Applied and Environmental Soil Science http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Uranium Leaching from Contaminated Soil Utilizing Rhamnolipid, EDTA, and Citric Acid Tue, 22 Jul 2014 11:45:06 +0000 http://www.hindawi.com/journals/aess/2014/462514/ Biosurfactants have recently gained attention as “green” agents that can be used to enhance the remediation of heavy metals and some organic matter in contaminated soils. The overall objective of this paper was to investigate rhamnolipid, a microbial produced biosurfactant, and its ability to leach uranium present in contaminated soil from an abandoned mine site. Soil samples were collected from two locations in northern Arizona: Cameron (site of open pit mining) and Leupp (control—no mining). The approach taken was to first determine the total uranium content in each soil using a hydrofluoric acid digestion, then comparing the amount of metal removed by rhamnolipid to other chelating agents EDTA and citric acid, and finally determining the amount of soluble metal in the soil matrix using a sequential extraction. Results suggested a complex system for metal removal from soil utilizing rhamnolipid. It was determined that rhamnolipid at a concentration of 150 μM was as effective as EDTA but not as effective as citric acid for the removal of soluble uranium. However, the rhamnolipid was only slightly better at removing uranium from the mining soil compared to a purified water control. Overall, this study demonstrated that rhamnolipid ability to remove uranium from contaminated soil is comparable to EDTA and to a lesser extent citric acid, but, for the soils investigated, it is not significantly better than a simple water wash. Sara Asselin and Jani C. Ingram Copyright © 2014 Sara Asselin and Jani C. Ingram. All rights reserved. Crop Diversity Effects on Near-Surface Soil Condition under Dryland Agriculture Tue, 22 Jul 2014 08:07:06 +0000 http://www.hindawi.com/journals/aess/2014/703460/ Unprecedented changes in agricultural land use throughout the northern Great Plains of North America have highlighted the need to better understand the role of crop diversity to affect ecosystem services derived from soil. This study sought to determine the effect of four no-till cropping systems differing in rotation length and crop diversity on near-surface (0 to 10 cm) soil properties. Cropping system treatments included small grain-fallow (SG-F) and three continuously cropped rotations (3 yr, 5 yr, and Dynamic) located in south-central North Dakota, USA. Soil pH was lower in the 3 yr rotation (5.17) compared to the Dynamic (5.51) and SG-F (5.55) rotations . Among cropping system treatments, 5 yr and Dynamic rotations possessed significantly greater soil organic C (SOC) and total N (mean = 26.3 Mg C ha−1, 2.5 Mg N ha−1) compared to the 3 yr (22.7 Mg C ha−1, 2.2 Mg N ha−1) and SG-F (19.9 Mg C ha−1, 2.0 Mg N ha−1) rotations . Comparison of SOC measured in this study to baseline values at the research site prior to the establishment of treatments revealed only the 5 yr and Dynamic rotations increased SOC over time. The results of this study suggest that a diverse portfolio of crops is necessary to minimize soil acidification and increase SOC. Mark A. Liebig, David W. Archer, and Don L. Tanaka Copyright © 2014 Mark A. Liebig et al. All rights reserved. Establishing Land Suitability Criteria for Cashew (Anacardium occidentale L.) in Indonesia Tue, 22 Jul 2014 00:00:00 +0000 http://www.hindawi.com/journals/aess/2014/743194/ Commodity development requires site selection which should be established prior to large scale development. The land suitability criteria for cashew are not presently available. The relationship between the biophysical aspects, especially land and soil with commodity productivity, is also not known in depth. The objective of this study is to establish the criteria of land suitability for cashew in Indonesia, based on its production and land characteristics. Cashew plantations in 5 provinces were sampled. The data of production per tree per year were obtained from farmers, while the soil was sampled and analyzed in the laboratory. Age-adjusted cashew production was used as the yield response and plotted against land characteristics. Boundary lines resulting from the scatter of points were described; these lines produced the limits of land suitability criteria. The criteria were established using a projection of the intersection between the boundary line and yield interval. The criteria were also built in accordance with the productivity index of FAO for the internal boundary inside the S (suitable) class and by calculating the break-event point production for the boundary between S (suitable) and N (nonsuitable) order. The main result of this research is land suitability criteria for cashew. Widiatmaka, Atang Sutandi, Anas Iswandi, Usman Daras, Muhammad Hikmat, and Ari Krisnohadi Copyright © 2014 Widiatmaka et al. All rights reserved. Survival of a Rifampicin-Resistant Pseudomonas fluorescens Strain in Nine Mollisols Mon, 21 Jul 2014 07:21:38 +0000 http://www.hindawi.com/journals/aess/2014/306348/ Pseudomonas fluorescens strain D7 (P.f. D7) is a naturally occurring soil bacterium that shows promise as a biological herbicide to inhibit growth of annual grass weeds, including downy brome (Bromus tectorum L.), in crop- and rangelands. Pseudomonas fluorescens strain D7rif (P.f. D7rif) is a rifampicin-resistant strain of P.f. D7. One of the greatest obstacles to successful biological weed control is survival of the organism under field conditions. Nine soils in the taxonomic order of Mollisols, collected from downy brome-infested areas of the Western and Central United States, were inoculated with P.f. D7rif and incubated in the laboratory to determine the effects of soil type, soil properties, incubation temperature, and soil water potential on survival of P.f. D7rif over 63 days. Silt loam soils from Lind, Washington, and Moro, Oregon, sustained the highest P.f. D7rif populations, and recovery was the lowest from Pendleton, Oregon soil. Survival and recovery of P.f. D7rif varied with soil type and temperature but not with the two soil water potentials tested. After 63 days, P.f. D7rif was recovered at levels greater than log 5.5 colony forming units (CFU) g−1 soil from five of the nine test soils, a level adequate to suppress downy brome under field or range conditions. Tami L. Stubbs, Ann C. Kennedy, and Horace D. Skipper Copyright © 2014 Tami L. Stubbs et al. All rights reserved. Potential of Igniscum sachalinensis L. and Salix viminalis L. for the Phytoremediation of Copper-Contaminated Soils Wed, 09 Jul 2014 07:48:44 +0000 http://www.hindawi.com/journals/aess/2014/654671/ The potential of Salix viminalis L. and Igniscum sachalinensis L. for phytoremediation of copper- (Cu-) contaminated soils was studied under greenhouse conditions. Approximately 5 kg of potted agricultural and sewage amended soils sampled from the top 0 to 20 cm depth in Neuruppin, Germany, was treated with CuSO4 at concentrations 0 (control), 250, 750, and 1250 mg Cu kg−1 soil and ethylenediaminetetraacetic acid (EDTA) at 1000 mg kg−1 soil, respectively. Each plant species was grown on four replicates of each soil treatment. Copper accumulated in aboveground tissues tends to increase with increasing soil Cu concentration and was the lowest in stem and leaf of both plant species grown on control soils. At 750 and 1250 mg Cu kg−1 soil, Cu accumulated in stem and leaf of I. sachalinensis increased by over 12- and 20-fold, respectively, whereas there was no vegetative growth in S. viminalis beyond 250 mg Cu kg−1 soil. Application of EDTA to sewage amended soils increased Cu accumulated in the stem and leaf, especially in I. sachalinensis. In general, I. sachalinensis seems to have the potential to tolerate high soil Cu content and simultaneously bioaccumulate Cu in tissues and thus may have better prospects for phytoremediation. Isong Godlove Tingwey, Seth Nii-Annang, and Dirk Freese Copyright © 2014 Isong Godlove Tingwey et al. All rights reserved. Determination of Biological Nitrogen Fixation Induced N2O Emission from Arable Soil by Using a Closed Chamber Technique Mon, 07 Jul 2014 09:09:44 +0000 http://www.hindawi.com/journals/aess/2014/685168/ Intensive use of mineral N fertilizers and organic amendments has resulted in higher N2O emissions. A growing worldwide concern for these problems has motivated researchers, environmentalists, and policy makers to find alternatives to overcome such losses. Biological nitrogen fixation is one of many natural biological approaches to minimize the use of fertilizers and to possibly reduce N2O emissions. A greenhouse study was performed by growing inoculated and noninoculated soybean seeds (Glycine max (L.) Merr.) in PVC columns. The objective was to measure the contribution of Bradyrhizobium Japonicum and mineral-N fertilizer to promoting N2O emission. A closed chamber technique was used for gas sampling. N2O measurements were carried out shortly after nodulation. Bradyrhizobium Jopanicum induced N2O cumulative (121.8 μg kg−1) fluxes of inoculated seeds was significantly (α = 0.05) higher than those of mineral N fertilized treatment (NIS) and the control (bare soil). Total nitrogen content of the roots and seeds was not affected by inoculation. Total carbon ( 42.1  ±  0.1%), total nitrogen (3.1  ±  0.1%), and crude protein (19.9  ±   0.7%) contents of leaves of the inoculated seeds were significantly higher than those of noninoculated seed treatments. N2O fluxes significantly increased with high dissolved organic carbon content (70.77  ±  3.99  mg L−1) at R3 and at R8 stages when (39.60  ±  0.94 mg L−1) concentrations were high. Ambreen Shah Copyright © 2014 Ambreen Shah. All rights reserved. Comparison of Three Supervised Learning Methods for Digital Soil Mapping: Application to a Complex Terrain in the Ecuadorian Andes Tue, 20 May 2014 07:15:05 +0000 http://www.hindawi.com/journals/aess/2014/809495/ A digital soil mapping approach is applied to a complex, mountainous terrain in the Ecuadorian Andes. Relief features are derived from a digital elevation model and used as predictors for topsoil texture classes sand, silt, and clay. The performance of three statistical learning methods is compared: linear regression, random forest, and stochastic gradient boosting of regression trees. In linear regression, a stepwise backward variable selection procedure is applied and overfitting is controlled by minimizing Mallow’s Cp. For random forest and boosting, the effect of predictor selection and tuning procedures is assessed. 100-fold repetitions of a 5-fold cross-validation of the selected modelling procedures are employed for validation, uncertainty assessment, and method comparison. Absolute assessment of model performance is achieved by comparing the prediction error of the selected method and the mean. Boosting performs best, providing predictions that are reliably better than the mean. The median reduction of the root mean square error is around 5%. Elevation is the most important predictor. All models clearly distinguish ridges and slopes. The predicted texture patterns are interpreted as result of catena sequences (eluviation of fine particles on slope shoulders) and landslides (mixing up mineral soil horizons on slopes). Martin Hitziger and Mareike Ließ Copyright © 2014 Martin Hitziger and Mareike Ließ. All rights reserved. Arsenic, Chromium, and Other Potentially Toxic Elements in the Rocks and Sediments of Oropos-Kalamos Basin, Attica, Greece Tue, 06 May 2014 12:38:08 +0000 http://www.hindawi.com/journals/aess/2014/718534/ Rocks and sediments are non-anthropogenic sources of elements contamination. In this study, a series of potentially toxic elements were quantified in rocks and sediments of the Oropos-Kalamos basin. Only As, Hg, Pb, and Sb contents, in all the examined rocks and sediments, were higher than the levels given in international literature. Concentration of the elements As, Cr, Hg, Mo, Ni, and U is highly elevated in the lignite compared to crustal element averages. The enrichment of Cr and Ni in the lignite can be attributed to the known ultramafic rock masses surrounding the basin, while enrichment of As, Hg, Mo, Sb, and U is associated with the past geothermal activity of the Upper Miocene (about 15 million years ago). Nickel and Cr were transported into the lignite deposition basin by rivers and streams draining ultramafic rock bodies. The results of this study imply the natural source of Cr3+ and Cr6+ contamination of the Oropos-Kalamos groundwater, since high Cr contents were also recorded in the lignite (212.3 mg kg−1), chromiferous iron ore occurrences (256.6 mg kg−1), and alluvial deposits (212.5 mg kg−1), indicating Cr leaching and transportation to the depositional basin dating from the Upper Miocene age. D. Alexakis and D. Gamvroula Copyright © 2014 D. Alexakis and D. Gamvroula. All rights reserved. Spatial Variability of Physical Soil Quality Index of an Agricultural Field Sun, 04 May 2014 06:48:46 +0000 http://www.hindawi.com/journals/aess/2014/379012/ A field investigation was carried out to evaluate the spatial variability of physical indicators of soil quality of an agricultural field and to construct a physical soil quality index (SQ) map. Surface soil samples were collected using m grid from an Inceptisol on Ganges Tidal Floodplain of Bangladesh. Five physical soil quality indicators, soil texture, bulk density, porosity, saturated hydraulic conductivity (), and aggregate stability (measured as mean weight diameter, MWD) were determined. The spatial structures of sand, clay, and were moderate but the structure was strong for silt, bulk density, porosity, and MWD. Each of the physical soil quality indicators was transformed into 0 and 1 using threshold criteria which are required for crop production. The transformed indicators were the combined into SQ. The kriged SQ map showed that the agricultural field studied could be divided into two parts having “good physical quality” and “poor physical soil quality.” Sheikh M. Fazle Rabbi, Bina R. Roy, M. Masum Miah, M. Sadiqul Amin, and Tania Khandakar Copyright © 2014 Sheikh M. Fazle Rabbi et al. All rights reserved. Mechanical Mastication of Utah Juniper Encroaching Sagebrush Steppe Increases Inorganic Soil N Sun, 27 Apr 2014 13:43:40 +0000 http://www.hindawi.com/journals/aess/2014/632757/ Juniper (Juniperus spp.) has encroached on millions of hectares of sagebrush (Artemisia spp.) steppe. Juniper mechanical mastication increases cover of understory species but could increase resource availability and subsequently invasive plant species. We quantified the effects of juniper mastication on soil resource availability by comparing total C, total N, C : N ratio, Olsen extractable P, sulfate S, and pH using soil samples and inorganic N () using ion exchange membranes. We compared resource availability in paired masticated and untreated areas in three juniper-dominated sagebrush and bunchgrass ecosystems in the Utah portion of the Great Basin. Inorganic N was 4.7 times higher in masticated than in untreated areas across seasons (). Within masticated areas, tree mounds of juniper leaf scales and twigs served as resource islands with 1.9 times higher inorganic N and total C, and 2.8 times higher total N than bare interspaces across seasons (). Bare interspaces had 3.0–3.4 times higher inorganic N than interspaces covered with masticated trees during late-summer through winter (). Soil fertility changes associated with mastication were not considered sufficient to favor establishment of annual over perennial grasses, and we expect both to increase in cover following juniper mastication. Kert R. Young, Bruce A. Roundy, and Dennis L. Eggett Copyright © 2014 Kert R. Young et al. All rights reserved. Soil Erosion Prediction Using Morgan-Morgan-Finney Model in a GIS Environment in Northern Ethiopia Catchment Tue, 22 Apr 2014 11:51:33 +0000 http://www.hindawi.com/journals/aess/2014/468751/ Even though scientific information on spatial distribution of hydrophysical parameters is critical for understanding erosion processes and designing suitable technologies, little is known in Geographical Information System (GIS) application in developing spatial hydrophysical data inputs and their application in Morgan-Morgan-Finney (MMF) erosion model. This study was aimed to derive spatial distribution of hydrophysical parameters and apply them in the Morgan-Morgan-Finney (MMF) model for estimating soil erosion in the Mai-Negus catchment, northern Ethiopia. Major data input for the model include climate, topography, land use, and soil data. This study demonstrated using MMF model that the rate of soil detachment varied from <20 t ha−1 y−1 to >170 t ha−1 y−1, whereas the soil transport capacity of overland flow (TC) ranged from 5 t ha−1 y−1 to >42 t ha−1 y−1. The average soil loss estimated by TC using MMF model at catchment level was 26 t ha−1 y−1. In most parts of the catchment (>80%), the model predicted soil loss rates higher than the maximum tolerable rate (18 t ha−1 y−1) estimated for Ethiopia. Hence, introducing appropriate interventions based on the erosion severity predicted by MMF model in the catchment is crucial for sustainable natural resources management. Gebreyesus Brhane Tesfahunegn, Lulseged Tamene, and Paul L. G. Vlek Copyright © 2014 Gebreyesus Brhane Tesfahunegn et al. All rights reserved. Characterization of Environmental Nano- and Macrocolloid Particles Extracted from Selected Soils and Biosolids Mon, 14 Apr 2014 09:28:04 +0000 http://www.hindawi.com/journals/aess/2014/506482/ Environmental nanoparticles found in soil systems and biosolids may pose a considerable risk to groundwater quality as contaminant carriers. Little effort has been invested in the characterization of natural nanocolloids compared to corresponding macrocolloids. This study involved physicochemical, mineralogical, and morphological characterizations of nanocolloids and macrocolloids fractionated from three Kentucky soils and one biosolid. Particle size and morphology were investigated using scanning/transmission electron microscopy and dynamic light scattering. Mineralogical composition was determined by X-ray diffraction and thermogravimetric and Fourier-transform infrared spectroscopy analyses. Zeta potentials and cation exchange capacities assessed surface charge and chemical reactivity. The estimated average hydrodynamic diameter of nanoparticles was nearly twice the ideal 100 nm range, apparently due to irregular particle shapes and partial aggregation. Nanoparticles were also found attached to surfaces of macrocolloids, forming macro-nano aggregates and obscuring some of their physical and chemical characteristics. However, nanocolloids exhibited greater surface reactivity, likely due to their smaller size, poor crystallinity, and morphological shape distortions. In spite of some behavior modification due to nanoaggregation phenomena, nanocolloids appeared to be much more potent vectors of contaminant transport in subsurface environments than their macrosize fractions. Nevertheless, their heterogeneous nature brings to light important considerations in addressing pollution prevention and remediation challenges. J. L. Ghezzi, A. D. Karathanasis, C. J. Matocha, J. Unrine, and Y. L. Thompson Copyright © 2014 J. L. Ghezzi et al. All rights reserved. Using Capacitance Sensors for the Continuous Measurement of the Water Content in the Litter Layer of Forest Soil Thu, 03 Apr 2014 07:34:18 +0000 http://www.hindawi.com/journals/aess/2014/627129/ Little is known about the wetting and drying processes of the litter layer ( layer), likely because of technical difficulties inherent in nondestructive water content (WC) monitoring. We developed a method for continuously measuring the WC of leaf litter (the “LWC method”) in situ using capacitance sensors. To test variants of this approach, five (for the LWC_5) or ten (for the LWC_10 method) Quercus serrata leaves were attached around capacitance sensors. The output voltage used for each LWC method was linearly correlated with the gravimetric WC (LWC_5: ; LWC_10: ), producing different slopes for each calibration line. For in situ continuous measurements of WC in the layer, two sensors were used, one placed on top of the layer and the other at the boundary between the and mineral layers. The average continuous WC of the layer was then calculated from the output voltage of the two sensors and the calibration function, and this value was linearly correlated with the gravimetric WC . However, because the layer characteristics (e.g., thickness, water-holding capacity, and species composition) may differ among study sites, appropriate approaches for measuring this layer’s moisture properties may be needed. Mioko Ataka, Yuji Kominami, Takafumi Miyama, Kenichi Yoshimura, Mayuko Jomura, and Makoto Tani Copyright © 2014 Mioko Ataka et al. All rights reserved. Soil Assessment along Toposequences in Rural Northern Nigeria: A Geomedical Approach Thu, 27 Mar 2014 11:29:06 +0000 http://www.hindawi.com/journals/aess/2014/628024/ Case numbers of endemic Ca-deficiency rickets (CDR) have been reported to be alarmingly rising among children of subsistence farms in developing countries within the last 30 years. Fluoride toxicities in the environment are known to not be related to the disease. To investigate if, instead, CDR is caused by a nutrient deficiency in the environment, subsistence farms in an endemic CDR area near Kaduna, northern Nigeria, were investigated for bedrock, slope forms, soil types, and soil characteristics. The natural environment was investigated according to the World Reference Base, soil texture was analysed by pipette and sieving, and plant-available macronutrients were determined using barium-chloride or Ca-acetate-lactate extraction. The analyses showed that granite and slope deposits were the dominant parent materials. The typical slope forms and soil types were Lixisols and Acrisols on pediments, Fluvisols in river valleys, and Plinthosols and Acrisols on plains. Compared with West African background values, all of the soils had normal soil textures but were low in macronutrients. Comparisons to critical limits, however, showed that only the P concentrations were critically low, which are typical for savanna soils. A link between nutrient deficiency in soils and CDR in the Kaduna area was therefore considered unlikely. Lena Hartmann, Marvin Gabriel, Yuanrong Zhou, Barbara Sponholz, and Heinrich Thiemeyer Copyright © 2014 Lena Hartmann et al. All rights reserved. Biosolids Soil Application: Agronomic and Environmental Implications 2013 Sun, 16 Mar 2014 09:38:53 +0000 http://www.hindawi.com/journals/aess/2014/314730/ Silvana I. Torri, Rodrigo Studart Corrêa, Giancarlo Renella, Leonid Perelomov, and Alejandro Valdecantos Copyright © 2014 Silvana I. Torri et al. All rights reserved. County-Scale Spatial Variability of Macronutrient Availability Ratios in Paddy Soils Tue, 11 Mar 2014 00:00:00 +0000 http://www.hindawi.com/journals/aess/2014/689482/ Macronutrients (N, P, and K) are essential to plants but also can be harmful to the environment when their available concentrations in soil are excessive. Availability ratios (available concentration/total concentration) of macronutrients may reflect their transforming potential between fixed and available forms in soil. Understanding their spatial distributions and impact factors can be, therefore, helpful to applying specific measures to modify the availability of macronutrients for agricultural and environmental management purposes. In this study, 636 topsoil samples (0–15 cm) were collected from paddy fields in Shayang County, Central China, for measuring soil properties. Factors influencing macronutrient availability ratios were investigated, and total and available concentrations of macronutrients were mapped using geostatistical method. Spatial distribution maps of macronutrient availability ratios were further derived. Results show that (1) availability of macronutrients is controlled by multiple factors, and (2) macronutrient availability ratios are spatially varied and may not always have spatial patterns identical to those of their corresponding total and available concentrations. These results are more useful than traditional soil macronutrient average content data for guiding site-specific field management for agricultural production and environmental protection. Mingkai Qu, Weidong Li, and Chuanrong Zhang Copyright © 2014 Mingkai Qu et al. All rights reserved. The Solid Phase Distribution and Bioaccessibility of Arsenic, Chromium, and Nickel in Natural Ironstone Soils in the UK Wed, 05 Mar 2014 13:31:23 +0000 http://www.hindawi.com/journals/aess/2014/924891/ Thirty soil samples (12 residential gardens and 18 allotments) were collected from the Cherwell District of north Oxfordshire in south-central England. The underlying parent geology of the area is dominated by Jurassic ironstone. The samples were analysed for their total contents of As, Cr, and Ni by X-ray fluorescence spectroscopy and for the bioaccessible fractions of these elements using a physiologically based extraction test. Four soils (two residential soils and two allotment soils) were chosen for further determination of their element solid phase distribution. The study showed that whilst total concentrations of As, Cr, and Ni are elevated due to the soil parent material, the bioaccessibility test showed that only a small proportion of the total concentration is available for absorption into the human body (<15%). The sequential extraction test showed that the nonmobile forms of the elements are strongly sorbed on to iron oxides. Parent material geology has a significant effect on the total element concentrations and the bioaccessibility of potentially harmful element (PHE). Land use does not show such a large effect but the allotment bioaccessibility data show a bigger spread and possibly higher values for As and Cr which may be due to agronomic (cultivation) practices such as addition of fertilisers and organic matter. Joanna Wragg, Mark Cave, and Sean Gregory Copyright © 2014 Joanna Wragg et al. All rights reserved. Soil Management for Sustainable Agriculture 2013 Wed, 26 Feb 2014 09:25:27 +0000 http://www.hindawi.com/journals/aess/2014/536825/ Philip J. White, John W. Crawford, María Cruz Díaz Álvarez, and Rosario García Moreno Copyright © 2014 Philip J. White et al. All rights reserved. The Effect of Trichoderma on Heavy Metal Mobility and Uptake by Miscanthus giganteus, Salix sp., Phalaris arundinacea, and Panicum virgatum Sun, 09 Feb 2014 07:00:41 +0000 http://www.hindawi.com/journals/aess/2014/506142/ The effect of land application of biomaterials based on two strains of Trichoderma fungus on phytoremediation processes was studied. Six metals (Cd, Cr, Cu, Pb, Zn, and Ni) were analysed in soil and soil leachate as well as in plant tissues. The translocation index () and metal bioconcentration factors (BCF) calculated for the inoculated plants were increased compared to the noninoculated control, except for Pb and Salix sp. Simultaneously, the mobilisation of metals in soil solution as an effect of biomaterials was noted. The highest values of —339% (for Cr), 190% (for Ni), and 110% (for Cu)—were achieved for the combination Miscanteus giganteus and Trichoderma MSO1. The results indicated that the application of fungus has positive effects on increasing the biomass, soil parameters (C, N, and P), and solubility of heavy metals in soil and therefore in enhancing phytoextraction for Miscanthus giganteus L., Panicum virgatum L., Phalaris arundinacea L., and Salix sp. Malgorzata J. Kacprzak, Karolina Rosikon, Krzysztof Fijalkowski, and Anna Grobelak Copyright © 2014 Malgorzata J. Kacprzak et al. All rights reserved. Novel Castellaniella denitrificans SA13P as a Potent Malachite Green Decolorizing Strain Thu, 06 Feb 2014 13:38:01 +0000 http://www.hindawi.com/journals/aess/2014/760950/ Triphenylmethane dyes represent a major group of dyes causing serious environmental hazards. Malachite Green is one of the commonly and extensively used triphenylmethane dyes although it is carcinogenic and mutagenic in nature. Various physicochemical methods have been employed for its elimination but are highly expensive, coupled with the formation of huge amount of sludge. Hence, biological methods being ecofriendly are good alternatives. In the present study, the novel bacterial isolate SA13P was isolated from UASB tank of tannery effluent treatment plant. Phylogenetic characterization of 1470 bp fragment of SA13P has revealed its similarity with Castellaniella denitrificans. This strain has been found to decolorize the dye (malachite green) at a concentration of 100 mg L−1 (80.29%). Decolorization was done by living bacterial cells rather than adsorption. Growth conditions have also been optimized for the decolorization. Maximum decolorization was observed at a temperature of 37°C and pH 8.0. Also, it has been found that bacterization of seeds of Vigna radiata with Castellaniella denitrificans SA13P increases germination rate. We have reported for the first time that Castellaniella denitrificans SA13P may be used as a novel strain for dye decolorization (malachite green) and biological treatment of tannery effluent. Ankita Chawla and Baljeet Singh Saharan Copyright © 2014 Ankita Chawla and Baljeet Singh Saharan. All rights reserved. The Sloping Mire Soil-Landscape of Southern Ecuador: Influence of Predictor Resolution and Model Tuning on Random Forest Predictions Wed, 05 Feb 2014 13:27:47 +0000 http://www.hindawi.com/journals/aess/2014/603132/ The sloping mire landscape of the investigation area, in the southern Andes of Ecuador, is dominated by stagnic soils with thick organic layers. The recursive partitioning algorithm Random Forest was used to predict the spatial water stagnation pattern and the thickness of the organic layer from terrain attributes. Terrain smoothing from 10 to 30 m raster resolution was applied in order to obtain the best possible model. For the same purpose, several model tuning parameters were tested and a prepredictor selection with the R-package Boruta was applied. Model versions were evaluated and compared by 100 repetitions of the calculation of the residual mean square error of a five-fold cross-validation. Position specific density functions of the predicted soil parameters were then used to display prediction uncertainty. Prepredictor selection and tuning of the Random Forest algorithm in some cases resulted in an improved model performance. We therefore recommend testing prepredictor selection and tuning to make sure that the best possible model is chosen. This needs particular emphasis in complex tropical mountain soil-landscapes which provide a real challenge to any soil mapping approach but where Random Forest has proven to be successful due to the testing of model tuning and prepredictor selection. Mareike Ließ, Martin Hitziger, and Bernd Huwe Copyright © 2014 Mareike Ließ et al. All rights reserved. Soil Quality Assessment Strategies for Evaluating Soil Degradation in Northern Ethiopia Tue, 04 Feb 2014 14:11:56 +0000 http://www.hindawi.com/journals/aess/2014/646502/ Soil quality (SQ) degradation continues to challenge sustainable development throughout the world. One reason is that degradation indicators such as soil quality index (SQI) are neither well documented nor used to evaluate current land use and soil management systems (LUSMS). The objective was to assess and identify an effective SQ indicator dataset from among 25 soil measurements, appropriate scoring functions for each indicator and an efficient SQ indexing method to evaluate soil degradation across the LUSMS in the Mai-Negus catchment of northern Ethiopia. Eight LUSMS selected for soil sampling and analysis included (i) natural forest (LS1), (ii) plantation of protected area, (iii) grazed land, (iv) teff (Eragrostis tef)-faba bean (Vicia faba) rotation, (v) teff-wheat (Triticum vulgare)/barley (Hordeum vulgare) rotation, (vi) teff monocropping, (vii) maize (Zea mays) monocropping, and (viii) uncultivated marginal land (LS8). Four principal components explained almost 88% of the variability among the LUSMS. LS1 had the highest mean SQI (0.931) using the scoring functions and principal component analysis (PCA) dataset selection, while the lowest SQI (0.458) was measured for LS8. Mean SQI values for LS1 and LS8 using expert opinion dataset selection method were 0.874 and 0.406, respectively. Finally, a sensitivity analysis (S) used to compare PCA and expert opinion dataset selection procedures for various scoring functions ranged from 1.70 for unscreened-SQI to 2.63 for PCA-SQI. Therefore, this study concludes that a PCA-based SQI would be the best way to distinguish among LUSMS since it appears more sensitive to disturbances and management practices and could thus help prevent further SQ degradation. Gebreyesus Brhane Tesfahunegn Copyright © 2014 Gebreyesus Brhane Tesfahunegn. All rights reserved. Sediment, Nutrient, and Bacterial Runoff from Biosolids and Mineral Fertilizer Applied to a Mixed Cool- and Native Warm-Season Grassland in the Ozark Mountains Wed, 29 Jan 2014 08:51:41 +0000 http://www.hindawi.com/journals/aess/2014/147818/ Rainfall simulations were conducted within mixed (cool- and native warm-season) grasslands in the sloping, rocky soils typical of the Ozark Mountains region to estimate nutrient and bacteria levels in runoff from biosolids and mineral fertilizer (MF). The ability of narrow (1 m) vegetated filter strips (VFS) to reduce losses was evaluated. Experiment 1 included an untreated control (C); 37 kg plant available nitrogen (PAN) ha−1 from biosolids applied to the upslope half of the plot with the downslope half serving as a VFS (LBF); 74 kg PAN ha−1 from biosolids, with VFS (HBF); and a uniform biosolids application at the lower rate and no VFS (LBU). Experiment 2 examined runoff from MF applied at 89 kg ammoniacal nitrogen (NH4-N) ha−1 and 147 kg phosphorous (P) ha−1 over the whole plot (MFW) or only on the upslope half (with VFS) (MFF). No significant differences were detected among mean fecal coliform levels despite large differences in magnitude. Losses of NH4-N and P were greater for LBU than for LBF. Although only marginally significant (), total phosphorous contained in runoff was nearly three times higher in MFW than in MFF. Results of this study suggest that even a small VFS can potentially reduce nutrient levels in runoff. Cody B. Wallace, Michael G. Burton, Steven G. Hefner, and Thomas A. DeWitt Copyright © 2014 Cody B. Wallace et al. All rights reserved. Clay and Soil Photolysis of the Pesticides Mesotrione and Metsulfuron Methyl Wed, 29 Jan 2014 00:00:00 +0000 http://www.hindawi.com/journals/aess/2014/369037/ Photolysis may represent an important degradation process of pollutants at the surface of soil. In the present work, we report a detailed study on the degradation of two pesticides: mesotrione and metsulfuron methyl using a sunlight simulator. In a first step, we studied the photochemical behaviour at the surface of clays from the kinetic as well as from the analytical point of view. In both cases, the quantum yields were found to be higher when compared to those obtained in aqueous solutions. The effect of iron(III), water, and humic substances contents was studied. In the former cases, an increase of the degradation rate was observed while an inhibition was observed with the latter owing to a filter effect phenomenon. In a second step, we studied the photodegradation at the surface of natural soil and identified the generated byproducts. They appear to mainly arise from photohydrolysis process. Marie Siampiringue, Pascal Wong Wah Chung, Moursalou Koriko, Gado Tchangbedji, and Mohamed Sarakha Copyright © 2014 Marie Siampiringue et al. All rights reserved. Soil Phosphorus Dynamics of Wheat-Based Cropping Systems in the Semiarid Region of Argentina Thu, 23 Jan 2014 07:57:32 +0000 http://www.hindawi.com/journals/aess/2014/532807/ The dynamics of soil P forms and particle size fractions was studied under three wheat-based cropping sequences in production systems of Argentina. The whole soil and its coarse (100–2000 µm) and fine (0–100 µm) fractions were analyzed to determine Bray-Kurtz extractable (Pe), organic (Po), inorganic (Pi), and total (Pte) phosphorus. The reference soil was determined at time 0 and compared to a four-year period (time 9 to 12) in three crop sequences: wheat (Triticum aestivum L.)-cattle grazing on natural grasses (WG), continuous wheat (WW), and wheat-legume (WL). Levels of Pe showed differences over time, from 10 to 16 µg g−1 in WG, in line with agriculture and cattle grazing alternate sequences. In WW, P level increased with time, while in WL systems a significant decrease in P from 33.7 to 10.4 µg P g−1 was found during the legume period. Soil P values varied between reference soil and soil samples in year nine and between treatments. Pi was significantly lower in WW, and its concentration increased with time. The coarse fraction of the reference plots had significantly higher levels of Po and Pi than the cultivated treatments, probably a consequence of the particulate organic matter decomposition and coarse mineral particle weathering. The observed changes in Pi content could be attributed to differences in occluded P equilibrium under different soil environments (mainly pH) and crop-tillage-climatic interaction. Liliana Suñer, Juan Galantini, and Gabriela Minoldo Copyright © 2014 Liliana Suñer et al. All rights reserved. Silvopastoral Systems Enhance Soil Quality in Grasslands of Colombia Wed, 22 Jan 2014 14:34:26 +0000 http://www.hindawi.com/journals/aess/2014/359736/ In the tropical drylands of Colombia, the soils subjected to traditional systems of livestock production are severely degraded and depleted of plant nutrients. Multistrata silvopastoral systems are viable alternatives to improve livestock production; however, it is unknown whether these systems can reduce the negative environmental impacts of traditional systems on soil quality. The objective of this study was to evaluate the effects of 13-year-old multistrata silvopastoral systems on soil quality parameters in degraded soils of the Sinu River Valley, Colombia. The results show that the trees in the silvopastoral systems increased or maintained soil pH values and nutrient availability (phosphorus, potassium, and calcium) with respect to the pastures with only grasses. The effects were significantly controlled by the types of plant species, particularly Guazuma ulmifolia and Cassia grandis. Judith Martínez, Yasmín S. Cajas, Juan D. León, and Nelson W. Osorio Copyright © 2014 Judith Martínez et al. All rights reserved. Soil Carbon Sequestration Resulting from Biosolids Application Mon, 20 Jan 2014 06:50:58 +0000 http://www.hindawi.com/journals/aess/2014/821768/ Carbon (C) sequestration in soils through the increase of the soil organic carbon (SOC) pool has generated broad interest to mitigate the effects of climate change. Biosolids soil application may represent a persistent increase in the SOC pool. While a vast literature is available on the value of biosolids as a soil conditioner or nutrient source in agricultural systems, there is still limited knowledge on soil sequestration mechanisms of biosolids-borne C or the main factors influencing this capacity. The emerging challenges posed by global environmental changes and the stringent needs to enhance C storage call for more research on the potential of soil biosolids incorporation as a sustainable C storage practice. This review addresses the potential of C sequestration of agricultural soils and opencast mines amended with biosolids and its biological regulation. Silvana I. Torri, Rodrigo Studart Corrêa, and Giancarlo Renella Copyright © 2014 Silvana I. Torri et al. All rights reserved. Managing the Selenium Content in Soils in Semiarid Environments through the Recycling of Organic Matter Sun, 29 Dec 2013 11:35:14 +0000 http://www.hindawi.com/journals/aess/2013/283468/ Around 30% of the world’s population suffers from either a lack of one or more essential micronutrients, or the overconsumption of these minerals, which causes toxicity. Selenium (Se) is a particularly important micronutrient component of the diet with a well-documented and wide-ranging role in maintaining health. However, this important micronutrient can be lacking because soil and crop management are focused on high yields to the detriment of the quality of crops required to ensure a healthy human diet. Currently around 15% of the global population has selenium deficiency. This paper focuses on Se availability in semiarid soils and how micronutrients can be effectively managed through the recycling of organic matter. Because many mineral reserves are being exploited unsustainably, we review the advantages of using organic by-products for the management of the biofortification of Se in crops. This type of practice is particularly useful in arid and semiarid environments because organic matter acts as a reservoir for Se, preventing bioaccumulation and leaching. There are also potential local economic benefits from using organic by-products, such as manures and sewage sludge. R. Garcia Moreno, R. Burdock, María Cruz Díaz Álvarez, and J. W. Crawford Copyright © 2013 R. Garcia Moreno et al. All rights reserved. Nitrogen Release in Pristine and Drained Peat Profiles in Response to Water Table Fluctuations: A Mesocosm Experiment Sun, 22 Dec 2013 10:05:41 +0000 http://www.hindawi.com/journals/aess/2013/694368/ In the northern hemisphere, variability in hydrological conditions was suggested to increase as a consequence of climate warming, which may result in longer droughts than the area has experienced before. Due to their predominately anoxic conditions, peatlands are expected to respond to changes in hydrological conditions, such as successive drying and rewetting periods. As peatlands are rich in organic matter, any major changes in water table may influence the decomposition of it. The hydrological conditions may also influence release of nutrients from peat profiles as well as affect their transport to downstream ecosystems. In our mesocosm experiment, artificial water table fluctuations in pristine peat profiles caused an increase in dissolved organic nitrogen (DON) and ammonium concentrations, while no response was found in drained peat profiles, although originating from the same peatland complex. Merjo P. P. Laine, Rauni Strömmer, and Lauri Arvola Copyright © 2013 Merjo P. P. Laine et al. All rights reserved. Nickel in Soil Modifies Sensitivity to Diazinon Measured by the Activity of Acetylcholinesterase, Catalase, and Glutathione S-Transferase in Earthworm Eisenia fetida Thu, 14 Nov 2013 15:05:02 +0000 http://www.hindawi.com/journals/aess/2013/642098/ Nickel in typical soils is present in a very low concentration, but in the contaminated soils it occurs in locally elevated concentrations. The aim of this study was to examine the effect of nickel in the concentrations of 300 (very high, close to LOEC for reproduction) and 900 (extremely high, close to LOEC for mortality) mg/kg dry soil on the life history and acetylcholinesterase, catalase, and glutathione S-transferase activities in earthworm Eisenia fetida and to establish how nickel modifies the sensitivity to organophosphorous pesticide—diazinon. Cocoons production and juveniles’ number were significantly lower only in groups exposed to Ni in the concentration of 900 mg/kg dry soil for two months. Diazinon administration diminished the AChE activity in the GI tract and in the body wall. The interaction between diazinon and nickel was observed, and, in consequence, the AChE activity after the pesticide treatment was similar to controls in worms preexposed to nickel. Both pesticide administration and exposure to nickel caused an increase in the GST activity in examined organs and CAT activity in body wall. Both biometric and development data and simple enzymatic analysis, especially the AChE and GST, show a Ni pretreatment effect on the subsequent susceptibility to pesticide. Agnieszka Zawisza-Raszka and Bogdan Dolezych Copyright © 2013 Agnieszka Zawisza-Raszka and Bogdan Dolezych. All rights reserved.