bluuebunny/crossref_metadata_2025 huggingface dataset:
Allophane Determination in Ando Soils By Cation‐Exchange Capacity Delta Value
Authors: Aomine Shigenori , Jackson M. L.
Published: July 2010

One sample of H2O2‐treated, iron oxide‐extracted soil is treated with 2% Na2CO3 solution for 60 minutes and another with NaOAc of pH 3.5 for 15 minutes, at boiling. Both samples are washed with neutral NaOAc and the cation‐exchange capacity is determined with Ca replaced with NaOAc. The difference obtained between the two samples is referred to as the “cation‐exchange capacity delta value,” and averaged 100 me. per 100 g. for allophane from Ando soils of Japan developed on rapidly weathered volcanic ash and in some allophanes of Ross and Kerr. For example, the allophane content of fine clay of an Ando soil containing predominantly halloysite determined by delta value was 23.8% compared to 21.4% by water contents of constituent minerals.
Decomposition and Aggregating Effect of Fungus Cell Material in Soil
Authors: Martin J. P. , Ervin J. O. , Shepherd R. A.
Published: July 2010

A study was made to compare the rate of decomposition and aggregating effect in soil of a variety of plant residues and fungus cell materials, and to study the influence of different fungus species and fungus cell constituents on soil aggregation. Based on CO2 evolution during incubation in soil, plant and fungus residues decomposed in the following order: light‐colored fungi > dark‐colored fungi = benzene‐alcohol‐extracted light‐colored fungi > plant residues > benzene‐alcohol‐extracted dark‐colored fungi. In all groups specific decomposition rates varied greatly. The soil‐aggregating influence of all five groups varied over approximately the same range. The ether‐soluble components of the fungus mycelium exerted a much greater binding action than the plant or whole fungus residues. In pure culture Epicoccum purpurascens was outstanding in its aggregating influence. Other effective species included Aspergillus versicolor, Diplodina sp., Pyrenochaeta sp., Stachybotrys atra, Stemphylium consortiale, and Volutella sp. A metabolic substance synthesized by E. purpurascens, crude polysaccharides from Phaeoscopulariopsis sp. and Acrotheca sp., and the alcohol‐soluble constituents of S. atra exerted a marked binding action on the soil. The E. purpurascens product was very resistant to decomposition. Methyl alcohol‐soluble material from Pullularia pullulans decomposed readily but exerted little binding action.
Analyses of Several Brazilian Soils in Relation to Plant Responses to Sulfur
Authors: McClung A. C. , de Freitas L. M. M. , Lott W. L.
Published: July 2010

Greenhouse studies indicated many soils of the central plateau of Brazil to have a poor S supply. The most acute deficiency was found on soil from an upland savanna, but surface soils (0 to 20 cm. A0 excluded) from virgin forests also responded. The B horizon of cultivated soils responded less frequently than that of the virgin soils, suggesting some downward movement of S under cropping. Such movement was also indicated by higher levels of NH4OAc‐extractable S. Sulfur extracted in this way correlated well with growth responses of millet grown in pot culture. In most soils, the addition of 20 pounds S as CaSO4 per 2 million pounds of soil resulted in maximum dry matter production under the intensive cropping existing in these experiments. It is postulated that responses to S in this region will not be common unless N and P levels are improved. If these elements are plentifully supplied, however, and cropping is intensive, S deficiencies may occur on many soils.
Evapotranspiration and Yield of Corn as Influenced by Moisture Level, Nitrogen Fertilization, and Plant Density
Authors: Carlson C. W. , Alessi J. , Mickelson R. H.
Published: July 2010

Yields and evapotranspiration rates by corn grown in Gardena loam at two levels of soil moisture, two plant densities, and several rates of N fertilization were studied for two growing seasons.

Neither N fertilizer nor plant density influenced yields in the nonirrigated treatment, but in the irrigated treatment corn yields in both plant densities increased when N fertilizer was applied. Measurements made on the number of kernels per square foot, and individual kernel weights showed that grain yields were most influenced by the number of kernels produced per unit area. Neither N fertilizer nor plant density appreciably affected the evapotranspiration rate. Evapotranspiration was considerably greater for the irrigation plots than for the nonirrigation plots. Rates of evapotranspiration were higher in 1957 than in 1956. The pounds of dry matter produced per inch of water used in evapotranspiration (water‐use efficiency) was appreciably increased by using a high plant density and N fertilizer. This effect was much less marked in the nonirrigated treatments than in the irrigated. The amount of dry matter produced per inch of water used was greater on the nonirrigated treatment than on the irrigated treatment, except at the high N rate in the high plant density. It is apparent that if maximum efficiency of moisture use is to be realized, adequate fertilizer and plant densities are required.
A Rainfall Erosion Index for a Universal Soil‐Loss Equation
Authors: Wischmeier Walter H.
Published: July 2010

Extensive regression analyses of basic soil‐loss data were designed to determine the best indicator of the capacity of a storm to erode soil. The rainstorm characteristic found to be outstanding as such an indicator is the variable whose value is the product of the rainfall energy and maximum 30‐minute intensity of the storm (designated as EI). This variable explained from 72 to 97% of the variation in individual‐storm erosion from tilled continuous fallow on 6 soils. Seasonal rainfall erosion index values computed by adding the EI values of storms > 0.5 inch explained as high as 94% of the yearly deviation in total soil loss from fallow during the summer season. Tested against data from plots in continuous row crop for 10 or more years at each of four widely separated locations, the summed EI values explained from 72 to 85% of the yearly variation in soil loss within corresponding cover periods. Expected annual values of the index and seasonal distribution of the erosion potential may be readily computed from local rainfall records. This has been done for 60 locations in the 31 Eastern States.

About 8,000 plot‐years of basic erosion data are being analyzed to evaluate factors for a universal soil‐loss equation for which the erosion potential of expected local rainfall serves as the base. Tests show that estimates of average erosion losses computed in this manner are sufficiently accurate to serve as sound bases for conservation farm planning.
The Influence of Alfalfa, Bromegrass, and Corn on Soil Aggregation and Crop Yield
Authors: Barber Stanley A.
Published: July 2010

The influence of alfalfa, bromegrass and a mixture of the two on soil structure was investigated in an experiment in which each crop was grown for 1, 2, 3, and 4 years. Continuous corn was also grown. All plots were heavily fertilized in an attempt to avoid yield differences due to nutrient factors. Soil samples for physical analyses were taken in each of two years. Percentages of water‐stable aggregates were determined. The aggregation index obtained by this procedure was higher after bromegrass than after alfalfa and higher after alfalfa than after corn. The alfalfa‐bromegrass mixture gave a value intermediate between alfalfa and bromegrass. The aggregation index increased in a linear fashion with each additional year of bromegrass or alfalfa up to the 4 years used in the experiment. The aggregation index was not affected by the number of years of corn. Preliminary data indicate that corn yields were affected little by the aggregation index.
Ion Movement in Wyoming Bentonite During Electroosmosis
Authors: Jacobs Hyde S. , Mortland M. M.
Published: July 2010

The comparative rates of removal of the ions from Wyoming bentonite‐quartz sand systems during electroosmosis were as follows: Na+ > K+ > Mg++ > Ca++. The differential movement of ions tends to separate the cations as they move through the media. The percentage of an ion removed by a given amount of electricity was increased by the addition of a complementary ion.

The rate of Na+ and K+ removal was proportional to the amount of these ions remaining in the system and decreased steadily as electroosmosis proceeded. The rate of Ca++ removal tended to remain more or less constant until the Ca++ concentration in the cell had been reduced to about 0.5 symmetry.

In the early stages of electroosmosis the transference numbers of Na+ and K+ in systems containing no free salt were very near unity. Under similar circumstances the transference number for Ca++ was greater than in some salt solutions but did not approach unity.

The amount of water flow per milliequivalent of cation removed was greatest for Ca++, intermediate for K+, and least for Na+.
A Characterization of the Sebree‐Chilcott Soil Series Association (Slick Spots) in Idaho
Authors: Sandoval Fred M. , Fosberg M. A. , Lewis G. C.
Published: July 2010

A study was made of the Sebree‐Chilcott soil series association of southwestern Idaho with respect to morphology, physiography, and physical and chemical properties.

Parent materials are of fluviatile and lacustrine origin occurring on terraces of different geologic age. The Sebree soil (slick spots) is relatively impermeable with little or no vegetation. Diameter of the spots vary from a few inches to 50 feet or more, with irregular shapes.

The soils studied exhibit solodized characteristics with textural and color B horizons of solonetz morphology overlying prominent CaCO3 accumulations. Degree of cementation of the calcareous layers appears to be related to geologic age. The surface has a silt loam texture.

Slick spot soils have a very thin A2 horizon overlying thicker B2 layers characterized by high exchangeable Na and in most cases high concentrations of soluble salts. Ions that predominate are Na+, SO42‐ and Cl‐. Gypsum is present in the lower B2 and B3 horizons. Horizons of prominent lime accumulation have a bowl‐shaped form under the slick spot. The data indicate that slick spots represent retarded soil‐forming processes which have somehow resisted the efforts of nature in their normal development.
Anion Elution Patterns from Soils and Soil Clays
Authors: Berg William A. , Thomas Grant W.
Published: July 2010

The leaching of Cl‐ and SO4= ions through columns of whole soil and soil clay was investigated by adding salts to the top layers, eluting with water, and measuring ion concentrations in column eluates. A “normal” anion elution curve with a distribution coefficient of 1 was interpreted as indicating no anion attraction to the soil. Deviations from a “normal” curve resulting in a skewed elution pattern were interpreted as indicating anion attraction. Creedmoor clay, with a high negative charge, attracted neither Cl‐ nor SO4=. Cecil clay and Cecil and Appling soils, which have low negative charges and are high in kaolin and oxides of aluminum and iron, gave asymmetric anion elution curves at lower pH values, indicating anion attraction. Cecil clay pre‐leached with HNO3 retained both SO4= and Cl‐ against moderate leaching, however, under less acid conditions (pH 4 to 6) only SO4= was retained.
The Effect of Sawdust on Crop Growth and Physical and Biological Properties of Cecil Soil
Authors: White A. W. , Giddens J. E. , Morris H. D.
Published: July 2010

A field experiment was conducted over a 3‐year period from 1954 through 1956 to determine the effect of pine sawdust on crop growth and soil properties. Corn was grown all 3 years of the experiment and tomatoes and lima beans for 2 years.

Sawdust incorporated with the soil had no beneficial effect on plant growth. However, when sawdust was applied as a mulch, crop yields were increased markedly with the exception of corn in 1954, an extremely dry year. Higher yields of crops on mulched soils apparently resulted from an increase in available water supply and a reduction in soil temperature as compared to the unmulched plots. A nitrogen variable included in the corn investigation revealed that high N application was required to obtain increased corn yields from sawdust mulch. Sawdust, applied either as a mulch or mixed with the soil, decreased the nitrate content of the soil. The soil microbial population was not influenced by the mulch but was increased by incorporating sawdust with the soil.
Runoff from Pasture Plots Analyzed by Fitting of Constants Technique
Authors: Gard L. E. , Jacob W. C. , Van Doren C. A.
Published: July 2010

Runoff data from erosion plots were analyzed by a technique known as analysis of variance by method of fitting of constants. This method permits nonorthogonal data to be handled in a reasonable fashion.

Data were collected from pasture plots at the Dixon Springs Experiment Station in Pope County, Illinois, during the period 1940 to 1951. Soil treatment reduced runoff during each of the four seasonal periods. Runoff was higher from severely grazed than moderately grazed plots during the grazing season (April through September) but not during the nongrazing season (October through March). As the seasons progress from January through September more intense storms are required to cause equal runoff.

Percent runoff generally increased with increases in antecedent moisture. Values obtained for the regression of runoff on amount of rainfall indicate that there are too many uncontrolled variables for ratios to be useful.
Measuring Water Stored Temporarily Above the Field Moisture Capacity
Authors: Nielsen D. R. , Kirkham Don , van Wijk W. R.
Published: July 2010

Using a neutron type soil moisture meter, amounts of water temporarily stored in soil profiles above the field moisture capacity were observed for two silt loam and two clay loam soils. The amounts of temporarily stored water for the 5‐foot depth, ranged from 4.7 inches for one of the silt loams to 2.1 inches for one of the clay loams, immediately after 6 inches of irrigation water had penetrated into the soil. After 90 hours, temporarily stored water could still be detected ranging from 1.5 inches to 0.3 inches. The soils had previously been wetted to the field moisture capacity. Evaporation was prevented by a polyethylene cover. The field measurements, and some laboratory physical measurements which were made on core samples, indicated that one of the silt loams and two of the clay loams would probably have aeration problems due to the stored water. One of the silt loams had adequate aeration for all depths and times studied regardless of the addition of extra water. The laboratory physical measurements provided an explanation for the storage behavior found in the field. The relations between depth, soil moisture suction and soil moisture percentage were plotted as a three‐dimensional diagram which enables a clear general view of the behavior of the soil water.
Characteristics and Genesis of a Solodized‐Solonetz of California
Authors: Whittig Lynn D.
Published: July 2010

Field and laboratory studies of a soil (Solano series) of the lower Sacramento Valley characterize it as a solodized‐solonetz. The profile has a sharply delineated, alkaline, fine‐textured, columnar B horizon below an acid, medium‐textured A horizon. Remnants of an older columnar B horizon persist in the present upper leached portion of the soil.

Soluble salts and free carbonates and much of the clay have been leached from the upper 15 inches of the profile, but are present in appreciable concentrations below this level. Na is the predominant soluble cation. Of the exchangeable bases, Mg is dominant throughout the profile, increasing markedly with depth. Exchangeable Na is low near the surface and increases with depth at a slightly faster rate than does Mg.

Montmorillonite is the predominant mineral of the clay fraction throughout the profile. Kaolin and a small amount of illite are also present throughout. Vermiculite and chlorite, as constituents of the coarse clay fraction (2 to 0.2µ), are concentrated in the A horizons of the profile.

It is concluded that the soil has been altered by solidization as indicated by the sharp boundary between the leached, acid A horizons and the alkaline, fine‐textured B horizon containing soluble salts. In its evolutionary past, this soil has been strongly affected by Na and other soluble salts as indicated by the occurrence of older column tops in the present A horizon, distributions of soluble and exchangeable cations and clay, and the distinctive morphology of the profile. At times, salinization, solonization, and solodization have all affected development of this soil. It is doubtful, however, whether it will develop eventually into a true solodi because of the presence of an abundant supply of divalent cations which are being returned annually to the surface by selective plant feeding.
A Portable Air Permeameter for Forest Soils
Authors: Steinbrenner E. C.
Published: July 2010

Forest soil productivity studies brought out the need for a rapid and quantitative method to determine macroscopic pore space in the soil. To meet this need, a portable soil permeameter was developed that measures macroscopic pore space directly in the field.

The instrument consists of a steel cylinder with carrying harness, constant pressure regulator, toggle‐valve, soiltube, and pressure gauge. In operation, the tube is inserted in the soil, a constant air pressure delivered, and the resistance of the soil to this pressure read on the pressure gauge.

For calibration, 68 samples covering a wide range of soil porosities were obtained from soil pits in residual and glaciated soils of western Washington. For each of those samples, permeameter readings taken in the field were related to determinations of volume of macroscopic pores drained by a pressure of 1/3 atm. From these calibration data, a dial‐face reading directly in percent macroscopic pore space was designed for the permeameter pressure gauge.

Data are presented that relate soil macroporosity, as determined by the permeameter, to growth of Douglas‐fir seedlings on soils of recently‐logged areas. Applications of this instrument to soil productivity studies are discussed.
Water and Ion Movement in Thin Films as Influenced by the Electrostatic Charge and Diffuse Layer of Cations Associated With Clay Mineral Surfaces
Authors: Kemper W. D.
Published: July 2010

Theory is developed and the effect of the ions and the electrostatic charge associated with clay platelets on the movement of water and ions in thin films between particles or on particle surfaces is calculated for several systems. Under postulated conditions which probably exist in fairly dry soils and compacted shales, movement of water was restricted by as much as 50% and movement of free electrolyte by more than 90%. Data are presented which illustrate this “salt‐sieving” effect and provide a “semiquantitative” check on the theory and calculations. Increases in apparent intrinsic permeability with increasing hydraulic pressure gradients in clay systems, which have been noted previously, are of an order which could be explained by the phenomena considered in this study.
Aluminum in Interlayers of Vermiculite
Authors: Rich C. I.
Published: July 2010

Aluminum sorbed from N AlCl3 in the interlayer space of a 2 to 0.2µ fraction of vermiculite was not entirely removed by extensive washing with neutral salt solutions. The amount fixed was increased by heating the Al‐saturated clay with an AlCl3 solution or with water. Treatment with a hydroxy‐Al solution for 4 days reduced the cation‐exchange capacity from 134 to 75 me. per 100 g. and treatment for 8 days reduced it to 1 me. Titration of Al‐vermiculite in N NaCl with NaOH to approximately pH 10 removed most of the Al from the interlayer space. Al‐vermiculite added to N NaCl formed two phases, one saturated with Na and the other with Na and Al. The extent and place of Al hydrolysis depended on the temperature, pH, and salt concentration of the system.

X‐ray diffraction analysis of the sample which had an apparent cation‐exchange capacity of 1 me. showed that the 7Å./14Å. intensity ratio was about equal to that of a Ca‐saturated sample but was much less than that of chlorite. Ammonium fixation was reduced greatly by a small amount of interlayer Al. The stability of the vermiculite to heat treatment also was increased and its ability to expand when glycol solvated was decreased.
A Kinetic Analysis of Phosphate Absorption by Excised Roots of Millet, Barley, and Alfalfa
Authors: Noggle J. C. , Fried Maurice
Published: July 2010

A kinetic analysis was made of P absorption at steady state by excised roots of millet, barley, and alfalfa. Short‐time absorption studies indicated that the rate of P absorption is greater for millet than barley and greater for barley than alfalfa. The specific reaction rate constants for the metabolic turnover of the two carriers of P are of the same order of magnitude for the three plant species. They are approximately 1 × 10‐2 moles of P per mole of combined carrier per second. The apparent dissociation constant for carrier “a” is approximately 9 × 10‐4 for all three plant species, but the value for carrier “b” varies from 3 × 10‐6 for millet and alfalfa to 8 × 10‐6 for barley. The major difference between species is in concentration of carrier. These values are 2 × 10‐7, 3 × 10‐8, and 1 × 10‐8 moles per g. of millet, barley, and alfalfa roots, respectively.
Wet‐Combustion Apparatus and Procedure for Organic and Inorganic Carbon in Soil
Authors: Allison L. E.
Published: July 2010

A quantitative wet‐combustion method for determining organic carbon in soils is described which employs a simple apparatus and a rapid procedure of analysis. All units of the purifying system are mounted on a compact panel which facilitates assembly and storage of the equipment.

Evolved CO2 in a carrier stream is passed successively through traps containing KI, Ag2SO4, concentrated H2SO4, zinc and anhydrone, after which the CO2 is absorbed on Mikohbite in a Nesbitt bulb and determined by weighing. The method determines total (organic plus inorganic) carbon unless any carbonates present in calcareous soils are previously destroyed. A rapid pretreatment for removing carbonates is described which permits the direct determination of organic carbon.

The method works satisfactorily on saline soils containing high concentrations of Cl salts and also on extracts that can be evaporated to dryness such as Na‐dispersed organic matter extracts.
Dissimilar Nitrifying Capacities of Soils in Relation to Losses of Applied Nitrogen
Authors: Clark Francis E. , Beard William E. , Smith Donald H.
Published: July 2010

Forty‐one soil lots from arable fields were found to vary widely in their nitrifying capacities when given an initial treatment of 400 ppm. of urea N and then incubated under standard conditions in the laboratory. Mineral N deficits exceeding 25% of the N applied were noted for poorly buffered soils which accumulated NO2‐ during incubation and which were initially acid in reaction or could achieve acidity during the course of nitrification of the added urea. Nitrogen deficits following treatment with KNO2 were directly linked to initial soil pH values; they occurred in acid but not in alkaline soil. Conversion of the added NO2‐ to NO3‐ did not change the reaction of initially alkaline soils nor was it accompanied by the development of any significant N deficit. The data are believed to support the hypothesis that the instability or reactivity of nitrous acid in soil is at times responsible for large losses of gaseous N from fully aerobic soils.
Some Aspects of the Kinetics of Moisture Flow into Unsaturated Soils
Authors: Biggar J. W. , Taylor Sterling A.
Published: July 2010

The movement of water into an air‐dry silt loam soil was studied as a function of temperature. The results are interpreted with the use of the Arrhenius equation in terms of energy barriers, and the activation energies necessary to overcome the barriers were calculated from the experimental measurements. Activation energies of 1 to 3 kilocalories per mole of water taken up were found.

Qualitative relationships were observed between the energy barriers found in the system studied and the soil particle size, bulk density and wetting suction.

The rate of water entry into soil and the rate of advance of the wetting front was faster in soils at lower bulk density. This effect is about the same at all temperatures; consequently, the activation energies are not significantly different. Activation energies appear to be high for the finer size fraction of Millville silt loam. The barriers opposing water movement into soil appear to operate at the air‐water‐interface associated with the advancing water front.

Theoretical consequences of these findings provide a physical explanation of the wetting front, an explanation for hysteresis, and a basis for including shrinking and swelling as contributing factors in modifying the rate of flow of water through soil.
Conversion of Relative Field Erodibility to Annual Soil Loss by Wind
Authors: Chepil W. S.
Published: July 2010

Relative field erodibility based on many previous wind tunnel and field measurements is merely an index of the quantity of soil loss that would occur under certain climatic conditions. This paper, based on additional measurements, shows the relationship between the relative field erodibility and the quantity of soil loss and presents a table for converting the relative field erodibility, as determined from seven major factors, to soil loss in tons per acre per annum as would occur under climatic conditions such as existed in the vicinity of Garden City, Kansas, during the years 1954 through 1956.
A Rapid Polarographic Method for Determining Extractable Zinc in Mineral Soils
Authors: Barrows Harold L. , Drosdoff Matthew
Published: July 2010

A rapid polarographic method for the determination of extractable zinc in mineral soils is described. Zinc is extracted by shaking the sample with 0.1N HCl for 2 minutes. After the soil extract is made to a known volume and filtered, an aliquot is diluted with electrolyte solution, and the polarogram is recorded. Significant correlations were obtained between extractable zinc in the soil and total zinc in leaves of tung trees growing in the soil.
The Preparation of Clay Suspensions With Specified Ionic Composition by Means of Exchange Resins
Authors: Bolt G. H. , Frissel M. J.
Published: July 2010

The rate of exchange of cations between a cationexchange resin and clay suspensions was investigated under varying conditions. The mechanism underlying the exchange process is discussed. the results indicate that the exchange Ca‐clay → Na‐clay is influenced strongly by the electrolyte concentration but is rather insensitive towards resin exhaustion. The preparation of clays saturated with monovalent cations may be done advantageously with a column procedure. The requirements for satisfactory column performance are given. On the other hand the exchange Na‐clay → Ca‐clay is extremely sensitive towards resin exhaustion such that the use of resins for the preparation of large quantities of clays saturated with divalent ions is in general impractical. Stirring of clays with resin seems to be suitable only for special purposes, e.g., the removal of CaCO3 and the preparation of clays with a specified mixed composition.
A Study of Extractable Soil Cobalt in Soils of the Southeastern United States
Authors: Alban L. A. , Kubota Joe
Published: July 2010

The relationship between 2.5% acetic acid‐dithizone extractable soil cobalt and the amount of cobalt in black gum leaves, a cobalt indicator, was investigated for 71 widely distributed soils of the southeastern United States. The soil samples were from both good areas and areas where cobalt deficiency in ruminants would be expected on the basis of previous analyses. The extractable cobalt values appeared to separate the Ground‐Water Podzols, the Humic‐Gleys and the Low Humic‐Gleys from the better drained Regosols and Red‐Yellow Podzolic soils studied. At comparable cobalt concentrations in the black gum, the extracted cobalt was less from the imperfectly to poorly drained soils than from the well‐drained soils. For each of the two broad groups of soils, a significant correlation was obtained between extractable soil cobalt for the A1 horizon and the cobalt concentration in the black gum. Because of the variability in horizon thickness among the different soils, the cobalt values were calculated for the 0‐ to 6‐ and 0‐ to 12‐inch depths. The correlation between these values and plant cobalt was also good. The acetic acid‐dithizone extractable cobalt appears useful in indicating areas of potentially low soil cobalt in the Southeast where deficiency in cattle or sheep might be a problem.
Chemical Extraction of Potassium from Soils and Micaceous Minerals With Solutions Containing Sodium Tetraphenylboron. I. Preliminary Experiments
Authors: Scott A. D. , Hunziker R. R. , Hanway J. J.
Published: July 2010

Soils and micaceous minerals were extracted with NaBPh4‐salt solutions to determine the ease with which nonexchangeable K can be removed when the blocking effect of fixable cations is reduced. Essentially all of the K in vermiculite, 12% of the K in muscovite and as much as 47% of the K in illite was extracted by the NaBPh4‐salt solutions even though most of the K in these materials was otherwise nonexchangeable with Na or NH4. The NaBPh4 reduced the blocking effect by precipitating the fixable cations.

The K in micaceous minerals was removed more effectively by successive extractions with NaBPh4‐salt solutions than it was by one continuous extraction because some of the K that had been precipitated was readsorbed by the mineral when the KBPh4 was removed with acetone.

The NH4 adsorption capacity of illite was increased by removing K with NaBPh4 solutions, but the increase was less than the amount of K removed. Most of the NH4 adsorbed as a result of the NaBPh4 treatment was fixed.
Effect of Saline Water on the Growth and Chemical Composition of Beans: I. Influence of Soil Dilution
Authors: Lunin Jesse , Gallatin M. H.
Published: July 2010

A Bladen clay was divided into two parts and one part diluted with an equal part of sand. Both the whole and diluted soil were potted and planted to beans. Between the seedling stage and the initiation of flowering, four 1‐inch applications of dilute synthetic sea water having EC values of 1, 2, 4, 6 and 8 mmho. per cm. were applied. After harvesting both pods and tops, beans were again planted and the saline irrigation treatments repeated.

Saline irrigations produced greater reductions in yield of both pods and tops on the diluted soil than on the whole soil. Little or no differences in composition were obtained between plants grown on the whole and the diluted soil. The Ca, Mg and Na content of the plant increased with increasing salinity, but no change in K content was observed. the cation composition of the saturation extract, expressed as me. per 100 g., was the same for both soils, but the exchangeable cation composition of the whole soil was double that of the diluted soil. It was concluded that the reduction in yield was a function of the salinity of the saturation extract and that plant composition was determined by the equilibrium soil solution rather than the exchangeable cation composition.
Statistical Evaluation of the Rhizosphere Effect
Authors: Rouatt J. W. , Katznelson H. , Payne T. M. B.
Published: July 2010

The paired t‐test was used to analyze the results of a microbiological study of soil on the surface of plant roots and soil apart from the roots. The increase in the numbers of bacteria, actinomycetes, fungi and protozoa in the rhizosphere soil of wheat was highly significant as was the increased incidence of ammonifying and denitrifying bacteria and “radiobacter” types. Anaerobes and aerobic cellulose decomposers were also more abundant on the root surface but not algae, anaerobic cellulose decomposers, spore formers or Azotobacter. Essentially similar results were obtained with barley and soybean plants. The preferential stimulation in the rhizosphere of bacteria requiring amino acids for optimal growth and the relative decrease in the proportion of those requiring factors in yeast and soil extracts were found to be highly significant with the three crops studied. However, the absolute numbers of both these groups of bacteria are higher in the rhizosphere soil.
The Effect of Partial Pressure of Oxygen on Denitrification in Soil
Authors: Allison F. E. , Carter J. N. , Sterling Luann D.
Published: July 2010

Laboratory experiments with Branchville sandy loam fertilized with nitrate salts showed that only trace losses of nitrogen occurred by denitrification when small samples were kept in air at approximately ⅓ atm. moisture content. This was true in both the presence and absence of up to 1% glucose or 2% wheat straw. When soils were aerated for 1 to 3 weeks with nitrogen gas containing 2.27% oxygen the losses of nitrogen were significant in about half of the tests and not in the others. When the oxygen partial pressure was only 0.46% the losses of nitrogen were as high as 10% of the added nitrate in the absence of any energy source and 50% in the presence of 0.5% glucose. Although appreciable denitrification did not occur until the oxygen partial pressure was much reduced, it is pointed out that under field conditions some denitrification would be expected at times even in open, well‐drained soils.
The Determination of Available Sulfur in Soils
Authors: Kilmer Victor J. , Nearpass D. C.
Published: July 2010

A laboratory procedure was sought which would determine available sulfur in soils. As finally evolved, the method consists of extracting the sulfur with 0.5M NaHCO3 at pH 8.5 and determining sulfur in the extract by the Johnson‐Nishita procedure. Sulfur determined in this manner correlated very well with sulfur “A” values, an “r” value of 0.89 being obtained for 30 surface soils. Soils having < 10 ppm. S as determined by the proposed procedure generally responded to applications of sulfur.
Influence of Neutral Salts on the Phosphate Ion Concentration in Soil Solution
Authors: Clark J. S. , Peech Michael
Published: July 2010

Certain cation activity ratios and ion activity products involving Ca++, H+, K+ and H2PO4‐ were found to remain constant in soil and clay suspensions as the electrolyte concentration was increased. The observed constancy of the cation activity ratios could be attributed to the fact that the concentrations of the cations on the surface of the soil particles remained constant under the conditions of the experiments. The constancy of the ion activity products involving Ca++, H+, K+, and the H2PO4‐ ion could be explained either by assuming that the phosphate ion is coadsorbed with exchangeable cations on the soil particles or by postulating the existence in the soil of any crystalline phosphate compound having a definite solubility product.
Chemical Extraction and Crop Removal of Manganese from Air‐Dried and Moist Soils
Authors: Hammes Jack K. , Berger K. C.
Published: July 2010

Oats were grown in the greenhouse on 20 different soils which had been stored in a moist condition prior to potting. Available soil Mn was estimated by extraction with 1.5M NH4H2PO4, 1.0N H3PO4, and 0.1N H3PO4 on moist as well as air‐dried soil samples. Correlations with soil and plant Mn showed that extraction of soil Mn from the moist samples with 0.1N H3PO4 gave the highest correlation coefficient (0.848). Other extractants resulted in much lower correlation coefficients (0.311 to 0.694), regardless of the sample moisture condition.

In a second greenhouse experiment, oats were grown on seven soils which had been stored under air‐dry as well as moist conditions. With one exception, the amount of Mn removed by the oats grown on the previously air‐dried soils was equal to or greater than the Mn removed from soils previously stored in a field moist condition.

Chemical extraction of soil Mn from moist as well as air‐dried soils revealed that the release of Mn upon drying requires aerobic conditions and is not a simple dehydration phenomenon. Extractions of moist as well as air‐dried samples with 0.1N H3PO4, 0.05M NaEDTA of pH 9.5, and 0.2% hydroquinone were performed to estimate the weakly acid‐soluble, organic, and easily reducible oxides of soil Mn, respectively. The results indicated that the release of Mn upon air drying stemmed from the organic fraction of soil Mn. This release of organically complexed Mn is thought to be a result of chemical oxidation of soil organic matter.
Comparison of Phosphate Sources for Alfalfa on a Calcareous Soil
Authors: Stanberry C. O. , Fuller W. H. , Crawford N. R.
Published: July 2010

An evaluation of phosphate sources for alfalfa production was made on P‐deficient Superstition fine sand under arid conditions. Factors studied included particle sizes, and methods, rates, and frequencies of application. These factors were evaluated under field conditions in terms of (a) hay yields, (b) P composition of plants, (c) total P removed from the soil by the hay, and (d) estimated residual P in the soil over a 3‐year cropping period using radiophosphorus techniques.

Supplemental P applications increased hay yields an average of 38%, P percentage 25%, P yield 66%, and A values or residual P, 126%.

A 3‐year summary demonstrated consistently that dicalcium phosphate, if mixed thoroughly with Superstition soil, was at least as efficient as concentrated superphosphate in increasing alfalfa hay yields, P percentage of the hay, total P removed from the soil, and available residual P. The two particle sizes of dicalcium phosphate were equally effective for the 3‐year period, but the finer, with greater surface area, appeared more efficient the first year.

The higher rate of application, 131 pounds P per acre, was 7 to 71% more effective than the 66‐pound rate in increasing yield, P percentage, P yield, and A values. A single initial P application for the 3‐year period was as effective as the same total amount applied annually. When applied properly, both particle sizes of dicalcium phosphate, the phosphoric acid, and concentrated superphosphate all appeared to be satisfactory phosphate sources.
Field Studies of a Clay‐Enriched Horizon in the Lowest Part of the Solum of Some Brunizem and Gray‐Brown Podzolic Soils in Illinois
Authors: Bartelli L. J. , Odell R. T.
Published: July 2010

The morphology, range in expression, and occurrence are described of a clay‐enriched layer (Beta horizon) found below the B2 horizon of selected soils in the area of Wisconsin glaciation in northern Illinois. The Beta horizon, characterized by a darker color and an abrupt, irregular lower boundary, was more pronounced in coarser textured drift, in Gray‐Brown Podzolic soils, and in well‐drained members of soil catenas.
Chloride Diffusion in Soils as Influenced by Moisture Content
Authors: Porter L. K. , Kemper W. D. , Jackson R. D. , Stewart B. A.
Published: July 2010

Chloride diffusivities were measured in medium‐ and fine‐textured soils at moisture tensions from 1/3 to 15 atm. Chloride diffusivities obtained from the soil systems were divided by the diffusivity of chloride in water to obtain transmission factors. These factors varied from 0.310 to 0.027 depending on the soil moisture content and soil texture. The results were interpreted in terms of volumetric moisture content, effective path length factors and clay‐water interactions.
Test of Two Methods for Measuring a Labile Fraction of Inorganic Phosphorus in Soils
Authors: Van Diest A. , Jespersen H. W. , White R. F. , Black C. A.
Published: July 2010

Measurements of the phosphorus extracted from samples of 70 soils by the 0.03N NH4F, 0.025N HCl method of Bray and Kurtz and the anion‐exchange resin method of Amer and co‐workers were used as the basis for predicting the yields of phosphorus in plants grown on the soils in the greenhouse. The latter method gave the more precise prediction, but the regression coefficient was smaller for alkaline soils than for acid soils. No distinction between acid and alkaline soils was necessary where the regression of the yield of phosphorus was calculated on the H2PO4‐ and HPO4= taken up from the soils by the resin. The closest agreement between observed and calculated yields of phosphorus in the test plants was obtained with an equation based on the kinetics of phosphorus absorption by plants.
Calcium and Magnesium Determinations by EDTA Titrations
Authors: Tucker B. B. , Kurtz L. T.
Published: July 2010

A comparison was made of four methods for the determination of magnesium by titration with EDTA (disodiumdihydrogen‐ethylenediaminetetraacetate).

The first method consisted of three steps: (a) estimation of the sum of calcium plus magnesium by EDTA titration to EBT (Eriochrome Black T) endpoint, (b) estimation of calcium by EDTA titration to murexide endpoint, and (c) estimation of magnesium by subtracting (b) from (a).

The other three methods consisted of direct titrations (d) of mangesium with EDTA to the EBT endpoint after calcium had been removed. If desired, calcium could then be estimated by subtracting the magnesium titration (d) from the titration for calcium plus magnesium (a).

For removal of calcium, three precipitation procedures were compared. These precipitations were by sulfate in alcoholic solution, by tungstate, and by oxalate. As compared in these experiments, the four methods listed in order of over‐all accuracy were tungstate > sulfate > indirect > oxalate. The indirect procedure is the most simple and rapid. Of the precipitation procedures, the tungstate is the most rapid because the precipitation and titration are carried out at the same pH and thus only one buffer is required.
Soil Organic Matter: II. Studies of the Origin and Chemical Structure of Soil Humic Acids
Authors: Johnston Harry H.
Published: July 2010

Small quantities of soil humic acids were supplied to cultures of Nostoc muscorum, resulting in stimulation of growth and nitrogen fixation. Various organic compounds were added to compare stimulations and structural relationships. Of all the compounds tested, catechol and humic acids were found to give the greatest increases of nitrogen fixed. Part of the increase in nitrogen fixation was thought to be due to boron contained by the humic acids. Lignin oxidized by H2O2 and microorganisms was analyzed by infrared spectroscopy. The product formed by microorganisms gave a material with similar paper electrophoretic mobility as natural humic acids. Controlled degradation of humic acids and lignin gave various phenols. Humic acid chromatograms showed four phenols present: catechol, phenol, guaiacol, and o‐cresol. One spot found in the humic acid chromatograms has not yet been identified. Bean root lignin when subjected to the same degradation gave a spot in the same position and with the same color. Guaiacol and phenol were also identified from bean root lignin.
A Classification of ca Horizons in Soils of a Desert Region, Dona Ana County, New Mexico
Authors: Gile Leland H.
Published: July 2010

A ca horizon is defined in the Soil Survey Manual as an accumulation of calcium carbonate. Field study in Dona Ana County, New Mexico shows that ca horizons occur in soils on a variety of sediments and geomorphic surfaces. A broad fan piedmont extends from the Rio Grande Valley eastward to the igneous Organ Mountains. To the north there is a desert bolson. In soils on these surfaces and in paleosols underlying the fan piedmont, ca horizons occur and range from thin CaCO3 coatings on pebbles or few CaCO3 filaments to indurated horizons many feet thick.

In soils of the study area, ca horizons have been classified as weak, moderate, strong and very strong. The classification is based on field morphology and pertinent laboratory data, including CaCO3 equivalent, particle size distribution, bulk density, unconfined compressive strength and infiltration rate.
Caliche in Southwestern Idaho
Authors: Stuart Darrel M. , Fosberg M. A. , Lewis G. C.
Published: July 2010

Deposition of caliche in the soils of southwestern Idaho probably results from soil‐forming processes. Caliche occurring on the lower, intermediate, and upper terraces of the Boise and Snake Rivers is described. Close correlation of the present ground surfaces with the top surfaces of the caliche layers is found. The pedogenic development of the soils is related to the ages of the terraces on which the soils occur, and also to the thickness and induration of the caliche layers. The thickness of the Cca horizon decreases or disappears entirely as the age of the soil and terrace increases. Calcium carbonate and silicates increase in the caliche horizons as the soils and terraces increase in age.
Soil Moisture Trends Following Thinning in Shortleaf Pine
Authors: McClurkin D. G.
Published: July 2010

In 19‐year‐old shortleaf pine plantations in northern Mississippi, thinning markedly increased available soil moisture in the middle and latter part of the growing season. In the second year after thinning the moisture increase was associated with more rapid and more prolonged diameter growth. Regardless of the amount of moisture available, diameter growth rates decreased during periods of rapid soil moisture depletion.
Tile Drainage for Layered Soil
Authors: Evans D. D. , Ashcroft Gaylen
Published: July 2010

The effect of a restricting layer (1 foot thick) on the flow of water to drain tiles has been evaluated by the relaxation method using a digital computer to perform the calculation. The following factors were varied alone and in combination: (a) depth to the restricting layer, (b) relative conductivity of the restricting layer to the surrounding soil, and (c) the depth of the drain. For all cases, a constant hydraulic head was assumed along the soil surface and within a gravel envelope surrounding the tile. An impermeable layer was considered to exist at 7 feet.

Drain flux was calculated for each case and compared to give the relative effectiveness of the drains at the selected depths. There is nearly a linear relationship between drain flux and depth of drain when the relative conductivity of the restricting layer to the surrounding soil is 1:10. For 1:100 and 1:1000 conductivity ratio cases, drain flux is nearly independent of depth. The surface intake rate distribution is presented for several cases. The calculations show that a sizeable tension extending over a large portion of the soil profile would be expected for several of the cases.
Origin of a Surficial Deposit in Soils of Eastern Fulton County, New York
Authors: Arnold R. W. , Cline M. G.
Published: July 2010

The origin of a loamy surficial deposit within the sola of Sols Bruns Acides on glacial till in an area adjacent to the Adirondack Mountains of New York was investigated by field studies, mechanical analysis, and microscopic study. Field criteria strongly support an eolian origin, but cumulative particle‐size curves are unlike those of typical loess. Both cumulative curves and degree of grain frosting resemble mixtures of material from silty lacustrine deposits and glacial till in the same area. It was concluded that the surficial deposits are mixtures of fines from nearby areas of glacial till and lake sediments transported partly by saltation and partly by suspension through wind action.
Phosphorus Absorption by Corn Roots as Affected by Moisture and Phosphorus Concentration
Authors: Olsen S. R. , Watanabe F. S. , Danielson R. E.
Published: July 2010

The relative uptake of P by corn seedlings was 100, 94, 80, 50, and 35 for 1/3, 1/2, 1, 3 and 9 bars soil moisture tension, respectively. Uptake of P was a linear function of the soil moisture content for a given soil. Thickness of moisture films, diffusion path length, degree of hydration and elongation of the roots appeared to be the factors controlling P uptake in relation to moisture tension. Uptake of P at constant moisture tension on soils differing in texture and soluble P level was a linear function of solution P concentration, but the range of concentration investigated was small. Phosphorus uptake from a soilroot system differs appreciably from a solution‐root system, which suggests that the soil introduces a limiting factor in rate of P uptake.