bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fixation of Iron and Zinc Applied as Chelates Into a Soil Column During Leaching
Authors: Lahav N. , Hochberg M. 
Published: July 2010

AbstractThe movement of iron in the form of FeEDDHA and FeEDTA and zinc in the form of ZnEDTA was studied in columns of Rehovot sand under several flow rates and in the presence of either Ca(NO3)2 or KNO3 with the same ionic strength of 0.0375M/liter. Chloride was used as a tracer.FeEDDHA was neither adsorbed nor fixed by the soil. Both ZnEDTA and FeEDTA were fixed in the soil column in the presence of Ca2+ but not in the presence of K+. ZnEDTA was not adsorbed significantly, whereas FeEDTA was adsorbed in the presence of either KNO3 or Ca(NO3)2 solutions. Reasonable agreement was obtained between experimental results and theoretical calculations of the breakthrough curves, based on the analytical solution of the general dispersion equation.
Dispersion of Clays in Ethanol Solutions
Authors: Leonard R. A. , Jackson W. A. 
Published: July 2010

AbstractKaolinite was found to disperse at critical electrolyte concentrations in ethanol solutions greater than 80 vol/vol% of 10‐5 to 10‐3M CaCl2 and 10‐5 to 10‐2M AlCl3. Cecil soil clay also dispersed under the same conditions, while montmorillonite did not disperse in these solutions. Kaolinite did not disperse in alcoholic NaCl solutions.The dispersed kaolinite migrated toward the cathode in electrophoresis experiments which supported our hypothesis that cation adsorption from the alcohol solution into the Stern layer at the clay surface imparted a positive electrical charge and promoted dispersion.Cationic reactions with clay surfaces in alcoholic media may provide additional insight concerning the nature of these surfaces. Dispersion of clays in alcohol may also be a useful technique for selectively concentrating clay for other characterization studies.
Effect of Method of Nitrogen Application on Corn (Zea Mays L.) Grown on Irrigated Sandy Soils
Authors: Rehm G. W. , Wiese R. A. 
Published: July 2010

AbstractStudies were conducted in 1970 and 1972 to determine the influence of method of Nitrogen application on corn production (Zea Mays L.) on irrigated, sandy soils. Conventional preplant and sidedress treatments were compared to situations where either preplant or sidedress applications were supplemented with added N in the irrigation water. Grain yields were recorded and the NO3‐‐N distribution to 150 cm in the soil profile was measured at the end of the growing season. The influence of method of application on corn yields was related to the textural profile of the soil. For a sandy soil with no accumulation of fine textured material, the application of N with the irrigation water increased grain yields. Also, the corn crop recovered a higher proportion of the applied N when some fertilizer N was added with the irrigation water. For a soil type characterized by an accumulation of fine textured material at 50–70 cm below the surface, method of N application had no influence on yield since the downward movement and loss of NO3‐‐N was restricted by the layer of fine‐textured material. The data show that the application of a portion of the N fertilizer requirement with the irrigation water should be a recommended practice for corn production on sandy soils having no accumulation of fine‐textured material.
Landsat Data, Its Use in a Soil Survey Program
Authors: Westin Frederick C. , Frazee C. J. 
Published: July 2010

AbstractThis study's three objectives were: first, to investigate the unique characteristics of LANDSAT imagery as they aid in recognizing soil survey boundaries; second, to explore the use of LANDSAT imagery for low intensity soil surveys; and third, to investigate LANDSAT imagery as a base map for publishing thematic soils maps.As an aid in recognizing soil boundaries, the following characteristics of LANDSAT imagery have a bearing on its use in a soil survey program: the synoptic view of 3.5 million ha on which the condition of the soils and stage of vegetative growth are recorded at nearly the same moment; the near‐orthographic character of the scenes, allowing for the construction of mosaics; the temporal feature, permitting study of soils and vegetation as they change with time and the multispectral capabilities which increase the possibilities of unique signatures for vegetation and soils.Using many of the characteristics of LANDSAT imagery, a low intensity soil survey of Pennington County, South Dakota was completed in 1974. The purpose of this survey was to determine the feasibility of preparing an inexpensive soil map which could be used in the Great Plains areas of South Dakota which presently lack a detailed soil survey. The LANDSAT survey cost 2¢/ha and took about 5 weeks.The first step using LANDSAT imagery as a base map for publishing thematic soil maps is to prepare a mosaic. Twenty LANDSAT scenes from several late spring passes in 1973 were selected and made into a mosaic of scale 1:1,000,000. Two LANDSAT mosaics of South Dakota containing soils information have now been published. On the first, the soil associations are keyed to information on land sale prices from 1967–1972. The result is a land value map on a LANDSAT mosaic. On the second, the soil associations are keyed to soil test results in South Dakota of the last 25 years for organic matter, P2O5, K2O and pH. Also given for each soil association is relief and texture. Each of these publications cost about $400 for 5000 copies.
Leaf Fall and Forest Floor Characteristics in Loblolly Pine Plantations in the South Carolina Piedmont
Authors: Van Lear D. H. , Goebel N. B. 
Published: July 2010

AbstractThe seasonal pattern and quantity of leaf fall were studied in three unthinned loblolly pine (Pinus taeda L.) plantations in the South Carolina Piedmont. Peak period of leaf fall occurred from October through December. Although the plantations ranged in age from 15 to 32 years, total quantities of leaf fall (4,100–4,400 kg/ha) did not differ significantly. Nutrients stored in forest floor components in the youngest stand ranged from 171 kg/ha for N to 16 kg/ha for K. Approximately 16.3, 2.2, 4.4, 18.0, and 4.8 kg/ha of N, P, K, Ca, and Mg, respectively, were returned in annual leave fall. The forest floor has a differential ability to store nutrients. Concentrations of N and P increase as leaf litter decomposes, probably because of slow mineralization rates and rapid immobilization by microorganisms. Calcium, Mg, and K are more easily leached into the soil.
Sulfur‐coated Fertilizers for Sugarcane: II. Release Characteristics of Sulfur‐coated Urea and KCl
Authors: Snyder G. H. , Gascho G. J. 
Published: July 2010

AbstractNitrogen release from sulfur‐coated urea and K release from S‐coated KCl were examined by several techniques under field conditions in three south Florida sand soils in order to assist in the interpretation of plant response data and to provide insight into the use of three slow‐release fertilizer materials. Decreased thickness of S coating, higher temperatures and higher moisture generally favored nutrient release. However, considering the range of field conditions involved in the studies, variations in N and K release were comparatively small. Release was rapid during the first 6 months, averaging 70–80% of that applied, but was much slower thereafter.
Mineralogy and Chemistry of Manganese Oxides in Some Indiana Soils
Authors: Ross S. J. , Franzmeier D. P. , Roth C. B. 
Published: July 2010

AbstractManganese‐rich mottles and glaebules are common in many soils and their presence is taken as morphological evidence of a fluctuating water table. Manganese‐rich material from soils of the Aqualf, Psamment, Udalf, Udoll, and Udult suborders was chemically and mineralogically characterized in order to better understand the role of Mn in soil formation. Concentrations of Mn, Al, Fe, Ca, Mg, Ba, Li, K and Na were found to vary greatly in the Mn mineral from among the different horizons studied. The Mn compounds from the soils studied were largely amorphous to X‐ray due to poor crystallinity, fineness, or both. Todorokite was present in a calcareous horizon and birnessite was present in some acid horizons. The previously reported association of birnessite with alkaline soils was not found in this study. To differentiate the X‐ray pattern of birnessite from that of kaolinite, the sample was boiled in 5N NaOH to destroy the kaolinite. This treatment either crystallized birnessite from amorphous compounds or improved the crystallinity of a weakly crystalline mineral already present.
Calculating the Unsaturated Hydraulic Conductivity and Diffusivity
Authors: Whisler F. D. 
Published: July 2010

AbstractThe methods of R. D. Jackson and R. H. Brooks and A. T. Corey for calculating the unsaturated hydraulic conductivity from water content‐pressure head relationships are compared. The corresponding diffusivity relationships can also be evaluated either by a numerical differentiation of the water content‐pressure head curves plus the conductivity, or by direct calculation from the differentiation of the Brooks and Corey function. Both methods give approximately the same results for the hydraulic conductivity relationships. The diffusivity values calculated from the Brooks and Corey functions are lower than those calculated by the numerical method for a Grenada silt loam soil. Both diffusivity relationships give essentially the same β values for the W. R. Gardner and M. S. Mayhugh diffusivity‐water content function.
The Resistance of Intact Maize Roots to Water Flow
Authors: So H. B. , Aylmore L. A. G. , Quirk J. P. 
Published: July 2010

AbstractUsing a novel tensiometer‐potometer system the relationship between the root resistance to water flow of maize and the water potential of the root tissue has been examined. Over the range of water potentials used a linear relation has been observed in contrast to previous observations. Calculations using published data indicate that the rhizosphere resistance is of the same order of magnitude as the root resistance when the soil moisture potential of the rhizosphere is about −1 to −2 bars.
Computer Simulation of Phosphorus Movement Through Soils
Authors: Harter Robert D. , Foster Bennett B. 
Published: July 2010

AbstractAlthough the movement of P through soil can be described by mathematical models, this approach has certain limitations in practical application, particularly when soil is used for waste water renovation. To circumvent the limitations of mathematical modeling, empirical adsorption equations can be obtained and utilized in computer simulation of phosphorus movement. In this way, the renovation lifetime of a soil can be estimated. This approach is not limited to P, and can be used for any potential ground‐water contaminate, whether inorganic or organic.
Comparison of Five Kinetic Models for Orthophosphate Reactions in Mineral Soils
Authors: Enfield Carl G. , Harlin Curtis C. , Bledsoe Bert E. 
Published: July 2010

AbstractThe kinetics of orthophosphate sorption with 25 mineral soils have been experimentally measured under laboratory conditions. The 25 mineral soils represent a wide range of physical and chemical properties. Regression analyses have been performed fitting the experimental data to five kinetic models. The five kinetic models include: a linearized first‐order sorption, a first‐order Freundlich sorption, an empirical function, a diffusion‐limited Langmuir sorption, and a diffusion‐limited Freundlich sorption. Mean correlation coefficients of 0.81, 0.83, 0.84, 0.86, and 0.88 were obtained for the models, respectively.
Influence of Soil pH on the Availability of Added Boron
Authors: Peterson L. A. , Newman R. C. 
Published: July 2010

AbstractA Plano silt loam (Typic Argiudoll) with five relatively constant pH levels (4.7, 5.3, 5.8, 6.3, 7.4) was used to study the influence of soil pH on the availability of added B. A greenhouse study was conducted using tall fescue (Festuca arundinacea Schreb. Cv. ‘Kentucky 31’) with five soil pH levels, and four rates of applied B essentially equivalent to 0, 5, 10, and 20 kg/ha, and five herbage harvests. Herbage yields of tall fescue were not affected by either soil pH or B treatments; however, tissue B concentrations ranged from 8 to 739 ppm for the five harvests. Boron uptake by tall fescue was relatively uniform for soil pH levels of 4.7, 5.3, 5.8, and 6.3 within each level of B availability. Recovery percentages of 30 to 50% of the added B by five cuttings of forage indicate a soil fixation of B. Highest recovery percentage was associated with the highest rate of added B. A 2.5‐fold drop in B uptake occurred at pH 7.4 as compared with the other soil pH levels indicating substantial fixation of B. Hot‐water‐soluble B content of the soil generally increased with an increase in pH and with added B. The soluble B test did not predict the low recovery of B at pH 7.4.
Surface Residue, Water Application, and Soil Texture Effects on Water Accumulation
Authors: Unger Paul W. 
Published: July 2010

AbstractSurface residue rates and water application amounts affect evaporation from soil. These factors were evaluated for their effects on water accumulation in a clay loam and a fine sandy loam soil. Surface residue rates ranged from 0 to 12,000 kg/ha and water was added at 0.25, 0.5, 1.0, or 2.0 cm/addition. At low residue rates and water applications, little or no water accumulated in the soils. The amount of water that accumulated in the soils increased as surface residue rates and water applications increased. Results for the two soils were remarkably similar, apparently because the liquid and vapor flow characteristics for the two soils were similar at high water contents, even though their water retention characteristics differed markedly. The results of this laboratory study are discussed with regard to residue management practices for low (dryland) and high (irrigated) residue production systems of the Great Plains.
Solution of the One‐Dimensional Linear Moisture Flow Equation with Implicit Water Extraction Functions
Authors: Lomen D. O. , Warrick A. W. 
Published: July 2010

AbstractAnalytical solutions of the one‐dimensional steady‐state moisture flow equation are presented for several functions modeling soil water extraction. These functions depend directly on the matric flux potential and thus are implicit with depth. A constant surface flux was assumed. Graphs of the matric flux potential and cumulative uptake are given depicting the effect of model parameters and comparing different water extraction functions. The results are useful in obtaining a variety of water extraction distributions.
Influence of Salt and Alkali on Ionic Equilibria in Submerged Soils
Authors: Pasricha N. S. , Ponnamperuma F. N. 
Published: July 2010

AbstractTo clarify the effects of salt and alkali on Fe2+ and Mn2+ equilibria in submerged soils, Maahas clay (a Haplustalf) was amended with NaCl and NaHCO3 to give initial electrical conductivities of 5, 10, 20, and 25 mmhos/cm at 25°C and exchangeable Na percentages of 5, 10, 15, 20, and 25, respectively. The amended soils and an untreated control were kept submerged in 16‐liter pots in a greenhouse at 25–30°C. The soil solutions, drawn anoxically by gravity, were analyzed fortnightly for Eh, pH, CO2, and the major ions. As the salt level increased, pH decreased and the concentrations of all cations increased. As alkalinity increased, the concentrations of all cations except K+ and Na+ decreased. In spite of wide variations in pH, Eh, ionic strength, and the concentrations of Fe2+ and Mn2+ in the soil solutions, the values of the expressions, pE − pFe2+ + 3 pH, pE − 1.5 pFe2+ + 4 pH, pE + pH, and pH − 0.5 pMn2+ − 0.5 pCO2 were nearly equal to 17.9, 23.3, 7.3, and 4.1, respectively, indicating that even in the salt and alkali treated soils, the Fe(OH)3‐Fe2+ and Fe3(OH)8‐Fe2+ systems controlled the solubility of Fe2+ while the MnCO3‐H2O‐CO2 system regulated the solubility of Mn2+.
Phosphorous Sorption and Desorption Characteristics of Soil as Affected by Organic Residues
Authors: Singh B. B. , Jones J. P. 
Published: July 2010

AbstractThe influence of seven organic residues on sorption and desorption of P by a high P‐fixing soil was determined after 30, 75, and 150 days of incubation. After incubating for 30 days, all residues decreased the amount of P sorbed by the soil, resulting in higher equilibrium solution P levels. However, after incubating for either 75 or 150 days, the P content of the organic residues had a marked influence on sorption of added P and desorption of sorbed P. The critical value of P in organic residues which resulted in no tie‐up of soil P was 0.3%. Sawdust, wheat straw, and cornstalks which contained < 0.3% P decreased labile soil P and increased sorption by soil after incubating for 75 or 150 days. Alfalfa (Medicago sativa), barley (Hordeum vulgare), beans (Phaseolus vulgaris), and poultry manure that contained P in excess of 0.3% decreased sorption of P. The results suggest that P fertilizer rates estimated from sorption isotherms may need to be modified following addition of organic residues.
The Influence of Cation Exchange Capacity and Depth of Incorporation on Ammonia Volatilization from Ammonium Compounds Applied to Calcareous Soils
Authors: Fenn L. B. , Kissel D. E. 
Published: July 2010

AbstractThe objective of this study was to determine the influence of soil cation exchange capacity (CEC) and depth of incorporation on NH3‐N volatilization from NH4+‐N compounds applied to calcareous soil. This study was conducted in the laboratory on soils with a wide range of CEC. An increasing CEC resulted in decreasing NH3 losses. Ammonium sulfate produced higher soil pH values and NH3 losses than did NH4NO3. The pH of the soil decreased with increasing NH4NO3 application rates. With NH4NO3, percent NH3‐N losses decreased with increasing application rate; however, with (NH4)2SO4, percent NH3‐N losses increased as the application rates increased.Incorporation of the NH4+‐compounds into the soil reduced NH3 losses. Increasing depths of NH4+‐incorporation resulted in reduced NH3 loss. Losses decreased as the CEC of soil increased. The effectiveness of soil depth in reducing NH3 loss was associated with soil water content. Decreasing the soil water increased the effectiveness of soil incorporation for reducing NH3 losses.Two regression equations were developed to describe NH3 losses with respect to CEC, soil pH, time, NH4+‐N application rate and temperature. Correlation coefficients were 0.86 and 0.81 for (NH4)2SO4 and NH4NO3 systems, respectively.
A Markovian Stochastic Basis for the Transport of Water Through Unsaturated Soil
Authors: Bhattacharya R. N. , Gupta Vijay K. , Sposito Garrison 
Published: July 2010

AbstractThe differential equation that describes the isothermal, isohaline transport of water through a homogeneous, isotropic, unsaturated soil is shown to result from a fundamental stochastic hypothesis: that the trajectory of a water molecule is a nonhomogeneous Markov process characterized by space‐ and time‐dependent coefficients of drift and diffusion. The demonstration makes possible a new theoretical interpretation of the water diffusivity and the hydraulic conductivity at the molecular level and results in a derivation of the Buckingham‐Darcy flux law that does not rely directly on experiment.
Ammonia Volatilization from Surface Applications of Ammonium Compounds on Calcareous Soils: V. Soil Water Content and Method of Nitrogen Application
Authors: Fenn L. B. , Escarzaga R. 
Published: July 2010

AbstractAmmonia‐nitrogen losses from soils were dependent on the existence of sufficient water for solubilization of the applied NH4‐compounds. Laboratory data revealed that NH3 volatilization from (NH4)2SO4 was greatly reduced on soils with 55% water at 12, 22 and 30°C as compared to soils with 30% water. Ammonia‐nitrogen losses were the highest at all temperatures and nitrogen applicatin rates when soils contained 13 to 30% soil water. Dry NH4‐chemicals did not dissolve in soils with 0 and 8% soil water, therefore, little NH3 was lost. Application of a concentrated (NH4)2SO4 solution to soils with 8% water resulted in near maximum NH3 loss. This same solution, when applied to the surface of an oven dry soil, resulted in lower losses. Application of NH4NO3 to soils with 55 water resulted in lower NH3 losses when compared to soils with 8 to 30% water. Soils with 0% water retained essentially all applied NH4+‐N whether applied in dry or concentrated liquid form.Apparent nitrogen recovery with barley (Hordeum vulgare L., cv. Griggs) in a greenhouse experiment corresponded well to nonvolatilized NH4+ determined in the laboratory. All nitrogen compounds were on the soil surface 7 days before application of irrigation water. Nitrogen uptake by barley was greatest when the material was applied as a dry salt to the surface of an air dry soil, intermediate when added as a dry salt to the surface of a recently saturated soil, and lowest when added as a solution to the surface of an air dry soil. Urea, urea + NH4H2PO4, and NH4NO3 were exceptions. These compounds resulted in equal plant nitrogen absorption whether applied as a dry salt or as an aqueous solution to the surface of an air dry soil. Plant absorption of nitrogen from soil with these same N‐compounds, however, was greatest when applied to the surface of a soil saturated with water.
Nutritional Problems of Pinus taeda L. (Loblolly Pine) Growing on Pocosin Soil
Authors: MacCarthy R. , Davey C. B. 
Published: July 2010

AbstractApart from drainage considerations, the main factors militating against good growth on most pocosin soils are a deficiency of available P and a high exchange acidity of the soil. Liming and fertilization with P both increased the height growth of loblolly pine. Combination applications of lime and P produced the greatest height increases. The results of chemical analyses of foliage and soil explain the large differences in growth of loblolly pine on treated and control plots. Significant linear correlations were found between the height of loblolly pine and available P in the soil and between tree height and the content of P in loblolly pine and Lyonia foliage. Critical values were established for P in the soil, loblolly pine needles, and Lyonia foliage as guides for P fertilization. The critical level of P in Lyonia foliage establishes predictor values of growth equal to those produced by the critical levels of P in loblolly pine needles, thus providing an indicator species in the absence of the pine.
Radial Movement of Saturated Zone Under Constant Flux: Theory and Application to the Determination of Soil‐water Diffusivity
Authors: Sawhney B. L. , Parlange J. ‐Y. 
Published: July 2010

AbstractA two‐dimensional similarity solution yields the soil‐water diffusivity of an unsaturated soil when the soil water content is measured as a function of the distance from the source. When ponding occurs, the positions of the saturated and unsaturated fronts are related to the diffusivity. If the diffusivity can be described with two parameters, it can be predicted from the position of the two fronts alone without measuring the moisture profile.Four experiments with a fine sandy loam at two different flow rates were performed to determine the diffusivity from the position of the two fronts. The moisture profile was then predicted from the measured diffusivity. The predictions are in good agreement with the observations.