bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction of Free Amino Acids from Soil
Authors: Paul E. A. , Schmidt E. L. 
Published: July 2010

AbstractAlternatives to extraction with ethanol were examined in order to obtain more effective removal of free amino acids from soil. Ba(OH)2 was a promising extractant and proved to be very effective in recovering a mixture of 17 amino acids that had been added to soil. Resolution of the extract by elution chromatography was followed by colorimetric analysis; 73 to 121% of the acidic and neutral components of the mixture and 36 to 41% of the basic amino acids were recovered. A second extraction procedure, based on the use of NH4OAc, was developed to avoid any slight hydrolysis of amino acid polymers that may have occurred during preparation of Ba(OH)2 extracts. The NH4OAc extraction procedure was 31 to 83% effective in the recovery of added amino acids from soil. When both extraction techniques were applied in preliminary trials to characterize the free amino acids fraction of a soil, the NH4OAc extraction was considered the better. Both NH4OAc and Ba(OH)2 extractions yielded many more kinds of free amino acids in concentrations 5 to 25 times greater than that reported earlier in comparable studies using ethanol extraction.
Soil Potassium Reactions as Related to Clay Mineralogy of Selected Kentucky Soils
Authors: Cook M. G. , Hutcheson T. B. 
Published: July 2010

AbstractClay mineralogy was related to soil K reactions of Heitt, Eden and Maddox series, representative soils of high K‐supplying power; and Maury, Bedford and Tilsit series, representative soils of low to medium K‐supplying power.Clay fractions of Heitt, Eden and Maddox soils contained more illite than Maury, Bedford and Tilsit clay fractions; thus illite is the probable seat of K‐supplying power.Effects of drying the soils on exchangeable K levels were investigated. Upon drying, fixation was observed when the initial, field‐moist level of exchangeable K was relatively high; release occurred when the initial level was low.The 14Å. vermiculite spacing contained by soils of high K‐supplying power was easily collapsed to 10Å. by K saturation and 100° C. heating, whereas that spacing of soils of low K‐supplying power was affected little by K saturation, requiring 300° C. or higher heating for closure. At least two possible explanations could account for the differences in collapsibility: (a) differences in magnitude, location and origin of interlayer charge; and (b) presence or absence of nonexchangeable Al in interlayer positions.
Activity Measurements in Water and Clay‐Water Systems With Tertiary Electrodes
Authors: Uehara Goro , Mortland M. M. 
Published: July 2010

AbstractA tertiary amalgam electrode was utilized in the measurement of CaCl2 and Ca++ activities. Activity coefficients from electromotive force data compared favorably with those in the literature. The relative influence of various metal ion salts on the CaCl2 and Ca++ activities followed the sequence Rb ≥ Mg > K > Na > Li for both kaolinite and Wyoming bentonite. The activities of CaCl2 and Ca++ in bentonite‐kaolinite mixtures differed from predicted activity values based on pure clay systems.
Nitrite Transformations in California Soils
Authors: Tyler K. B. , Broadbent F. E. 
Published: July 2010

AbstractIncubation studies of factors influencing nitrite oxidation in four California soils were conducted at two temperatures—45° and 75° F. In acid soils nitrite transformations were found to be highly sensitive to nitrite concentration in the soil and were inhibited by very low levels. Nitrite had less effect on the second step of nitrification in alkaline soils. Nitrite oxidizers were shown to be very sensitive to low temperature soil conditions.Although nitrite disappeared rapidly following addition to acid soils, little nitrate was produced during the incubation period. Much of the nitrite‐nitrogen was lost from the system. Experiments using acid soils which had been sterilized showed similar losses in added nitrite‐nitrogen and lead to the conclusion that these losses result from nonbiological processes. Studies to determine the nature of these losses suggest nitrogen gas as the principal product.Investigations of respiration rates of the soil population where various concentrations of nitrite were added reveal that nitrites inhibit the respiratory activity of the soil microorganisms as a whole and not merely the nitrifying group. Very low concentrations were inhibitory in acid soils; however, in a calcareous soil more than a hundred‐fold increase in nitrite concentration was required to achieve the same magnitude of respiratory inhibition.
Conifer Establishment on Coal Spoils as Influenced by Certain Site Factors and Organic Additions at Planting Time
Authors: Lowry Gerald L. 
Published: July 2010

AbstractEight conifer species were planted on Ohio spoil banks at five locations of widely different site characteristics. At any one location five tree species and three root mulch treatments were tried. Mulch treatments included (a) no treatment, (b) steam‐sterilized sawdust mulch, and (c) unsteamed sawdust mulch. One pint of mulch was placed in the tree root zone at planting time.Results of 2‐year measurements indicated significant survival differences between tree species on all areas where average survival was greater than 10%. On acid spoils pitch pine appeared best when considering both survival and total height. Jack pine, white pine, and ponderosa pine were intermediate white shortleaf pine was consistently poor. On mildly acid clay spoils northern white cedar was best while eastern red cedar, ponderosa pine, and jack pine were intermediate.Significant differences due to mulch treatments were noted, especially on very strongly acid sandy spoils where raw mulch showed a 90% increase in survival over the controls. Steamed mulch resulted in some increase in survival on sandy areas, but a decrease in survival when used on areas high in silt and clay. No difference in seedling height resulted from these treatments.Certain site and soil factors were studied to determine their effect on seedling survival. Of the factors studied only moisture equivalent, sand content and reaction were significant. A prediction equation for survival is given.
Nitrogen Movement and Transformations in Soils as Evaluated by a Lysimeter Study Utilizing Isotopic Nitrogen
Authors: Owens L. D. 
Published: July 2010

AbstractA lysimeter experiment was conducted to determine the fate of N applied to soils several months prior to cropping. Ammonium sulfate, labeled with N15, was applied to soils in lysimeters at the rate of 120 pounds of N per acre during each winter of the 2 years that the experiment was conducted. Each year, three moisture rates, 12, 18 and 24 inches were established on the soils during the 5 months prior to crop seeding. Total and labeled N were determined in the leachates, crops, and soils at the end of the experiment.An average of 33 ± 6% of the applied N was unaccounted for at the end of 2 years and was assumed to have been denitrified. Denitrification losses were not affected by the moisture treatment imposed. Leaching losses were directly proportional to the amount of water moving through the profile and ranged from 5 to 20% from the low to high moisture rates. Losses of fertilizer N by leaching occurred largely at the expense of crop uptake. The amount of fertilizer N remaining in the soils at the end of the experiment was around 38% and not affected by moisture treatment.
Sand‐Model Study of Buffer Effects in the Double‐Ring Infiltrometer
Authors: Swartzendruber Dale , Olson Tamlin C. 
Published: July 2010

AbstractInfiltration of water has been studied for a wedgeshaped sand model built as a sectorial portion of the double‐ring infiltrometer flow system. Determinations of infiltration velocity for localized portions of the flooded sand surface permit the assessment of buffer effects.At any given time after infiltration has commenced, the velocity is essentially constant over a rather large central portion of the flooded area, but increases sharply as the outer ring radius, rn, is closely approached. However, the essentially invariant central velocity cannot be taken as the one‐dimensional velocity, or infiltration rate, unless rn is sufficiently large; in this study, the smallest permissible value for rn was 12 inches. For rn = 8 inches, which corresponds approximately to many of the ring systems used heretofore, the essentially invariant central velocity was as much as double the infiltration rate.
Deuterium and the Self‐Diffusion Coefficient of Soil Moisture
Authors: Kunze R. J. , Kirkham Don 
Published: July 2010

AbstractAn experimental technique for studying soil water movement using heavy water (DOH) as a tracer is described. The heavy water is analyzed with a mass spectrometer. By means of techniques described, it is possible to measure differences in D concentration of ± 0.0005 mole percent for the range of heavy water concentrations used. Two experiments in self‐diffusion are described in detail. They consisted of following the movement of water, in a soil core and in a glass beads core, by means of water molecules tagged with the heavy hydrogen. After arbitrary selected times the cores were sectioned and D analyses made of the moisture in each section. The experimental data were used in a theoretical diffusion equation to obtain self‐diffusion coefficients. For the soil core the self‐diffusion coefficient was found to be about one‐fourth that of pure water; for the glass beads, about one‐half that of pure water.
Availability of Nonexchangeable Soil Potassium to Plants as Affected by Added Potassium and Ammonium
Authors: Welch L. F. , Scott A. D. 
Published: July 2010

AbstractUndried Marshall and Clarion surface and subsoil samples were cropped in the greenhouse (short‐term cropping) to determine the effect of NH4 and K additions on the availability of nonexchangeable soil K to corn plants. When 0, 10, 25, 50 and 100 mg. of NH4 was added to 100 g. of soil, the corn absorbed 21.8, 16.4, 11.6, 4.96 and 0.12 mg. of nonexchangeable K from the Marshall surface soil and 5.19, 4.74, 3.55, 0.91 and −1.44 mg. from the Clarion surface soil. This reduction in the uptake of non‐exchangeable K by plants was due to the blocking effect of NH4 on the release of K, and was not an effect of NH4 on the absorption of available K. Similar results were obtained with the Marshall subsoil. The Clarion subsoil, however, did not release K even in the absence of added NH4.K additions also reduced the release of nonexchangeable soil K. When NH4 and K were both added, the order of addition proved to be important because NH4 also blocked the release of added K that was fixed by the soil.
Moisture Loss and Corn Yields on a Silt‐Pan Soil as Affected by Three Levels of Water Supply
Authors: Gard L. E. , McKibben G. E. , Jones B. A. 
Published: July 2010

AbstractSoil moisture extraction patterns were obtained on a silt‐pan soil during four corn production seasons at three levels of water supply. Water requirements under southern Illinois average temperature conditions were determined for corn at different stages of development. The water requirements were compared with the amount and pattern of rainfall for the previous 21 years in order to estimate irrigation needs for maximum corn yields.A requirement in excess of 3 to 4½ inches of soil‐stored water resulted in reduced corn yields. The use of two 2‐inch irrigations 10 to 14 days apart during the tasseling and shooting stages of growth resulted in economically desirable corn yield increases 3 out of 4 years. Irrigation other than the 4 inches during tasseling and shooting stage resulted in no yield increases or only slight increases.Lack of easily available moisture apparently lowers the corn yield potential on this soil in over one‐half of the years. Water stored below 2 feet was of very limited direct value to the corn crop. A high state of soil fertility was conducive to efficient water use.
Diffusion Equation Calculations of Field Soil Water Infiltration Profiles
Authors: Nielsen Donald R. , Kirkham Don , van Wijk W. R. 
Published: July 2010

AbstractTheoretical moisture profiles calculated from a numerical analysis of the equation
urn:x-wiley:03615995:saj2sssaj196103615995002500030008x:equation:saj2sssaj196103615995002500030008x-math-0001 were compared with experimental profiles for two field soils. Both soils were loess‐derived and were of silt loam texture throughout their profiles. After previously being wet to their field capacities, the soil surfaces were kept at saturation for a definite time interval. The distribution of soil water throughout the profiles immediately following this time interval was measured by neutron scattering. Soil cores were removed from the plots at 15.2‐cm. depth intervals. Using these cores, moisture release curves and capillary conductivity values were determined for those soil moisture contents which occurred in the field. The numerical solution used for the above equation requires a homogeneous soil. The calculated soil moisture profiles were based upon the physical measurements made on the surface 30 cm. of soil only. Discrepancies between measured and calculated profiles are explained on basis of variation of the physical properties of the entire profile from those of the first 30 cm., and on basis of plot size.
The Influence of Phosphorus Fertilization and Moisture on Growth and Nutrient Absorption by Spring Wheat: I. Plant Growth, N Uptake, and Moisture Use
Authors: Power J. F. , Grunes D. L. , Reichman G. A. 
Published: July 2010

AbstractThe effects of stored soil moisture, seasonal precipitation, and P fertilization upon spring wheat growth were studied in a field experiment under controlled moisture conditions on a Chestnut soil in eastern Montana. Plant growth, grain yields, and nutrient uptake were proportional to available moisture and were increased by P fertilization. A uniform yield increase from P fertilization was measured under all moisture conditions on this relatively low P soil, with no interactions between moisture supplies and P fertilization.Phosphorus fertilization had no consistent effect upon total moisture use at any stage of growth. However, at soft dough and harvest, P fertilization increased the plant material produced per unit of moisture used. Correlation coefficients between plant growth or nutrient uptake and moisture use were extremely high as the crop approached maturity, for both fertilized and nonfertilized treatments.
Buffer Methods for Determining Lime Requirement of Soils With Appreciable Amounts of Extractable Aluminum
Authors: Shoemaker H. E. , McLean E. O. , Pratt P. F. 
Published: July 2010

AbstractStudies were conducted to determine why certain soil test methods fail to indicate the actual lime requirement in many Ohio soils. Samples of 14 soils from various areas of the State were collected for study. The soils were incubated with various rates of applied CaCO3 to determine actual lime requirement of each soil. Attempts were made to find laboratory methods that would accurately indicate the lime requirement of each. For these soils the Woodruff method had indicated only about half the amount of the actual lime requirement. The Mehlich triethanolamine method indicated accurately the amount of lime required for the unlimed acid soils. However, this method indicated too high a lime requirement on soils partially limed. Subtraction of the acidity measured above pH 6.8 by the triethanolamine method and then addition of the extractable Al, gave a very good indication of lime needs on all soils not limed above neutrality regardless of lime additions. Addition of extractable Al to total bases and triethanolamine‐measured acidity to pH 6.8 gave nearly constant cation‐exchange capacities of soils regardless of lime additions. These studies have led to development of an improved soil test buffer method for rapid routine laboratory analyses. It appears to be adequate for indicating lime needs of soils regardless of extractable (soluble) Al present.
Restoring Productivity to Leveled Land
Authors: Reuss J. O. , Campbell R. E. 
Published: July 2010

AbstractField and greenhouse fertilizer tests on subsoils of the Yellowstone Valley which had been exposed by land leveling operations indicate that these subsoils are very deficient in N and P. This conclusion is substantiated by soil analyses. In the greenhouse, yields of barley on untreated subsoil were low, but excellent yields resulted when both N and P were supplied. Nitrogen alone was not effective. Excellent yields of corn were obtained in the field when adequate N and P were supplied or where heavy rates of manure were plowed down. Field response to N alone was good but generally less than that obtained by the combination. Phosphorus used alone did not increase crop yields. Neither physical properties nor minor elements were found to be limiting.
The Response of Several Vegetables to Applied Nitrogen, Phosphorus and Potassium on a Sphagnum Peat Soil
Authors: MacKay D. C. , Chipman E. W. 
Published: July 2010

AbstractThe N, P and K requirements of a strongly acid sphagnum peat soil were determined for several vegetable crops over a 4‐year period. Six rates of each nutrient ranging from deficiency to excess were applied in a randomized block experiment designed to measure main effects and selected interactions. The analyses of variance indicated that at practical rates of application, interactions were negligible, and the curves of best fit, derived by polynomial regression analyses, characterized the scatter diagrams closely.Heavy rates of N were necessary for all crops, and there was little indication of reduced requirements at the end of 4 years. Initially, large responses were obtained from small amounts of P. There was some effect from K but less than that generally reported for other organic soils.
The Effect of Gamma Radiation on the Microbial Population of the Soil
Authors: Popenoe Hugh , Eno Charles F. 
Published: July 2010

AbstractArredondo fine sand was exposed to gamma radiation from a cobalt60 source at doses of 1, 4, 16, 32, 64, 256, 512, 1024, and 2048 kiloroentgens (kr.).Percentage survival of fungi and bacteria decreased with each increase in radiation dose to < 4% at 1024 kr. Algae were not as drastically reduced as bacteria and fungi: some survived at 2048 kr. and greatest reduction occurred above 64 kr. A few nematodes remained in the soil 2 days after irradiation with 1024 kr., but none were recoverable from doses > 256 kr. after 14 and 28 days. The effects of lower doses were not resolvable.Carbon dioxide evolution was initially reduced by irradiation of the soil. The reduction was generally inversely related to radiation dose except for the 64‐kr. treatment. Later, all irradiated soils, except those which received doses > 256 kr., essentially equaled or exceeded the control in CO2 production. Soils treated with 512 and 1024 kr. produced only very small amounts of CO2 throughout the 23‐day period; soil receiving 256 kr. later recovered completely. The soil irradiated by 64 kr. attained the highest daily production rate. Similar relationships for CO2 evolution occurred in an earlier study except for some shifts in time and magnitude.Nitrate production in a 14‐day period was progressively reduced by increasing doses of radiation. Recovery from 32 kr. or less occurred in 28 days; these soils produced at least 87% as much nitrate as the control during this period of time. Average production in 28 days at 64, 256, and 1024 kr. was 55, 7, and 3% of the control, respectively.The production of sulfate from elemental sulfur was also affected by radiation in much the same manner as nitrate production, though radiation damage at doses less than 64 kr. were not readily apparent until the third week. Two populations, one more sensitive to radiation than the other, were probably involved in this reaction.
Inefficiency of Fertilizer Use Resulting from Nonuniform Spatial Distribution: II. Yield Losses Under Selected Distribution Patterns
Authors: Jensen Don , Pesek John 
Published: July 2010

AbstractYield losses due to nonuniform application of fertilizer to homogeneous soil areas were examined by methods developed previously. Cosine functions were chosen to represent spatial distributions of applied fertilizers and quadratic equations were selected to characterize yield responses to fertilizer inputs.Yield depressions were estimated for cases in which nitrogenous fertilizers are nonuniformly applied to Iowa soils which differ in initial fertility. These losses vary directly with the square of the amplitude of the cosine distribution function, but they are inversely related to soil nitrification rate. Assuming a profit‐maximizing fertilization rate and valid mathematical models, upper bounds for yield losses are 12.4, 4.3, and 0.6 bushels per acre for representative very low, low and medium soil test classes, respectively.Physical characteristics of complete fertilizer materials were considered for the case of corn production on a Haynie soil. Yield losses due to nonuniform application of an aggregated material, which retains a constant nutrient ratio, exceed 4.3 bushels per acre when amplitude of the distribution function is larger than half the optimum fertilization rate. Physical segregation of dry‐blended nutrient carriers may result in different distribution patterns for the component nutrients. As a consequence, nutrient ratios as well as rates may vary over the treated area when complete fertilizer materials are subject to physical separation.
Characterization and Genesis of a Moody‐Nora‐Crofton Soil Sequence in Northeastern Nebraska
Authors: Cunningham Robert L. , Drew James V. 
Published: July 2010

AbstractSoils of the Moody, Nora, and Crofton series are derived from loess in northeastern Nebraska. Morphologically, these soils exhibit a decreasing degree of horizon differentiation and depth to lime concretions in the order Moody‐Nora‐Crofton. Particle size and chemical data substantiate these differences in soil development. The Moody and Nora series have been classed as Chernozems and the Crofton series as a Regosol.The distribution of these soils on the landscape, however, does not correspond entirely with an idealized soil‐relief sequence in which the degree of soil development varies with erosion and land surface age. Further, irregularities in depth to lime concretions occur in these soils, particularly in the Moody soils. Petrographic studies show marked variations in amounts of hornblende, epidote, biotite, and muscovite in these soils, reflecting parent material nonuniformity. Montmorillonite and illite minerals dominate the clay fraction of these soils with some kaolinite and mixed‐layer minerals, and a vermiculite‐like mineral in the Moody and Nora soils. A hypothesis presented to explain these data is that the Moody and Nora soils developed in a loess mantle of irregular thickness overlying a highly calcareous and concretionary older loess. Crofton soil is formed in places where outcrops of the older loess occur.