bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micronutrient Cation Complexes in Soil Solution: Partition Between Complexed and Uncomplexed Forms by Solvent Extraction
Authors: Hodgson J. F. , Geering H. R. , Norvell W. A. 
Published: July 2010

AbstractProcedures were developed for the partition of heavy metals (Cu, Co, and Zn) between complexed and uncomplexed forms in soil solution. Competition for the above cations by complexing agents naturally present in soil solution and added complexing agents that form metal complexes soluble in organic solvents was determined by measuring the distribution of metal between aqueous and organic phases in a two‐phase system. The degree to which the metal was complexed in the original soil solution could be deduced by comparing the amount of metal extracted from soil solution with that extracted from water at the same pH. Examination of soil solutions from several mineral soils indicated that in the case of Cu as much as 99% of the metal may exist in a complexed form.
The Influence of Temperature and Time on the Adsorption of Paraquat, Diquat, 2,4‐D and Prometone by Clays, Charcoal, and an Anion‐Exchange Resin
Authors: Weber J. B. , Perry P. W. , Upchurch R. P. 
Published: July 2010

AbstractThe effects of temperature and exposure time on the adsorption of four organic compounds by montmorillonite, kaolinite, charcoal, and an anion‐exchange resin in a phosphate buffer of pH 6.0 were investigated. Organic cations (diquat and paraquat) were preferentially adsorbed by the clays up to the cationexchange capacity. Adsorption appeared to be one of ion exchange. X‐ray analysis indicated the cations were held in the lattice of the montmorillonite with the plane of the ring parallel to the silicate sheets. An organic anion (2,4‐D) was negatively adsorbed by the clays; and a s‐triazine compound (prometone) in molecular form, was adsorbed by montmorillonite but not kaolinite. X‐ray analysis indicated that prometone was located within the clay lattice but the orientation was uncertain. The adsorption mechanism was physical in nature being temperature dependent.The 2,4‐D was adsorbed by the anion‐exchange resin through ion exchange forces and the equilibrium was influenced by temperature and exposure time. Prometone was adsorbed by the anion‐exchange resin to a much lesser degree, was also temperature and time dependent, and appeared to be physically bound.All of the organic compounds were adsorbed by charcoal and each was influenced differently by temperature and exposure time.
Use of Amorphous Material to Identify Spodic Horizons
Authors: Franzmeier D. P. , Hajek B. F. , Simonson C. H. 
Published: July 2010

AbstractThe illuvial amorphous material that occurs as pellets or grain coatings in the B horizons of some New York Podzols contains much carbon, iron, and aluminum. This amorphous material has high cation‐exchange capacity (CEC) that can be destroyed by heat treatment or extraction with solutions of a complexing agent (citrate or pyrophosphate) combined with a reducing agent (dithionite). Most of the carbon, iron, and aluminum of the amorphous material is removed with extracting solutions.The study included 19 New York soils, ranging from those with strong spodic horizons to those with cambic horizons. In the uppermost B2 horizon of each profile, the CEC loss caused by 240C heating is highly correlated with total organic carbon (r=0.99), with the amount of carbon extracted (r=0.98), and fairly well correlated with the amount of iron plus aluminum extracted (r=0.88). The degree of Podzol development, as judged in the field, is related to the loss of CEC caused by heating or extraction, and also to the amounts of carbon, iron, and aluminum extracted. These relationships are used as the basis for proposed quantitative limits that would separate spodic horizons from cambic and other diagnostic horizons.
Effect of Crop Cultures on the Infiltration of Water Into a Chestnut Soil
Authors: Fernandez Benjamin , Wilkinson G. E. 
Published: July 2010

AbstractTwo crop cultures, one consisting of 2 years of corn following a rotation of small grains and corn, the other of 7 years of continuous crested wheatgrass, were selected for a study of the infiltration of water into Morton loam, a Chestnut soil in the Northern Great Plains. Infiltration rates were measured with the Purdue sprinkling infiltrometer in June and August. The equilibrium infiltration rates during the wet run averaged 0.4 inch/hr for corn which was significantly lower than the 1.0‐inch/hr for crested wheatgrass. The effect of dates was not significant. The average aggregate stability index of the surface 8 cm of soil was also significantly lower for the corn. However, the lower aggregate stability under corn had little effect on the absorption of water during the first 30 min. The antecedent moisture level of the soil had its greatest influence on infiltration during the first 30 min. The probability of receiving rains with intensities greater than the infiltration rates is high enough to make Morton loam susceptible to soil erosion under a corn culture.
Variables‐Separable Solution of the Horizontal Flow Equation with Nonconstant Diffusivity
Authors: Swartzendruber Dale 
Published: July 2010

AbstractSolution of the nonlinear diffusion‐type equation is approached by both an additive form and a product form of separation of variables. The problem considered is the special case of one‐dimensional water absorption by a horizontal, semi‐infinite column of uniform soil initially at a uniform water content, and which from time zero on has a higher constant water content applied and maintained at one end. The additive separation of variables implies boundary conditions for which the water content depends on distance and time. On this basis, it is shown that an equation proposed in the literature, and arrived at by a transformation equivalent to a special case of additive variables‐separation, is not a solution to the problem.However, the problem is solved by using a product form of separation of variables, which reduces to the equivalent of the Boltzmann transformation by virtue of one boundary condition. Hence, in the light of this approach, the Boltzmann transformation appears as a consequence of the governing partial differential equation and one boundary condition, rather than as an additional assumption in need of separate justification.
The pH Values of Soils Suspended in Dilute Salt Solutions
Authors: Clark J. S. 
Published: July 2010

AbstractThe pH values of dilute solutions and soils were measured with the standard glass‐reference electrode combination and with the glass‐silver, silver chloride pair without liquid junction. At low ionic strengths, the pH values of the soils and solutions determined with the glass‐Ag, AgCl Combination were about 0.1 to 0.2 unit lower than those obtained using the standard reference electrode. With the soils, the differences were observed even when the KCl junction was kept in the clear supernatant liquid. Stirring the solutions and the soil suspensions and increasing the salt concentration decreased the pH values measured with the glass‐reference pair but not with the glass‐halide electrode combination. From these observations it was concluded that pH measurements made at low ionic strengths using the standard reference electrodes with restricted diffusion of KCl were subject to direct liquid junction errors. These liquid junction potentials were distinct from Donnan‐electromotive force (emf) effects caused by interaction of the charged soil particles with the KCl junction. Like the Donnan‐emf effects, they could be reduced by increasing the electrolyte concentration in solution.
Proferential Hydroxyaluminum Interlayering in Montmorillonite and Vermiculite
Authors: Barnhisel R. I. , Rich C. I. 
Published: July 2010

AbstractThe rate of Al diffusion in both montmorillonite and vermiculite was a function of the relative humidity, and the initial saturating cation. In both clay systems, it is proposed that Al‐interlayers were produced in alternate layers giving a regularly interstratified sequence. The clay exhibited 001 reflections integral with a 25A to 27A spacing. These high angstrom spacings were obtained only after the clays had been heated to temperatures of 110 and 300C for montmorillonite and vermiculite, respectively. The sequence is believed to consist of alternating layers, one predominately Al‐saturated and the other Na‐saturated. The Al layers contained enough hydroxy‐Al to provide sufficient stability to these layers to prevent their collapse when the samples were heated at moderate temperatures. The Na layers were either partially or completely dehydrated when heated and these layers collapsed to either 12A or 10A.The difference in the temperature required to produce the regular interstratification in vermiculite is presumably related to the rapid rehydration of vermiculite samples after the 110C heat treatments.
Applicability of Models to Predict Rates of Cation Movement in Clays
Authors: Gast R. G. 
Published: July 2010

AbstractResults of electrical conductance and diffusion measurements in dilute bentonite pastes show significant changes in Na+ and Sr2+ ion mobility on increasing solution or clay concentration. Any useful model to predict rates of cation movement in those systems must allow for these changes in mobility. A three‐component model does provide for these changes and appears promising to predict rates of cation movement in systems where the geometry is not affected by varying the electrolyte levels or the nature of the cation species. The use of two‐component models to predict rates of cation movement in such systems requires the capability to predict the mobility of exchangeable cations (those cations on the clay) by some independent measurement or fundamental property of the system. Exchangeable cation mobility did not vary in Na‐ and Sr‐kaolinite systems with increasing electrolyte levels. Two‐component models could be used to predict rates of cation movement in these systems provided the geometry factor and mobility of exchangeable cations is known.
Infiltration and Erosion as Affected by Minimum Tillage for Corn (Zea mays L.)
Authors: Mannering J. V. , Meyer L. D. , Johnson C. B. 
Published: July 2010

AbstractMinimum tillage for corn substantially increased infiltration and reduced soil erosion during a 5‐year study on a sloping, silt loam soil in Indiana. These results were obtained under high‐intensity, simulated rainfall with rows and tillage parallel to the slope. Infiltration averaged 24% greater and soil loss averaged 34% less from minimum tillage treatments than from conventional treatments. The different forms of minimum tillage tested, including plow‐plant (with and without a trailing harrow) and wheel‐track plant, resulted in about the same amount of erosion control. Erosion comparisons were made on first, third, and fifth year of corn following several years of alfalfa (medicago sativa) orchardgrass (dactylis glomerata) meadow. The relative erosion‐reducing effectiveness of minimum tillage as compared with conventional tillage declined from 44% to 34% to 27% during this period. Destruction of surface crusts by cultivation greatly reduced both soil and water losses throughout the remainder of the crop year. Soil aggregation, organic matter content, and porosity were slightly higher on minimum tillage plots than on conventional plots after 5 years of treatment. Three tons per acre of dry hay used as surface mulch applied after the first cultivation essentially eliminated soil and water losses during the remainder of the crop season. The mulch also effected major reductions in soil and water losses in the succeeding year.
The Characterization of Dry Matter and Nitrogen Accumulation by Loblolly Pine (Pinus taeda L.)
Authors: Switzer G. L. , Nelson L. E. , Smith W. H. 
Published: July 2010

AbstractFifty trees, equally distributed to represent five tree developmental stages were sampled in central Mississippi on uplands and bottomlands having average site indices of 65 and 105, respectively. Trees were divided into seven components and the dry matter and total nitrogen contents of each determined. The total dry weight and the N accumulated in a 60‐year old good site stand was ca. 227,000 and 232 lb/acre, respectively, Comparable weights for the poor site are 152,000 and 194 lb. Calculations indicate in pure even‐aged, natural stands on both sites that the dry weight of the foliage, current branches and stembark becomes relatively constant between 20 and 30 years while subsequent increases are chiefly older branches and stemwood. The pattern of N accumulation closely follows canopy development on both sites although in later life a considerable portion is accumulated in the stemwood.
Hysteretic Moisture Characteristics and Hydraulic Conductivities for Glass‐Bead Media
Authors: Topp G. C. , Miller E. E. 
Published: July 2010

AbstractThe hysteretic effects in the moisture characteristics and the hydraulic conductivity characteristics of two different glass‐bead media were measured while unsteady water flow was occurring. A gamma‐ray moisture sensor, a combination of pressure transducers and tensiometers, and a capillary‐tube flux meter were combined with a simple box‐like flow chamber for simultaneous measurement of (i) the degree of saturation, (ii) the water‐phase pressure, and (iii) the hydraulic conductivity. These quantities were recorded through out water‐pressure changes which traversed the main‐branch wetting and drying curves as well as the families of “rewet” and “redry” scanning loops.Large hysteresis was recorded in the relation of pressure to saturation or to conductivity. The relation of conductivity to saturation showed hysteresis which, though significantly larger than the experimental error, would for most practical purposes be negligible.The independent domain theory of hysteresis was used to check the relation between the “rewet” and “redry” families of moisture characteristics. By this test the theory was found to be very poorly suited to a description of these media. Two basic approximations of the theory were assumed to be responsible for this lack of applicability.
Chemical Extraction of Potassium from Soils and Micaceous Minerals with Solutions Containing Sodium Tetraphenylboron: IV. Muscovite
Authors: Reed M. G. , Scott A. D. 
Published: July 2010

AbstractMethods of extracting the interlayer K in micaceous minerals with NaTPB solutions were modified to maximize the extraction of K from muscovite. In the method adopted, 0.500‐g samples were placed in 10 ml of 2n NaCl‐0.2n NaTPB‐0.01m EDTA solution at 25C, and the precipitated K was separated with a boiling 0.5n NH4Cl solution that contained HgCl2. Even with this method, muscovite released its K much slower than did biotite. However, it was possible to remove 96% of the K in <10µ muscovite in 16 weeks. This was also the maximum amont of K that was extracted.
Phytotoxic Substances Extracted from Soil
Authors: Guenzi W. D. , McCalla T. M. 
Published: July 2010

AbstractPhytotoxic substances were extracted from soil with 0.1m Na4P2O7 and acetone. The ether‐soluble substances from the pyrophosphate extract were separated into acidic, neutral, and basic fractions. Acidic materials exhibited the highest phytotoxicity, followed by basic materials and then by the neutral fraction. The acetone extract of soil was fractionated on an alumina column using a solvent elution series. A number of compounds were isolated by paper chromatography and the majority of these substances were either ninhydrin‐positive or acidic. Three phenolic acids were isolated and identified as vanillic, p‐hydroxybenzoic, and protocatechuic.Ferulic, p‐coumaric, p‐hydroxybenzoic, vanillic, and syringic acids were extracted with 2n NaOH from plowed and subtilled soil. Larger amounts of ferulic and p‐coumaric acids were found in subtilled soil as compared with the plowed soil. Only traces of these phenolic acids were found with 0.1m sodium pyrophosphate, calcium oxide, 2n HCl, and methanol extracts of soil.
Comparisons of Laboratory and Greenhouse Tests for Nitrogen and Phosphorus Availability in Soils
Authors: Ozus Turgut , Hanway John J. 
Published: July 2010

AbstractGreenhouse techniques were developed for estimating nutrient availability in soils which would provide standards for comparison of different chemical soil tests. Plants were grown on undried soil samples to which nothing except water was added, but where other nutrients were supplied to the plants. Plant growth and P contents were highly correlated with the results of a chemical soil test. Plant uptake of N during the early period of growth was highly correlated with the initial NO3 content of the soils. Later plant uptake of N was highly correlated with the aerobic and anaerobic rates of N mineralization in the soils, but the relationships were different at different levels of P availability in the soils.
Responses of Different Lines of Soybeans (Glycine max L. Merr.) to High Levels of Phosphorus and Potassium Fertility
Authors: Dunphy E. J. , Kurtz L. T. , Howell R. W. 
Published: July 2010

AbstractComparisons were made of the response to fertilizer of many varieties and Plant Introduction lines of soybeans in field experiments at different locations in Illinois over a 3‐year period. At each experiment one‐half the area within each replication received a large application of P and K and the other half remained untreated. Varieties and lines were then planted in random arrangements in each half of each replication. Yields of each variety and line were measured and observations of some morphological characteristics were made. Results were analyzed to learn whether the different soybeans responded differently to the high level of soil fertility.Some varieties and lines do possess, to a greater degree than others, the ability to respond to high levels of fertility. Other varieties are insensitive to variations in fertility, and yield nearly as well at mediocre fertility levels as on highly fertilized soils. A majority of the lines and varieties tend to respond to a similar degree.“Ability to respond” was usually exhibited consistently though different years. In a few instances varieties appeared to respond differently in different years but the year‐variety interaction was never statistically significant in this study.At one location, ratings of several morphological characteristics (e.g. standability) were made and the effect of fertilizer on these ratings was determined for each genotype. While correlation coefficients between pairs of those effects were low, several were statistically significant and suggested some interesting relationships. For example, varieties that responded more to fertilizer were usually the higher‐yielding varieties. Increases in stem length tended to be associated with increased yield response. Varieties that exhibited the most severe potassium‐deficiency symptoms were not usually the ones that gave the greatest yield response to fertilizer.
A New General Soil Map of the United States: A Progress Report
Authors: Gallup Darrell L. , Austin Morris E. , Orvedal Arnold C. 
Published: July 2010

AbstractCompilation of a new general soil map of the USA is under way. A new map is needed to provide new information accumulated over the past 20 or 30 years, to express our knowledge about soils in terms of the new classification, and to incorporate new ideas in map and legend design that improve interpretation potential. An experimental map, on which most map units are geographic associations of great groups of the new classification, is being compiled on a 1:7,500,000 base. In the legend, map units are grouped under the order, suborder, and great group of their most extensive soils, an organization which permits three levels of generalization. The map will be published in the National Atlas of the USA being prepared by the US Geological Survey.
Evaluation of Ureaform Fertilizer Using Nitrogen‐15‐Labeled Materials in Sandy Soils
Authors: Brown M. A. , Volk G. M. 
Published: July 2010

AbstractA quantitative account of labeled ureaform and ammonium nitrate fertilizer N was made in outdoor lysimeters, greenhouse pots, and laboratory incubation vessels. A major portion of the labeled fertilizer N applied to lysimeter and greenhouse pots was recovered by crops. A greater proportion of labeled ammonium nitrate N was recovered in the plants than labeled ureaform N. However, more labeled N was found in the soil after 1 year when ureaform was the source. As a result, there were no differences in total recovery of labeled N in plants plus soil between sources. Approximately half of the N in the ureaform used in these studies was in a state of availability approaching that of ammonium nitrate. Extended availability of ureaform N over ammonium nitrate N was only apparent at the high rate of ureaform application. Approximately 15 to 20% of the ureaform material remained apparently unchanged in the soil after 1 year.Unaccounted for N is thought to have been lost as a gas after it entered the organic N complex of the soil, since similar total recoveries were obtained for ammonium, nitrate, and ureaform N. Under anaerobic conditions significant quantities of N were lost from soils incubated with ureaform as well as from soils incubated with ammonium nitrate.
Soil‐Moisture Measurement by the Neutron Method in Rocky Wildland Soils
Authors: Koshi Paul T. 
Published: July 2010

AbstractTo accurately interpret moisture readings taken by the neutron‐scattering technique in rocky soils, methods of access tube installation, influence of voids and rocks around access tubes, and accuracy of factory calibration curve were evaluated. Because access tubes could not be installed by the hand‐auger method where hard rocks were present, power‐driven portable drilling rigs were tried. Vacuum evacuation of cuttings in wet soils failed. Water injection worked well except in the presence of loose rocks. Air injection was most satisfactory except in wet clays. Voids around access tubes of < ⅜ inch had little or no influence on slow neutron count rates. Rocks had little influence on soil moisture determination unless they were large. Because readings of soil moisture from factory calibration seemed too high, a laboratory calibration curve was developed.
Influence of Applied Sulfur on Availability of Soil Nutrients for Corn (Zea mays L.) Nutrition
Authors: Hassan Nouri , Olson R. A. 
Published: July 2010

AbstractInfluence of applied sulfur on soil properties and nutrient uptake was studied on three soils ranging from acid to calcareous with growth of corn in the greenhouse. The heaviest rate of 5,000 ppm S produced toxic effects on the acid and neutral soils, a consequence of sharp pH reduction and excessive S and Manganese uptake. Otherwise, S treatment had beneficial effects on: Phosphorus nutrition on neutral and calcareous soils; S and Mn nutrition (up to modest rate of S) on all soils; zinc in early nutrition on all soils with slight benefit carrying over to late harvest only on calcareous soil; iron nutrition on calcareous soil; and copper nutrition until early harvest with all soils and through late harvest with neutral and calcareous soils. With a low rate of 50 ppm S, mixing was more efficacious than banding on all soils.