bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Determination of Exchangeable Bases, Acidity, and Base Saturation for Soil Characterization
Authors: Hajek B. F. , Adams F. , Cope, J. T. 
Published: July 2010

AbstractRoutine, rapid, soil‐testing procedures were used for measuring both exchangeable bases and exchangeable acidity. Exchangeable bases were extracted by a single wash with a dilute HCl + H2SO4 solution and analyzed by flame spectrophotometry and atomic absorption. Exchangeable acidity was determined by the pH change of a buffered solution‐soil suspension. The values obtained compared favorably with values determined by NH4OAc, NaOAc, and BaCl2‐triethanolamine and were suitable for separation of Ultisols from Alfisols and mollic from umbric epipedons.
Growth, Mineral Composition, and Seed Oil of Sesame (Sesamum Indicum L.) as Affected by NaCl
Authors: Yousif Yousif H. , Bingham Frank T. , Yermanos D. M. 
Published: July 2010

AbstractThe tolerance of sesame to NaCl salinity was studied first during germination (72 hours), and later during plant growth up to maturity. Germination was conducted in the laboratory at 25C. Sesame plants were tested for response to salinity using nutrient solution cultures with sodium chloride added when test plants were approximately 10 cm tall. Experiments were continued until mature seed pod formation. The data showed a high tolerance during germination but sensitivity at later growth stages.Although seed yield was strongly reduced, the seed oil content and its fatty acids were not changed. Analyses of leaf blades at different growth stages did not reveal changes in Ca, Mg, K, P, and N indicative of a nutrient deficiency(s). Chlorides, however, accumulated to levels considered toxic. The chloride absorption isotherm showed a marked increase at all growth stages for the same substrate NaCl concentration. This increase was coincident with severe leaf injury and growth reduction. The Na levels in the leaf blades were very low relative to Cl. For example, Na and Cl levels of plants under the highest NaCl treatment at 6 weeks were 0.20% Na and 5.13% Cl. Growth was reduced approximately 50% by this NaCl treatment. The 0.20% Na level is not high enough to indicate Na toxicity.
Response of Rice to Nitrogen and Calcium Nutrition
Authors: Krasaesindhu Prateep , Sims J. L. 
Published: July 2010

AbstractThe influence of N and of Ca nutrition on growth and chemical composition of ‘Nova 66’ rice (Oryza sativa L.) was studied in the greenhouse. Rice plants were grown in soil supplied with four levels each of N (0, 100, 200, and 300 ppm) and Ca (0, 400, 800, and 1,200 ppm) fertilizer. The soil was submerged throughout the experiment.Significant N × Ca interactions were obtained for both grain yield and straw weight. The interactions for grain yield revealed that yield increased as rate of N fertilizer increased, and increases were greatest when Ca levels increased simultaneously. In contrast, interactions for straw weight showed that N increased weight but the increases were lessened in the presence of Ca. Total dry weight (grain + straw) was significantly increased by N but was only slightly affected by Ca. Thus Ca increased grain yield, decreased straw weight, and markedly increased the grain:straw ratio.Nitrogen content (g/pot) and Ca concentration of grain were greatly enhanced by both N and Ca fertilization. Greatest contents were obtained at the highest levels of N and Ca. In contrast, Ca lowered concentration of N (%) in both grain and straw and N content (g/pot) of straw. Total N contents (straw + grain) were also slightly lower in the presence of Ca. The reductions in N concentration and content increased with increasing Ca added. Evidence indicated that the effect of Ca may have been largely indirect, through its effect on K accumulation. The inhibiting effect of Ca was overcome partially when N fertilizer level was increased.
Clay Mineralogy of Soils Developed Partially from Volcanic Ash
Authors: Pettapiece W. W. , Pawluk S. 
Published: July 2010

AbstractLuvisols (Alfisols) in the Front Ranges of the Canadian Rocky Mountains of west‐central Alberta have several distinctive features including surface horizons with a variable volcanic ash content and reddish Bt (B2t) horizons characterized by the presence of expanding clays. A study of the clay fractions indicates a marked increase in the content of smectitic clay in the sola and particularly in the Bt (argillic) horizons compared with the parent materials. Also, the expanding component is poorly organized and appears to result from the synthesis of amorphous material, probably from a volcanic ash source, accompanied by some degradation of primary chlorite and illite. The clay mineral profile does not fit the concepts generally held for lessivé soils (Luvisols, Alfisols, Sols Lessivé, pseudo‐podzolic soils) and in some portions of the sola is similar to that noted in true podzols.
Weathering of Mica Flakes in Two Soils in Northern Greece Evaluated by Mössbauer and Conventional Techniques
Authors: Yassoglou N. J. , Nobeli Catherine , Kostikas A. J. , Simopoulos A. C. 
Published: July 2010

AbstractThe weathering of the fine sand‐size mica flakes in two soils (I and II) developed in northern Greece under the same climatic, drainage, and age conditions, but under different vegetational cover, was investigated by chemical analysis, X‐rays, differential thermal analysis (DTA), infrared, and Mössbauer spectroscopy. It was found that hydrobiotite was inherited from the consolidated bedrock and underwent further pedogenetic oxidation, vermiculitization and kaolinitization in the soil. The oxidation of Fe seemed to take place preferentially in the larger and more symmetrical octahedral sites of the latice. Kaolinite was formed through transformation of the mica flakes in soil II which is now covered by scotch pine (Pinus sylvestris L.) and Vaccinium, while gibbsite was formed in the flakes of soil I, which has a spruce (Picea excelsa L.) cover. No detectable montmorillonite was found in the flakes examined in this study.Rates of weathering and physical disintegration result in conditions which produce a more weathered appearance of the fine sand‐size flakes in the section of the profiles immediately below the surface in soil II compared to those in soil I.The Mössbauer parameters of the flakes indicate that weathering of biotite to 2:1 minerals results in oxidation of the ferrous ions to ferric in the two octahedral sites of the lattice. Of these two sites the less symmetrical with hydroxyls in cis position is more resistant to oxidation.
Humic‐Fulvic Acid Content in Soils as Related to Ley Clipping Management and Fertilization
Authors: Tan K. H. , Beaty E. R. , McCreery R. A. , Powell J. D. 
Published: July 2010

AbstractStudies on changes of humic‐fulvic acid content in a Eustis loamy sand due to weekly clipped Pensacola bahiagrass (Paspalum notatum Parodi) and fertilization showed that nitrogen fertilization encouraged formation of humic acid and decreased fulvic acid contents in soils. Longer clipping intervals tended to increase the amount of both humic and fulvic acid when nitrogen fertilization was applied.A significant positive correlation between nitrogen or organic‐P contents of the soil and humic/fulvic acid ratios indicated that humic‐fulvic acid formation was affected by soil nitrogen content (or organic‐P). A correlation also existed between humic‐fulvic acid and pH, in which a decrease of soil pH resulted in an increase of humic/fulvic acid ratio.
Hydrolysis of Propazine by the Surface Acidity of Organic Matter
Authors: Nearpass D. C. 
Published: July 2010

AbstractPropazine [2‐chloro‐4, 6‐bis (isopropylamino)‐s‐triazine] hydrolysis in acidic aqueous soil‐free systems was pH dependent, increasing with lower pH values. At a given pH, degradation followed first‐order kinetics. At 23.5C, the relationship was log t½ (days) = 0.59 pH −0.21. Adsorption of propazine by organic matter prepared from Michigan peat was also pH dependent, but both molecular and cationic adsorption occurred. An increased rate of degradation in the presence of organic matter was postulated as due to hydrolysis by ionized surface hydrogen. Increasing the calcium saturation resulted in decreased hydrolysis. Increasing the CaCl2 concentration of the propazine‐organic matter‐aqueous system had no effect on acid hydrolysis. In the salt‐amended systems, an increased hydrolysis, to be expected from the lower pH in the ambient solution, was apparently offset by a decreased hydrolysis due to the lowered amounts of ionized surface hydrogen.
Phytolith Size Characteristics Between Udolls and Ustolls
Authors: Yeck R. D. , Gray Fenton 
Published: July 2010

AbstractTo test a phytolith size‐annual rainfall relationship hypothesis, the sizes of opaline phytoliths from four Oklahoma soils were compared. Opaline phytoliths form in intimate association with plant cells and the variation of plant cell size with moisture stress forms the theoretical basis for the hypothesis. The soils sampled were St. Paul, a Typic Argiustoll; Zaneis and Vanoss, Udic Argiustolls; and Fitzhugh, a Typic Argiudoll. Opaline phytoliths were isolated from the 5–20µ, 20–35µ, and 35–50µ soil fractions. The relative amounts of phytoliths in these size fractions in the upper 10 cm of each soil was used to measure their size variation among soils. Phytoliths were further characterized by shape in each soil. Distribution of phytoliths with depth was also noted.There was a higher incidence of the 5–20µ phytoliths in the Ustoll than in the Udoll (66.9% vs. 53.2%) and a correspondingly higher percentage of 35–50µ phytoliths in the Udoll compared to the Ustoll (14.8% vs. 4.4%). The Udoll‐Ustoll intergrades contained intermediate quantities of the 35–50µ phytoliths but not of the 5–20µ and 20–35µ phytoliths. It was concluded that the hypothesized relationship seemed to exist with further work required to understand the relationships in the intermediate areas. Such a relationship would be a very useful tool in paleosol and paleoclimate studies.
Field Test for Spodic Character Based on pH‐Dependent Phosphorus Adsorption
Authors: Bartlett R. J. 
Published: July 2010

AbstractA field method based on P adsorption is proposed for measuring the relative amounts of reactive organic Al in suspected spodic horizons. A soil sample to be tested is equilibrated by shaking with a pH 9.1 phosphate solution. If high in reactive Al, the sample will remove the P from the solution as indicated by the absence of blue‐colored molybdophosphate in the filtrate. Phosphorus adsorbed by soil samples under the test conditions was found to be correlated with Al extracted by pH 4.8 NH4OAc, but not by neutral KCl. It is suggested that soils be initially screened for presence of reactive hydroxy Al by testing with NaF and alizarin yellow, with the expressed caution that occasional high organic spodic horizons may give negative NaF tests.
Soil Morphology and Water Table Relations: I. Annual Water Table Fluctuations
Authors: Boersma L. , Simonson G. H. , Watts D. G. 
Published: July 2010

AbstractWater table positions with respect to the soil surface and precipitation were measured daily over a 2‐year period at representative sites of five soil series comprising the Willamette association of nearly level soils with good to poor natural drainage. All soils had water tables present for some period during the winter. Perched water tables were present near the surface of the two most poorly‐drained series most of the winter.A mathematical model was developed for predicting water table positions on the basis of rainfall input and soil physical characteristics. The model was calibrated with measurements made during the 2 years and then used with rainfall data from the previous 29 years, to reconstruct water table positions as they had occurred in the past. The computer procedure did not apply to the two poorly‐drained series because of the presence of an impermeable soil horizon (clay B) near the surface. However, water table positions of these series were estimated satisfactorily by correlation with water table positions on the better‐drained series. The average percent of time the water table was above a given level during each month, calculated for the period of 1929 to 1957 showed that for a specific depth and month, the percent of time the water table was above a given level increased as the natural drainage conditions became poorer. The percentages for the 30.4‐cm depth during April for example were 1.8, 15.4, 66.7, 81.5, and 92.0, respectively, for the five series. Thus, particular water table regimes are associated with drainage conditions of specific soil series.
Soil Phosphorus Level Adequate for Growth of Ocala Sand Pine Seedlings, A Greenhouse Evaluation
Authors: Baker James B. , Brendemuehl R. H. 
Published: July 2010

AbstractA greenhouse study was conducted to determine the level of soil P adequate for satisfactory growth of Ocala sand pine (Pinus clausa (Chapm.) Vasey) seedlings. Various quantities of Lakeland sand with low and high P contents were blended to provide soil mixtures with a range of available P. Ocala sand pine seedlings were grown in these mixtures for 10 months. On the basis of the seedlings' dry matter production, the level of soil P adequate for satisfactory growth of Ocala sand pine is in the neighborhood of 1 ppm available [NH4OAc (pH 4.8)‐extractable] P. Seedlings growing in soils containing < 1 ppm available P showed a marked reduction in dry weight. Tissue analyses indicate that concentrations of foliar P of < 0.15% may denote a deficiency of available soil P.
Amorphous Material in Some Papua New Guinea Soils
Authors: Parfitt R. L. 
Published: July 2010

AbstractThe clay fraction of five tropical soils was extracted successively with dithionite‐citrate‐bicarbonate, 2% sodium carbonate and, 0.5M sodium hydroxide. Large amounts of clay were dissolved from all soils except the solodic soil. Differential infrared spectroscopy showed that allophane was dissolved from the volcanic ash soils together with iron and alumina gels. Goethite and disordered kaolinite were extracted from the latosol. No amorphous silica was present in the solodic soil.
Potentiometric Titration of Sulfate in Water and Soil Extracts Using a Lead Electrode
Authors: Goertzen J. O. , Oster J. D. 
Published: July 2010

AbstractSulfate concentrations in natural waters and soil‐water extracts were determined semiautomatically using a lead‐ion electrode to indicate the solution potential change at the endpoint, a constant flow device to deliver the titrant, a pH‐mV meter to measure the potential, and a strip chart recorder to plot the solution potential thus indicating the endpoint. Sulfate concentrations as low as 0.5 meq/liter in the sample solution were determined by the potentiometric titration system. This semiautomated direct titration of sulfate has the advantages of increased sensitivity and speed as compared with the precipitation method.
The Transport of Cations in Soil Columns at Different Pore Velocities
Authors: Lai Sung‐ho , Jurinak J. J. 
Published: July 2010

AbstractThe transport of Na+ and Mg2+ in Ca2+‐saturated Yolo loam soil column under saturated steady state flow of different pore velocities was studied. The cation solution was maintained at a concentration such that a linear adsorption isotherm described the cation adsorption. Experimental retention curves were compared to the theoretical solutions obtained from a linear equilibrium model. At low relative concentrations, the equilibrium adsorption of Na+ was significantly less than that of Mg2+. At high pore velocities, the agreement of the experimental retention curves with that of the theoretical calculation was good. At low pore velocity, the agreement was poor. The retention volumes of Na+ and Mg2+ were smaller than those theoretically calculated and those obtained experimentally at high pore velocity. Extensive tailing of Mg2+ observed in the experimental data was not described by the theoretical model.
Reactive Aluminum Estimated from the Formation of Magnesium‐Aluminum Double Hydroxide
Authors: Schalscha E. B. , Pratt P. F. , Gonzalez M. C. 
Published: July 2010

AbstractReactive Al in volcanic ash soils of Chile was estimated from the buffering in the pH interval of 8.2 to 8.5 for potentiometric titration curves obtained from serial titrations of 5‐g samples of field‐moist soil suspended in 50 ml of 0.5N MgCl2 using NaOH as the base. The period of time allowed for reaction was 24 hours. Reactive Al thus measured was highly correlated with the Al extracted by 1N NH4OAc at pH 4.8, with the ratio of Al2O3 to SiO2 dissolved by NaOH, with phosphate fixation, and with the CEC measured by saturating with KH2PO4, but not with organic matter content. The reactive Al in A horizons was highly correlated with that in B horizons. An alkaline soil containing no volcanic ash showed no buffer capacity in the pH 8.2 to 8.5 range when titrated in MgCl2 solution. Volcanic ash soils titrated without MgCl2 showed no buffering in this pH range. This method of measuring reactive Al appears to be promising but needs to be further tested.
Calcium and Strontium Transport to Plant Roots
Authors: Elgawhary S. M. , Malzer G. L. , Barber S. A. 
Published: July 2010

AbstractMass‐flow and diffusion of Ca and Sr to tomato (Lycopersicon esculentum) roots were studied in two exchange resin rooting media. Six harvests were made from plants grown over a 26‐day period under low and high humidities in a growth chamber. With low humidity, the rate of supply of Ca and Sr by mass‐flow exceeded uptake rate during the entire growth period. Under high humidity, the rate of mass‐flow supply exceeded uptake only until the second harvest, thereafter diffusion became the dominant supply mechanism.The Ca/Sr ratio of uptake was compared with the Ca/Sr ratios on the resins and in solutions to determine the source of Ca and Sr. Supply by mass‐flow came from the solution, where‐as supply by diffusion apparently came mainly from the exchangeable fraction indicating exchange diffusion was important. Both log of root length and log of water uptake were linearly correlated with time for the 26‐day growth period investigated. The rate of water absorption ranged from 1.1 × 10‐7 to 6.0 × 10‐7 cm3/cm of root per sec.The root uptake coefficient for Ca uptake varied between 1.43 × 10‐6 and 2.72 × 10‐6 cm/sec and for Sr 1.0 × 10‐6 to 2.38 × 10‐6 cm/sec where an average root radius of 0.015 cm was used in the calculations.
Relationships Among Physical and Chemical Properties of Representative Soils of the Tropics from Puerto Rico
Authors: Philipson Warren R. , Drosdoff Matthew 
Published: July 2010

AbstractIn an investigation of the extent to which predictive soil property relationships can be relied upon in characterizing soils of the tropics classified at the reconnaissance level, 9 to 15 soil properties, of 370 horizons, from 84 Puerto Rican profiles, were studied by correlation and multiple linear regression. The soils represented six orders of the new US Soil Taxonomy (7th Approximation): Vertisols, Mollisols, Alfisols, Inceptisols, Ultisols, and Oxisols. Multiple regression equations were formed from the data of each order, with 15‐bar moisture content, CEC, organic carbon, extractable iron, and base saturation as dependent variables. The results indicate that, although it is possible to eliminate certain properties from tropical soil data acquisition and still adequately characterize the soil, the specific properties that can be successfully eliminated depend on the soil order.
Influence of Sand on the Amount of Water‐Dispersible Clay in Soil
Authors: Ashford E. M. , Shields L. G. , Drew J. V. 
Published: July 2010

AbstractWater‐dispersible clay in soils from a number of geographic locations increased in relation to clay measured by a standard procedure as the proportion of sand in the soils increased. Additions of sand to soils containing relatively small amounts of water‐dispersible clay relative to “regular” clay markedly increased the yield of water‐dispersible clay; medium sand and coarse sand were the most effective. Conversely, the removal of sand from soil containing large amounts of sand reduced the yield of water‐dispersible clay. The abrasive action of sand during agitation associated with water dispersion evidently breaks down aggregates containing clay.
Improved Mercury Well for Multiple Tensiometer Systems
Authors: Doering E. J. , Harms J. P. 
Published: July 2010

AbstractDetails are presented for the fabrication of an improved mercury well for multiple tensiometer systems. The well is mounted on the back of the manometer support and is so designed that individual manometers can be repaired without disturbing the other manometers. Scale zero is visible and low moisture tensions can be read.
Total Mercury Content in Morrow Plot Soils over a Period of 63 Years
Authors: Jones Robert L. , Hinesly T. D. 
Published: July 2010

AbstractOver a 63‐year period, Hg varied from 0.1 to 3.92 ppm in samples from surface horizons of soils from Plots on the University of Illinois campus. The dominant secular trend has been to lower levels in recent time. Neither changes in organic carbon content nor agronomic practices were related to Hg levels. Large amounts of coal burned in a nearby power plant did not contribute a fallout of Hg to the soils. A change toward improved internal soil drainage caused by tile drainage is thought to be the major factor causing the trend.
Growth, Mineral Composition, and Seed Oil of Sesame (Sesamum indicum L.) as Affected by Boron and Exchangeable Sodium
Authors: Yousif Yousif H. , Bingham Frank T. , Yermanos D. M. 
Published: July 2010

AbstractA solution culture boron experiment was conducted with sesame (Sesamum indicum L.) to show the effects of excessive B. The boron content of leaf blades, petioles, and stems was highly correlated with substrate boron. The leaf blades contained the highest amount of boron, and the stems the least. Concentrations of 5 mg B/liter or higher inhibited growth, seed production, and resulted in a leaf necrosis and premature leaf drop. Foliage of plants receiving excess B contained > 700 µg B/g on a dry weight basis.An exchangeable sodium experiment using clay soil with and without a synthetic soil conditioner showed that yields were sharply reduced at an ESP level of 15 or greater. Leaf blade sodium was higher for the treatments without the soil conditioner but in both series (± conditioner), 50% growth depression was associated with leaf values of about 0.4% Na. Potassium and Mg in the leaf blades did not vary significantly, and although calcium was decreased 50% with increasing ESP, no visual deficiency symptoms were detected. The oil content of the seed was decreased slightly with ESP levels of about 25.