bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leaching of Added Selenium From Alkaline Soils as Influenced by Sulfate
Authors: Brown M. J. , Carter D. L. 
Published: July 2010

AbstractA BaSO4‐BaSeO4 mixture (S:Se = 10) and BaSeO4 alone were applied at 1.60 and 3.20 mg Se per column to two soils and leached with water or gypsum solution. Eight hundred milliliters (10‐cm depth) of leaching solution were added to columns containing 2,100 g of Portneuf silt loam and 2,500 g of Gooding loamy sand at 4‐week intervals for 20 weeks. More Se was leached by gypsum solution than by water from all columns. Where 1.60 mg Se per column was applied, more Se was leached from Gooding loamy sand than from Portneuf silt loam soil with both water and gypsum solution. Where 3.20 mg Se per column was applied, more Se was leached by water from Gooding than from Portneuf soil, but the reverse was true with gypsum solution. The Se leached from the Portneuf soil treated with the BaSO4‐BaSeO4 mixture ranged from 0.34 mg, where 1.60 mg Se per column was applied and soils leached with water, to 2.32 mg, where 3.20 mg Se per column was applied and soils leached with gypsum solution.Much less Se was leached where only BaSeO4 was applied to Portneuf soil. The amount leached ranged from 0.07 mg, where 1.60 mg Se was applied and water used for leaching, to 0.64 mg Se, where 3.20 mg Se was applied and gypsum used for leaching. The Se recovery from the Gooding soil was within these ranges for the same treatments. The Se leached increased with application rate, but not proportionately. The data indicate that addition of SO42‐ increases the solubility of BaSeO4 in these soils.
Effects of Petroleum Mulch on Soil Water Content and Soil Temperature
Authors: Kowsar Ahang , Boersma L. , Jarman G. D. 
Published: July 2010

AbstractChanges in soil temperature and soil water content of mulched and unmulched soil, subjected to the same radiation load, were measured at 2‐hour intervals under controlled laboratory conditions. Soil was packed into boxes with inside dimensions of 40.0 by 4.0 by 50.0 cm at a pre‐determined water content. Part of the soil surface was covered with petroleum mulch. The soil was subjected to a diurnal temperature cycle by varying the output of infrared heat lamps.At a depth of 1 cm the mulch‐covered soil was 5C warmer than the bare soil at the time the soil temperatures attained their maximum value. At all other times the temperature difference between mulched and bare soil was smaller. The bare soil rapidly lost water in the upper 4 cm. The mulch‐covered soil lost water in the upper 1 cm of soil but gained water at depths below this zone. This gain in water in the zone where seedlings are normally placed, indicates that the beneficial effect of petroleum mulch on germination and seedling growth must be attributed to improved soil water conditions as well as to improved soil temperature conditions.
Conductivity Instrumentation for In Situ Measurement of Soil Salinity
Authors: Enfield C. G. , Evans D. D. 
Published: July 2010

AbstractA transducer has been developed which is capable of assessing, in situ, the electrical conductivity of soil water. The transducer is constructed of porous glass with platinum electrodes and operates over the entire field moisture range. The transducer is accurate to within 10% when measured with an associated soild state meter in a conductivity range of 1–20 millimhos/cm @ 25C and a temperature range of 5–45C. Typically, the time required to achieve 63% of equilibrium response, in aqueous solutions, is less than 2 hours.
A Simple X‐Ray Fluorescence Technique for the Determination of Iron and Manganese in Soils and Concretions
Authors: Barnhisel R. I. , Phillippe W. R. , Blevins R. L. 
Published: July 2010

AbstractA simple technique for the determination of Fe and Mn in concretions and soils was developed using X‐ray fluorescence. A 25 mg sample was suspended in a 1% glue‐methyl alcohol solution and transferred to a 4.25‐cm circle of filter paper. The filter paper containing a thin layer of uniformly distributed sample was placed in an X‐ray emission spectrograph for analysis, and highly reproducible and accurate results were obtained. Precision was achieved over a wide range of Fe and Mn oxide contents.
Suction Apparatus for Mounting Clay Specimens on Ceramic Tile for X‐Ray Diffraction
Authors: Rich C. I. 
Published: July 2010

AbstractA simple suction apparatus for preparing clay mineral specimens for X‐ray diffraction on unglazed ceramic tile is described. A large rubber stopper is modified by forming a molded recess with silicon rubber to reduce air leakage about the tile. Specimens of proper thickness can be prepared quickly with the apparatus.
Reactions of 12 s‐Triazines with Soil Clays
Authors: Brown Cyril B. , White Joe L. 
Published: July 2010

AbstractTwelve herbicides—chloro, methoxy and methyl‐thio compounds—of the s‐triazine family were reacted with chloroform and water suspensions of soil clays of varying mineralogical composition, and also with Wyoming bentonite. IR spectra of air‐dried KBr pellets of the reacted samples were made. NMR data of a chloro and methoxy s‐triazine were studied.Data showed that protonation and hydrolysis of the triazine had occurred in certain samples. The highly acidic environment of montmorillonitic clay surfaces provided conditions suitable for the hydrolysis. The order of hydrolysis of the chloro s‐triazines used in the study is trietazine > chlorazine > propazine > ipazine > simazine = atrazine. The corresponding methoxy or methyl‐thio compound hydrolyzed less than the chloro analogue. Protonation and adsorption are directly related to the basicity of the triazine but hydrolysis has an inverse relation. NMR data can be used to obtain the relative basicities of s‐triazine herbicides and thus be an indicator of ease of hydrolysis.
Locus of Urease Activity in Soil
Authors: Paulson K. N. , Kurtz L. T. 
Published: July 2010

AbstractA model is proposed to determine the location of active urease in soil; that is, whether the urease was associated directly with soil microorganisms or free from microorganisms and adsorbed on the soil colloids. An indirect approach was used which consisted of making periodic measurements of urease activity during a period of time when the microbial population was undergoing change. Multiple regression analysis was applied to the data to determine the relationship between urease activity and microbial population. Under steady state conditions, 79–89% of the urease activity of the soil examined was due to urease adsorbed on soil colloids. An increase in microbial population reduced this percent temporarily until a new steady state was reached. Addition of a small amount of urea (13 ppm of urea‐N) to the soil induced microorganisms to produce more urease.
Diffusion and Analysis of Carbon‐14 Labeled Dieldrin in Soils
Authors: Farmer W. J. , Jensen C. R. 
Published: July 2010

AbstractLiquid scintillation techniques were used in developing a rapid method for the analysis of carbon‐14 labeled dieldrin in soils. Treated soil samples up to 1 g in weight were added to 20‐ml liquid scintillation counting vials and the labeled dieldrin extracted into the toluene counting media. The diffusion coefficient of dieldrin was measured in soils of varying texture and relative humidity at 20C in transient state systems. At 53% relative humidity the diffusion coefficient in eight soils varied between 0.049 and 0.36 mm2/week. No correlation was found between soil texture and the diffusion coefficient. The diffusion coefficient in three soils varied between 0.40 and 0.64 mm2/week at 75% relative humidity and between 3.8 and 9.7 mm2/week at 94% relative humidity. At the higher humidity, the diffusion coefficient increased with increasing clay content.
Seasonal Variability of pH and Lime Requirements in Several Southern Michigan Soils When Measured in Different Ways
Authors: Collins J. B. , Whiteside E. P. , Cress C. E. 
Published: July 2010

AbstractThe seasonal variability of pH and lime requirement of the plow layer of 13 soil series, at 19 sites, by various methods on field‐moist, air‐dry and oven‐dry samples were observed from May through September 1966 near East Lansing, Mich. Several factors associated with variation in pH were also observed.At the beginning of the season, the mean glass electrode‐pH of air‐dry and oven‐dry samples measured in each of three suspending media—water, 1.0N KCl, and 0.01M CaCl2—were each significantly lower than the corresponding field‐moist pH. On air‐dry samples, pH measurements with the glass electrode in water are significantly correlated with those in 0.01M CaCl2 (r = 0.96) and in 1.0N KCl (r = 0.92) or those measured with the Truog kit (r = 0.90).The pH of field‐moist samples in water showed a maximum seasonal variability of 1.6 pH units and an average variation of 0.8 pH unit. The pH of samples in 1.0N KCl showed the least average seasonal variability of the methods used, 0.2 pH units. Electrical conductivity gave the highest correlation (r = ‐.82) with seasonal variability of pH on air‐dry samples in water. The glass electrode pH on air‐dry samples in 1.0N KCl were better correlated (r = .63) with percentage base saturation than those in water (r = .53) and slightly better than those in 0.01M CaCl2 (r = .61).Four of 11 sites studied had a lime requirement early in the season but each of the 11 sites had a lime requirement in midsummer.
Organic Phosphorus and Inositol Phosphates in Molecular Size Fractions of a Soil Organic Matter Extract
Authors: Moyer J. R. , Thomas R. L. 
Published: July 2010

AbstractSoil organic matter extracted with the chelating resin Dowex A‐1, was fractionated into three fractions on a column of Sephadex G‐75. The first fraction, which has an approximate lower molecular weight limit of 50,000, contained 36% of the total organic P in the extract. The second fraction, with intermediate molecular weights in the range 1,000–50,000, contained 31% of the P. The third fraction, which was considered below the fractionation range and therefore is below 1,000 molecular weight, contained 7.8% of the organic P in the extract. Inositol phosphates were detected in the second and third fractions but not in the first fraction. Inositol phosphates in the third fraction were considered to be in the free form, while those in the second fraction must be in either a polymer form or bound to other organic compounds.
Influence of Nitrogen on Phosphorus Absorption and Translocation in Zea mays
Authors: Thien S. J. , McFee W. W. 
Published: July 2010

AbstractThe effect of metabolized N and N in solution on P absorption and translocation in corn was studied in growth chamber experiments. Two‐week‐old corn plants of various N and P contents were prepared by pre‐treatment in NH4+, NO3‐, P or water solutions for 24 hours. Plants were then transferred to treatment solutions containing labelled P alone or with a N source. Uptake and translocation of labelled P was continuously monitored for 6 hours.Nitrogen pretreatment of corn plants significantly increased P absorption and translocation rates during the following 6 hours. These effects were absent when N was omitted from the pretreatment solution and accompanied P only during the treatment period, indicating no companion effect of these two nutrients on movement into root cells. Phosphorus absorption and translocation were stimulated to different degrees suggesting two separate transport systems involved in P uptake and translocation. The observations suggest the existence of a N‐requiring metabolite influencing the efficiency of P absorption and translocation mechanisms in corn. No significant difference between the N sources, NH4Cl or NaNO3, was observed.
Zonal Salinization of the Root System with NaCl and Boron in Relation to Growth and Water Uptake of Corn Plants
Authors: Bingham F. T. , Garber M. J. 
Published: July 2010

AbstractCorn seed (Zea mays L.) was germinated in the top portion of a soil column separated by thin amber wax layers into three equal horizons. Each soil unit contained 500 g of soil aggregates, a tensiometer, and tubing to facilitate irrigation and drainage. Differential treatments of NaCl and B were separately imposed for 3 to 4 weeks upon the various root zones once the plant had extended roots throughout all horizons. Each horizon was irrigated with a dilute nutrient solution with and without NaCl to have an EC of 12 mmho/cm for the NaCl treatments; and with H3BO3 to have concentrations of 10‐, 20‐, and 40‐mg B/liter for the B treatments.Results include data on plant growth, water use, and ion uptake. The NaCl treatments were associated with reductions in root growth and water use/plant in proportion to percent root system treated. However, little or no reduction in shoot weights occurred upon zonal salinization of two‐thirds of the root system. Also, the NaCl treatments did not restrict uptake of NPK to any serious extent. The B experiments showed corn plants to be injured by soil solution levels of 20 mg B/liter or greater, the degree of injury being a function of soil solution B and percent root system under treatment.
Runoff as Affected by Salt Treatments and Soil Texture
Authors: Kemper W. D. , Noonan L. 
Published: July 2010

AbstractRunoff was measured on soils during rains applied with a rainfall simulator in the laboratory. These soils were dried and rained on again and this sequence was repeated several times with runoff measured during each rain. The texture providing maximum runoff consisted of high sand contents (50 to 80%). Higher percentages of clay and silt resulted in surface cracking and considerable infiltration through those cracks.Marked increases occurred in runoff due to NaCl treatments and decreases occurred due to CaSO4 treatments. Since the amounts of the salts required was small (244 to 896 kg/ha) and the cost of these salts is low (approximately $1.00/50 kg in bulk), emergency water control of bare surfaces using salt treatments appears to be economically feasible.
Translocation of Hydrophobic Substances into Soil by Burning Organic Litter
Authors: DeBano L. F. , Mann L. D. , Hamilton D. A. 
Published: July 2010

AbstractUnknown hydrophobic substances were vaporized in surface layers of litter and water repellent soil by an imposed heat treatment. The vaporized substances moved downward and condensed in different test soils where they produced a water repellent layer. The thickness of the water repellent layer in the underlying test soil increased as per cent soilt and clay decreased. The thickest and most intensely water repellent layer was produced in a uniform 35‐mesh sand. The effect of texture on water repellency was attributed to large differences in specific surfaces of the soils which ranged from 0.0077 to 55 m2/g. The induced water repellency was not directly related to a given amount of organic matter translocated by the heat treatment. Generally, however, the degree of water repellency increased as the amount of translocated organic matter increased in a given test soil.
Nonpedogenetic Texture Bands in Outwash Sands of Michigan: Their Origin, and Influence on Tree Growth
Authors: Hannah Peter R. , Zahner Robert 
Published: July 2010

AbstractOrigin of many thick well‐developed nonpedogenetic texture bands is attributed to deposition in glacial outwash concurrent with the deposition of adjoining layers of sand outwash. Nonpedogenetic bands are thicker, less stratified, finer textured, and more massive and convoluted than pedogenetic bands. Roots of forest trees tend to branch and proliferate in the region immediately above thin bands and penetrate and develop normally in thick till‐like bands. Site indexes for natural jack pine (Pinus banksiana Lamb.) and bigtooth aspen (Populus grandidentata Michx.) stands, and stemwood production in red pine (Pinus resinosa Ait.) plantations are significantly higher on soils with prominent texture bands than on soils where bands are absent or weakly developed.
Effect of Complexing Agents and Acids on the Diffusion of Zinc to a Simulated Root
Authors: Elgawhary S. M. , Lindsay W. L. , Kemper W. D. 
Published: July 2010

AbstractPorous ceramic tubes were embedded in soil tagged with 65Zn. Solutions were slowly passed through the tubes, allowing diffusion of the solutes into the soil and diffusion of Zn from the soil to the tubes. Solution from the tubes was analyzed for 65Zn. The solutes used were EDTA (ethylenediaminetetraacteic acid), HCl, citric acid, an amino acid mixture, and glucose. EDTA caused the greatest increase of Zn transport into the ceramic tubes (simulated roots). For example, when 10‐3M EDTA was passed through such a tube Zn diffusion increased 17‐fold over that occurring with water alone. The effectiveness of other agents decreased in the order listed above. Increasing the concentrations of solute generally increased 65Zn diffusion. This study demonstrates how complexing agents or acids from root exudates or from decomposing organic residues in soils may increase the transport and availability of insoluble nutrients.
Nitrogen Immobilization in Flooded Soils
Authors: Broadbent F. E. , Nakashima T. 
Published: July 2010

AbstractNitrogen immobilization in flooded soils amended with straw was measured by following incorporation of tagged inorganic N into the soil organic fraction. Increases in tagged organic N were found to be highly correlated with net immobilization as measured by decrease in mineral nitrogen in the soil. Since most of the soils used contained clay minerals capable of ammonium fixation, apparent immobilization figures were corrected by subtraction of clay‐fixed ammonium.In comparisons of nitrogen immobilized under different soil conditions it was found that values obtained in flooded soils were intermediate between those obtained under aerobic and anaerobic conditions. The nitrogen factor, or additional N immobilized, per unit weight of straw, was found to vary with quantity of straw added, nitrogen content of the straw, and nature of the soluble nitrogen supplied, but in no case was it negligible. Rice straw (Oryza sativa L.) containing 0.47% N immobilized an additional 0.51% N in a flooded soil, and another sample of rice straw containing 1.17% immobilized 0.43% N.
Concentration of NH3(aq) Required for Incipient NH3 Toxicity to Seedlings
Authors: Bennett A. C. , Adams Fred 
Published: July 2010

AbstractShort term experiments with sudangrass (Sorghum sudanensis L.) and cotton (Gossypium hirsutum L.) were conducted in a growth chamber to determine incipient toxic levels of NH3(aq). Sudangrass seedlings were grown for 14 days in potted Lucedale sandy loam surface soil treated with different rates of N from NH4OH, (NH4)2SO4, and (NH4)2HPO4. Root growth of cotton seedlings was measured over a 3‐day period in split‐root experiments in which the upper portion of the root medium was a sandy loam surface soil and the lower portion was either a nutrient solution or a treated soil at various levels of pH and ammoniacal‐N. Symptoms of NH3 toxicity were evident on sudangrass foliage at NH3(aq) concentration in the soil solution in situ of 0.17mM and greater; there was no evidence of NH3 toxicity at 0.13mM and less. Symptoms of NH3 toxicity on cotton roots were evident in soil solutions in situ at NH3(aq) concentrations of 0.24mM and greater but not at 0.17mM and less; in nutrient solutions, symptoms were evident at 0.22mM NH3(aq) but not at 0.16mM. The critical concentration for incipient NH3 toxicity was concluded to be 0.15 to 0.20mM NH3(aq).
Effects of Aluminum Toxicity and Phosphorus Fixation on Crop Growth on Oxisols in Natal
Authors: Reeve N. G. , Sumner M. E. 
Published: July 2010

AbstractSimple, routine methods for estimating exchangeable Al and P‐fixing capacity of acid soils are described. A glass‐house study on eight Oxisols revealed marked growth response of ‘trudan’ (Sorghum sudanense) to amelioration by lime, gypsum, and Ca silicate which is ascribed to elimination of Al toxicity rather than to improved P availability. Growth response to ameliorants took place up to the point of elimination of exchangeable Al after which a significant reduction in yield occurred. P fixation is shown to be a major fertility limitation in the soils studied. Since no apparent relationship between P fixing capacity and exchangeable Al existed and since lime did not decrease P fixation despite its ability to eliminate soluble Al, it is concluded that P fixation is the result of an adsorption reaction rather than a precipitation reaction. Although the soils studied are all capable of fixing large quantities of P considerable variation exists between them. Fertilizer recommendations based only on an estimate of available P in the soil per se could thus be in serious error.
Quantitative Prediction of Leaching in Field Soils
Authors: Terry D. L. , McCants C. B. 
Published: July 2010

AbstractLeaching experiments were conducted under controlled water regime conditions on a variety of soils in the field to study the distribution of certain ions by percolated water. When NH4, NO3, and K were leached, their movement was generally in the form of a “normal” distribution. The movement of Mg was not as well defined as the other ions.Multiple regression equations for predicting the leaching of these ions were developed which utilize the parameters of a normal distribution as the dependent variables and properties of the soil and quantities of percolated water as the independent variables. The R2 values for mean movement ranged from 0.92 to 0.97 and those for the standard deviation from 0.56 to 0.91. The principal independent variables were (i) quantity of percolated water, (ii) soil porosity as expressed by the weighted porosity index, (iii) cation exchange capacity, and (iv) the water content at 0.1 bar suction.
Effect of American Beech Trees on the Gamma Radioactivity of Soils
Authors: Gersper P. L. 
Published: July 2010

AbstractVarious factors that affect the distribution of gamma‐emitting radioisotopes in soils under mature American beech trees (Fagus grandifolia L.) were investigated. Because of its smooth bark and consequent greater amounts of stemflow this species concentrates more fallout radioisotopes in soil near its stem than most other species.Soil near the stems of beech trees contained considerably more fallout and was subjected to greater leaching of natural radioisotopes, to a depth of 30 cm or more, than soil not affected by stemflow water. Depth penetration of fallout and leaching of natural radioisotopes was greater in Dekalb fine sandy loam than in Bennington silt loam.Radioisotope distribution in soil under these trees was also affected by variations of stemflow around the stems, slope gradient, and the quantity and distribution of organic litter on the forest floor. Near two trees that had variable stemflow, the surface soil contained an average of five times more fallout on the high‐stemflow sides of the stems than on the low‐stemflow sides. Under a beech tree growing on a 20% slope, soil on the downslope side of the stem contained more fallout than soil on the upslope side. Organic litter had a much higher content of fallout than of naturally occurring radioisotopes.As a consequence of the greater concentrations of fallout, herbaceous plants, spicebush (Lindera benzoin L.), and American beech saplings growing near the stems of mature beech trees had higher uptakes of these radioisotopes than those growing farther from the stems.
Molecular Weight of Montmorillonite from Optical Transmission Measurements
Authors: Lahav N. , Banin A. 
Published: July 2010

AbstractThe weight average molecular weight of small Na‐montmorillonite particles in aqueous suspension have been determined by means of optical density (OD) measurements. In the wavelength range of λ = 4000A to 6000A and in dilute clay suspension which obeys Beer‐Lambert Law, the slope of the straight line of log (OD) vs. log λ is proportional to the major dimension of the particles. Assuming a disc geometry and the number of unit layers in a clay particle, and working with suspension with a slope near −4, the weight average molecular weight was found by using light scattering theory. The results agree reasonably with other data from the literature.