bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molybdenum Deficiency Symptoms in Cotton
Authors: Kallinis Thomas L. , Vretta‐Kouskoleka Helen 
Published: July 2010

AbstractMolybdenum deficiency symptoms were developed in first generation cotton (Gossypium hirsutum, var. Coker) growing in purified nutrient solutions. The first symptoms appeared when the plants were 7 weeks old. The young leaves became chlorotic between the veins, while the old leaves became greasy and swollen between the veins. Cupping of their margins occurred either upward or downward. Addition of Mo in the nutrient solution of the deficient plants corrected all deficiency symptoms and allowed the plants to develop normally again. The Mo content of the leaves exchibiting advanced deficiency symptoms was 1.14 ppm, of leaves exchibiting incipient deficiency symptoms was 1.88 ppm, and of healthy leaves was 2.37 ppm.
Phosphorus and Zinc Interactions in Flax
Authors: Burleson C. A. , Page N. R. 
Published: July 2010

AbstractPhosphorus‐Zn interactions in fiber flax, Linum usitatissimum L., were studied in growth chambers by means of a two‐zone root technique and nutrient solutions. Zinc and P were added separately from each other and the other essential elements; therefore, any interactions that occurred between them or with other elements had to take place at root surfaces or within the plant.Increasing either Zn or P in the substrate increased the concentration and total uptake of the respective element in the roots and tops of the flax plants.When P was added first, Zn increased total P in the lower and upper roots and decreased total P in the tops. When Zn was added first, P increased total Zn in the lower roots and decreased total Zn in the tops.The results indicate that P and Zn react together within the roots in a manner that reduces either their mobility or solubility.
Soil Phosphorus in South Dakota: III. Phosphorus Fractions of Some Borolls and Ustolls
Authors: Westin F. C. , Buntley G. J. 
Published: July 2010

AbstractThe data for the phosphorus fractions and carbon and nitrogen for 8 soils classified as Borolls and 8 as Ustolls along a 260‐km transect are compared. The Ustolls generally have, in their upper horizons, appreciably more Fe‐P, and reductant‐P, less Ca‐P, and slightly less Al‐P than the Borolls. Organic P values are a little higher and carbon and nitrogen percentages are slightly lower among the Ustolls.In general, the ratio of carbon to phosphorus in the organic matter is lower among the Ustolls indicating that there probably is a higher rate of mineralization of organic P taking place in the Ustolls than in the Borolls.The proportions of the phosphorus fractions in the various horizons of the soils appear to reflect the climatic change occurring along the transect.
The Influence of Crop Management on Runoff, Erosion, and Soil Properties of a Marshall Silty Clay Loam
Authors: Moldenhauer W. C. , Wischmeier W. H. , Parker D. T. 
Published: July 2010

AbstractA series of field plots at Clarinda, Iowa, were operated from 1932 through 1963 to study effects of crop and soil management on infiltration, erosion, and crop yield. Major treatment changes were made in 1943 and 1953. Before 1953, soil‐erosion rates were high, especially when corn (Zea mays L.) followed several years of corn, and were inversely related to organic carbon content and aggregate stability of the soil.After the 1953 revision of the study, erosion loss from continuous corn that received annual applications of 179 kg of N per ha (160 lb/acre) were relatively low and were not closely correlated with soil carbon content or with aggregate stability. However, erosion was inversely related to high nitrogen fertility, which, in turn, was accompanied by a trend toward increased soil carbon and high carbohydrate content of the soil. The erosion‐reducing effect of the nitrogen additions were most evident under intense July and August thunderstorms. Soil loss from corn following good meadow was, however, substantially less than from the nitrogen‐treated continuous corn, particularly when erosive rains occurred during the corn seedling stage of the crop year. Crop yield was directly related to N fertility and not to aggregate stability or to organic‐matter content of the soil.
Retention of Boron by Layer Silicates, Sesquioxides, and Soil Materials: I. Layer Silicates
Authors: Sims J. R. , Bingham F. T. 
Published: July 2010

AbstractThe characteristics of boron retention by layer silicates were studied. Boron retention was determined by a procedure developed for use with solution concentrations ranging from zero up to several hundred parts per million B, which consisted of treatment of the adsorbent with B solutions, washing with methanol to remove excess B, and extracting the retained B with 0.01N NaCl (pH 3).Vermiculite, kaolinite, montmorillonite, and hydrobiotite all exhibited a pH‐dependent affinity for B with maxima in the alkaline range. Access to the interlayer surfaces of the expanding lattice clays was necessary for maximum B retention by these clays. Boron retention by these layer silicates was, in the main, attributed to hydroxy iron and aluminum compounds occurring in the samples as impurities.
Reactions Affecting Cation Exchange Kinetics in Vermiculite
Authors: Klobe W. D. , Gast R. G. 
Published: July 2010

AbstractStrong retention of cations, commonly referred to as fixation, was studied using Cs and Sr exchange reactions with Montana vermiculite. Fixation was defined as the property of an exchanger to retain cations in a state such that they are not available for rapid isotopic exchange in a well‐stirred system. Efforts were directed toward qualitatively determining some of the conditions under which fixation occurs.Equations were derived to calculate fixation using isotopic equilibrium values attained with separate aliquots of carrier‐free isotope. Cesium fixation occurred in all size fractions of vermiculite ranging from 40–20 mesh through < 0.2 µ upon addition of 1 symmetry stable CsCl. The amount of 134Cs fixed at this Cs level depended on the sequence of adding separate aliquots of isotope and the corresponding stable salt, and appeared to be caused by lattice collapse.The amount of Cs fixed increased with increasing additions of CsCl. However, when Cs saturation of the vermiculite exchange capacity exceeded 4.5%, the fraction of sorbed Cs that became fixed was relatively constant. A plot of Cs fixation vs. percent Cs saturation of the exchange capacity indicated that fixation was independent of time over an interval of 4 months.In contrast to the Cs results, Sr was always readily exchangeable, with no evidence of lattice collapse.
Determination of the Partial Pressure of Ammonia in Soil Air
Authors: Blanchar R. W. 
Published: July 2010

AbstractA method for determining partial pressures of NH3 from 0.01 to 0.50 mm Hg in soil air was studied. Soil samples which had been treated with various amounts of ammonium hydroxide were placed in 1‐liter polyethylene bottles and allowed to equilibrate. A known volume of air from the bottle was removed by partially compressing the bottle with a press. The air was bubbled through 0.1N HCl and the ammonium content of the acid determined by the Nessler reaction. The partial pressure of NH3 (PNH3) was calculated from the ideal gas law equation.The method gives a reliable estimate of the partial pressure of NH3 in soil air. It was shown that the PNH3 of a sample placed in the polyethylene bottle could be determined after a 1‐hour equilibration period.Samples which were sealed in the polyethylene bottles for 48 hours had lower PNH3 and higher PCO2 values than samples placed in the bottles for only 1 hour. Reduced PNH values in bottles which had been sealed for 1 day or more were attributed to pH reduction due to CO2 accumulation.Germination of corn seeds (Zea mays L.) was damaged when the initial PNH2 value was 0.156 and final values were between 0.077 and 0.104 mm Hg. The germination of corn seeds was not reduced when initial PNH3 values were 0.091 and final values were 0.067 and 0.048 mm Hg.
Deaired Water Installations for Measuring the Hydraulic Conductivity of Clays
Authors: Yevnin A. 
Published: July 2010

AbstractDeaired water is commonly used in order to reach and maintain complete saturation during hydraulic conductivity determination of soils. One falling head and one constant head installation are described for the storage of deaired water and for the measurement of head and rate of flow. Methods of operation and calculation are given.
The Applicability of Darcy's Law
Authors: Swartzendruber Dale 
Published: July 2010

AbstractDeviations from Darcian proportionality between flow velocity v and hydraulic gradient i are considered in terms of a gradient‐dependent hydraulic conductivity K(i) = v/i. Published greater‐than‐proportional data for saturated flow indicate measured variations in K(i) of 2‐ to 4‐fold, with a potentiality for 5‐ to 15‐fold variations inferred from fitted non‐Darcian flow equations. Non‐Darcian effects for two‐dimensional radial flow are also analyzed. The hydraulic head distribution is shifted from the Darcian‐derived logarithmic pattern toward the characteristic linear distribution for one‐dimensional flow, and the amount of the shift is velocity dependent. This implies that the flow net for two‐dimensional non‐Darcian flow would generally change with flow velocity, and that the high‐gradient flow regions would be more permeable than for Darcian flow.For a particular unsaturated soil, the soil‐water diffusivity D appears to be a gradient‐dependent quantity D(θ,ω), where θ is the soil‐water content, and ω is the water‐content gradient. A maximum 8‐fold variation in D at given low water contents is associated with a 40% discrepancy between experimental water‐absorption rates and those calculated from proportional flow theory. Similarly, a 115% discrepancy is found for the vertically downward rate of infiltration into a mixture of quartz sand and ground silica, but the deviating behavior can be precisely accommodated with a non‐Darcian infiltration equation derived by a simplified analysis. Various implications of non‐proportional effects are discussed and enumerated briefly.
Solubility and Redox Criteria for the Possible Forms of Selenium in Soils
Authors: Geering Harold R. , Cary Earle E. , Jones L. H. P. , Allaway W. H. 
Published: July 2010

AbstractThe solubility of Se in seven soils indicate that Se concentration in solution is governed primarily by a ferric oxide‐selenite‐adsorption complex (Se oxidation state +4). However, under certain conditions Se may also exist in the oxidation states +6, 0, and −2. The proportions of Se in the four oxidation states are treated theoretically as they are affected by the redox potential, soil pH, and ions with which Se combines.
Self‐Diffusion of Phosphorus in Clays and Soils: I. The Effect of Phosphorus Rate
Authors: Phillips R. E. , Place G. A. , Brown D. A. 
Published: July 2010

AbstractSelf‐diffusion coefficients of 32P were measured in kaolinite clay, montmorillonite clay, illite clay, Dundee silt loam soil, and Sharkey clay soil. Phosphorus in the form of concentrated superphosphate was added to each clay or soil at the rates of 10, 20, 40, 80, 160, and 320 ppm. The clays and soils were maintained near a neutral pH and at a water content in equilibrium with 173 mbar tension. The water‐soluble, Ca, Fe, Al, occluded Fe, and occluded Al fractions of phosphorus were measured for each clay and soil at each rate of added phosphorus.The self‐diffusion coefficients and phosphorus rates of each clay and soil were linearly and positively correlated. The diffusion coefficients in kaolinite and montmorillonite clays were approximately 40 times larger than those in illite clay, Dundee silt loam, and Sharkey clay. No general relationship was established between the self‐diffusion coefficients and the various fractions of soil phosphorus when all soils and clays were considered as a group. When each clay or soil was considered individually, there was a highly significant relationship between the diffusion coefficients and water‐soluble phosphorus, aluminum phosphate, or the combination of the two. The amounts of phosphorus found in the various fractions differed greatly between soils. The kaolinite and montmorillonite clays initially contained relatively small quantities of phosphorus while illite clay, Dundee silt loam, and Sharkey clay initially contained relatively large quantities of phosphorus.
Uptake of Fertilizer and Soil Nitrogen by Ryegrass, as Affected by Carbonaceous Residue
Authors: Terman G. L. , Brown M. A. 
Published: July 2010

AbstractAnnual ryegrass (Lolium multiflorum) was grown on limed Hartsells fine sandy loam and Decatur silty clay loam fertilized with 0, 120, 300, 600, and 900 mg of N as 15N‐labeled (NH4)2SO4 per pot (3 kg of soil). Half of the pots also received 15 g of corn (Zea mays) forage residue (1.05% N) mixed with the soil and half received none. Six clippings of forage and roots were harvested after the final clipping.Total yield of dry forage and uptake of N were linear for all rates of applied N without residue and for the 300‐, 600‐, and 900‐mg rates with applied residue. As estimated by linear regression from total N uptake, apparent recovery by six clippings of ryegrass plus roots, grown without residue, was 78% from Hartsells soil and 76% from Decatur. The corresponding slightly lower recoveries of 75 and 72% of the fertilizer N applied reflect uptake of soil N. Recoveries of fertilizer N were 90% from the Hartsells and 85% from the Decatur soil‐plant systems. As estimated by difference, recoveries of fertilizer N by ryegrass increased, and recoveries from the plant‐soil systems decreased with increase in amount of applied N.Crop uptake of soil N increased as fertilizer N was depleted from the soils.Addition of the carbonaceous residue caused apparent immobilization of 141 mg of fertilizer N in Hartsells and 164 mg in Decatur soil. Percentages of fertilizer N immobilized in the soils decreased, but actual amounts increased with increasing amount applied. A portion of the fertilizer N, independent of amount applied, was immobilized in each soil.
Limitations of Quantitative Soil Clay Mineralogy
Authors: McNeal Brian L. 
Published: July 2010

AbstractAnalysis of the effects of varying the parameters assigned to soil mineral species for the purpose of quantitative mineralogical analysis suggests that absolute determination of mineral contents may be precluded by the variations in soil mineral properties which can be reasonably expected to occur. Rejection of those variations that produce unreasonable results for specific groups of soils, however, verifies that estimation of sample mineral contents for these soils is often valid to within ± 5%.
System Dependence of the Water Content‐Pressure Head Relationship
Authors: Watson K. K. , Whisler F. D. 
Published: July 2010

AbstractThe drainage to a water table of a saturated, stratified sand column in which a fine sand overlay a course sand evidenced a relationship between water content and pressure head for the coarse sand which was characteristically different from that obtained during the drainage of a uniform column of the coarse sand. The water content‐pressure head relationship for each system is presented and the system dependence of the relationship discussed. The effect of this system dependence, and the limitation it places on the use of current analytical approaches in predicting pressure head and water content profiles during the drainage of layered soils, is then considered.
A Rapid, Qualitative Method for Determining Movement of Applied Manganese in Soil
Authors: Hossner L. R. 
Published: July 2010

AbstractA rapid, qualitative method for estimating the rate and distance of Mn movement from fertilizer granules in soil is presented. A filter paper saturated with 5N HNO3 is pressed on the soil surface and soluble soil Mn absorbed by the filter paper is then oxidized to permanganate by NaBiO3.
Adsorption and Desorption of Diquat, Paraquat, Prometone, and 2,4‐D by Charcoal and Exchange Resins
Authors: Weber J. B. , Ward T. M. , Weed S. B. 
Published: July 2010

AbstractThe adsorption of diquat, paraquat, prometone, and 2,4‐D by charcoal and cation‐ and anion‐exchange resins and their desorption with water and 1M NaCl solutions has been investigated. Prometone and 2,4‐D were adsorbed by charcoal in much greater amounts than were diquat and paraquat, but all of the compounds were readily desorbed with deionized water following normal Freundlich isotherms. Diquat and paraquat were adsorbed by the cation exchange resins (H and Na forms) and both herbicides were readily desorbed by Na+ ions but not with deionized water. Diquat was preferentially adsorbed over paraquat by the cation‐exchange resins and diquat was also more effective in displacing paraquat from the resins. Prometone was adsorbed in small amounts by the cation resin in the Na form and the anion resin in the Cl form and was readily desorbed with deionized water. Prometone was adsorbed by the cation resin in the H form in amounts which were similar to those for diquat and paraquat. None of the prometone adsorbed by the H‐resin was desorbed by equilibrating with water. Prometone desorbed from the H‐resin with 1M NaCl solutions was identified as hydroxypropazine.
Electromotive Force of Inert Electrodes in Soil Suspensions
Authors: Bohn H. L. 
Published: July 2010

AbstractAttempts to relate the emf of gold, graphite, and platinum electrodes in soil suspensions to the electrode potentials of redox couples in the soil were unsuccessful. EAu and EC did not respond to aeration of the suspensions or to the presence of sucrose as a reducing agent. EPt responded to these conditions, but did not correspond to the electrode potentials of the Mn2+‐Mn oxide, O2‐H2O, or H+‐H2 couples. It is concluded that EPt is a mixed potential whose major components are the O2‐H2O couple in aerated suspensions or the H+‐H2 couple in anaerobic suspensions, but whose value is not related to the Nernstian distribution of oxidized and reduced species. Although EPt is a qualitative measure of the oxidation‐reduction conditions in the soil, it has no quantitative significance.
Occurrence and Synthesis of Soil Zeolites
Authors: Baldar N. A. , Whittig L. D. 
Published: July 2010

AbstractAnalcime has been identified by X‐ray diffraction analysis in a number of strongly alkaline soils developed from granitic alluvium in the San Joaquin Valley, California. Analcime occurrence is restricted to soils containing Na2CO3 and with pH above 9. The analcime is generally concentrated near the soil surface and is most abundant in fine silt (5 to 2µ) and coarse clay (2 to 0.2µ) fractions. The occurrence and distribution of the analcime support the conclusion that it is of pedogenic origin. Cation exchange data indicate that the analcime Na is slowly replaced by NH4 and that divalent cations Ca and Ba, as compared with K and NH4, replace relatively little of the analcime Na. Analcime was effectively destroyed in a soil by treatment with 0.5 N HCl. The mineral was readily synthesized in the acid‐treated soil and in the acid extract from the soil by titration of the systems to pH 9 and above with NaOH followed by digestion at 95C for 14 days.
Genesis of Layer Silicates in Representative Soils in a Glacial Landscape of Southeastern Wisconsin
Authors: Borchardt G. A. , Hole F. D. , Jackson M. L. 
Published: July 2010

AbstractQuantitative mineralogical analysis of the clays and silts of two representative soil profiles of a glacial landscape indicated the relative extent of depositional influence as well as the effect of mineral weathering. The more intensely leached upland Lapeer loam of about pH 5 has a clay mineralogical content of 20% mica and 12% kaolinite. Clay in the less leached, neutral Saylesville silt loam occurring on a plain at a lower topographic position contains 40% mica and 6% kaolinite, as does the calcareous till under the Lapeer solum. A direct relationship exists between the pH of the horizon and content of mica in soil clay (r = 0.97) for 13 horizons of these and related soils. Variable total sand contents of the different horizons demonstrated the variable origin of the material from which the horizons developed.About 20 cm of loess was incorporated into the Lapeer loam. The Lapeer solum and weathered Peorian loess of Illinois are similar with respect to (i) content of about 2% K2O in the clay fractions, and (ii) a coarse silt/fine silt ratio of about 0.7. The dolomitic lacustrine deposits of the C2 and C4 horizons of the Saylesville soil had a vermiculite/mica ratio in the clay of 0.18. These horizons contain no sand and have clay mineral components nearly identical to those of the sandy loam till of the Lapeer, which has a vermiculite/mica ratio of 0.19.
A Genetic Study of Two Soils Developed on Granite in Llano County, Texas
Authors: Goss D. W. , Allen B. L. 
Published: July 2010

AbstractStudies were made of an excessively drained soil and a somewhat poorly drained soil, tentatively named Click and Bauman, respectively, to determine the effects of topography upon their genesis and resulting mineralogy. Heavy mineral data indicate that the soils have developed from relatively homogeneous parent materials. Clays were fractionated at 0.2µ for X‐ray diffraction, differential thermal (DTA), and cation exchange capacity (CEC) studies. The data indicate that the clay mineralogy of both soils is mixed but that the fine clay of the Bauman soil is dominated by a montmorillonite mineral that increases with depth in the profile. The fine clay fraction of the Click soil apparently contains near equal portions of kaolinite, illite, montmorillonite, and X‐ray amorphous material. Appreciable exchangeable Na is present in the subsoil of the Bauman profile but is essentially absent in the Click soil. Soluble weathering products from the surrounding slopes have moved laterally at the soil‐unweathered granite interface and accumulated in the Bauman soil thereby causing its morphology and clay mineralogy to differ markedly from that in the better drained soil.
Movement of Silt‐Sized Particles in Sand Columns
Authors: Wright W. R. , Foss J. E. 
Published: July 2010

AbstractPlastic columns containing fine or medium sand, and capped with fine or medium silt, were leached with distilled water. Both coarse and fine silt moved readily through the medium sand; however, only the fine silt moved appreciably through the fine sand. Deposition of the fine silt in bands was also observed in the fine sand columns.
In Situ Measurement of Soil and Plant Leaf Water Potential
Authors: Rawlins S. L. , Gardner W. R. , Dalton F. N. 
Published: July 2010

AbstractFor a pepper plant (Capsicum frutescens L.) growing in a greenhouse, soil water potential was measured with tensiometers and a thermocouple psychrometer, plant water potential was inferred from a calibrated beta gauge, and transpiration was measured by weighing the soil‐plant system. Water moved through the transpiration stream in the direction of the gradient of the water potential. Regardless of the distribution of water in the soil, transpiration was unaffected by soil water content until it dropped to a value corresponding to −6 to −8 bars water potential. Below this water content, transpiration decreased linearly with soil water content to a soil water potential of −37 bars. At this time the plant water potential was below −50 bars and the transpiration rate was near zero. After irrigation the plant regained full turgor.