence
Authors: Lilienfein Juliane , Qualls Robert G. , Uselman Shauna M. , Bridgham Scott D.
Published: January 2014

Leaching of dissolved organic matter (DOM) and the associated nutrient elements can be a significant form of loss from developing ecosystems. We studied how the adsorption of dissolved organic C (DOC) and N (DON) changes during soil development and determined which soil characteristics control adsorption. We sampled 77, 255, 616, and about 1200+ yr‐old andesitic soils at five depths and did adsorption isotherm experiments fit to a modified Langmuir equation. We measured DOC and DON in soil solution at the 10‐ to 20‐, 40‐, and 150‐cm soil depths during the snowmelt period to compare with adsorption experiments. Ability of the soils to adsorb DOM increased with soil age. Regression analyses were performed between adsorption capacity or the null point concentration of either DOC or DON and the independent variables soil organic C (SOC), N, allophane, oxalate extractable Fe, crystalline Fe, and specific surface area. The best relationships were found between adsorption capacity and the allophane/SOC ratio (r2 = 0.88), and between the null point concentration of DOC or DON and the SOC/allophane ratio (DOC: r2 = 0.85; DON: r2 = 0.77). Stepwise multiple regression indicated that oxalate‐extractable Fe and specific surface area contributed only small increases in the multiple R2 High correlations between the null‐point adsorption of DOC or DON and the DOC (r2 = 0.92) or DON (r2 = 0.86) field soil solution concentrations indicated that results obtained in laboratory experiments were applicable to field conditions. The cause of the increased ability of the soils to adsorb and retain DOM during soil development appears to be an increase in allophane concentrations.
An Efficient Markov Chain Model for the Simulation of Heterogeneous Soil Structure
Authors: Wu Keijan , Nunan Naoise , Crawford John W. , Young Iain M. , Ritz Karl
Published: January 2014

The characterization of the soil habitat is of fundamental importance to an understanding of processes associated with sustainable management such as environmental flows, bioavailability, and soil ecology. We describe a method for quantifying and explicitly modeling the heterogeneity of soil using a stochastic approach. The overall aim is to develop a model capable of simultaneously reproducing the spatial statistical properties of both the physical and biological components of soil architecture. A Markov chain Monte Carlo (MCMC) methodology is developed that uses a novel neighborhood and scanning scheme to model the two‐dimensional spatial structure of soil, based on direct measurements made from soil thin sections. The model is considerably more efficient and faster to implement than previous approaches, and allows accurate modeling of larger structures than has previously been possible. This increased efficiency also makes it feasible to extend the approach to three dimensions and to simultaneously study the spatial distribution of a greater number of soil components. Examples of two‐dimensional structures created by the models are presented and their statistical properties are shown not to differ significantly from those of the original visualizations.
Three‐Dimensional Numerical Modeling of a Capacitance Probe
Authors: Bolvin Hervé , Chambarel André , Chanzy André
Published: January 2014

In this study, a three‐dimensional model represents a capacitance probe measurement. It is based on Laplace's equation, which is solved using the Finite Element Method. A three‐dimensional model can accurately represent both the probe geometry and nonaxisymmetric components of soil heterogeneity. As a result we have obtained a three‐dimensional‐cartography of electrical potential V(x, y, z) in the medium surrounding the electrodes and the effective dielectric constant of the media observed. The model was implemented to address such questions as the influence of the air/soil boundary when making measurements near the surface and the probe's volume of influence. It is shown that the volume of influence of the probe can be derived from a weighting function based on the density of electromagnetic energy and can be computed for a homogeneous medium. It is numerically observed that the probe's volume of influence is quite independent of the permittivity of the medium in which the probe is embedded. It is then verified that dielectric perturbations located outside the so defined volume of influence have little effect on the calculation of the effective dielectric constant seen by the capacitance probe.
SIMPLIFIED COMPUTATIONAL APPROACH FOR DUAL‐PROBE HEAT‐PULSE METHOD
Authors: Knight J. H. , Kluitenberg G. J.
Published: January 2014

Two equations are currently available for estimating soil volumetric heat capacity (ρc) with the dual‐probe heat‐pulse (DPHP) method. One is simple but gives only approximate results because it assumes that the DPHP sensor releases an impulse of heat instantaneously. The other explicitly accounts for the finite duration of heating and gives exact results. Unfortunately, the equation that gives exact results involves the exponential integral function, which is not available in most computer spreadsheet software packages or data logger function libraries. In this note we introduce an approximation of the exact equation that contains only simple algebraic functions. The approximation consists of the first five terms of a Taylor series, which are written as a telescoped polynomial for computational purposes. For most applications of the DPHP method, the polynomial approximation gives estimates of ρc that are at least an order of magnitude more accurate than estimates obtained from the simple equation based on instantaneous heating.
Interaction of Iron Chelating Agents with Clay Minerals
Authors: Siebner-Freibach H. , Hadar Y. , Chen Y.
Published: January 2014

Organic ligands play an important role in metal transport and availability in soils. However, their interaction with the solid phase of soils has not been sufficiently investigated. Two efficient Fe chelators were investigated in this study, as free ligands as well as Fe complexes: (i) the microbial siderophore ferrioxamine B (desferrioxamine B [DFOB] and ferrioxamine B [FOB], respectively); (ii) the synthetic chelating agent ethylenediamine di‐o‐hydroxyphenylacetic acid (EDDHA and FeEDDHA, respectively). Batch experiments were conducted to characterize their adsorption to Ca‐ and Na‐montmorillonite as well as to Fe‐montmorillonite (for EDDHA and FeEDDHA) and Ca‐kaolinite. Kinetics of adsorption, equilibrium adsorption isotherms, and effects of pH on adsorption were measured. Adsorption of DFOB and FOB to montmorillonite was rapid and adsorption isotherms indicated high affinity. The type of saturating cation affected the adsorption of DFOB but not that of FOB. Significant hysteresis between adsorption and desorption was exhibited. The effect of Ca2+in solution on desorption compared with that of Na+, was found to vary with their solution concentrations. Ethylenediamine di‐o‐hydroxyphenylacetic acid adsorption to montmorillonite exhibited a linear adsorption isotherm and significantly higher affinity than that of FeEDDHA. The adsorption decreased significantly with the following order of saturating cation: Ca2+> Fe3+> Na+Adsorption of all examined substances to kaolinite was extremely low. Adsorption mechanisms of DFOB and EDDHA and their Fe complexes to clays and the environmental implications are discussed.
Recementation of Crushed Ortstein by Blueberry Leaf Extract
Authors: Bronick C. J. , Mokma D. L. , Li H. , Boyd S. A.
Published: January 2014

Cementing of sand grains by organo‐Al and organo‐Fe complexes is thought to be a gradual process and takes at least a few thousand years. The resulting ortstein inhibits root penetration. Blueberries (Vaccinium corymbosum L.) in isolated regions of blueberry fields in Michigan experience reduced growth that has been attributed to the presence of ortstein. Growers have used deep tillage to break up ortstein in these regions with only temporary benefits. This study was conducted to determine (i) if crushed ortstein would recement upon exposure to aqueous blueberry leaf extract, (ii) rate of recementation, (iii) the degree of recementation, (iv) the strength of recemented materials, and (v) the nature of the cementing agents. Crushed ortstein from Saugatuck sand (sandy, mixed, mesic, shallow, ortstein Typic Durorthod) was passed through a 2‐mm sieve and used in column experiments to assess recementation. Aqueous blueberry leaf extracts were added daily to crushed ortstein columns for 1.5‐, 3‐, 6‐, and 12‐wk periods. Green and brown blueberry leaves were used to prepare extracts and compare the effect of leaf age on recementation. The degree and strength of aggregation were assessed by determining the amount of treated ortstein remaining on a 2‐mm sieve, and by tensile strength analysis of aggregated material. Extensive recementation (96% aggregation) of crushed ortstein occurred after 1.5 wks. Cementation was highest in the upper layers and decreased with depth in the column. Degree and strength of cementation tended to increase with duration of the experiment. Green leaf extract caused more recementation of crushed ortstein than brown leaf extract. Recementation is thought to result from relocation of Al by organic compounds, originating from leaf extracts, to contact points between sand grains.
Scale‐Dependent Relationship between Wheat Yield and Topographic Indices
Authors: Si Bing Cheng , Farrell Richard E.
Published: January 2014

Topography can have a significant influence on crop yield, thus a better understanding of the effects of topographical parameters on crop yield is important—especially for site‐specific soil management. The objective of this study was to determine whether topographical indices developed for hydrological studies could be used as indicators of crop yield using a wavelet approach. The effects of soil curvature, upslope length, and a wetness index on wheat grain yields in a hummocky terrain were investigated along a transect on a clay loam Black soil (Blaine Lake Association) in Saskatchewan, Canada. A wavelet approach was used to elucidate the processes underlying the relationships between crop yield and topographical parameters. Wheat grain yields had significant correlations with upslope length (R2 = 0.60) and the wetness index (R2 = 0.46), whereas soil surface curvature explained only 15% of the variations in grain yield. Wavelet analyses revealed that significant variations occurred at scales <160 m for wheat grain yield, 280 m for upslope lengths, and 110 m for the wetness index. The cross wavelet analysis indicated that significant covariance existed at scales <180 m between wheat grain yield and upslope lengths and at scales <140 m between wheat yield and the wetness index, at a 99% confidence level.
Root Development of Young Loblolly Pine in Spodosols in Southeast Georgia
Authors: Adegbidi H. G. , Comerford N. B. , Jokela E. J. , Barros N. F.
Published: January 2014

Determining fine‐root dynamics is fundamental to forest soil nutrient management yet root development of fast‐growing loblolly pine (Pinus taedaL.) is poorly documented. The objectives of this study were to (i) investigate the spatial and temporal root development of loblolly pine; (ii) evaluate the relationship between root length, number of roots exiting a trench face, and root mass densities; and (iii) determine if there is a relationship between fine root and foliage mass as well as root and shoot mass during the early stages of stand development. Thirteen forest sites in southeastern Georgia covering ages 1 to 4 yr old were used. Roots temporal and spatial distributions were investigated using a trench method. The value ofNX(# roots cm−2) was measured in August/September during the first 4 yr of stand development. Root density depth distributions fit a natural logarithm relationship with soil depth. An empirical model for root development over time was developed. A two‐dimensional evaluation of root development showed that roots were present in 13 to >60% of the soil volume from Year 1 to Year 4. Regressions between root length density,LV(cm root cm−3soil), andNXwere weak until root mass and soil depth were included. Lastly, it was shown that the ratio of fine root mass/foliage mass was stable after the establishment phase, as was the ratio of root to shoot.
Adsorption of Dissolved Organic and Inorganic Phosphorus in Soils of a Weathering Chronosequence
Authors: Lilienfein Juliane , Qualls Robert G. , Uselman Shauna M. , Bridgham Scott D.
Published: January 2014

Leaching of dissolved organic matter (DOM) and associated nutrients can be a significant loss from developing ecosystems. We studied how the adsorption of dissolved organic P (DOP) and PO4 changes during the development of young andesitic soils and determined which soil characteristics are responsible for these changes. We sampled 77, 255, 616, and about 1200+ yr‐old andesitic soils at the 0‐ to 10‐, 30‐ to 40‐, and 140‐ to 150‐cm soil depths and performed adsorption isotherm analyses that were described using a modified Langmuir (for DOP) or linear equation (for PO4). We also sampled soil solution at the 10‐ to 20‐, 40‐, and 150‐cm soil depths during the main snow melt period in 2001 and 2002 and analyzed it for DOP and PO4 The ability of the soils to adsorb DOP and PO4 increased with soil age. Stepwise multiple regression analyses between the adsorption capacity for DOP, or the slope of the adsorption isotherm for PO4, and several soil parameters showed that allophane concentrations control the adsorption of DOP and PO4 in these soils. Tests of preferential adsorption of DOP vs. PO4 and DOC vs. DOP showed that the adsorption strength increased in the following order: DOC < DOP < PO4 The preferential adsorption of PO4 vs. DOP and DOP vs. DOC increased significantly with increasing soil development, whereas the soil depth did not have a consistent and significant effect. Significant correlations between the null‐point adsorption of DOP or PO4 and field soil solution concentrations indicated that the results obtained in laboratory experiments were applicable to field conditions. Consequently, the tendency of DOP and PO4 to leach from these andesitic soils decreases as soils and ecosystem develop.
Three‐Porosity Model for Predicting the Gas Diffusion Coefficient in Undisturbed Soil
Authors: Moldrup Per , Olesen Torben , Yoshikawa Seiko , Komatsu Toshiko , Rolston Dennis E.
Published: January 2014

The soil gas diffusion coefficient (DP) and its dependency on air‐filled porosity (ε) govern most gas diffusion‐reaction processes in soil. Accurate DP(ε) prediction models for undisturbed soils are needed in vadose zone transport and fate models. The objective of this paper was to develop a DP(ε) model with lower input parameter requirement and similar prediction accuracy as recent soil‐type dependent models. Combining three gas diffusivity models: (i) a general power‐law DP(ε) model, (ii) the classical Buckingham (1904) model for DP at air saturation, and (iii) a recent macroporosity dependent model for DP at −100 cm H2O of soil–water matric potential (ψ), yielded a single equation to predict DP as a function of the actual ε, the total porosity (Φ), and the macroporosity (ε100; defined as the air‐filled porosity at ψ = −100 cm H2O). The new model, termed the three‐porosity model (TPM), requires only one point (at −100 cm H2O) on the soil–water characteristic curve (SWC), compared with recent DP(ε) models that require knowledge of the entire SWC. The DP(ε) was measured at different ψ on undisturbed soil samples from dark‐red Latosols (Brazil) and Yellow soils (Japan), representing different tillage intensities. The TPM and five other DP(ε) models were tested against the new data (17 soils) and data from the literature for additional 43 undisturbed soils. The new TPM performed equally well (root mean square error [RMSE] in relative gas diffusivity <0.027) as recent SWC‐dependent DP(ε) models and better than typically used soil type independent models.
Critical Coagulation Concentration of Paddy Soil Clays in Sodium–Ferrous Iron Electrolyte
Authors: Saejiew Atinut , Grunberger Olivier , Arunin Somsri , Favre Fabienne , Tessier Daniel , Boivin Pascal
Published: January 2014

Sodium affected rice (Oryza sativa L.)‐cropped fields are very common. Due to their high exchangeable Na percentage, clay dispersion is one of the major risks for these soils when they are flooded. During flooding, Fe2+ may become a major cation due to reductive dissolution of Fe oxides, but the flocculation effect of Fe2+ is not known. In this paper, the effect of Fe2+ on clay flocculation is studied by establishing critical coagulation concentration (CCC) curves of clays extracted from a paddy soil of Northeast Thailand. The effect of Na‐Fe2+ and Na‐Ca electrolytes on the CCC values is compared for sodium adsorption ratio (SAR) values ranging from 0 to 40 and total electrolyte concentration (TEC) ranging from 0.5 to 10 mmol L−1 The extracted clay is a mixture of kaolinite and smectite but only the smectite and some poorly ordered kaolinite could be dispersed. The CCC values largely reflected the behavior of smectite, in agreement with previous studies. The CCC values were equal for electrolytes with Fe2+ or Ca2+ cations, suggesting that Fe2+ strongly adsorbs on smectite exchange sites and behaves similarly to Ca2+ The Fe2+ concentration needed to flocculate the clays was at maximum 0.6 mmol L−1 for the most dispersive electrolytes, which is a common concentration in flooded rice fields. Reductive dissolution of Fe can protect sodic soils from clay dispersion upon flooded rice cropping.
Oxidation Potentials of Soil Organic Matter in Histosols under Different Tillage Methods
Authors: Morris D. R. , Gilbert R. A. , Reicosky D. C. , Gesch R. W.
Published: January 2014

Organic soils in the Everglades Agricultural Area (EAA) of southern Florida, USA, are subsiding due primarily to oxidation by aerobic microorganisms. Since there are large C losses in drained Histosols, it is not certain if minimum tillage will significantly reduce soil C losses below the background levels. The objective of this experiment was to determine if increasing the surface soil disturbance through tillage significantly increases the soil organic matter oxidation potential (OP) in Histosols. Tillage treatments from lowest to highest soil disturbance consisted of (i) no‐till; (ii) tine implement cultivation, one pass; (iii) tine implement cultivation, two passes; (iv) heavy harrow disking; and (v) switchplowing. Treatments were conducted on two fields (bare fallow and plant residue covered). Surface soil samples (0–15 cm) and all microbial measurements were taken on 0, 1, 4, 13, 28, and 42 d after tillage. The switchplow treatment had the greatest OP (14C oxidation of benzoate) and soil microbial CO2 respiration (RESP) averaged across the 42‐d period compared with the other treatments. No‐till tended to have the lowest OP and RESP. Other tillage treatment effects were intermediate depending on field type. Correlation analyses indicated that greater quantities of extractable N (EXN) were related to increased OP in both fields, while higher quantities of extractable C (EXC) were related to increased RESP in both fields. This research demonstrates that minimum tillage can be used on Histosols to reduce C loss and thereby reduce soil subsidence.
Evaluation of Soil Surface Charge Using the Back‐Titration Technique
Authors: Ge Ying , Hendershot William
Published: January 2014

Variable surface charge (Qv) is one of the most important soil properties controlling ion adsorption on the soil solid phase. In this study, the back‐titration technique was used to determine the Qv of soils with a wide range of properties. The procedure defines the Qv as the OH− consumption by surface reactions corrected for dissolution of the solid phase and other solution reactions (e.g., metal hydrolysis). The Qv, varying from 0 to 80 cmolc kg−1, was dependent on the pH of the soil suspension and the amount of soil organic matter. We used the non‐ideal competitive adsorption (NICA)–Donnan model to simulate the surface charge, assuming a bimodal distribution of H+ affinity on the soil solid phase. With the charge data and Microsoft Excel, the NICA‐Donnan model parameters were optimized. The model provided an excellent fit to the experimental data. When the pH was below 8, the surface charge was dominantly distributed to the Type 1 sites; the Type 2 sites started to contribute to the total surface charge at pH > 8. Multiple linear regressions showed that the charge maxima (Qmax) of the two sites were related to soil cation‐exchange capacity (CEC) and organic C (Org. C); these significant statistical relationships may be used to estimate the surface charge of soils using values of commonly measured soil parameters.
A Case‐based Reasoning Approach to Fuzzy Soil Mapping
Authors: Shi Xun , Zhu A-Xing , Burt James E. , Qi Feng , Simonson Duane
Published: January 2014

Some problems in traditional soil mapping—high cost, high subjectivity, poor documentation, and low accuracy and precision—have motivated the development of a knowledge‐based fuzzy soil mapping system, named SoLIM (Soil Land Inference Model). The rule‐based method of the current SoLIM has its limitations. It requires explicit knowledge of the details of soil–environment relationships and it assumes that the environmental variables are independent from each other. This paper presents a case‐based reasoning (CBR) approach as an alternative to the rule‐based method. Case‐based reasoning uses knowledge in the form of specific cases to solve a new problem, and the solution is based on the similarities between the new problem and the available cases. With the CBR method, soil scientists express their knowledge by providing locations (cases) indicating the association between a soil and a landscape or environmental configuration. In this way, the soil scientists avoid the difficulties associated with depicting the details of a soil–environment relationship and assuming the independence of environmental variables. The CBR inference engine computes the similarity between the environmental configuration at a given location and that associated with each case representing a soil type, and then uses these similarity values to approximate the similarity of the local soil at the given location to the given soil type. A case study in southwestern Wisconsin demonstrates that CBR can be an easy and effective way for soil scientists to express their knowledge. For the study area, the result from the CBR inference engine is more accurate than that from the traditional soil mapping process. Case‐based reasoning can be a good solution for a knowledge‐based fuzzy soil mapping system.
Predicting Soil Properties from Organic Matter Content following Mechanical Site Preparation of Forest Soils
Authors: Prévost Marcel
Published: January 2014

The difficulties of sampling forest soils and their high spatial variability make estimation of soil physical properties following forest operations laborious. To develop prediction tools, soils were sampled from two sites located in the boreal forest of northern Québec, Canada. Soil organic matter (OM) content was found to be closely related to bulk density (Db) and porosity after clearcutting and mechanical site preparation (MSP) on these sites. Reasonably good estimates ofDb, with an average error of 18 to 20%, can be made from the easily measurable OM concentration and the logarithmic relationships (R2= 0.731 and 0.847, respectively for the Alma and Chibougamau sites) developed in this study. The organic density approach, recently developed for forest soils in New England, was found to be less precise (R2= 0.637) than the logarithmic relationships following soil disturbance. For the two sandy till soils in northern Québec, the equation based on this concept best fit the data with a pure OM bulk density (Dbo) of 0.159 Mg m−3and a pure mineral matter bulk density (Dbm) of 1.561 Mg m−3The equations presented in this study also explain between 60 and 70% of the variation in porosity and C/N ratio from OM concentration, with prediction errors of 13 and 24%, respectively. In spite of soil surface disturbance associated with MSP, the easily measurable OM concentration can be used to predictDb, porosity, and C/N ratio.
Reforestation and Topography Affect Montane Soil Properties, Nitrogen Pools, and Nitrogen Transformations in Hawaii
Authors: Scowcroft Paul G. , Haraguchi Janis E. , Hue Nguyen V.
Published: January 2014

Land use changes, such as deforestation and reforestation, modify not only the organisms inhabiting affected areas, but also above‐ and belowground environments. Topography further influences local vegetation and environment. Effects of topography and re‐establishment of N‐fixing koa (Acacia koaA. Gray) trees in +100‐yr‐old montane grassland on surface soil properties, N pools, and N transformations were assessed using standard and15N‐isotope pool dilution methods. Data were collected for soils on slopes and in drainage bottoms located in grassland, under 9‐ to 11‐yr‐old planted koa, and in nearby old‐growth koa‐ohia (Metrosideros polymorphaGaud.) forest. Soil under planted koa had significantly lower fine soil bulk density and pH than soil in grassland, and had concentrations of total C, total N, and extractable Mg and C/N ratio intermediate between grassland and forest. Topographic position affected pH and concentrations of total C, total N, and extractable P. Ten years after koa trees were re‐introduced to grassland, the concentration of soil NH4+–N had increased above levels found even in intact forest, and the concentration of NO3−–N was intermediate between forest and grassland. Ammonium dominated the inorganic N pools in grassland soil and NO3−dominated in forest soil. Under planted koa, NH4+domination was beginning to give way to NO3−domination. Soil microorganisms were potentially strong competitors for inorganic N on grassland slopes where they immobilized nearly all the inorganic N that was produced during short‐ and medium‐term field incubations, thus leaving little for plant growth. Re‐establishment of koa trees increased soil N availability.
Boron Release from Weathering of Illites, Serpentine, Shales, and Illitic/Palygorskitic Soils
Authors: Su Chunming , Suarez Donald L.
Published: January 2014

Despite extensive research on B adsorption and release from soils, mineral sources of B within natively high B soils remain poorly understood. The objectives of this study were to identify source minerals contributing to the continued B release after extraction of soluble B and to estimate B release rate from weathering of B‐containing minerals and soils. Two specimen illites (Morris and Fithian), two shales (Salt Creek and Moreno Gulch), a fresh and a weathered serpentine (antigorite) from the Coastal Range of California, a Traver silt loam (coarse‐loamy, mixed, superactive thermic Natric Haploxeralfs) and a Twisselman clay loam [fine, mixed (calcareous), superactive thermic Typic Torriorthents] both containing illite and palygorskite were successively extracted 7 to 26 times following each 12‐h equilibration in 0.1 and 0.01 M CaCl2 solution until the supernatant solutions contained less than the detection limit of 0.001 mmol B L−1 Subsequently, the <2‐μm and 2‐ to 20‐μm size fractions were separated and reacted in deionized water at pH 5, 7, and 9 adjusted with HCl and NaOH. The total B of the separated fractions ranged from 5.1 to 28 mmol B kg−1 and the surface areas from 5.7 to 126 m2 g−1 Boron release rates decreased with time and increasing pH. Average B release rates from 150 to 180 d ranged from 0.005 fmol m−2 s−1 for Salt Creek shale (2–20 μm) to 0.342 fmol m−2 s−1 for Traver silt (<2 μm) at pH 5, 0.004 fmol m−2 s−1 for Salt Creek shale (2–20 μm) to 0.060 fmol m−2 s−1 for Traver silt (<2 μm) at pH 7, and 0.002 fmol m−2 s−1 for weathered serpentine (2–20 μm) to 0.044 fmol m−2 s−1 for Traver silt (<2 μm) at pH 9. Nonstoichiometric dissolution was found for all materials at all pH levels. Illite, chlorite, and palygorskite were identified in the clay and silt fractions of the soils. Boron release from the two soils was accompanied with high Mg release into the solution, suggesting palygorskite as a major source for B.
Metabolic profiling of biofilm bacteria known to cause microbial influenced corrosion
Authors: Beale D. J. , Morrison P. D. , Key C. , Palombo E. A.
Published: January 2014

This study builds upon previous research that demonstrated the simplicity of obtaining metabolite profiles of bacteria in urban water networks, by using the metabolic profile of bacteria extracted from a reticulation pipe biofilm, which is known to cause microbial influenced corrosion (MIC). The extracellular metabolites of the isolated bacteria, and those bacteria in consortium, were analysed in isolation, and after exposure to low levels of copper. Applying chemometric analytical methodologies to the metabolomic data, we were able to better understand the profile of the isolated biofilm bacteria, which were differentiated according to their activity and copper exposure. It was found that the metabolic activity of the isolated bacteria and the bacteria in consortium varied according to the bacterium's ability to metabolise copper. This demonstrates the power of metabolomic techniques for the discrimination of water reticulation biofilms comprising similar bacteria in consortium, but undergoing different physico-chemical activities, such as corrosion and corrosion inhibition.
Treatment of municipal wastewater using horizontal flow constructed wetlands in Egypt
Authors: Abou-Elela Sohair I. , Golinelli G. , Saad El-Tabl Abdou , Hellal Mohammed S.
Published: January 2014

The aim of this study was to evaluate the performance of two pilot horizontal flow constructed wetlands (HFCWs) with and without vegetation. Three types of plants namely Canna, Phragmites australis and Cyprus papyrus were used. The surface area of each plant was 654 m2. The flow rate was 20 m3 d−1 and the organic loading rate range was 1.7–3.4 kg BOD d−1 with a detention time of 11 days. The results obtained showed that planted HFCW produced high quality effluent in terms of reduction of chemical oxygen demand (COD; 88%), biochemical oxygen demand (BOD; 91%) and total suspended solids (TSS; 92%) as well as nutrient removal. In addition, 4 logs of total coliform were removed from the planted unit compared with only 3 logs in the unplanted one. The phosphate uptake by the plants reached 29, 30.91 and 38.9 g P m−2 for Canna, Phragmites and Cyprus, respectively, with 60% removal rate in the treated effluent. The nitrogen uptake by the same plants reached 63.1, 49.46 and 82.33 g N m−2. Although, the unplanted unit proved to be efficient in the removal of COD, BOD and TSS, it lacks efficiency in pathogen and nutrient removal. The reclaimed wastewater, after disinfection, could be reused for non-restricted irrigation purposes.
The need for electronic noses for environmental odour exposure assessment
Authors: Capelli Laura , Dentoni Licinia , Sironi Selena , Del Rosso Renato
Published: January 2014

This paper focuses on the opportunities for using electronic noses for odour exposure assessment purposes, especially in cases where dispersion modelling is not applicable. Such cases include, for instance, those sources where a detailed characterisation and quantification of the odour emissions for every hour of the simulation time domain is particularly difficult, due to the nature of the source or to the variability of the emissions over time. In such situations, it is useful to determine odour exposure directly at receptors instead. This paper critically discusses the state of the art of electronic nose technology as far as its application to the determination of odour exposure at receptors is concerned. One example of electronic nose application to the monitoring of odours from an Italian municipal solid waste (MSW) landfill is reported, in order to discuss the instrument's potential and limits. The monitoring results are represented by the number of measures that are classified in a specific olfactory class; this information allows the odour exposure at each monitoring site in terms of odour detection frequency to be determined. Besides a quantification of the odour episodes, electronic noses allowed the identification of the landfill gas as the monitored landfill major odour source.
Enhanced photocatalytic activity of CeO2 using β-cyclodextrin on visible light assisted decoloration of methylene blue
Authors: Pitchaimuthu Sakthivel , Velusamy Ponnusamy
Published: January 2014

An attempt has been made to enhance the photocatalytic activity of CeO2 for visible light assisted decoloration of methylene blue (MB) dye in aqueous solutions by β-cyclodextrin (β-CD). The inclusion complexation patterns between host and guest (i.e., β-CD and MB) have been confirmed with UV–visible spectral data. The interaction between CeO2 and β-CD has also been characterized by field emission scanning electron microscopy analysis. The photocatalytic activity of the catalyst under visible light was investigated by measuring the photodegradation of MB in aqueous solution. The effects of key operational parameters such as initial dye concentration, initial pH, CeO2 concentration as well as illumination time on the decolorization extents were investigated. Among the processing parameters, the pH of the reaction solution played an important role in tuning the photocatalytic activity of CeO2. The maximum photodecoloration rate was achieved at basic pH (pH 11). Under the optimum operational conditions, approximately 99.6% dye removal was achieved within 120 min. The observed results indicate that the decolorization of the MB followed a pseudo-first order kinetics.
Is H2S a suitable process indicator for odour abatement performance of sewer odours?
Authors: Wang B. , Sivret E. C. , Parcsi G. , Wang X. , Le N. M. , Kenny S. , Bustamante H. , Stuetz R. M.
Published: January 2014

Odour abatement units are typically designed and maintained on H2S concentrations, but operational failures are reported in terms of overall odour removal, suggesting a wide range of malodorous compounds emitted from sewers that may not be efficiently removed by existing odour abatement processes. Towards providing greater insight into this issue, several activated carbon filters and biofilters treating odorous emissions from sewer systems in Sydney (Australia) were monitored by collecting and analysing gas samples before and after treatment. The monitoring studies were conducted by both olfactometric measurements and gas-chromatography-based chemical analysis. Single H2S assessment often failed to indicate the odour abatement performance for treatment systems in the abatement units studied, particularly when the incoming H2S concentrations were in the sub-ppm range (i.e. below H2S odour threshold). Chemical analysis indicated that some non-H2S odorous compounds were not removed efficiently during odour treatment. Additionally, when odour eliminations were correlated with the removal of individual compounds (Pearson's correlations) it was observed that the correlation (with a coefficient of 0.79) was best when the overall removal of all the measured odorous compounds that exceeded their odour threshold values was used for the analysis. These findings may help to further advance the design and operation of odour abatement processes to address the treatment of sewer odour emissions.
French vertical flow constructed wetlands: a need of a better understanding of the role of the deposit layer
Authors: Molle Pascal
Published: January 2014

French vertical flow constructed wetlands, treating directly raw wastewater, have become the main systems implemented for communities under 2,000 population equivalent in France. Like in sludge drying reed beds, an organic deposit layer is formed over time at the top surface of the filter. This deposit layer is a key factor in the performance of the system as it impacts hydraulic, gas transfers, filtration efficiency and water retention time. The paper discusses the role of this deposit layer on the hydraulic and biological behaviour of the system. It presents results from different studies to highlight the positive role of the layer but, as well, the difficulties in modelling this organic layer. As hydraulic, oxygen transfers, and biological activity are interlinked and impacted by the deposit layer, it seems essential to focus on its role (and its quantification) to find new developments of vertical flow constructed wetlands fed with raw wastewater.
Perfluorooctanoate and perfluorooctane sulfonate in South African river water
Authors: Mudumbi J. B. N. , Ntwampe S. K. O. , Muganza F. M. , Okonkwo J. O.
Published: January 2014

This study examined the prevalence of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in river water samples (n = 56) and suspended solids (n = 5) from three major Western Cape rivers, in South Africa. Solid phase extraction (SPE) followed by liquid chromatography combined with electrospray tandem mass spectrometry (LC-MS/MS) using an analytical method developed in ISO 25101 (2009), PFOS and PFOA concentration in river water and in suspended solids from the rivers was investigated and quantified. From the results, PFOA and PFOS were detected in all the river water samples and were found in concentrations up to 314 and 182 ng/L for Diep River; 390 and 47 ng/L for Salt River; and 146 and 23 ng/L for Eerste River, respectively. In suspended solids, concentrations for PFOS and PFOA were 28 and 26 ng/g for Diep River; 16 and less than limit of detection for Eerste River; and 14 and 5 ng/g for Salt River, respectively. Some of these concentrations are higher than those previously reported in similar studies in various countries, and this suggests there is a cause for concern, in the Western Cape, South Africa, particularly in catchments where river and ground water is drawn for agricultural purposes in the province.
Simultaneous carbon and nitrogen removal from municipal wastewater in full-scale unaerated/aerated submerged filters
Authors: Jácome A. , Molina J. , Novoa R. , Suárez J. , Ferreiro S.
Published: January 2014

Characterization and evaluation of a biological submerged filter was carried out on a full-scale pilot plant performing removal of biochemical oxygen demand (BOD) and total nitrogen (TN) from pre-treated urban wastewater. The average influent values of BOD5, chemical oxygen demand (COD) and TN were 370, 1,015 and 60 mg/L, respectively. The pilot plant produced good discharge quality during steady-state operation. Average effluent BOD5, COD and TN values were 11, 58 and 15 mg/L, respectively. The reactor had been operating beyond its organic design capacity (200 population equivalent (PE)). At 480 PE the removal achieved for BOD, COD and TN were 98, 97 and 78%, respectively. This technology can absorb pollutant overloads while maintaining stable performance. Denitrification was performed by using sewage itself as carbon source. It was used as an intermittent aeration cycle in the unaerated cell to improve the denitrification process. The predenitrification with submerged unaerated filter has proved to be an efficient process for advanced removal of TN.
Patient Reported Outcome Measure (PROM) of Quality of Life After Prostatectomy - Results from a 5-Year Study
Authors: Jakobsson Liselotte , Fransson Per
Published: January 2014

Prostate cancer is the most common cancer among men in Sweden, and treatment is negatively affecting the patients' quality of life. Even so, long term experiences are sparse and implications for nursing practice are little known. The aim of this study was to determine areas of functioning and factors impacting quality of life, QOL, during and five years after radical prostatectomy (RP) using a quality of life questionnaire and a specific module for prostate cancer. A longitudinal study was performed with consecutively included Swedish men from baseline and after RP treatment (n=222) from 2003 to 2011 to obtain their opinions on quality of life. Data was gathered through a mail out - mail in procedure at baseline, 3 months, 1-3 and 5 years after treatment with a response rate of 94.14% - 75.2%. One reminder was sent on each occasion. Identified areas with increased functioning after five years were emotional and social functioning. QOL ratings did not change over the years. Sexual activity and functioning decreased and hormonal treatment-related symptoms increased. Impact on QOL was found regarding emotional and social functioning, nausea/vomiting, pain and hormone-related symptoms. Increasing age, living with a partner and educational level had no significant impact on QOL. Implications for nursing are to initially focus on physical problems and at times for follow-up visits pay attention also to emotional and social aspects of life. To be able to make a difference in the patient’s life, nurses need to bridge the gap between in-hospital treatment and everyday life outside hospital.
Sponsored Neo-Conservative Challenges to Diversity and Intercultural Competence in the US Undergraduate Curriculum
Authors: Selden Steven
Published: January 2014

For the past six decades, conservative foundations in the United States have targeted their funding on a transformation of the public's understanding of markets, culture, and the undergraduate course of study. These foundations, and their sponsored researchers, have specifically challenged the place of diversity and intercultural competence in the undergraduate curriculum in the USA. The article describes the close links between conservative foundations which give millions of dollars to a set of conservative activists, associations, and institutes who, in turn, develop conferences, meetings, and publications for public consumption. In addition, the article follows the public distribution and use of these documents, monographs, and guides. The article reveals them as politically motivated tools calculated to influence university policies regarding the content of the curriculum, and issues concerning diversity and intercultural competence. The article links funding from the J.M. Olin, Lynde and Harry Bradley, Earhart, Castle Rock, and Sarah Scaife Foundations to six conservative educational centers and councils from the early 1950s to the first decade of the twenty-first century, and to products designed to influence the undergraduate curriculum. Among others, it analyzes products developed by the Intercollegiate Studies Institute (ISI), the Madison Center for Educational Affairs (MCEA), and the American Council for Trustees and Alumni (ACTA).
Creative Research Ethics in the Enterprise University: What Price Academic Freedom?
Authors: O'Neill John
Published: January 2014

Between 1990 and 2010, the New Zealand university adopted an enterprise form. The nature of academic work changed commensurate with changes in the external regulatory and funding environment, the internal performative research culture, the proliferation of trans-national researcher networks, and the growing managerial codification of acceptable academic behaviour. Based on emergent trends in these areas between 1990 and 2010, and using the author's institution as an illustrative case, the article looks forward to the possible relationships between academic freedom and research ethics in the New Zealand enterprise university of 2030.