bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrite Transformations in California Soils
Authors: Tyler K. B. , Broadbent F. E.
Published: July 2010

Incubation 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

Eight 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

A 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

Infiltration 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

An 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

Undried 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

Soil 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

Theoretical 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

The 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

Studies 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

Field 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

The 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

Arredondo 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

Yield 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

Soils 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.
Improvements in Construction and Use of Resistance Networks for Studying Drainage Problems
Authors: Vimoke B. S. , Tyra T. D. , Thiel T. J. , Taylor G. S.
Published: July 2010

A resistance network analog is described which incorporates some improved features in flexibility, accuracy, and ease of operation. The network consists of 575 variable resistance units and is mounted on a 6‐ by 8‐foot board. The resistive units are of the plug‐in type, and the mesh size is smaller on one‐fourth of the board. The use of a control console, automatic digital voltmeter and numerous switches permits rapid measurement of voltages and currents.

Improved equations are presented for calculating network resistances adjacent to the drain. These equations utilize a logarithmic expression rather than a linear one as reported by previous investigators. Comparisons are made of drain flow rates in homogeneous medium as evaluated by the network and by analytic solutions of Kirkham. Compared to the analytical solutions, the network data generally deviates < 2% if the logarithmic expression is used to calculate drain resistors; while deviations as high as 30% or more may occur if a linear relationship is utilized.
Moisture, Pressure, and Formation of Water‐Stable Soil Aggregates
Authors: Rogowski A. S. , Kirkham Don
Published: July 2010

Moisture and pressure treatments were applied to soil samples consisting of particles of 0 to 0.5 mm. diameter obtained by grinding 2 to 8 mm. aggregates of a Webster silty clay loam collected at the field moisture capacity and then air dried. The application of the moisture and pressure treatments formed the soil material into cylindrical briquettes and these, while moist, were broken into aggregates; these aggregates were then air‐dried and tested for water stability and finally the water‐stabilities resulting from the moisture‐pressure treatments were compared with the water‐stability of 2 to 8 mm. diameter aggregates of untreated soil material. It was found that, although pressure and moisture applied to ground soil material did increase water stability, the water‐stability which resulted from the pressure (maximum 1000 psi.) and moisture (maximum 30.5% referred to oven‐dry weight) was much less than was the water‐stability found in soil material not ground and not subjected to the pressure and moisture treatments. An important conclusion is that, since pressures as high as 1000 psi., which are in excess of pressures exerted by farm machinery, plant roots and soil fauna, failed to produce water‐stability comparable to that of untreated soil material, other forces are more responsible for water‐stable aggregate formation. These other forces may be due to chemical, biological or other natural factors. Concurrently with the work on 0 to 0.5‐mm. soil, identical moisture and pressure treatments were also applied to 2‐ to 8‐mm. diameter aggregates of this same Webster silty clay loam soil material. It was found that the moisture and pressure treatments resulted in decreased water‐stability of these treated 2‐ to 8‐mm. aggregates in comparison with the untreated 2‐ to 8‐mm. aggregates.
Determination of Al(III) in Plant Materials and Soil Extracts
Authors: Page A. L. , Bingham F. T.
Published: July 2010

Accurate colorimetric determinations of Al(III) in plant materials and soil extracts containing up to 60 µg. Al(III) are made by employing the pH 4.2 aluminon buffer in conjunction with an ion‐exchange technique to remove interfering ions. Data are presented to show that it is not necessary to heat or to use a protective colloid when the Al(III) determination by the aluminon method is carried out at pH 4.2.

The method was tested by comparing values obtained from plant materials and soil extracts using the proposed method with values obtained using the procedure of Yuan and Fiskell, and/or adding Al(III) to the extracts and determining the percent of recovery. Agreement between the two methods was satisfactory. The percent of recovery was essentially 100%. The effects of pH, temperature, boiling, and concentration of aluminon on the color intensity of the Al(III)‐aluminon complex are also reported.
The Relationship of Nitrogen in Corn Leaves to Yield
Authors: Baird Bruce L. , Fitts J. W. , Mason D. D.
Published: July 2010

The propriety of specifying rates of N fertilization by the use of the N content of the leaves of corn was evaluated.

Steep slopes of both curves relating yield and N content of corn leaves to rates of N fertilization were associated with high correlation coefficients for the former two variables. These correlation coefficients consistently decreased, often becoming negative, as the rates of N fertilization were increased.

An evaluation also was made of the percent N of corn leaves corresponding to the economic optimum yields and maximum yields of grain for the fertility experiments at 38 locations.

Even though there may be good correlation between yield and N in the leaves, N content of leaves was a poor indicator of the rate of N fertilization. This was true for both economic optimum and maximum yields. The use of the percent N in the leaf should therefore be limited to the comparison of the effect of known factor variation under research conditions and not for the prediction of rates of fertilizer application.
Thermally Driven Liquid and Vapor Phase Transfer of Water and Energy in Soil
Authors: Cary J. W. , Taylor S. A.
Published: July 2010

The basic rate equation developed from Onsager's theory and thermodynamics of irreversible processes was modified for liquid phase moisture diffusion. This was done by accounting for the thermal dependence of the phenomenological coefficients with Eyring's theory of rate processes.

The total simultaneous heat and water transfers through unsaturated soil samples were measured as a function of temperature gradient. By making use of the thermal dependence of vapor flow as reflected in the heat flux data, it was possible to separate the total water transfer into components of vapor phase flow and liquid phase flow. The rate equations were then tested and found to give reliable predictions of water and energy transfer through soil over the range of conditions applied. The interaction coefficients between heat and moisture transfer were also evaluated and found to be approximately the same, which was in agreement with the Onsager theory.
Laboratory and Greenhouse Investigations of Nitrogen Immobilization
Authors: Broadbent F. E. , Tyler K. B.
Published: July 2010

Immobilization of tracer nitrogen added as ammonium sulfate or as nitrate was followed by analysis of inorganic nitrogen in Moreno sandy loam and Sacramento clay during the course of incubation experiments. In Sacramento clay receiving ammonium sulfate plus straw the nitrifying bacteria were able to compete effectively with the immobilizing flora for nitrogen, whereas in the Moreno soil this was not the case. In both soils immobilization attained a maximum in 6 to 10 days. There was some increase in inorganic nitrogen thereafter, but none of this resulted from remineralization of the tracer nitrogen added initially. In greenhouse experiments competition for added tracer nitrogen between a growing crop and the immobilizing flora emphasized preferential utilization of ammonium nitrogen by soil microorganisms and of nitrate nitrogen by the crop. In Moreno sandy loam, overall recovery of the added tracer was higher under treatments favoring immobilization than in pots receiving only fertilizer.
Radial‐Flow Cell for Soil‐Water Measurements
Authors: Richards L. A. , Richards P. L.
Published: July 2010

A cylindrical ceramic cup, centrally placed in a cylindrical core sample of soil has several advantages over the conventional arrangement of a plane suction control surface at one end of a soil column. Flow disturbance arising from change of contact with the cup membrane when the sample shrinks is minimized and gaseous diffusion through the membrane is less troublesome for the evlindrical case. Ceramic cups usable to 15 bar are available. A drop counter is used for recording outflow and approach to equilibrium. The solution of the radial‐flow equation is given for the appropriate boundary conditions. The radial‐flow cell is useful for measuring retentivity, specific capacity, diffusivity, and conductivity of water in a core sample of soil having quasi‐undisturbed structure.
Soil Aeration and Plant Root Relations: IV. Testing the Cylindrical Shell Model in the Transient Case
Authors: Covey Winton , Lemon E. R.
Published: July 2010

This is a further study of the model of oxygen diffusion through a liquid cylindrical shell to plant roots, and the use of an oxygen cathode made of platinum wire to evaluate the resistance to diffusion. The transient current to the oxygen cathode is here analyzed mathematically, and the results compared to new measurements. Differences are believed due to an inadequate representation of the geometry of the soil‐air interface.
Numerical Solution of the Moisture Flow Equation for Infiltration into Layered Soils
Authors: Hanks R. J. , Bowers S. A.
Published: July 2010

A numerical solution of the moisture flow equation was devised and programmed for an IBM 650 computer. Solutions obtained for infiltration into a loam over a silt loam and vice versa showed that infiltration was governed by flow through the less permeable soil, provided the wetting front had extended well into the second layer. Solutions were also obtained for vertical upward and vertical downward infiltrations and for horizontal infiltration into two soils. The numerical solution was found to give excellent results when compared with the methods of E. J. Scott et al. and J. R. Philip for horizontal infiltration into homogeneous soils at a uniform initial water content.
Soil Colloids as a Factor in the Uptake of Cobalt, Cesium, and Strontium by Plants
Authors: Graham E. R. , Killion D. D.
Published: July 2010

A study of the uptake of Co, Cs, and Sr by rye, garden peas, and soybeans showed that the amount of these elements harvested, as well as the concentration in the plants, varied with the nature of the soil colloid on which they were grown.

Illite, kaolinite, montmorillonite, peat (fibrous), peat (sedimentary), and Putnam clay were Ca‐saturated, mixed with nutrients and sand; and treated with known amounts of radioactive Co60, Cs137, and Sr85. Cultures of rye, peas, and soybeans were started in sand‐nutrient solution mixtures, then transferred to the radioactive colloid‐sand‐nutrient mixture. After a period of growth, the plants were harvested, weighed and assayed for their content of radioactivity. A study of the adsorption of the nuclides by the colloids was made by the determination of the distribution coefficient of each radioactive nuclide as a trace amount in Ca‐saturated exchange systems in 0.01M CaCl2 solution.

The order of uptake of Co by the rye plants was highest on illite followed in order by kaolinite, Putnam clay, peat (sedimentary), montmorillonite, and peat (fibrous). The uptake of Cs by the rye plants was highest in the plants grown on (fibrous) peat (10.59% harvested), and lowest for the plants grown on Putnam clay (0.36% harvested). The uptake of Sr by the rye plants was highest for the plants grown on montmorillonite (2.08% harvested). The uptake of the nuclides by peas and soybeans followed closely that of rye.

Data obtained from the distribution coefficient studies of the elements for the exchangers after equilibration in 0.01M CaCl2 solution reveals more Co adsorbed by the peats than by the clays; a high adsorption of Cs by illite and Putnam clays; and small differences with Sr with exchangers other than kaolin. The adsorption of the three elements was lower for kaolin than for the other cation‐exchangers. The percentage of Co and Cs harvested by the plants was correlated with the reciprocal of the distribution coefficient.
Factors Responsible for Poor Response of Corn and Grain Sorghum to Phosphorus Fertilization: I. Soil Phosphorus Level and Climatic Factors
Authors: Olson R. A. , Dreier A. F. , Hoover C. A. , Rhoades H. F.
Published: July 2010

Field experiments designed to measure the response of corn and grain sorghum to starter fertilizer containing P in Nebraska have shown both negative and positive responses to the starter. Positive responses have been associated with low soil P levels and negative responses with high soil P. These experiments also have shown that corn and sorghum are quite efficient in utilization of soil P, making optimum yields without fertilization possible with these crops on soils of substantially lower soil P supply than is possible with small grains.

Excessive vegetative growth and water use with accentuated drouth damage accounted for yield decreases due to starter P in some experiments in dry years. In other cases, it appeared that a hastened physiological development due to applied P may have left the plant in the most critical stage of the reproductive cycle when dessicating weather conditions occurred, with resulting damage that was not apparent in later or earlier corn. In still other cases, there was evidence in plant appearance of a disturbed utilization of trace element(s) where starter P was applied, which is the subject of later papers in this series.
Cationic Effects on Sulfate Adsorption by Soils
Authors: Chao Tsun Tien , Harward M. E. , Fang S. C.
Published: July 2010

The magnitude of sulfate adsorption from different salt solutions, ranging 5 to 100 ppm. S, by soils was in the order CaSO4 > K2SO4 > (NH4)2SO4 > Na2SO4. The magnitude of sulfate adsorption by soils saturated with different cations followed the order of chemical valency of the saturating cations (Al3+ > Ca2+ > K+). The influence of different cations on sulfate adsorption was shown to be associated with two factors: nature of cations and pH. Resolution of the two factors indicated that pH had greater influence than the type of cations. As neutrality was approached, sulfate adsorption decreased considerably regardless of the type of saturating cation. However, there was still a cation effect in addition to the pH effect over the pH range studied. The influence of different cations was attributed to possible effects of electrokinetic potentials and anion repulsion. The effect of pH on sulfate adsorption was greater in soils containing higher amounts of sesquioxides, exchangeable aluminum and/or amorphous materials.
Urea Hydrolysis and Transformation in Some Illinois Soils
Authors: Simpson D. M. H. , Melsted S. W.
Published: July 2010

Samples of several representative Illinois soils, ranging in pH from 4.9 to 7.2, were incubated under different conditions of temperature (1° and 25°C.), soil moisture content (24 and 60%), and urea concentration (200 and 400 ppm. N). The samples were analyzed for residual urea and NH4+ formed after time intervals ranging from 1 day to 4 weeks. Urea hydrolysis occurred at a nearly constant rate for an individual soil under given conditions. Hydrolysis rates varied widely among the different soils and environmental conditions studied, ranging from a minimum of about 6 ppm. N per day to a maximum of about 225 ppm. N per day. Urea hydrolysis rates were from 2 to 6 times greater at 25°C. than at 1°C., depending upon the particular soil involved. An increase in pH resulted in an increase in the hydrolysis rate. Different soil moisture contents and urea concentrations caused little change in the urea hydrolysis rates for individual soils. Nitrification of 400 ppm. urea‐N was followed over a period of 8 weeks for several soils. No measurable nitrification occurred in any of the soils at 1°C. The amount of nitrates formed at 25°C. varied from a minimum of 102 ppm. N in a Herrick silt loam, pH 4.9, to a maximum of over 400 ppm. in a Muscatine silt loam, pH 6.3.
Cicadas and Their Effect upon Soil Genesis in Certain Soils in Southern Idaho, Northern Utah, and Northeastern Nevada
Authors: Hugie V. K. , Passey H. B.
Published: July 2010

The occurrence, activity and effect of Western species of cicadas on soil formation and their relationship to soil characteristics were studied on 70 semiarid rangeland soils. The distinctive soil structure of some Western soils is attributed to the burrowing of cicada nymphs and has been produced over a long period of time. Filled cicada nymph burrows are called “cicada krotovinas.” Little mixing of soil horizons results from the activities of these insects.

A new type of blocky soil structure, “cylindrical,” is proposed to describe cicada‐induced soil structure.

Well‐drained, moderately permeable, moderately deep and deep silt loam, Brown and Sierozem soils, formed in loess parent materials, are well suited to cicada nymph activity. Few cicada nymphs or krotovinas are observed in soils with coarse textures, fine textural B horizons, and high bulk density.
Porosity and Soil‐Water Diffusivity Relations
Authors: Jackson Ray D.
Published: July 2010

Water at −2mb pressure was absorbed by horizontal columns of three soil materials of differing texture each at three porosities, each porosity in duplicate. The soil materials were Adelanto loam, Pachappa loam, and Pine silty clay. From the water content distributions, soil‐water diffusivities were calculated, assuming applicability of diffusion theory. For a total porosity change of about 0.05, Pachappa loam exhibited little change in soil‐water diffusivity but Adelanto loam and Pine silty clay exhibited twofold to threefold changes in diffusivity at the same relative water content. Cumulative infiltration and distance of penetration of water into horizontal soil columns decreased 50% and 40%, respectively, for Adelanto and Pine and 15% and 12%, respectively, for Pachappa when the total porosity was decreased 0.05.

Water content distributions were calculated using exponential diffusivity‐water content functions obtained by a least squares fit to the diffusivity data measured over a limited water content region. Predictions of water contents based on these functions were considerably in error.
Mathematical Study of the First Stage of Drying of a Moist Soil
Authors: Covey Winton
Published: July 2010

In the classical “first stage of drying” of a moist soil, constant external conditions produce a constant evaporation rate. The exponential dependence of moisture diffusivity on water content, suggested by W. R. Gardner, has been used for working out the changing soil moisture profiles in homogeneous soil columns, initially uniformly moistened, with gravity neglected. The characteristic parameter for the process is (βq0L/DI), where q0 is the evaporation rate [cm.3/(cm.2sec.)], β is a constant in the diffusivity equation D = γ · exp (β θ), L is the length of the column, and DI(cm.2/sec.) is diffusivity at initial moisture content θ1(cm.3/cm.3). If (β q0L/DI) is > 5, then the column behaves as an infinitely long column throughout the first stage of drying, and a newly‐computed universal relationship holds: β(θI − θ) = F [(βq0 x/DI), (β2 q02 t/DI)], where x is distance from evaporation surface and t is time. If (βq0L/DI) is < 5, then finiteness of length becomes important within the first stage of drying. The variable β(θI − θ) has been computed as a function of (x/L), (βq0t/L), and (βq0L/DI) for selected values of the latter. These new mathematical functions facilitate theoretical studies and the determination of desorption parameters from observations.
Comparison of Electrode and Flame Photometer Methods for Sodium Analysis of Soil Water
Authors: Fehrenbacher J. B. , Wilding L. P. , Beavers A. H.
Published: July 2010

A total of 126 soil water samples from solonetzic soils in southern Illinois were analyzed for sodium by the electrode method using a Beckman (No. 78187V) Na+ sensitive electrode, and by the flame photometer method. The results obtained from these two methods agree closely as indicated by the highly significant correlation coefficient, r = 0.9989.
Sorption of Gaseous Ammonia by Clay Minerals as Influenced by Sorbed Aqueous Vapor and Exchangeable Cations
Authors: Brown James M. , Bartholomew W. V.
Published: July 2010

Ammonia sorption by homoionic clay systems containing small amounts of adsorbed aqueous vapor was investigated by manometric techniques employing equilibrium measurements in a special sorption apparatus.

Sorption isotherms from this investigation indicated that there is considerable interaction between ammonia sorption and moisture levels of the clays. At ammonia pressures below 60 to 100 mm. Hg, “dry” bentonite and halloysite sorbed more ammonia than comparable moist clays. At higher ammonia pressures, moist clays sorbed more ammonia than “dry” clays with the greatest amount of sorption occurring at the higher moisture levels.

There was evidence of competition between aqueous vapor and ammonia for sorption sites on the clays. The kind of cation on the exchange complex also exerted an influence on ammonia sorption by moist clay, the mechanism of influence probably arising in part through alteration of the quantity and nature of the water of hydration.

The same order of influence of exchangeable cations on ammonia sorption occurred with the moist clays as was previously reported for dry clays, i.e., Al‐clay > Ca‐clay > K‐clay.
Effect of Soil Temperature on Corn Plant Development and Yield: I. Studies With a Corn Hybrid
Authors: Mederski H. J. , Jones J. B.
Published: July 2010

The effect of 10° to 15° F. increase in field soil temperature on growth, yield, and ion accumulation by corn was investigated. In Ohio, normal field soil temperatures are below optimum for maximum corn plant development. Increasing soil temperature with heating cables installed beneath the row accelerated the rate of plant development, and produced significant increases in dry matter production and corn yield. Soil heating significantly increased N, P, K concentrations in plants sampled 30 days after planting. Soil heating did not significantly affect the composition of plants sampled at 60 days or at maturity.
Sulfur Supply of Soils and Crop Yields in the Southeastern United States
Authors: Bardsley C. E. , Kilmer V. J.
Published: July 2010

The sulfur level of soils from the no‐sulfur plots of 21 field experiments was estimated by three chemical methods using soil from the 0 to 12‐inch depth. The three methods were significantly correlated with percentage yield
urn:x-wiley:03615995:saj2sssaj196303615995002700020031x:equation:saj2sssaj196303615995002700020031x-math-0001 (R = 0.60) while the simple correlations with percentage yield were r = 0.55 for acetate‐soluble sulfate, r = 0.59 for bicarbonate‐extractable sulfur, and r = 0.44 for reserve + SO4‐sulfur.
The Canadian System of Soil Classification and the Seventh Approximation
Authors: Leahey A.
Published: July 2010

Soil classification in Canada has developed on the concepts of great soil groups and soil series. The present system, officially adopted in 1960 by the soil survey organizations in this country, introduced the two categories of family and subgroup between the series and great groups and the category of order for combinations of great groups. Though based on soil profile features it has a strong genetic bias, expressed through selection of the differentiating criteria. The Canadian system and the Seventh Approximation are analogous at the series and family categories but differ markedly in the subgroup, great group, and order categories. Differences at these higher classification levels are due to differences in the selection of differentiating criteria, to the more restricted scope of the Canadian system, and to its lack of a suborder. The distinctly different nomenclature accents these differences.
Soil Investigations and the Seventh Approximation
Authors: Flach Klaus W.
Published: July 2010

The Seventh Approximation was developed because of the need for precise soil classification for agricultural and other uses. It incorporates recent advances in soil science and allows classification of all soils, whether cultivated, eroded, or virgin. Classes are defined in terms of morphology although the grouping of classes is based on genetic relationships. The Seventh Approximation presents challenges to soil characterization research because classes must be defined by measurable parameters and to soil genesis research because parameters at high categorical levels must reflect important soil‐forming processes. Precise definition of classes may, in turn, aid in evaluating the relative importance of soil‐forming factors and in the application of the results of research on one soil to similar soils in widely separated areas.
Effect of N, P, and K Fertilization on Yield and Sugar Content of Sap of Sugar Maple Trees
Authors: Watterston Kenneth G. , Leaf Albert L. , Engelken John H.
Published: July 2010

Sap yield, sap sugar concentration, and sugar yield data from sugar maple trees collected over 3 years revealed great intra‐ and interseasonal variations. The effect of N, P, and K fertilizers, applied singly and in combination, affected the yield of sugar by affecting sap yield and/or sap sugar concentration. The combination fertilizer depressed sugar yield the first sap flow season after treatment and increased this yield in the second season. The N or K fertilizer resulted in little change in sugar yield over the control trees while P fertilizer produced a significant effect on sap sugar concentration, thus affecting sugar yield.
Some Characteristics of the Soil Deformation Process
Authors: McMurdie John L.
Published: July 2010

Existing deformation theories—infinitesimal and finite deformation elasticity theory, plasticity theory, and linear viscoelasticity—were discussed as to their applicability to soils. Analysis of data obtained on a Yolo loam utilizing triaxial compression equipment showed that deformation is nonlinear, finite, irreversible, that the component ratios such as Young's modulus and Poisson's ratio were not constants during the deformation process, and therefore elasticity theory is not generally applicable. Plasticity theory was found to be unsatisfactory as as general theory because of its assumption of a region of Hookean behavior or of yield after only small deformations, neither of which condition holds for soils. Performance of creep tests showed that the basic assumption of viscoelasticity theory, the time‐dependence of the relationship between stress and strain states, is valid for soils. It is concluded that viscoelasticity offers the best hope for a deformation theory for soils.
Diffusion of Tritiated Water in Soils
Authors: Nakayama F. S. , Jackson R. D.
Published: July 2010

The apparent diffusion coefficient of tritiated water (DTHO) was measured in four soil materials and two sizes of glass beads at about 40% water content by volume, and in agar gel. The apparent tritiated water diffusion coefficient may include diffusion in the liquid, vapor, and possibly adsorbed phases. For Pachappa loam, DTHO was determined in detail as a function of water content. The DTHO was nearly constant for volumetric water contents of 10 to 40%. As the water content decreased below 10%, the DTHO rapidly increased to a maximum at about 4% water content, then rapidly decreased as the water content was further reduced. The maximum value of DTHO is 3.5 times greater than DTHO at 40% water content.
Variation in Exchangeable K and Relation to Intergrade Layer Silicate Minerals
Authors: Carter D. L. , Harward M. E. , Young J. L.
Published: July 2010

A mica‐vermiculite material was treated with MgCl2 and converted to a typical Mg‐vermiculite. The same material was treated with AlCl3 and converted to a 14Å. mineral concluded to be a vermiculite‐chlorite intergrade similar to those recently reported in the literature. AlCl3 treatment of Mg‐vermiculite also resulted in intergrade formation. In B22 and C horizon samples of a Dayton soil, added aluminum blocked K fixation and increased K release when samples were cycled through various wetting and drying treatments. The roles of aluminum in release of K and in intergrade mineral formation were shown to be interrelated. It was concluded that Al3+ replaces K+ in mica and Mg2+ in vermiculite lattices and then probably forms a sixfold coordination compound with H2O or (OH)‐ which blocks lattice collapse upon subsequent K‐saturation. The increase in exchangeable K upon drying of soils appears to be related to the replacement of fixed K+ by Al3+ arising from degradation of minerals.