bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Sorption of Exogenously Applied Ferulic, p‐Coumaric, p‐Hydroxybenzoic, and Vanillic Acids in Soil
Authors: Dalton Barry R. , Blum Udo , Weed Sterling B. 
Published: July 2010

AbstractPlant phenolic acids are found in soils and their importance has been implicated in various soil processes, including biochemical weathering of minerals, humus formation, interactions between plants (allelopathy), and nutrient availability to plants. P‐hydroxybenzoic, vanillic, p‐coumaric, and ferulic acids were added to soils at a rate of 5.15 mmol/kg, extracted with Mehlich III extractant immediately and on Days 1, 2, 4, 8, 16, and 32, and quantified by high‐performance liquid chromatography. The recovery of phenolic acids from Cecil (Typic Hapludults, clayey, kaolinitic, thermic), Portsmouth (Typic Umbraquualts, fine loamy, mixed, thermic), and White Store (Vertic Hapludalfs, fine, mixed, thermic) soils varied with soil type, horizon (A1 and B1), time, and type of functional group present on the aromatic ring. There was significant instantaneous sorption of all compounds in all soils; in A1 horizon materials, recovery decreased as soil organic matter increased. There was generally greater sorption of phenolic acids in the A1 horizon materials than in the B1 horizon materials of a particular soil type. Significant declines in recovery occurred with time for all phenolic acids in each type of soil, irrespective of horizon. The sharpest decline in recovery of phenolic acids from soils generally occurred within 2 d after addition of the compounds. The presence of methoxy groups and acrylic side chains on the aromatic ring of phenolic acids increased the “sorption” of these compounds in soils. Sorption of the phenolic acids by the various soils was generally in the order of p‐hydroxybenzoic ≤ vanillic <p‐coumaric < ferulic.
Soil Potassium Balance and Cumulative Cotton Response to Annual Potassium Additions on a Vermiculitic Soil
Authors: Cassman K. G. , Bryant D. C. , Higashi S. L. , Roberts B. A. , Kerby T. A. 
Published: July 2010

AbstractCumulative effects of annual K additions on cotton (Gossypium hirsutum L.) growth and soil K balance were examined in a field study on an irrigated, vermiculitic soil. In each of 3 consecutive yr, cotton ‘Acala SJ2’ was grown with 0, 120, 240, or 480 kg K ha−1 applied to the same treatment plots in a randomized complete block design with 10 replications. The relationship between seed cotton yield and petiole K concentration was similar across years (r2 = 0.61, P < 0.001), but slopes of the yield response to applied K increased each year; 2.6‐fold more seed cotton was obtained per unit K input in 1987 than in 1985. This cumulative response reflected a yield decline without K addition and increasingly higher yield with each additional input of 480 kg K ha−1. Two processes appeared to control this response. First, without K input, NH4‐extractable K+ in surface soil decreased 20% from August 1985 to August 1987. This decrease greatly exceeded the K removal by cotton, and we surmise that an 11% decrease in soil organic C content contributed to this phenomenon. Loss of cation exchange capacity associated with the loss of soil humus may shift K equilibria towards fixation at interlayer sites in vermiculite at the expense of external K pools extracted by NH+4. Second, with high levels of K input, apparent K uptake efficiency from applied K was 50% greater in 1987 than in 1985. Increased efficiency was attributed to the partial saturation of K fixation sites from previous K additions and thus a larger proportion of newly added K remained in plant‐available K pools. At the highest K addition level, 86% of the 1440 kg K ha−1 applied in the 3‐yr period was fixed beyond extraction by NH+4, and plants remained marginally K deficient. The existence of a cumulative response to applied K on vermiculitic soils would have a marked impact on the economics of K fertilization on cotton.
Tillage Effects on Nitrogen Recovery by Corn from a Nitrogen‐15 Labeled Legume Cover Crop
Authors: Varco J. J. , Frye W. W. , Smith M. S. , MacKown C. T. 
Published: July 2010

AbstractThe purpose of this study was to determine the effects of tillage on corn (Zea mays L.) total N uptake and recovery of N from 15N‐depleted legume residue. A conventional tillage (CT) variable was introduced into a 7‐yr‐old no‐tillage (NT) corn study in 1984 by moldboard plowing and disking half of each no N plot having either corn residue (winter fallow) or hairy vetch (Vicia villosa Roth.) cover. Prior to plowing each year, in situ hairy vetch vegetation was removed and replaced with fresh 15N‐depleted hairy vetch vegetation at a comparable rate. In 1984, final total N uptake by corn with vetch cover was 31 kg ha−1 greater with CT than with NT; however, no difference in grain yield occurred. This was a year characterized by limited precipitation during grain fill. In 1985, early season N uptake was greater with CT but there was no difference in final total N accumulated between tillage systems. Averaged across cover treatments, CT resulted in more grain yield than with NT. With vetch, corn N uptake in excess of that with corn residue averaged 60 kg ha−1 yr−1 across tillage systems. Recovery of vetch (15N (Nv) averaged over years was 32% with CT and 20% with NT. In both years this difference was established by 42 d after planting and the pattern of Nv recovery after this day was similar for both tillage systems. Residual recovery of Nv by corn the second year after application was greater with NT (7%) than with CT (3%). With vetch cover, extractable soil N levels were most elevated early in the growing season, particularly with CT in the 0.1‐ to 0.2‐m soil depth.
Field Techniques for Measuring Wetland Soil Parameters
Authors: Faulkner S.P. , Patrick W.H. , Gambrell R.P. 
Published: July 2010

AbstractDelineating wetlands from nonwetlands in seasonally inundated ecosystems is often difficult and requires data on soil functions and attributes. Techniques (including equipment design, construction, and installation) for assessing wetland soil attributes have been developed that allow direct field measurements of soil O2 content, oxidation‐reduction potential, water‐table depth, and presence of ferrous iron. Soil O2 content is measured from diffusion chambers with a specially fitted polarographic probe. Redox potential is measured with permanently installed platinum electrodes and a voltmeter. Determination of water‐table depth may require piezometers in addition to unlined observation wells. The presence of ferrous iron can be detected with α, α,‐dipyridyl and indicates anaerobic conditions, although interpretation and extrapolation of results must be carefully made. These parameters are particularly diagnostic and results of field studies reveal their dynamic nature and utility in wetland delineation efforts.
Hydrological and Sedimentological Influences on Boroll Catenas, Central Saskatchewan
Authors: Pennock D. J. , Acton D. F. 
Published: July 2010

AbstractThe distribution of soils in a three‐dimensional catena is the result of the action and interaction of hydrologic and sedimentological processes. We examine the relative dominance of the two processes at three study sites in the Black Chernozem (Udic Boroll) soil zone in central Saskatchewan by comparing the distribution of surface soils and postglacial sediments to the present slope morphology and the reconstructed paleo‐slope configuration. Postglacial sedimentation was confined to convergent backslope and footslope configurations on the paleo‐surface and thick sola were associated with these elements. Soil characteristics on shoulder elements, divergent back slopes, and divergent footslopes were relatively unaffected by post‐glacial sedimentation, and the soil characteristics in these elements were in accordance with established differences in water movement in the landscape.
A Rapid Method for Analysis of Soil Macropore Structure. I. Specimen Preparation and Digital Binary Image Production
Authors: Moran C. J. , McBratney A. B. , Koppi A. J. 
Published: July 2010

AbstractPreviously the use of direct observation of soil pore structure in assessing tillage trials has been restricted by the slowness of specimen preparation and data generation. It is desirable that pore structure assessment be performed within a similar time‐scale required for other routine chemical and physical measurements. This would aid the interpretation of routine measurements and enhance the ability to make management decisions in the same growing season as sampling. A method developed for rapid analysis of soil pore structure is presented in two parts. In this paper, a new technique for production of an undisturbed planar face through soil with pore space in the field condition is described. Field impregnation with opaque epoxy resin, that will cure in moist soil, is followed by sawing, laboratory impregnation of the exposed face, and grinding back beyond the original surface to a smooth finish. Grinding is followed by digitization, and digital grey‐level image segmentation to produce a binary image. Methods of image production are described, explained, and illustrated. Samples of Vertisols from a tillage and fallow management trial are shown as examples of the technique. The method can be completed in 4 d for a single specimen. It is emphasized that high quality binary images should be used for image measurement. The discipline of mathematical morphology is used to ensure this quality. This paper finishes with production of high quality digital images that provide graphic illustration of the nature of the pore structure in the vertical plane under the different tillage treatments.
Modeling the Transport of Chromium (VI) in Soil Columns
Authors: Selim H. M. , Amacher M. C. , Iskandar I. K. 
Published: July 2010

AbstractMiscible displacement experiments were conducted to describe chromium [Cr(VI)] mobility and interactions in six different soils. For Calciorthid, Webster, and Norwood soils Cr breakthrough curves (BTCs) indicated that the interactions with the soil matrix were similar to those for a nonreactive solute where no or small retardation of the equilibrium type was observed. These observations are in support of earlier kinetic batch results where little retention was observed for a wide range of Cr concentrations in these (high pH) soils. The BTCs from Olivier, Cecil, and Windsor soils indicated high Cr retention capacity as indicated by increased retardation, low peak concentrations, irreversible sorption and extensive effluent tailing during desorption (leaching). A nonlinear retention/release model is proposed for the purpose of describing Cr(VI) reactions during transport in soils. The model is incorporated into the convection‐dispersion transport equation for reactive solute in uniform soils. The model was capable of providing a good description of the Cr BTCs for all soils where model parameters were obtained using a nonlinear least squares (best fit) parameter optimization scheme. The model grossly underestimated effluent concentrations for Olivier and Windsor BTCs when independently measured retention/release rate coefficients from the batch data sets were used. Model predictions overestimated the amount irreversibly retained by Cecil soil. Model predictions indicated that a unique set of independently measured rate coefficients was not capable of providing an adequate description of Cr BTCs for these soils.
Role of Fungi in Stabilizing Aggregates of Sewage Sludge Amended Soils
Authors: Kinsbursky R. S. , Levanon D. , Yaron B. 
Published: July 2010

AbstractThe effect of sludge amendment on the percentage of water‐stable aggregates (WSA) of five soils with different physical and chemical properties was studied in an incubation experiment. A 5% sludge addition to soil incubated at 25 °C increased the per cent of WSA after 30 d in all of the soils. Bactericides were added to soil‐sludge mixtures to assess the role of fungi in the aggregation process. Bactericide addition resulted in the suppression of bacterial growth and a concomitant proliferation of fungal hyphae. The WSA was highly correlated with water‐soluble carbohydrates in all of the soils, and with hyphal length in two loessial soils. This suggests that cementing by fungal carbohydrates is a relatively more important binding mechanism than physical entanglement by mycelium in WSA formation of sludge‐amended soils. By using a soil washing technique, it was determined that fungi involved in stabilizing aggregates were indigenous soil saprophytes which replaced the native sludge fungal flora.
Preferential Microbial Reduction of Hematite Over Goethite in a Brazilian Oxisol
Authors: Macedo J. , Bryant R. B. 
Published: July 2010

AbstractResearch was conducted to evaluate Fe transformations in a hydrosequence of Oxisols from the Central Plateau of Brazil. The best‐drained member of the hydrosequence of soils selected for the study classifies as an Anionic Acrustox (Dark‐Red Latosol) and has codominant hematitic and goethitic iron oxide mineralogy and reddish hues (2.5 YR). X‐ray diffraction and chemical extraction techniques were used to make detailed analyses of the iron oxides. Peak positions for hematite are coincident with those reported for hematite without foreign ion substitution. Peak positions for goethite are shifted toward a lower d‐spacing, which corresponds to 34 mole % of AlOOH substituting for FeOOH. Soil samples from the Bo horizon were subjected to reducing conditions in the laboratory over a range of time periods, using sucrose as a source of energy to speed up the activity of the soil microorganisms. The observed changes in soil mineralogies confirm the preferential reduction and removal of hematite over goethite. Mineralogies and soil colors after reduction treatments are comparable to that of the Anionic Acrustox (Red‐Yellow Latosol) found in the wetter section of the hydrosequence. The results of this study support the hypothesis that differences in color and iron oxide mineralogy of soils in this hydrosequence are the result of the preferential reduction of hematite over Al‐substituted goethite in the presence of a seasonally high water table.
Fragipan Bonding by Silica and Iron Oxides in a Soil from Northwestern Italy
Authors: Marsan F. Ajmone , Torrent J. 
Published: July 2010

AbstractAn Aquic Fragiudalf developed from a fluvial terrace of Pleistocene age in northwestern Italy was investigated to determine the possible role of different compounds in fragipan bonding. Fragipan characteristics appeared only in yellow, goethite‐containing zones of the fragipan horizon but not in gray, essentially Fe oxides‐free zones. Citrate‐bicarbonate‐dithionite (CBD), but not acid oxalate, extracted more Si in the yellow zones than in the gray zones. These data, and the fact that citrate‐bicarbonate (CB) without dithionite extracted very little Si demonstrate that CBD extracted a Si compound specifically associated with the Fe oxides (mostly goethite). In the fragipan the ratio CBD‐extractable Si goethite reached a profile maximum suggesting that the Si compound associated with the goethite particles could, if present in sufficient amount, cement goethite particles together thus providing a framework to mechanically hold other soil particles; alternatively, that compound could bind goethite with other soil mineral particles. Although the amounts of CBD‐extractable Si were low, a simple calculation showed that they were clearly in excess of those needed to saturate the theoretical sorption capacity of goethite, giving a surplus of Si able to promote bonding. Selective extraction methods provided no evidence for implication of Al in bonding. Consequently amorphous silica could be the bonding agent.
Forest Soil Uniformity Along Toposequences in the Loess‐Mantled Driftless Area of Wisconsin
Authors: Frolking Tod A. 
Published: July 2010

AbstractForest soils in the loess‐mantled ridge and ravine topography of the Driftless Area of southwest Wisconsin show minimal effects related to hillslope gradient. Twelve undisturbed Fayette silt loam profiles (Typic Hapludalf, fine silty, mixed, mesic) that developed in Peoria loess and silty colluvium on slopes of 2 to 55% were examined to ascertain systematic differences as a function of slope. Climate, vegetation, parent material, and time of development were similar for the 12 profiles. Physical and chemical properties of the A and E horizons (including texture, pH, dithionite extractable Fe and Mn, and total P) do not vary significantly as a function of slope gradient. Of the B and C horizon properties measured, only Bt horizon pH, clay accumulation, and total P distribution show statistically significant variations with slope gradient. The Bt horizon pH decreases with increasing slope gradient (r2 = 0.63). Illuvial horizons show less clay accumulation in profiles on steeper slopes (r2 = 0.37). Total P content is higher throughout the B and C horizons of profiles on steep slopes (45%) compared to soils on level and moderate slopes (2–20%). Together these results indicate slightly less leaching of the subsoil on steep slopes. Exchangeable Ca/Mg, Fed, Mnd, maximum clay, and depth to maximum clay reveal no trends as a function of slope gradient. Soil conditions have favored infiltration and minimized surface erosion, leading to nearly uniform soil development in homogeneous parent materials on ridgecrests and sideslopes.
Application of Regionalized Variable Theory to Large‐Plot Field Experiments
Authors: van Es H. M. , van Es C. L. , Cassel D. K. 
Published: July 2010

AbstractSpatial soil heterogeneity poses problems on field experiments which use large treatment plots, as in tillage research. Recent studies have established that many soil properties do not vary in a random manner, but often exhibit spatial dependence. Presently available methods to account for spatial effects either do not fully address these problems or they are too complicated to be widely accepted. The purpose of this study was to develop an experimental design which was based on the principles of regionalized variable theory. Using incomplete blocks of size two, the method estimates treatment effects by means of short‐distance comparisons; this prevents inflation of the error term due to spatial soil variability and eliminates biases caused by variable distances between plots. The analysis of variance for the method is simple and well established. A Monte Carlo simulation study using uniformity trial data was performed to compare the proposed method with a randomized complete block design. The study revealed that the use of incomplete blocks reduces the average error mean square by 44%, and the average coefficient of variation by 25% compared to using complete blocks. The proposed method was, on the average, 21% more efficient then a complete block design.
Runoff, Soil, and Dissolved Nutrient Losses from No‐Till Soybean with Winter Cover Crops
Authors: Zhu J. C. , Gantzer C. J. , Anderson S. H. , Alberts E. E. , Beuselinck P. R. 
Published: July 2010

AbstractSoils are more vulnerable to erosion following cropping to soybean (Glycine max [L.] Merr.) than corn (Zea mays L.). This has been attributed to lower dry matter production, less residue cover, and soil‐loosening action by soybean roots. To augment soil cover, common chickweed (Stellaria media L.), Canada bluegrass (Poa compressa L.), and downy brome (Bromus tectorum L.) were grown as winter cover crops with no‐till soybean on natural rainfall erosion plots located on a poorly drained Mexico claypan soil (Udollic Ochraqualf). No‐till soybean without a cover crop served as the check. Winter cover crops significantly increased soil cover by 30 to 50% during the critical erosion period of late spring to early summer. Compared to the check, mean annual soil losses from the chickweed, downy brome, and Canada bluegrass were decreased by 87, 95, and 96%, and runoff was reduced 44, 53, and 45%, respectively. Dissolved NH+4 concentration in runoff from cover crops was 1.61 to 3.72 times more, and dissolved PO3‐4 was 1.61 to 2.86 times more than that of the check. However, runoff from the check plots had 96 to 117% greater concentration of dissolved NO‐3 than cover crop plots. Mean annual dissolved nutrient losses were decreased 7 to 77% by using winter cover crops. Thus, winter cover crops were very effective in reducing soil erosion and dissolved nutrient losses from no‐till soybean.
Moisture and Nutrient Status of Extremely Acid Umbrepts in the Black Mountains of North Carolina
Authors: Richter D. D. , King K. S. , Witter J. A. 
Published: July 2010

AbstractMoisture and nutrient conditions are poorly characterized in soils at elevations >1500 m in the southern Appalachian Mountains. In the Black Mountains, high elevation soils are Typic and Lithic Haplumbrepts, with umbric epipedons that are extremely acid, organic‐rich, rocky, and unstable due to the steep slopes. Many of the Umbrepts in the Black Mountains have been disturbed by exploitative logging, repeated wildfires, and depredation by the balsam woolly adelgid (Adelges piceae Ratzeburg), each of which has caused major fluctuations in C, nutrient, and hydrologic cycles of soils and ecosystems. The objective of this study was to evaluate predictions based on climate, forest disturbance, and soil genesis: that these soils are rarely subjected to low water potential, that soil N mineralization rates are currently high, and that availability of soil nutrient cations is low. A water balance model appropriate for soils with average water‐holding characteristics indicated that, on a 6‐yr recurrence interval, plants deplete soil moisture to <‐0.2 MPa during low rainfall periods of one‐month duration. High rock contents (about 0.40 m3/m3 of soil volume in 40‐cm depth) limit soil water storage capacity, and make the spruce‐fir forests very dependent on regular rainfall supplies. Soil N appears mineralizable at moderately high rates, as indicated by three soil and plant indices of N availability, whereas plant availability of Ca and Mg appears marginal. Exchangeable Ca and Mg total only 6.4 and 3.4 kmolc/ha, respectively, in the surface 40 cm of mineral soil, low contents that indicate rapid rates of biogeochemical cycling of divalent cations in these ecosystems. The long‐term recovery of these soils from 20th century disturbances depends directly on the dynamics of soil organic matter, due to organic matter's susceptibility to disturbance and to its control over soil moisture and nutrient availability.
Effect of Application Method and Dicyandiamide on Urea‐Nitrogen‐15 Recovery in Rice
Authors: Norman R.J. , Wells B.R. , Moldenhauer K.A.K. 
Published: July 2010

AbstractField studies were conducted on a Crowley silt loam (Typic Albaqualf) to investigate the influence of split applications, subsurface placement, and the nitrification inhibitor (DCD) dicyandiamide (cyanoguanidine) on the plant uptake of 15N‐labeled urea by dry‐seeded rice (Oryza sativa L. ‘Newbonnet’). Fertilizer N topdressed in three split applications (TD3SA) resulted in the highest rice grain yields and highest percent recovery of fertilizer N in the rice plant. Fertilizer N applied all preplant with DCD resulted in slightly less grain yield, but similar total dry matter yield, total N uptake and fertilizer N recovery in the soil‐plant system as the TD3SA method. Fertilizer N applied all preplant without DCD was inferior to the other treatments. Subsurface preplant incorporation (SSPPI) of N resulted in greater fertilizer N uptake by the rice plant compared to broadcast preplant incorporation (BCPPI); but, this did not translate into more total N utilized or grain produced. It appeared that DCD, by maintaining more of the fertilizer N as NH4‐N, caused less fertilizer N to be lost via denitrification after flooding and may have enabled more of the fertilizer N to participate in the mineralization‐immobilization turnover cycle and exchange for soil N. Overall, DCD increased the uptake and yield effectiveness of preplant N in dry‐seeded rice cultivation.