bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Fumigants on the Soil Status and Plant Uptake of Certain Elements
Authors: Smith Donald H. 
Published: July 2010

AbstractFumigants commonly used or studied in relation to pineapple production in Hawaii are D‐D, EBD, BBC (1,2‐dibromo‐3‐chloropropane), and methyl bromide. These fumigants sometimes increase and sometimes decrease the quantity of iron that may be extracted from the soil. Use of D‐D and methyl bromide appears to improve the utilization of iron within the plant but not the uptake of iron by the plant. Fumigants sometimes lower the oxidation‐reduction potential in otherwise unamended soil. When combined with easily decomposable organic matter, they very markedly reduce this potential. The effect of fumigants in increasing availability of maganese in the soil and to the plant may be large, and may persist for many months. Fumigants frequently increase the phosphorus content of soil extracts, and D‐D has increased the phosphorus “A value” in greenhouse tests, but use of D‐D or methyl bromide in the field consistently results in reduced phosphorus uptake by the plant.
Clay Mineral Characterization of Modal Soil Profiles in Several Pennsylvania Counties
Authors: Johnson L. J. , Matelski R. P. , Engle C. F. 
Published: July 2010

AbstractAs part of the detailed soil survey of Pennsylvania, clay mineral types in modal soil profiles are being identified to determine: (1) weathering trends within profiles, (2) the distribution of clay types, and (3) the utility of clay mineral data for soil correlation. The clay mineral data is summarized on triangular diagrams which graphically illustrate the distribution of clay mineral types among horizons within a profile and between profiles of the same soil type. Differences in distribution of clay types between profiles of the same type are very common. The major change with increasing depth within the profiles studied is the increase in illite and the decrease in vermiculite and/or aluminum interlayered vermiculite. Kaolin minerals are relatively constant with increasing depth. Montmorillonite is generally associated with poor drainage and high organic matter content. It is concluded that soil correlation with clay mineral data is helpful but only of restricted application. Weathering is manifested by the sequence illite to vermiculite to aluminum interlayered vermiculite. Parent material controls the occurrence of kaolin and trioctahedral chlorite.
Residual Effects of Perennial Grass Sod on the Physical Properties of a Chernozem Soil
Authors: Mazurak Andrew P. , Ramig Robert E. 
Published: July 2010

AbstractResidual effects of perennial grass sod on a Chernozem soil were studied in two experiments. In the first experiment, two cool‐season grasses were in sod for 2, 4, 6, and 8 years in the second 10‐year cycle of a 20‐year study. Sod was plowed and then cropped to a fallow‐wheat sequence for 4 years. In the second experiment, seven cool‐season and four warm‐season grasses were in sod for 7 years. Sod was plowed and then cropped to a fallow‐wheat sequence for 6 years. In both experiments the plots were split or paired and one‐half of each plot or one of each pair of plots received nitrogen fertilizer.In the first experiment the residual effects of grasses on the rates of water entry into soil and on the water stability of aggregates were evident 4 years after plowing sod. The degree of residual effect increased as the years in sod prior to plowing increased. Residual effect of grasses augmented the yields of wheat. Similarly in the second experiment, favorable effects of cool‐ and warm‐season grasses were noted on the rate of water entry into soil.
Threshold Gradient for Water Flow in Clay Systems
Authors: Miller Raymond J. , Low Philip F. 
Published: July 2010

AbstractIn this work the presence of a threshold gradient for water flow in clays was established. The threshold gradient is the hydraulic gradient below which no flow occurs. The threshold gradient decreased with decreasing clay concentration and increasing temperature. At gradients above the threshold gradient, the flow rate‐gradient relationship was essentially linear, except at low gradients, for the concentrated clay systems but curvilinear for the less‐concentrated clay systems. These results were explained on the basis of a quasi‐crystalline water structure which developed in the clay‐water systems as a result of water‐surface interaction.
Solubility of Gypsum and Dicalcium Phosphate Dihydrate in the System CaO‐P2O5‐SO3‐H2)O and in Soils
Authors: Moreno E. C. , Osborn G. 
Published: July 2010

AbstractThe solubility isotherm (25°C.) for gypsum was determined in the concentration range from 1.5 × 10‐2 to 6.0 × 10‐2 mols of S per liter by equilibrating CaSO4 · 2H2O with H2SO4 solutions of varying concentrations. The solubility product of gypsum calculated from these data was 2.45 × 10‐5. The effect of gypsum upon the solubility of dicalcium phosphate dihydrate (DCPD) was related to the pH. The percentage of calcium in solution which was derived from DCPD was 80% and 3% at pH 3.6 and 6.3, respectively. The data from exchange resin and solubility studies are consistent with a hypothesized complex in solution of the form Ca(H2PO4)+. Equilibrations of DCPD and gypsum in soil systems indicated that apparent supersaturation with respect to both salts was obtained at pH values above 5.8. This anomalous behavior was explained by the complexing of Ca by soluble organic matter. The research findings are discussed in the light of soil and fertilizer chemistry.
Diffusion of Phosphorus as Related to Soil Texture and Plant Uptake
Authors: Olsen S. R. , Watanabe F. S. 
Published: July 2010

AbstractDifferences in the diffusion coefficients of phosphorus (P) between sandy and clay soils were applied to explain variations in rates of P uptake by corn seedlings from equal initial concentrations of P in the soil solution. The relation between labile P of the solid phase and P concentration in solution or the phosphate capacity, also varies with the clay content. An equation relating uptake of P by plant roots to the diffusion coefficient and the phosphate capacity showed that the rate of uptake was proportional to where Dp is the diffusion coefficient and b is the slope of the line relating labile P to concentration of P in solution or the phosphate capacity, when other factors are constant. The equation predicts that the rate of uptake of P will be one‐third as much from the sandy soil as from the clay soil at equal concentrations of P in the soil solution. Actual measurement of the rate of P uptake by corn seedlings agreed closely with the predicted values from the equation for P concentrations < 0.2 ppm. As the clay content of three soils increased from 17 to 51%, the diffusion coefficient for P increased from 1.1 × 10‐7 to 6.7 × 10‐7 cm.2 per sec. and the b value increased from 110 to 178.
Influence of Straw Mulch on Soil Moisture, Soil Temperature and the Growth of Corn
Authors: Moody J. E. , Jones J. N. , Lillard J. H. 
Published: July 2010

AbstractIn a 3‐year study, corn was grown on plots treated with 3 tons of wheat straw per acre, either placed on the surface or plowed under, and with two rates of N. Soil temperature, soil moisture, plant height and weight, N and K content of the plant and yields were obtained. Soil temperature at the 4‐inch depth was lower throughout the growing season under mulch conditions. The low temperature under mulch was associated with a temporary depression of growth during the early growing season. A significant increase in growth of mulched over unmulched corn, beginning in late June, was attributed to the greater moisture under mulch during the period of high plant requirements. Mulched corn was 64 cm. taller at tasseling and produced 42 bushels per acre more grain than corn which had the straw plowed down. Runoff was seven times greater from the unmulched plots.
Pressure Dependence of the Relative Vapor Pressure of Water in Soil
Authors: Richards L. A. , Low P. F. , Decker D. L. 
Published: July 2010

AbstractThe equation ∂ ln (p/po)/∂P = (v̄ − vo)/RT, expressing pressure dependence of the relative vapor pressure in terms of the difference between the partial molar volume v̄ of the water in the system and the molar volume of pure water vo, was derived and was used in interpreting the experiments. A thermocouple psychrometer (TP) was calibrated at 25°C. using 0.10 and 0.20 molal KCl solutions at several air pressures in the sample chamber, ranging up to 15 bar. The TP reading for a sample of soil, when referred to the measurement for an appropriate sample of KCl solution, did not change significantly as the air pressure in the soil chamber was increased by 5‐bar steps up to 15 bar. The total suction of water in soil is directly related to the relative vapor pressure p/po of the soil water and for our test sample the total suction was 6.44 bar at atmospheric pressure. The values of the standard deviation of total suction corresponding to the standard deviation of the TP readings were calculated to be 0.053, 0.084, and 0.109 bar for pressure increases of 5, 10, and 15 bar. Decreases in total suction greater than these amounts were not found.
Entrapped Air Content and Hydraulic Conductivity of Quartz Sand During Prolonged Liquid Flow
Authors: Gupta Rajinder P. , Swartzendruber Dale 
Published: July 2010

AbstractBoiled deionized water, with and without 0.1% phenol, was passed through permeameters filled with several types of quartz sand. In addition to measurements of hydraulic conductivity, the sand‐water system inside the permeameters was periodically subjected to a static gauge pressure ΔP, and the resulting volume change Δv was recorded by the movement of a mercury droplet in a capillary tube. The quantity Δv/ΔP was found to be a highly sensitive indicator of the air entrapped within the wet sand. For sand wetted at atmospheric pressure, Δv/ΔP was found to be high initially, and then to decline sharply as flow proceeded. When the hydraulic conductivity reached its maximum value, the decrease in Δv/ΔP flattened out abruptly, but a slow decline persisted as flow continued. When the sand was wetted under vacuum, the high initial value and subsequent rapid decline in Δv/ΔP were eliminated.Since Δv/ΔP was always observed to decline with continued flow, even when the hydraulic conductivity was undergoing a drastic decrease, it was concluded that flow‐associated reductions in hydraulic conductivity, observed in the present and in previous similar experiments, were not caused by an accumulation of entrapped air originating from dissolved air released by the flowing liquid.
Toxic Factors in Acid Soils: II. Differential Aluminum Tolerance of Plant Species
Authors: Foy C. D. , Brown J. C. 
Published: July 2010

AbstractDifferential Al tolerance of plant species in nutrient solution and in acid Bladen soil was closely associated with the ability of plants to absorb and utilize P in the presence of excess Al.Chelating agent (EDDHA), added to the nutrient solution portion of a split medium, increased the solubility of Al but decreased its toxicity to Al‐sensitive plants. EDDHA at 1/4 the molarity of the Al added gave near‐maximum yields for Al‐tolerant buckwheat. For Al‐sensitive barley, EDDHA at twice the molarity of the Al was required for normal growth. The beneficial effects of EDDHA on Al‐sensitive barley in nutrient solution were associated with marked increases in the solubility of P and with increased uptake of P by plants.
The Dissolution of Calcium Aluminum Phosphate, CaAlH(PO4)2·6H2O
Authors: Taylor A. W. , Gurney E. L. 
Published: July 2010

AbstractThe solubility product of CaAlH(PO4)2·6H2O is not less than 10‐39. Although the salt is formed readily by reaction of gibbsite with concentrated calcium phosphate solution, it is unstable in dilute solutions and hydrolyzes to amorphous aluminum phosphate.
The Effect of Root Aeration on Plant Growth
Authors: Williamson R. E. 
Published: July 2010

AbstractRates of oxygen diffusion were measured in soil contained in 3‐foot‐cube lysimeters in field installations. Water tables were maintained by subsurface watering at 6‐ to 30‐inch depths below the soil surface. Some lysimeters were sheltered from rain. Soybeans, cabbage, grain sorghum, sweet corn, and dwarf field corn were grown in these lysimeters.The highest yields were obtained at oxygen diffusion rates of approximately 15 g. X 10‐8 per cm.2 per minute. The maximum yields were high in comparison with yields obtained in most field experiments. Oxygen diffusion rates at 6‐inch water table depths were below 5 g. X 10‐8 per cm.2 per minute. Under these conditions of extremely poor aeration, yields of grain sorghum, soybeans, cabbage, sweet corn, and dwarf field corn were reduced 25, 35, 40, 65, and 75%, respectively.
Soil Water Diffusivity and Hysteresis Data from Radial Flow Pressure Cells
Authors: Klute A. , Whisler F. D. , Scott E. J. 
Published: July 2010

AbstractThe theory and advantages of radial flow geometry for the determination of soil water diffusivity are discussed. A description is given of a cylindrical pressure cell in which this theory is applied. Values of the soil water diffusivity, D, were obtained from a comparison of the experimental volume outflow or inflow‐time curves with the theoretical relationship between volume outflow or inflow and the factor Dt where t is time. Diffusivities were measured in the pressure range up to 1 ½ atmospheres on two porous media. The diffusivity‐water content hysteresis function was observed to be composed of crossed‐curve segments forming a skewed and distorted “bowtie.”
Water Vapor Diffusion in Relatively Dry Soil: I. Theoretical Considerations and Sorption Experiments
Authors: Jackson Ray D. 
Published: July 2010

AbstractWater transfer was measured in three soil materials at water content ranges corresponding to a relative pressure range of 0.97 to about 0.05. At these water contents vapor flow is probably the predominant transfer mechanism. The data were obtained from a transient sorption experiment and diffusion coefficients were calculated from analyses of water content distribution curves. The evaporation‐condensation reaction between the liquid and vapor phases was treated by using simultaneous diffusion‐reaction theory. Within the water content ranges used the diffusion coefficients increase and then decrease with increasing water content.
Sorption and Fixation of Microquantities of Cesium by Clay Minerals: Effect of Saturating Cations
Authors: Sawhney B. L. 
Published: July 2010

AbstractSorption and fixation of microquantities of Cs by six minerals, as affected by the saturating cations, were studied. Micas and vermiculite sorbed more Cs in the presence of Ca and similar divalent cations than in the presence of K and similar monovalent cations. Montmorillonite and kaolinite, on the other hand, sorbed more Cs in the presence of K than in the presence of Ca. While micas and vermiculite fixed large proportion of the Cs sorbed, mont‐morillonite and kaolinite did not fix significant amounts of Cs against replacement by neutral salts. Thus, whereas Cs‐sorption by montmorillonite and kaolinite appeared to be largely electrostatic, the sorption and fixation of Cs by micas and vermiculite was governed by the size and hydration, rather than valence, of the competing cation. Micas particularly exhibited a large fixation of Cs. It is suggested that the fixation of Cs by micas occurs at the crystal edges where Cs may replace K and thus become a part of the stable mica structure.
Cobalt Content of New England Soils in Relation to Cobalt Levels in Forages for Ruminant Animals
Authors: Kubota Joe 
Published: July 2010

AbstractThe Co content of soils and common forage plants was low and related to reported areas of Co deficiency in ruminant animals in two extensive areas of granitic drift deposits in New England. One of the areas extends from southestern Maine to southeastern New Hampshire, encompassing an area mantled by granitic drifts from the White Mountains. The other area occurs in southeastern Massachusetts and includes Cape Cod. The low Co soils within these areas are Podzols, Brown Podzolic soils and Ground‐Water Podzols of sand to fine sandy loam textures. These soils have 5 ppm. or less Co, and legumes grown in them have 0.07 ppm. or less Co. Similar soils outside of the areas noted and soils of loam, silt loam and clay surface textures have sufficient Co to produce legumes with adequate amounts of Co. Grasses with very few exceptions had low amounts of Co irrespective of soil.
Ammonia and Ammonium Reactions with Some Pacific Northwest Soils
Authors: Young J. L. 
Published: July 2010

AbstractRetention and fixation of NH3 and NH4+ by 76 horizon samples from 20 different Pacific Northwest soils were investigated using aqua and anhydrous NH3, NH4Cl, and different degassing and fixing conditions.Retention of NH3 by ammoniated air‐dry samples was approximately 0.7 me. N per each me. of soil cation‐exchange capacity. In the surface horizons, retention of NH3 was roughly 0.3 and 2.6 me. N per 100g. of soil for each percent clay and organic carbon, respectively.Ratios of “NH3 retained by air‐dry ammoniated samples” to “H2O retained by the air‐dry samples prior to ammoniation” ranged from 0.03 to 0.19 but were generally < 0.1.As with expandable lattice minerals, vacuum degassing increased NH3 retention substantially beyond that of free diffusion degassed samples open to moisture of the atmosphere. Loss of retained NH3 by diffusion and/or water vapor displacement continued at a slow rate for many weeks and while total retention was decreasing, mineral‐fixed values were generally increasing.Infrared absorption patterns were completely dominated by the soil mineral fraction thereby nullifying possible determination of sites or functional groups reactive in NH3 fixation. An absorption band peaking near 7µ appeared most closely correlated with mineral‐fixed NH4+.Generally, three‐fourths or more of the retained anhydrous NH3 was KCl leachable. Of the fixed NH3 (that not leachable with KCl) the major part was associated with the organic fraction except in most subsurface horizons of the recent silty alluvial and water‐deposited silt soils wherein the major part was fixed by the mineral fraction.Comparative NH3/NH44 fixation revealed widely variable behavior, suggesting that a considerable gradation of mineral structures may be involved in soil NH3/NH4+ reactions and that a correspondingly broad range in availability of fixed NH3/NH4+ is to be expected. A number of the minerals giving significant fixation exhibited characteristics intermediate between specimen montmorillonites and vermiculites, implicating beidellitic and/or expanding vermiculite‐like structures.
Ammonium Sorption and Release from Rocks and Minerals
Authors: Adams R. S. , Stevenson F. J. 
Published: July 2010

AbstractSome igneous rocks and primary silicate minerals were found to retain added NH4+ against extraction with 1.0N KCl. The amounts ranged from 15 to 244 ppm., and were 3 to 15 times the quantity of NH4+ in the original rock or mineral. At least two types of reactions were involved, namely, sorption at particle surface and intraparticle penetration. In contrast to the NH4+ held in difficultly exchangeable forms by soils and secondary silicate (clay) minerals, part of the nonexchangeable NH4+ in rocks and primary silicate minerals was released readily with hot 1.0N KOH. The micas were primarily responsible for NH4+ fixation by igneous rocks.
Retention of Cu and Zn by H‐Montmorillonite
Authors: Bingham F. T. , Page A. L. , Sims J. R. 
Published: July 2010

AbstractStudies were conducted on the retention of Cu and Zn by H‐montmorillonite in relation to associated anion, salt concentration reaction time, pH of the equilibrium solution, and techniques.Under conditions where the pH of the equilibrium solution was too acid for formation of Cu(OH)2, the amounts of Cu and Zn retained were similar for Cl, NO3, and SO4 salts and equal to the cation‐exchange capacity (CEC) as measured with NH4+. Detailed studies of metal retention in relation to pH of equilibrium solutions for Cl systems revealed no retention of Cu or Zn in excess of the CEC provided the pH of the system was below 5.5 to 6.5. The exact pH favoring excess retention varied according to salt concentration and the metal in question. Retention of the metals in excess of the CEC was explained in terms of precipitation of Cu(OH)2 and Zn(OH)2 in the clay systems.In the acetate systems, Cu and Zn retention was usually greater than the CEC even under acid conditions. As the pH of the systems increased, metal retention increased. In addition to metal retention, acetate retention was measured. Acetate retention was found to be related to the concentration of acetate and essentially independent of the quantity of metal retained.
Calcium Uptake and Transport by Wheat Seedlings as Affected by Aluminum
Authors: Johnson Ray E. , Jackson W. A. 
Published: July 2010

AbstractUptake and distribution of Ca was studied with excised roots and intact seedlings of wheat. Patterns characteristic of inorganic ion uptake by roots were obtained, namely a rapid initial adsorption phase followed by a linear rate of accumulation. The former was relatively large compared to the latter. It also was reduced to a greater extent by increasing acidity from pH 6 to pH 4. The Ca accumulation phase was reduced by modest restrictions in aerobic metabolism. Treatments resulting in severe reductions in metabolism produced a loss of internal inorganic cations and an increase in influx of external Ca indicating serious objections to the sole use of isotopic procedures for ion uptake studies under such extreme conditions.Aluminum treatments reduced both the adsorption and accumulation phases of Ca uptake. The reduction in the accumulation phase could not be overcome by supplying additional Ca. Increasing the Al concentration from 10‐4N to 10‐3N at constant Ca did not alter the extent of inhibition, suggesting that a portion of the Ca accumulation mechanism was inactivated completely by Al at 10‐4N or less.Transport of Ca to shoots of intact seedlings also was restricted by Al although appreciable transport still occurred when root uptake was inhibited completely.
The Effect of Gamma and Neutron Irradiation of Soil on the Yield and Nutrient Uptake of Rye
Authors: Cummins D. G. , McCreery R. A. 
Published: July 2010

AbstractCecil sandy loam and Lakeland sand with 6 fertility treatments, at field capacity and air dry, were subjected to 3 rates of mixed gamma and neutron radiation from an airshielded 10 megawatts thermal reactor. Rye was grown as a test crop on these soils in the greenhouse. Forage yield and uptake of N, P, K, Ca, Mg, and Na by rye were used to evaluate irradiation effects. Yields of rye on Cecil soil were increased as a result of irradiation when N was limiting, probably as a result of increased mineral N from dead organisms. The uptake of P, K, Ca, Mg, and Na was not affected by irradiation, except where influenced by an increased yield due to N. Soil moisture at irradiation time did not influence irradiation effects on rye yields.