bluuebunny/crossref_metadata_2025_split huggingface dataset:
Manganese Deficiency in Soybeans as Affected by FeEddha and Low Soil Temperature
Authors: Moraghan J. T. 
Published: July 2010

AbstractSoybeans [Glycine max (L.) Merr.] developed an interveinal chlorosis, which eventually turned into a yellow‐green mottling on older leaves, when grown on certain calcareous soils treated with FeEDDHA. It was hypothesized that the problem was due to Mn deficiency, the intensity of which is known to be accentuated in soybeans at low soil temperatures. The influence of FeEDDHA, a foliar application of MnSO4, and soil temperature on growth of soybeans on a Glyndon loam, Aeric Calciaquolls, was studied under green‐house conditions. Increasing the FeEDDHA concentration from 0.2 to 2 mg of Fe kg−1 decreased dry matter yield at 15 but not at 24°C. The higher rate of FeEDDHA also caused a leaf chlorosis that was much more intense at 15 than at 24°C. The yield depression and the chlorosis were overcome by a foliar application of MnSO4. Soybean plants grown with the higher rate of chelated Fe contained 8 and 20 mg Mn kg−1 at 15 and 24°C, respectively, after 43 d. It was concluded that the chlorosis observed in soybeans growing on the calcareous soil was due to Mn deficiency induced by FeEDDHA and low soil temperature.
Transport of Cadmium by Organic Solvents Through Soil
Authors: Sheets P. J. , Fuller W. H. 
Published: July 2010

AbstractSolutions of 0, 50, and 100% 2‐propanol and ethylene glycol in water containing 1 mM Cd were perfused through soil columns of river sand, Anthony sl (coarse‐loamy, mixed [calcareous], thermic Typic Torrifluvents), or Davidson c (clayey, kaolinitic, thermic Rhodic Paleudults) at two initial soil moisture contents (air dry and water saturated) to determine if organic solvents have the potential to alter the rate of Cd movement through soils as compared with water alone. Soils adsorbed less Cd from ethylene glycol than from water. Cadmium breakthrough was rapid and Anthony sl and river sand adsorbed <6 µmol Cd g−1 when leached with Cd‐enriched 2‐propanol. The 2‐propanol increased Cd adsorption compared to water in the Davidson c. Cadmium adsorption increased with increasing 2‐propanol concentration in the Davidson c but decreased with increasing 2‐propanol concentration in the River Sand and Anthony sl. No consistent trends occurred with increasing ethylene glycol concentration. Davidson c and river sand adsorbed significantly more Cd at 95% confidence levels from 2‐propanol when initially air dry, while Anthony sl adsorbed more Cd when initially water saturated. Initial soil moisture content did not significantly affect ethylene glycol transport of Cd at the 95% confidence level.
Structural Characteristics of a Fungal Melanin and a Soil Humic Acid
Authors: Schnitzer M. , Chan Y. K. 
Published: July 2010

AbstractA melanin produced by Hendersonula toruloidea and a soil humic acid were characterized by a number of chemical (elemental and functional group analyses, carbohydrate content, amino acid, amino sugar, and NH3 analyses) and spectroscopic methods (IR and 13C NMR) before and after 6 M HCl hydrolysis. The following distinct differences were observed between the two materials: (i) phenolic components were prominent in the untreated and hydrolyzed melanins but not in the corresponding soil humic acids (HA); (ii) the melanin contained more complex unidentified N than did the soil HA; and (iii) following hot acid hydrolysis, the melanin was more aliphatic but considerably less aromatic than the soil HA. Hot acid hydrolysis, by removing practically all of the proteinaceous materials and carbohydrates from the two materials, made it possible to focus on the structural chemistry of the residual materials.
Comparison of Procedures for Reducing Cross‐contamination During Steam Distillations in Nitrogen‐15 Tracer Research
Authors: Mulvaney R. L. 
Published: July 2010

AbstractA study was conducted to compare the effectiveness of various procedures for reduction of cross‐contamination errors when unenriched samples of (NH4)2SO4 containing 0.5 mg of N were steamdistilled in a glass distillation apparatus following samples enriched with 50 atom % 15N. Twelve procedures were compared in this study, including most of those previously proposed in the literature. None of the procedures completely eliminated cross‐contamination; however, some were considerably more effective than others. The results suggest that, when a glass distillation apparatus is used in 15N‐tracer research, the best way to reduce cross‐contamination error is to distill two aliquots of each sample whenever possible, discarding the first distillate and retaining the second for isotope‐ratio analysis. When this is not possible, it is recommended that 1 mL of 1M formic acid be distilled for 1 min and 25 mL of 16.4 M (95%) ethanol be distilled for 3 min between samples. This procedure can be made more effective by increasing the amount of formic acid used and extending distillation beyond 1 min.
Available Nitrogen and Nitrogen Cycling in Forest Soils Exposed to Simulated Acid Rain
Authors: Stroo H. F. , Alexander Martin 
Published: July 2010

AbstractThe formation of NO‐3 and NH+4 was measured in columns containing samples from the surface horizons of 12 forest soils both during and after exposure to simulated rain applied at three times the ambient deposition rates for 116 d. The relative responses to increased acidity were correlated with organic matter and N levels of the soils. The average inhibition for the 12 soils was linearly related to the amount of acidity added. The quantity of N mineralized was less in some soils after their exposure to simulated rain at pH 3.5 than at pH 5.6 and greater in other soils, but the average amount mineralized after exposure of the 12 soils was not significantly affected by the pH of the simulated rain during the treatment period. The mean percentage of the inorganic N produced in the 12 soils that was in the NO‐3 form was lower during but not after the exposure to simulated rain at pH 3.5 than at 5.6. The amount of inorganic N added in the simulated acid rain exceeded the diminished supply arising because of the inhibition of mineralization during the exposure. The suppression of N mineralization in Crary soil (Aquic Fragiorthods) containing white pine (Pinus strobus L.) seedlings and in Mardin soil containing red oak (Quercus rubra L.) seedlings was less than in unplanted soil. The simulated rain at pH 3.5 altered the amounts of K, Ca, Mg, Al, Fe, and Mn leached from the soil. It is suggested that the inhibition of inorganic N formation by microorganisms in short periods of acid precipitation may be compensated by the N added with the precipitation, but the impact on available N over long periods of exposure is unknown.
Effects of Phosphorus/Aluminum Molar Ratio and Calcium Concentration on Plant Response to Aluminum Toxicity
Authors: Alva A. K. , Edwards D. G. , Asher C. J. , Blamey F. P. C. 
Published: July 2010

AbstractTotal aluminum (Al) in solution often comprises both monomeric and polymeric Al species. Concentrations of total and monomeric Al and Σ activities of monomeric Al species (Σ aAl mono) were determined in nutrient solutions at 40 µM Al with varying P/Al molar ratios (0, 0.02, 0.2, 2.0 and 4.0) and calcium (Ca) concentrations (0.5, 1.5, 5.0, 15 mM). Effects of these treatments on root elongation of soybean [Glycine max (L.) Merr.], sunflower (Helianthus annuus L.), subterranean clover (Trifolium subterraneum L.), and alfalfa (Medicago sativa L.) were determined. Concentrations of total and monomeric Al in solution decreased with increasing P/Al molar ratio. Ca concentration had no significant effect on concentration of total or monomeric Al, but significantly affected the Σ aAl mono in solution. Root elongation of the plant species increased with increasing P/Al molar ratio and Ca concentration. The increase in root elongation with increase in P/Al molar ratio was associated with a decrease in monomeric Al in solution. The beneficial effect of Ca on root elongation was evident even when Al in the root environment was expressed as Σ aAl mono, which effectively removes the ionic strength effect of Ca. However, at Σ aAl mono ≥ 18 µM, increasing Ca concentration failed to improve root elongation. The range of critical Al values for a 50% reduction in root elongation with varying Ca concentration was much narrower if based on Σ aAl mono than on the concentration of monomeric Al in solution. The critical Σ aAl mono, with increasing Ca concentration from 0.5 to 15 mM, varied from 12 to 17 µM for soybean, <8 to 16 µM for sunflower, <7 to 15 µM for subterranean clover, and <5 to 10 µM for alfalfa.
Soils at Prehistoric Agricultural Terracing Sites in New Mexico: I. Site Placement, Soil Morphology, and Classification
Authors: Sandor J. A. , Gersper P. L. , Hawley J. W. 
Published: July 2010

AbstractSoils and landscapes used for runoff terrace agriculture sometime between 1000 to 1150 A.D. in a semiarid area of New Mexico were studied in order to infer criteria for site selection, and to determine possible long‐term effects of the land use. Terracing involved construction of small rock dams across hillslopes and drainageways with subsequent sedimentation occurring upslope of each dam. Sites occur primarily within a narrow range of possible locations, implying deliberate placement with respect to climatic, topographic, and soil factors. Locational characteristics commonly include elevations of 1800 to 2000 m, 3 to 10% slopes, <1‐ to 8‐ha drainage areas, and soils with strongly developed argillic horizons (claypans). These soils, Paleustolls and Argiustolls, are developed in Pleistocene volcanic alluvium. The claypan probably served to confine moisture within the crop rooting zone. Terracing functioned to reduce runoff velocity, increase soil moisture, and thicken a naturally thin loamy A horizon overlying the claypan. Soil morphological changes continuing to the present are mainly limited to surface horizons. Although A horizon texture was not appreciably altered by terrace sedimentation, A horizons are usually 10 to 30 cm thicker in cultivated soils. Peds in cultivated A horizons are generally coarser, blockier, and compacted relative to the dominantly granular structure of their uncultivated counterparts, and are lighter in color value. The structure and color changes are attributed to decreased organic matter contents resulting from cultivation and persisting conditions of reduced grass cover and accelerated erosion.
Soils at Prehistoric Agricultural Terracing Sites in New Mexico: III. Phosphorus, Selected Micronutrients, and pH
Authors: Sandor J. A. , Gersper P. L. , Hawley J. W. 
Published: July 2010

AbstractIn this third paper examining long‐term effects of prehistoric cultivation on some New Mexico Mollisols about 900 yr after abandonment, data on total P, inorganic P fractions, Fe, Mn, Zn, Cu, and pH are presented. Cultivation‐induced soil changes, involving losses of total and moderately available P and total Cu but gains in total Mn, were inferred by comparing cultivated soils with nearby, similarly developed uncultivated soils (controls). Comparisons were also made between A horizons and sediment deposits accumulated upslope of recently fallen trees. These deposits are considered analogous to fresh agricultural terrace deposits just prior to cultivation. Total P losses in cultivated soils avg 15, 18, and 18% in the upper A, A, and BAt horizons, respectively, relative to control soils, and about 22% in the A horizon relative to recent sediment deposits. Below the BAt horizon, total P levels in cultivated and control soils converge. Moderately available P is not significantly lower (p <0.05) in cultivated upper A horizons but is about 40% lower in cultivated complete A horizons. Other inorganic P fractions have not changed much in cultivated soils. While total Fe and Zn levels are unchanged in cultivated soils, Cu is lower by about 20% and Mn is 20% higher in cultivated A horizons. Manganese increase is attributed to sedimentation under reducing conditions accompanying terracing in cultivated areas. There is a trend towards slightly higher pH in cultivated A horizons.
Properties, Classification, and Interpretations of Minesoils at Two Sites in West Virginia
Authors: Thurman N. C. , Sencindiver J. C. 
Published: July 2010

AbstractMinesoils on two surface mines in Monongalia County, West Virginia, were classified using a proposed amendment to Soil Taxonomy. Minesoil properties and interpretations for selected nonagricultural uses were determined for both mine sites. The proposed amendment grouped minesoils into families based on differences in rock fragment lithology, soil reaction (pH), and particle size. The minesoils had a high rock fragment content (33–45%), high bulk density (1.55–1.86 Mg m−3), low porosity (26–38%), low water retention capacity (0.07–0.12 kg kg−1), moderately slow estimated hydraulic conductivity (0.1‐1 µm s−1), an irregular distribution of organic C with depth, and strongly acid pH (4.1‐5.1). Soil factors affecting the nonagricultural use of the mine sites were slow percolation, stoniness, acidity, and droughtiness. Site factors—slope, irregular topography, size of the site, and the presence of highwalls and steep outslopes—were more limiting to development than soil factors. Classification using the proposed amendment to Soil Taxonomy aided in separating minesoils according to differences in management‐related properties and can be useful for general planning purposes.
Soybean Growth and Yield Responses to Starter Fertilizers
Authors: Touchton J. T. , Rickerl D. H. 
Published: July 2010

AbstractOn highly fertile soils, increases in plant growth resulting from starter fertilizers, applications generally do not occur unless root growth is restricted or temperatures are cool. The use of some conservation‐tillage systems may result in restricted root growth and cooler soils at planting. The purpose of this 3‐yr field study was to determine if growth and yield of soybeans [Glycine max (L.) Merr.] planted in a conservation‐tillage system would be increased by starter fertilizers, and if interactions occurred between residual fertility levels and starter fertilizers. Treatments included residual fertility levels (low P and K, low P and high K, high P and low K, and high P and K) and starter fertilizers (no starter, N, P, K, N‐P, N‐K, and N‐P‐K). The N, P, and K starter fertilizer rates were 16, 19, and 44 kg ha−1, respectively. Raising both residual P and K to the high soil test rating improved soybean yields 43%. The N‐containing starter fertilizers, especially those also containing P, increased early season plant root and top weights, but the K starters did not. However, the P, K, N‐K, and P‐K starter fertilizers had the greatest effect on yields; when compared to the control, they increased yields 46% when residual P, K, or both were low, and 26% when the residual P and K were high. The N, N‐P, and N‐P‐K starter fertilizers increased yields 21% when residual P was low, but had no effect on yields when P was high. Seed quality did not vary among residual fertility levels, but was improved by the starter fertilizers, especially those containing K. The P and K concentrations in the leaves just prior to pod set corresponded to differences in yields among residual fertility levels, but not to differences among starter fertilizers.
A Centrifuge Method for Obtaining Soil Solution Using an Immiscible Liquid
Authors: Elkhatib E. A. , Bennett O. L. , Baligar V. C. , Wright R. J. 
Published: July 2010

AbstractThe low toxicity organic liquid ethyl benzoylacetate (EBA) was found to be an effective immiscible displacent for soil solution removal. The ionic composition of soil solution displaced by EBA was, in general, comparable to that removed by the toxic, immiscible displacent CCl4. Increasing the relative centrifugal force (RCF) from 4.8 × 105 to 49.4 × 105 m s−2 nearly doubled the volume of soil solution displaced but did not affect the ionic composition of the soil solution. The procedure provided an adequate volume of soil solution for chemical analysis when 120 g of moist soil were centrifuged for 0.5 h at an RCF of 49.4 × 105 m s−2.
Nitrogen Mineralization in Profiles of Differently Managed Soil Types
Authors: Hadas Aviva , Feigenbaum Sala , Feigin A. , Portnoy Rita 
Published: July 2010

AbstractNitrogen mineralization kinetics and relations between potentially mineralizable N and chemical availability indices have been studied mainly in surface soils. In this study, the rate of mineralization was measured, by incubation techniques, in various soil types and soil depths, in order to evaluate the contribution of different soil layers to mineral nitrogen (N) of the whole root zone and to relate the rate parameters obtained to various soil N fractions. Soil layers of 60 to 120 or 160 cm contributed about 30% of the N mineralized in the whole soil profile. Ammonium accumulated and its nitrification was delayed in deeper soil layers of several profiles. Several rate equations were fitted to the experimental data. The first order rate constant varied from 0.02 to 0.10 week−1, without any consistent trend. Similar random variations of rate parameters were observed in other models with two or more parameters. The potentially mineralizable N (No) of one‐parameter models was highly and better correlated with the amount actually mineralized in 32 weeks of incubation and with various N forms in soil than the No obtained from two‐parameter models. Total N weighted with respect to soil layer depth was the best estimate of N mineralized in soil profiles.
Soil Losses of Dinitrogen and Nitrous Oxide from Irrigated Crops in Northeastern Colorado
Authors: Mosier A. R. , Guenzi W. D. , Schweizer E. E. 
Published: July 2010

AbstractEmissions of nitrous oxide (N20) and dinitrogen (N2) from irrigated fields were monitored during the 1982 and 1983 cropping season to assess the magnitude of N loss by denitrification. Miniplots were established within larger fields of corn (Zea mays L.) in 1982, and barley (Hordeum vulgare) in 1983. Soil inside the miniplots was amended at a rate of 200 kg N ha−1 as 99 atom % 15N ammonium sulfate, and the vertical N20 and N2 fluxes were measured periodically by sampling gases from a soil cover method, and analyzing the N20 by gas chromatography and the N2 by mass spectrometry. Maximum N20 emissions occurred in May for barley and in July for corn, and emissions for both crops increased with increasing soil‐water content. During 1982, total volatile N loss of N20 + N2 from the moderately well‐drained clay loam soil was about 2.5% of the applied fertilizer N, and about 70% of the total was N20. From the barley field in 1983, about 1% of the applied fertilizer N was emitted with about equal amounts of each gas. These data suggest that the role of denitrification as a N loss mechanism has been historically overemphasized for soils in this area.
Spectroscopic Investigations of Cultivation Effects on Organic Matter of Vertisols
Authors: Skjemstad J. O. , Dalal R. C. , Barron P. F. 
Published: July 2010

AbstractSolid state carbon‐13 nuclear magnetic resonance (13C NMR) spectroscopy with cross polarization and magic angle spinning (CP/MAS) was used to study the effect of cultivation on the nature of organic matter in a Vertisol (mesic, mixed, clayey, Typic Chromusterts). Continuous cultivation for 20, 35, and 45 yr resulted in 50, 61, and 66% loss in organic matter, respectively, from the 0‐ to 0.1m layer. However, 13C NMR spectroscopy performed directly on samples from these cultivated soils (0–0.1 m depth) and on adjoining virgin soil under native, virgin brigalow (Acacia harpophylla) scrub showed only minor differences in the in situ organic matter. Resonance bands representing long‐chained alkyl groups were the dominant feature of all four spectra and represented >50% of the organic C. Fractions obtained from density separations (<1.6, 1.6–2.0, 2.0–2.4, >2.4 Mg m−3) made on the soil under native scrub and the soil that had been cultivated for 35 yr showed that the organic C content of the light fractions (<2.0 Mg m−3) was greatly reduced after cultivation, while the heaviest fraction remained unchanged. Carbon‐13 NMR spectra determined on the fractions with a density <2.4 Mg m−3 showed that the organic matter with the highest alkyl content occurred in the 2.0‐ to 2.4‐Mg m−3 fraction. Also, the relative amount of humic acid decreased after cultivation, while the relative amount of clay‐bound organic matter increased. Ultraviolet/visible and infrared spectroscopic analyses of the humic acid and humin fractions agreed well with the NMR data. It is concluded that the major mechanism responsible for the relative stability of the persistent soil organic matter is a physical association with the inorganic components of the soil, rather than an inherent chemical or biochemical inertness of the organic matter itself.
Long‐term Effects of Mesquite Removal on Soil Characteristics: I. Nutrients and Bulk Density
Authors: Tiedemann A. R. , Klemmedson J. O. 
Published: July 2010

AbstractIn 1981, we compared soil carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and bulk density (BD) for sites with three different mesquite (Prosopis juliflora) histories: (i) where mesquite had been removed 13 yr earlier (MR history), (ii) where mesquite was removed, but sprouted and regrew (MRS history), and (iii) where mesquite was left intact (MI history). Three soil depths from the surface to 19.5 cm were sampled in the canopy location (areas presently or once under the influence of mesquite canopy) and in adjacent open areas. Comparisons between canopy and open locations and among depths were similar to those we observed in 1968. In the surface soil layer of canopy soils, C and N concentrations were arrayed significantly among histories: MI > MRS > MR. There were no significant differences among histories for P, S, or BD, although reduced C following mesquite removal (MR history) was reflected in a tendency for increased BD, which will likely become significant in the future. The differential response of N to mesquite history compared to P and S is probably explained by differences in the amounts of organic and inorganic forms of these elements in soils, and by the differential rates of mineralization and ion mobility.
Reactions of Sechura Phosphate Rock and Single Superphosphate in Soil
Authors: Syers J. K. , Mackay A. D. 
Published: July 2010

AbstractThe reactions of Sechura phosphate rock (SPR) and single superphosphate (SSP) were investigated in an incubation study using contrasting soils over 90 d. The rate and extent of dissolution of SPR, measured by a single extraction with 0.5 M NaOH, increased as the phosphate (P)‐sorption capacity of the soils increased. In contrast, the initial dissolution of SSP was independent of soil type. Whereas the amounts of water‐ and Olsen‐extractable P in soils to which SSP was added declined from the time of application, the amounts of Olsen‐ and Bray‐extractable P in soils to which SPR was added initially increased. With both P sources, the amounts of extractable P decreased as P‐sorption capacity increased. In a glasshouse experiment a poor relationship (r = 0.051) was found between P uptake by ryegrass (Lolium perenne L. var. Nui) from soil to which SPR was added and the extent of dissolution at 90 d. In contrast a very good relationship (r = 0.954**) was found between P uptake by ryegrass and Bray‐extractable P in soil to which SPR was added. It is important to distinguish between those soil properties that promote the dissolution of a PR and those that control the subsequent amounts of plant‐available P in soil.