bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Criteria for Separating Soils with Xeric and Udic Moisture Regimes
Authors: Thomas B. R. , Simonson G. H. , Boersma L. 
Published: July 2010

AbstractThis study was designed to evaluate criteria for classifying soil series in the Coast Range Mountains of western Oregon into categories with xeric and udic moisture regimes. Relationships among soil‐water suction, plant‐water suction, and cambial activity of Douglas‐fir (Pseudotsuga menziesii [Mirb.] Franco) were also evaluated. Soil‐water content was measured with gypsum blocks. Plant‐water suction of Douglas‐fir branch tips was measured with a pressure bomb. These measurements were taken early in the morning at least once every 10 days. Experimentals sites were selected on three soil series and one north slope soil phase tentatively classified as xeric and on four soil series tentatively classified as udic. The four study sites in the xeric zone had soil‐water suctions equal to or greater than 15 bars within the soil‐water control section for at least 60 consecutive days. None of the four study sites in the udic zone were dry that long. Cumulative water deficit in the xeric zone was about 75% of the seasonal total when the entire soil‐water control section attained 15 bars. Almost all available water was removed from the upper third of the profile in the xeric zone when the trees stopped producing springwood. Much less water was removed from the upper third of the profile in the udic zone. The same relationship held true for the available water in the entire profile at time of dormancy. Trees in the xeric zone produced springwood an average of 23 more days and have 26 more days total growing time than trees in the udic zone. Changes of soil and plant‐water suction with time showed similar patterns but different magnitudes. It was concluded that plant‐water suction cannot be used in lieu of soil‐water suction for purposes of soil classification.
Micro‐Determination of Cation‐Exchange Capacity by Neutron Activation Analysis
Authors: Dudas M. J. 
Published: July 2010

AbstractNeutron activation analysis was evaluated as a method to determine the cation‐exchange capacity (CEC) of clay samples. Cation‐exchange capacity values of satisfactory reproducibility and accuracy were obtained on 5‐ to 50‐mg subsamples of kaolinite and montmorillonite clays previously saturated with Na, Rb, or Cs. use of Cs as the index ion provided the simplest and most flexible conditions for the activation analysis method.
Test of a New Model for the Kinetics of Adsorption‐Desorption Processes
Authors: Griffin R. A. , Jurinak J. J. 
Published: July 2010

AbstractA new model for the kinetics of adsorption‐desorption processes proposed by Lindstrom, Haque, and Coshow (1970) was tested with adsorption and desorption data for the interaction of phosphate with the calcite mineral surface. The model was found to offer considerable advantages in speed and convenience to those users whose experimental conditions correspond to the assumptions inherent in the derivation of the model. There was reasonable agreement between the predicted adsorption kinetic parameters and experimental data. However, considerable disparity was observed between predicted and experimental desorption parameters. It was concluded that the model was not valid for endothermic processes.
Geomorphic Occurrence of Pelloxererts, Willamette Valley, Oregon
Authors: Parsons R. B. , Moncharoan L. , Knox E. G. 
Published: July 2010

AbstractDocumentation of the time factor in the genesis of Vertisols in western Oregon is provided by this study of Bashaw soils on four geomorphic surfaces that range in age from Holocene to middle Pleistocene. Bashaw soils are in a very fine, montmorillonitic, mesic family of Typic Pelloxererts. Although these soils have slickensides and high clay contents, they lack gilgai microrelief and tonguing between the A and C horizons. Stratification in the parent alluvium has not been obliterated by churning, suggesting that one annual cracking and closing cycle will not produce all of the morphological features commonly associated with Vertisols. Pedons from surfaces only 550 years old have developed sufficiently to be classified as Xererts. Morphological, chemical, and physical data indicate that the pedons studied are similar enough to lie within the range of one soil series. This study shows that Xererts occur on very young landscapes and that very little change takes place with increasing age.
Effect of Long‐Term Management on Physical and Chemical Properties of the Coshocton Watershed Soils
Authors: Edwards W. M. , McGuinness J. L. , Van Doren D. M. , Hall G. F. , Kelley G. E. 
Published: July 2010

AbstractAfter 30 years of differential treatment, 0.7‐ to 3.2‐ha watersheds in improved management (contouring, recommended fertilization and pH level, alfalfa in rotation) had higher crop yields and less runoff and erosion than watersheds under prevailing management. Soil samples were taken from the topsoils, plowsoles, and B horizons of the watersheds to determine the effect of such management on soil physical and chemical characteristics.Large changes in chemical characteristics resulted from the higher fertilization associated with improved management but the changes generally did not persist below the topsoil layer. Measurable differences in physical characteristics of the watershed soils were slight and were confined to the topsoil layer. Differences in crop yield and hydrologic performance are attributed to fertilization, crop growth, and tillage differences associated with the two levels of management.
Grain Sorghum Response to Iron in a Ferrous Sulfate‐Ammonium Thiosulfate‐Ammonium Polyphosphate Suspension
Authors: Mortvedt J. J. , Giordano P. M. 
Published: July 2010

AbstractForage yields and Fe uptake by grain sorghum (Sorghum bicolor L., Moench) from a band application of a FeSO4‐ammonium polyphosphate suspension in a greenhouse pot experiment on a calcareous soil were doubled over those of the polyphosphate alone. Inclusion of (NH4)2S2O3 with this mixture resulted in another 15–25% increase in crop response. Extraction of soil around the fertilizer bands after harvest showed that inclusion of (NH4)2S2O3 resulted in increased Fe movement from the fertilizer band. Band placement of fertilizers containing (NH4)2S2O3 must be at least 3 cm from the seed to prevent toxicity to emerging seedlings.In a laboratory study with the same soil, inclusion of (NH4)2S2O3 with a FeSO4‐ammonium polyphosphate fertilizer resulted in a decrease in the level of 0.5N HCl‐extractable Fe in the soil around the fertilizer band and concomitant increases in the 1‐1.5 and 1.5‐2 cm zones, indicating increased diffusion of the applied Fe from the fertilizer band. Application of (NH4)S2O3 alone or with a polyphosphate fertilizer to soil resulted in increased levels of extractable Fe2+, suggesting that (NH4)2S2O3 also reduced some soil Fe for a short period after soil application.
Gamma Radiation Measurements of Bulk Density Changes in a Soil Pedon Following Irrigation
Authors: Reginato Robert J. 
Published: July 2010

AbstractBulk density in a soil pedon was measured with a gammaray transmission technique utilizing 137Cs and 241Am. Both gamma‐ray sources could not be used simultaneously for bulk density determinations in a system where the sources were uncollimated and the detector was not shielded. By alternating sources for each scan down the soil profile, it was shown that bulk density decreased in the top 6 cm of soil about 30 minutes after water was ponded on the soil surface. As soon as the water drained from the surface, bulk density values approached preirrigation levels. Changes in height of the soil surface upon irrigation corresponded with changes in bulk density.
Artificial Weathering of Oxidized Biotite: III. Potassium Uptake by Subterranean Clover
Authors: Gilkes R. J. , Young R. C. 
Published: July 2010

AbstractPotassium uptake from biotites by subterranean clover decreased as the proportion of oxidized Fe in octahedral sites increased. The relative availability of K from sequentially oxidized biotites may be predicted by sodium tetraphenylboron extraction.No major changes in mica structure due to removal of interlayer K by plants were detected.
Azide and Ethylenethiourea Mobility in Soils
Authors: Helling Charles S. , Thompson Susan M. 
Published: July 2010

AbstractA masking technique was developed for visualizing nonradioactive compounds on soil thin‐layer chromatographic plates. To determine azide mobility, leached plates were sprayed with a kaolinite slurry in 95% ethanol, air‐dried, and resprayed with 2% Fe(NO3)3 in 5% HNO3. The average RF of azide in four mineral soils was 0.87, and in a muck 0.21; it is thus quite mobile in most soils. The form of azide (NaN3, KN3, or KN3 + K2CO3) did not affect mobility. 2‐Imidazolidinethione (ethylenethiourea, or ETU), a degradation product of ethylenebis (dithiocarbamate) fungicides, was evaluated after masking with kaolinite + alumina (1:2), sprayed onto soil plates in 95% ethanol. Nitroprusside and Grote's reagents were useful chromogenic reagents. Mobility was also determined by autoradiography of [14C]ETU; average RF's for four mineral soils ranged from 0.83 to 1.00, decreasing to 0.61 in a muck. Although weakly adsorbed from solution, ETU is immobilized by drying the soil before leaching. 2‐Imidazolidone (ethyleneurea) and possibly sulfur were detected in soil incubated 7 days with ETU.
Plant Availability of Native and Added Potassium in Undried Soils
Authors: Suarez‐Hernandez Arturo , Hanway J. J. 
Published: July 2010

AbstractUndried surface and subsurface samples from 15 soils in Iowa were analyzed in the laboratory and used for a greenhouse experiment. K2SO4 was added to the soil samples at rates of 0, 50, 100, 150, and 200 ppm K. Increases in NH4OAc‐exchangeable K due to the K fertilizer additions were equivalent to 49 to 80% and 18 to 78% of the added K in the soil samples from the 0–15 and 30–45 cm depths, respectively. Percentages of K in the first harvest of ryegrass (Lolium multiflorum) were highly correlated, R2 = 0.89**, with the amounts of exchangeable K in the undried soil samples with and without additions of fertilizer K. Total plant uptake of K in six ryegrass harvests from soil samples without added K2SO4 was highly correlated with and generally greater than 2.67 times the amount of exchangeable K initially present in the soil samples. Added K2SO4 resulted in increases in total plant uptake of K equivalent to 42 to 97% of the added K. At a given level of exchangeable K, percentages of K in the first harvest of ryegrass grown on undried calcareous soil samples were higher than in grass grown on noncalcareous soil samples.
Geomorphic Relationships of Oxisols and Ultisols on Kauai, Hawaii
Authors: Beinroth F. H. , Uehara G. , Ikawa H. 
Published: July 2010

AbstractA succession of Eutrustox‐Eutrorthox‐Gibbsiorthox‐Gibbsihumox occurring in northeastern Kauai, Hawaii, is shown to be a climosequence. These soils developed synchronously on basic lavas forming one geomorphic surface of Pleistocene age. Ultisols found along the knickpoint of this surface to recent erosion surfaces are the result of soil creep. The mechanisms of clay mobilization by soil shear caused by creep are discussed.
Charge Characteristics of Soils as Affected by Phosphate Sorption
Authors: Sawhney B. L. 
Published: July 2010

AbstractThe increase in cation exchange capacity (CEC) of six Connecticut soils varied from 11 to 88% on phosphate sorption from dilute solutions. As the phosphate sorbed increased, the exchange capacity also increased. The amount of P required to produce an increase of 1 meq in CEC varied with pH; at pH 5, 80 mg P was required for an increase of 1 meq in CEC while at pH 7.5, only 40 mg P was required for the same increase. The increase in CEC at pH 5 is attributed primarily to the replacement of octahedrally coordinated water molecules on sesquioxide surfaces while at higher pH values, replacement of hydroxyl ions by phosphate ions becomes more important.
Anion Adsorption by Allophanic Tropical Soils: II. Sulfate Adsorption
Authors: Gebhardt H. , Coleman N. T. 
Published: July 2010

AbstractVolcanic ash‐derived soils (Andepts) from Mexico, Colombia, and Hawaii have large capacities for sulfate adsorption: 10–20 meq/100 g for surface soils and 15–60 meq/100 g for subsoils. The sulfate adsorption capacity is pH‐dependent. For a typical case, B‐horizon material from San Gregorio, Michoacan, Mexico, capacity in meq/100 g was 13 at pH 6.3, 22 at pH 5.1, 38 at pH 4.4, and 48 at pH 4.1. Sulfate adsorption was accompanied by and dependent upon the simultaneous adsorption, or consumption, of protons. Increasing solution concentration of sulfate beyond 5–10 meq/liter at a given pH resulted in relatively minor additional uptake by the soil. At a given pH, sulfate adsorption capacities, expressed as mmole/100 g soil, nearly equaled Cl adsorption maxima. This, together with the consumption of 1 meq H for each mmole of HCl or H2SO4 adsorbed, suggests that the two anions are adsorbed on the same sites and that site protonation is a prerequisite for adsorption.Sulfate adsorbed by the San Gregorio soil at pH 4 was strongly bound against hydrolysis (removal by water leaching) and was only partly displaced by 1N KNO3. It was completely displaced by 1N NH4OAc, pH 7. Sulfate may be adsorbed by Andepts, specifically, by ligand exchange. Its affinity for soil is at least 10 times that of nonspecifically adsorbed anions such as Cl and NO3.
Comparison of Soil Carbohydrate in Several Prairie and Forest Soils by Gas‐Liquid Chromatography
Authors: Folsom B. L. , Wagner G. H. , Scrivner C. L. 
Published: July 2010

AbstractSoil carbohydrate in thirteen different profiles was investigated using gas‐liquid chromatography to identify and determine quantities of monosaccharides released by acid hydrolysis. Total quantities of monosaccharides extracted by sulfuric acid were positively correlated with organic carbon for the soils studied. Differences in monosaccharide determined for the various profiles related to the influence of native vegetation and parent material. Generally high concentrations of monosaccharides occurred in the Al horizons of forested soils, while the prairie soils which had thicker surface layers contained the larger total quantities. Total monosaccharides accounted for from 9 to 24% of organic carbon. Where the influence of vegetation and parent material on development was similar for a sequence of soils, those showing a greater degree of weathering had a lower proportion of the organic carbon occurring as saccharides. Glucose, galactose, and mannose were the predominant sugars in all soils and glucose was always present in the greatest amount. Appreciable quantities of arabinose and xylose were present in all soils, and small amounts of rhamnose, fucose, and ribose were found. Changes in distribution of the various monosaccharides with depth in the profile were noted, the most consistent of which was that the amount of mannose relative to total measured carbohydrate increased with depth. There were proportionately more pentoses than hexoses in the prairie soils than the forest soils.
Losses of Nitrogen and Mineral Nutrients from Corn Grown in Greenhouse Pot Experiments
Authors: Terman G. L. , Allen S. E. 
Published: July 2010

AbstractThree greenhouse pot experiments were conducted: the first to compare rates of N as ammonium nitrate (AN) and S‐coated urea products (SCU, 6 and 12% initial dissolution in water) for corn (Zea mays L.); the second to measure dissolution of SCU‐5, SCU‐12, and SCU‐20 in uncropped soil; and the third to compare rates of N, P, and K for corn. Accumulation by and subsequent losses of nutrients from corn tops and roots at three harvest dates were measured. Significant losses of N, P, and K from corn tops or tops + roots fertilized with high rates of N as AN and SCU‐12 or of P and K occurred during growth from 6 to 8 or 9 weeks. These losses were closely associated with reduction in growth rates resulting from depletion of N, P, or K under test. No appreciable nutrient losses occurred from slower growing plants fertilized with SCU‐6. Three SCU products released N in uncropped cultures over a 9‐week period. Leaching of nutrients from corn top growth by guttation, dew, or rain was not a factor in these experiments. Consequently, most of the losses were through the roots. Competition by growth of microorganisms stimulated by root exudates is a probable explanation.
Picloram Sorption by Soils
Authors: Farmer W. J. , Aochi Y. 
Published: July 2010

AbstractPicloram (4‐amino‐3,5,6‐trichloropicolinic acid) adsorption‐desorption isotherms were derermined on six western USA soils. Adsorption isotherms were determined as a function of temperature, soil/solution ratio, and solution ionic strength. Special attention was given to the effects of pH and organic matter content in the analysis of the result. Adsorption increased with increasing organic matter with soils varying in organic matter content from 0.94% to 4.2%. Variations in adsorption between soils were not correlated with clay content or soil pH in the pH range 5.6 to 7.4, but increased adsorption resulted with decreasing solution pH of any individual soil. Sorption was described by the Freundlich isotherm at equilibrium concentrations less than 20 µg/ml. Temperature had only a slight effect on adsorption by the three soils examined. Increasing temperature from 10 to 20 to 30C generally resulted in decreased adsorption. Increasing the soil/solution ratio from 1:5 to 1:2 increased the Freundlich k value for the five soils tested. Freundlich k values were higher for the desorption isotherms than for the adsorption isotherms for all six soils. Increased adsorption with increasing ionic strength was predictable from associated pH changes and the dissociation constant for picloram.
A Double Buffer Method for the Determination of Lime Requirement of Acid Soils
Authors: Yuan T. L. 
Published: July 2010

AbstractA buffer method to take into consideration both the acidity and buffering property of individual acid soils was investigated. The buffer was composed of tris, imidazol, chromate, and pyridine in a 0.2M CaCl2 solution. It was prepared so that each addition of 0.1 meq of a strong acid to 50 ml of this buffer would reduce the pH by 0.1 unit within the pH range of 8.0 and 5.4. Two buffers of the same composition, one adjusted to pH 7.00 and the other to pH 6.00, were added to two separate soil samples. After shaking for 1 hour the pH was determined. The depression of the buffer pH measured the soil acidity neutralized to the equilibrium pH in these systems. The soil acidity to be neutralized from the equilibrium pH to the desired pH was determined by the buffering property of soil which, in turn, was defined by dividing the difference in soil acidity neutralized in the two buffer systems by the difference of the two equilibrium pH values. This is to represent the acidity released by the soil at each increment of pH. The lime required to raise the soil to the desired pH was calculated from the sum of these two acidity portions. The results from this method were highly correlated with and comparable to those by the lime incubation and BaCl2‐triethanolamine methods.
Interaction of Potassium in the Availability and Uptake of Iron From Ferric Hydroxide
Authors: Oertli J. J. , Opoku A. A. 
Published: July 2010

AbstractThe uptake of iron from ferric hydroxic by corn plants (Zea mays L.) was stimulated by the presence of increasing levels of potassium sulfate. Potassium nitrate had a much smaller effect. During the 48‐hour absorption experiments, the pH of the SO4 solution dropped from 9.2 to nearly 4, while that of the NO3 solution dropped only from 8.4 to between 6.5 and 6.8. The different behavior of the two solutions must be due to different imbalances of cation and anion uptake. Nitrate is taken up at a rate similar to that of K, which is faster than that of SO4. Thus NO3 causes a smaller decline of the pH. Reduced pH has a favorable effect on Fe solubility. The phenomenon was also observed (i) in CaCO3‐buffered solutions, in which case the pH drop in the root boundary zone may have been important and different from that in the buffered bulk solutions, and (ii) when Fe was present together with a synthetic cation exchanger.
The Amount and Nitrogen‐15 Content of Nitrate in Soil Profiles from two Central Illinois Fields in a Corn‐Soybean Rotation
Authors: Feigin Amos , Shearer Georgia , Kohl Daniel H. , Commoner Barry 
Published: July 2010

AbstractThis paper reports the concentration and the δ15N (per mill 15N excess) of nitrate present in soil cores as a function of depth and time. The cores were taken at approximately monthly intervals from two central Illinois fields which were in a corn and soybean rotation.During the period of October 1971 through April 1972, the mean δ15N value of nitrate present at all depths of both fields was + 1.2 ± 1.5. The most striking variation from this mean occurred after the application, on 4 May 1972, of anhydrous ammonia to the field being sown to corn, when a dramatic decrease was observed in the δ15N values of the nitrate in the 0–30 layer of that field. The difference in the δ15N values of the nitrate found in the two fields disappeared after about 2 months. The δ15N values of the ammonium ion found in the soil after application of fertilizer increased with time as the concentration of ammonium decreased and the concentration of nitrate increased. These observations indicate that the observed changes following fertilization in δ15N of nitrate were due primarily to isotopic discrimination associated with incomplete conversion of ammonium to nitrate. The δ15N values of the nitrate in both fertilzed and unfertilized fields were higher in late summer than in the period October to May.The nitrate content of the 150‐cm profile did not show significant variation with time in either field from October 1971 until 4 May 1972, when anhydrous ammonia was applied to the field being sown to corn. The nitrate concentration in the soil profiles of both fields decreased during the period of crop growth. Fertilizer application and crop uptake appeared to exert a larger influence on the total amount of nitrate in the soil profile than did movement of nitrate out of the 150‐cm profile by leaching, since rainfall in amounts sufficient to redistribute the nitrate within the profile did not lower the total amount of nitrate in the profile.
A Capillary Tube Diffusion Cell for Measuring Ion Diffusion in Aqueous Solutions
Authors: Brown D. A. 
Published: July 2010

AbstractA capillary tube diffusion cell unit with directions for its preparation and use in measuring ion diffusion in aqueous solutions is described. Self‐diffusion data for Sr, Rb, and Na in single and mixed ion systems and one herbicide, metribuzin (14C) are reported. Values can be routinely obtained with coefficient of variations below 3%.
Effect of Phosphate Adsorption on the Cation‐Exchange Capacity of Volcanic Ash Soils
Authors: Schalscha E. B. , Pratt P. F. , Soto D. 
Published: July 2010

AbstractThe CEC of five subsoils derived from volcanic ash (Trumao soils) in southern Chile was measured following treatment with phosphate solutions with concentrations ranging from 0.0042 to 0.416 moles KH2PO4/liter. The average ratio of increase in CEC to P reacted was 0.6 with only small variations among soils.