bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the Sol‐Gel Transformation in Clay‐Water Systems on Biological Activity: II. Sodium Uptake by Corn Seedlings
Authors: Baker D. E. , Low P. F. 
Published: July 2010

AbstractHomoionic Na‐ and K‐ clay were prepared from the < 2µ fraction of Wyoming bentonite. The Na‐ clay separately, or combined with the K‐clay, was mixed with water to produce clay‐water systems having different clay contents. These systems were extruded through a hypodermic needle to orient the particles within them. Thereafter, some of them were disturbed by tapping their containers on the laboratory bench. Then the following quantities were measured on all or part of them: viscosity, relative partial molar free energy, (F̄ − F̄°), of NaCl, KCl and HCl, and water tension. It was found that the viscosity, the (F̄ − F̄°) of HCl, and the water tension were decreased by disturbing the clay systems, whereas, the (F̄ − F̄°) of both NaCl and KCl were increased. The physical significance of these changes was discussed.Samples of the Na‐ clay systems were mixed with 22Na and extruded around the radicles of corn seedlings (Zea mays L.). Then Na+ uptake was determined by analyzing the seedlings for 22Na. It was found that Na+ uptake increased curvilinearly with Na‐ clay content in the range 0–4% clay and then leveled off. In the curvilinear range, Na+ uptake was directly proportional to the (F̄ − F̄°) of NaCl. Combined samples of Na‐ and K‐ clay were also mixed with 22Na and extruded around the radicles of corn seedlings. The K‐ clay was used to maintain consistency and yet dilute the Na‐ clay enough so that the seedlings would respond to changes in the (F̄ − F̄°) of NaCl. As before, some of the systems were disturbed by tapping. It was found that Na+ uptake was greater from the disturbed than from the undisturbed systems. And since the disturbance also increased the (F̄ − F̄°) of NaCl, it was concluded that Na+ uptake depended on this quantity.
Effect of Chlorinated Aliphatic Acids on Gas and Volatile Fatty Acid Production in Anaerobic Soil
Authors: Laskowski D. A. , Broadbent F. E. 
Published: July 2010

AbstractBy means of gas chromatography, inhibitory effects of chlorinated acetic and propionic acids on gas and acid production by amended anaerobic soil were measured in Landlow clay receiving 0, 10, and 100 ppm monochloroacetic (MCA), dichloroacetic (DCA), trichloroacetic (TCA), and 2,2‐dichloropropionic (DCP, dalapon) acids. The data show that the chlorinated acids inhibited methane production with resultant accumulation of acetate and to a lesser extent propionate. The length of methane inhibition was correlated with chlorinated acid disappearance, varying from a few days for MCA to more than 30 days for TCA and DCP at 100 ppm. In the presence of CaCO3, DCP (100 ppm) was inhibitory for less than 12 days.The data of these experiments indicate that use of the herbicides dalapon and TCA at concentrations approximating normal field rates probably should have no lasting adverse effects on anaerobic systems buffered near neutral pH.
A Simple Procedure for Drying Solutions for Boron Determinations by the Curcumin Method
Authors: Mulford F. R. , Martens D. C. 
Published: July 2010

AbstractA procedure for drying solutions for B determinations by the curcumin procedure is described. Using polypropylene centrifuge tubes in place of quartz or porcelain containers simplifies both the drying of solutions for formation of the colored complex, rosocyanine, and redissolution of the complex. Drying samples for 15 to 19 hours in a water bath at 55 ± 3C gives consistently good results.
Water Repellency and Infiltration Resistance of Organic‐Film‐Coated Soils
Authors: Fink D. H. 
Published: July 2010

AbstractWater repellency and infiltration resistance of porous soils coated with a variety of thin, organic films were examined. Water repellency was determined by measuring the effective contact angle of water resting on the soil surface and infiltration resistance was determined by measuring the breakthrough pressure, i.e., the threshold pressure required to force water into the soil pore structure of these water‐repellent soils. The effective contact angle of water on these treated soils was found to be a function of (i) the structure of the hydrophobic portion of the organic admolecules, and (ii) the proportion of soil surface covered with the organic film, but was relatively independent of soil chemical and physical properties. Effective angles as high as 150 to 160° were recorded for several types of organic materials. These included several silicone water repellents, an amine‐ and a hydroxy‐substituted phenol, and an acetic acid salt of a long‐chain fatty amine. The breakthrough pressure was directly affected by the factors that controlled the contact angle, and was inversely related to the effective pore radii of the porous, water‐repellent soils.
A Salt Sensor for Use in Saturated and Unsaturated Soils
Authors: Reicosky Donald C. , Millington R. J. , Peters D. B. 
Published: July 2010

AbstractA salt sensor, suitable for use in situ in saturated and partly saturated soils, has been designed and constructed from readily available materials. The behavior of the sensor, within limits, is independent of the geometry of the surrounding medium. Under hydraulic stress, the sensor is limited to a range from 0 to −0.65 bars. Failure below −0.65 bars appeared to be due to cavitation of solution within the sensor. The response time in free solution is short and the calibration of sensors remained stable over periods of weeks.
Interaction Among Atrazine, Temperature, and Phosphorus‐Induced Zinc Deficiency in Corn (Zea mays L.)
Authors: Rudgers L. A. , Demeterio J. L. , Paulsen G. M. , Ellis R. 
Published: July 2010

AbstractCorn (Zea mays L.) was grown with two levels each of P and Zn with and without atrazine in the field on recently leveled P‐ and Zn‐deficient soil and in nutrient solutions in environmental chambers. Severe Zn deficiency symptoms were exhibited by field‐grown corn receiving no Zn and were accentuated by P fertilization. Atrazine had no evident effect on deficiency development. Phosphorus and Zn concentrations in leaves, but not in grain, of field‐grown corn were increased by atrazine. In environmental chambers, corn seedling growth was decreased more by atrazine toxicity than by P or Zn nutrition. Phosphorus and Zn concentrations were increased frequently by atrazine at low but not at high growing temperatures. Atrazine had little apparent effect on P‐induced Zn deficiency development in the field or in environmental chambers.
Drainage and Nutrient Effects in a Field Lysimeter Study: II. Mineral Uptake by Corn
Authors: Lal Rattan , Taylor George S. 
Published: July 2010

AbstractThe mineral uptake by corn (Zea mays L.) was studied in field lysimeters for the following variables: constant water table (WT) depths, intermittent flooding, and two levels each of N and the micronutrients Zn and Cu. The WT depths. of 15 and 30 cm and intermittent flooding during early growth decreased the ear leaf concentrations of N, P, K, Zn, Cu, and B and increased the leaf concentrations of Al, Fe, Mn, and Mo. Applications of N, Zn, and Cu increased the concentrations of N, P, Zn, Cu, B, Mn, and Fe but decreased that of K. Mineral uptake under wet soil conditions was associated with reducing conditions, inhibited soil mineralization and an increase in soil pH.
Geomorphic Surfaces and Soils in the Black Creek Valley, Johnston County, North Carolina
Authors: Gamble E. E. , Daniels R. B. , Nettleton W. D. 
Published: July 2010

AbstractThe Black Creek Valley in the dissected upper Coastal Plain is a complex of geomorphic surfaces that ranges in age from Pliocene to Recent. Soils on the Pliocene surfaces are on the interstream divides and on old terrace remnants within the valley. They are classed as Paleudults. These soils are formed in relatively uniform sediments, have sola 2–4 m thick, little or no B horizon structure, and few clay films in the upper B horizon. Discontinuous phase plinthite is found in the middle B horizon. These soils have uniform profile characteristics, are easily mapped, and the delineations have few inclusions.The soils on the late Pleistocene to Recent valley‐side slopes and low terraces have sola less than 1.25 m thick and are classed as Hapludults. There is much variation in A2 horizon thickness, B horizon color, and texture. This arises from the variation of the sediments outcropping on the valley sides. Further variability is caused by Recent valley‐side alluvium that has irregular distribution and unpredictable thickness. Regardless of their variability, these soils all have weak to moderate B horizon structure, common clay skins on ped faces, and no plinthite. They are best mapped as complexes because of their variability. A delineation contains many inclusions.
Numerical Taxonomy of Soils from Nine Orders by Cluster and Centroid‐Component Analyses
Authors: Cipra J. E. , Bidwell O. W. , Rohlf F. J. 
Published: July 2010

AbstractMultivariate statistical procedures of numerical taxonomy were used to investigate the patterns of similarities among 59 soils. Twenty‐one morphological and laboratory characteristics of modal soil profiles from nine orders of the new classification system were used. Characters were selected to avoid high intercorrelations. Raw character values were transformed to give each character a mean of zero and variance of unity. Centroidcomponent analysis with projections of soils onto centroidcharacter axes was employed. This facilitated expression of similarities among soils in three dimensions in a manner which did not assume that clusters of soils existed. Correlation and distance matrices also were computed to obtain two estimates of the similarity of each individual to every other. Similarities among soils as indicated by these two matrices were summarized by cluster analysis. Results were displayed in phenograms yielding a system of nested clusters of soils.The three methods of estimating and summarizing similarity relationships gave comparable results. The numerical classifications agreed, in general, with the new classification system with respect to Mollisols, Alfisols, Inceptisols, Entisols, and Spodosols. Vertisols showed little affinity for one another, Aridisols clustered with Mollisols and Alfisols, and the single Oxisol clustered with Ultisols. Ultisols showed no special affinity for other Ultisols. Numerical taxonomic methods are capable of summarizing large amounts of new data efficiently, making them a valuable soil classification tool.
Loess Distribution from a Source
Authors: Frazee C. J. , Fehrenbacher J. B. , Krumbein W. C. 
Published: July 2010

AbstractLoess thickness and particle size changes along six Peoria loess traverses in Illinois and southwestern Indiana were investigated by fitting the data to various mathematical models by computer. An exponential model, a logarithmic model, a power function, and an additive exponential model developed in this study were tested. The decrease in mean particle size, which is due to changes in the coarse silt content, both windward and leeward from the source is explained best by the additive exponential model. Mean particle size changes much more rapidly near the source than afar.Leeward of the source, two changes in the rate of loess thinning occurred. The change closest to the bluff is related to particle size differences with distance from the source. The second change is attributed to greater loess deposition in a wider zone near the source by winds from different directions. Windward of the source, no change in the rate of loess thinning due to particle size differences was observed.Based upon the particle size and thickness data presented, the decrease in loess thickness from its source is explained best by an additive exponential model. Leeward of the source where two changes in the rate of loess thinning occur, three exponential terms are needed to accurately characterize loess thickness. The decrease in loess thickness with distance from the source which is due to the more rapid decrease in particle size near the source is defined by the first exponential term. The decrease in loess thickness associated with deposition by winds of different directions is described by the second exponential term. The third exponential term depicts the regional loess thinning due to a decrease in the number of loess particles with distance from the source. Windward of the source only two exponential terms are needed to accurately describe loess thickness because no change in the rate of loess thinning due to particle size differences was observed.
Growth Rate and Yield of Cotton as Influenced by Depth and Bulk Density of Soil Pans
Authors: Lowry F. E. , Taylor H. M. , Huck M. G. 
Published: July 2010

AbstractEffects of depth and bulk density of soil pans on cotton growth and yield, oxygen concentration, and water extraction were measured. At each depth‐to‐pan treatment, final plant height and yield of seed cotton were reduced as soil bulk density or penetrometer resistance increased. Growth rate and yield were less on the 10‐cm depth‐to‐pan treatment than on the 20‐ or 30‐cm depth treatments. A restricted water supply due to limited rooting volume probably was the principal factor causing reduced yield of cotton grown on the higher strength soil pans.
Interactions of Phosphorus Availability, Mycorrhizae, and Soil Fumigation on Coniferous Seedlings
Authors: Henderson Gray S. , Stone E. L. 
Published: July 2010

AbstractFactorial experiments under nursery and greenhouse conditions were used to study P uptake and growth of coniferous seedlings. Vapam, Trizone, and methyl bromide effectively eliminated mycorrhizal fungi from the rooting zone of tree seedlings and thus afforded a means of studying mycorrhizae in a relatively natural environment. Growth and P content of nonmycorrhizal seedlings grown in fumigated soil without P fertilization were less than for any other treatment; this is attributed to absence of mycorrhizae. Beinoculation with mycorrhizal roots or soil, or high rates of P fertilization without inoculation prevented the reduced P uptake and poor growth caused by fumigation alone. Fumigation followed by both inoculation and P fertilization resulted in the largest seedlings and greatest P uptake. Greater absorbing surface, together with high P concentrations, presumably accounts for the greater uptake and corresponding growth increase.
Agronomic Effectiveness of Ammonium Orthophosphate and Ammonium Polyphosphate as Measured by Ion Uptake and Yield of Corn
Authors: Dobson J. W. , Wells K. L. , Fisher C. D. 
Published: July 2010

AbstractAmmonium orthophosphate (AOP) and ammonium polyphosphate (APP) were compared as P sources for corn on an acid bottomland and an upland soil, both of which tested low in available P. Determinations were made for dry matter and ion accumulation by corn plants (Zea mays L.) harvested 30 days after emergence, and for grain yield. No significant differences (p = .05) were found between AOP and APP for any of the parameters measured. All significant differences determined were due to rate of applied P. In a related study to determine the interaction of P source, Zn, and lime rate on dry matter, ion accumulation, and yield of grain, no differences were observed due to source of P. Both sources of P were equally effective on corn production for the parameters measured.
Semimicro Determination of Sulfate in Water Extracts of Soils
Authors: Nelson R. E. 
Published: July 2010

AbstractSulfate in water extracts of soils is precipitated in 2:1 acetone‐water solution by adding excess Ca(NO3)2 and HNO3 to the acid pH indicated by thymol blue. The precipitate is filtered and washed free of occluded ions by leaching with ethanol. The amount of sulfate is calculated from the Ca content (0.005–0.05 meq) in the precipitate, which is determined by EDTA titration. Since the procedure is simple and rapid, the method is suitable for routine soil analysis.
Precision in Pesticide Adsorption Measurements
Authors: Green R. E. , Yamane V. K. 
Published: July 2010

AbstractThe precision of solute adsorption measurements (based on change of concentration in a solution equilibrated with an adsorbent) depends upon the magnitude of the solution concentration change. Coefficients of variation for measurements of atrazine adsorption on soil were inversely related to the amount adsorbed. Such variation in precision is the consequence of the indirect method of determination rather than variable experimental technique. Unsatisfactory precision is common in adsorption measurements; improvement can sometimes be achieved by altering the soil:solution ratio to obtain larger concentration changes.
Solid State Circuitry to Activate Event Recorders Used with Drop‐Counters
Authors: Unger Paul W. , Roberson G. M. 
Published: July 2010

AbstractA drop‐counting apparatus is used to determine soil moisture flow rates. A drop of water (soil solution) extracted from soil falls between two electrodes of the drop counter and initiates a series of events in the circuitry that activates the relay coil of the event recorder. The chart is marked at the time the drop passes between the electrodes.
Environment and Its Role in the Development of a Scientist
Authors: Kemper W. D. 
Published: July 2010

AbstractFactors influencing the development of a scientist are discussed. The most important factors motivating a scientist to greater effort are generally those provided by fellow scientists and the people whom we serve. These factors include assurance that his objectives are worthwhile, recognition of his efforts, and the opportunity to publish the truth as he sees it and bear the consequences of his actions.Budget, technical help, and facilities are also important factors determining his production. However, the development of an enterprising scientist cannot be prevented and may sometimes be accelerated by deficiencies in his physical environment.
Soil Development and Geomorphic Surfaces, Willamette Valley, Oregon
Authors: Parsons R. B. , Balster C. A. , Ness A. O. 
Published: July 2010

AbstractSoil development in the Willamette Valley is related to a sequence of seven extensive geomorphic surfaces ranging in age from postsettlement to middle Pleistocene. The surfaces were mapped on high‐altitude aerial photographs for an area about 7,800 km2. The oldest surface associated with the present drainage system is at least 5,250‐years‐old and may be as old as 34,410 years. One soil series considered representative of each geomorphic surface was chosen to illustrate soil development on successively older surfaces. Soils on the most recent surfaces have developed only A1 horizons containing about 4% organic matter. Soils develop cambic B horizons within 550 years, whereas Bt horizons are formed within a period of 5,250 years. Base saturation progressively decreases from 100% in the Haploxerolls on the younger surfaces to less than 35% in the Haplohumults on the oldest surfaces.
Water Relations of a Profile‐Modified Slowly Permeable Soil
Authors: Unger Paul W. 
Published: July 2010

AbstractA study was conducted with samples obtained from Pullman silty clay loam modified to 0 (check), 90, or 150 cm with a large ditching machine. Objectives were to determine the potential for increasing water intake, retention, and storage by profile modification, and to characterize the modified soil.Profile modification to 90 and 150 cm effectively disrupted the slowly permeable horizon of Pullman soil. Soil bulk density and strength were significantly decreased, and soil porosity was significantly increased. Unmodified soil retained more water on a volumetric basis than modified soil at ⅓‐ and 15‐bars tension, but plant‐available water as estimated from the ⅓‐ and 15‐bar values was not altered by modification. The lower water contents of the modified soil at low tensions provided for potentially greater aeration. Water entered modified soil more rapidly than unmodified soil under field conditions.
Irrigation‐Nitrogen Studies in Asparagus and Measurement of Soil Moisture Changes by the Neutron Method
Authors: Cannell Glen H. , Takatori F. H. 
Published: July 2010

AbstractThree irrigation levels controlled at 0.4, 0.8, and 2 to 5 bar soil suction were combined factorially with two N levels and two varieties of asparagus (Asparagus officinalis) in a 4‐year study. The two N treatments consisted of 112 kg N/ha and 560 kg N/ha obtained from (NH4)2SO4 and the two varieties were ‘309’ and ‘500W’. Significantly higher spear yields were obtained in the 0.8 and 2 to 5 bar irrigation treatments as compared to the 0.4 bar level. The decreased spear yields in the relatively wet treatment were attributed to the effects of lower soil temperatures in that treatment prior to and during the cutting season. Fern yields were highest in the 0.4‐bar suction treatment and decreased progressively with drier irrigation treatments. High N significantly increased both spear and fern yields and was significantly superior in efficient use of water in spear production as compared to a lower N level.Soil moisture changes with irrigation treatments were measured with neutron equipment and the data used to determine depth of root activity, depth of wetting, and the volume of water in the soil following each irrigation. The water measured in the soil was compared to that applied. The differences ranged from ± 1.2% to 1.6% which is within the range of counting error for the neutron equipment.Efficiency in production was calculated from water applied because this included all plots rather than only those with access tubes used for neutron measurements.
Manganese Reactions and Availability as Influenced by pH and Pyrophosphate Content of Ammonium Phosphate Fertilizers
Authors: Hossner L. R. , Blanchar R. W. 
Published: July 2010

AbstractAmmonium phosphate, composed of mixtures of ammonium ortho‐ and pyrophosphate, were tested to determine their effectiveness as carriers of Mn. The mixtures contained 0, 20, 40, 60, 80, or 100% of their total P as pyrophosphate with the remainder being orthophosphate. Each series of mixtures was prepared at saturated pH values of 3.6, 4.0, 5.0, 6.0, 7.0, and 8.0. Residues, formed when the ammonium phosphates were blended with MnSO4 · H2O and reacted with the soil, were analyzed to determine their composition.Essentially all of the applied Mn precipitated as manganese ammonium phosphate when the pH of the fertilizer was greater than 6.0. As the pH was decreased from 5.0 to 3.6 there was a decrease in precipitated manganese with decreasing pyro‐ to orthophosphate content at each pH value. When the fertilizer pH was 3.6 or 4.0 and the P was present as 100% orthophosphate there was no residue formed indicating complete movement of Mn from the site of placement.Four manganese ammonium phosphates were identified in the residue samples. The compound Mn(NH4)2H4(P2O7)2·2H2O was present at pH 3.6 and 4.0 and a pyrophosphate content of 40% or greater. Mn3(NH4)2(P2O7)2·2H2O formed at pH values of 5.0 or less and with pyrophosphate contents of 20% or greater. When the fertilizer pH was 5.0 or greater Mn(NH4)2P2O7·H2O was the dominant compound identified in the residues. The only manganese orthophosphate identified was MnNH4PO4·H2O which precipitated at pH values above 5.0 when 80% or more of the P was present as orthophosphate.Plant utilization of Mn spot‐placed with ortho‐pyrophosphate mixtures as measured with 54MnSO4·H2O was proportional to decreasing precipitation of applied Mn. Maximum uptake of applied Mn occurred at a pH of 3.6 and 100% orthophosphate. Residual uptake of Mn from reaction products blended with the soil was high from all treatments. There was a tendency for a reduction in Mn uptake with increasing pyrophosphate at each level.