bluuebunny/crossref_metadata_2025 huggingface dataset:
Tree Growth as Affected by Soil Moisture Availability
Authors: Bassett John R.
Published: July 2010

Merchantable volume growth in a managed southern pine forest was measured every 3 years from 1940 through 1960. Available soil moisture in the surface foot was estimated for each day of the 21 growing seasons. The soil‐moisture estimates were combined with estimates of potential evapotranspiration to calculate indexes of potential growth. Linear regressions of measured growth on calculated potential growth explained 95 to 97% of the variation about the regression lines. With sufficient soils information and past measurements of growth, foresters may be able to estimate current annual growth in timber stands.
Determination of Thermal Conductivity and Volumetric Heat Capacity of Soils Near the Surface
Authors: Van Wijk W. R. , Bruijn P. J.
Published: July 2010

Thermal conductivity and volumetric heat capacity of a soil near its surface are in situ simultaneously determined using a heat flux plate on the soil surface and thermocouples in the soil. The rise of the temperature caused by a heat pulse of short duration is recorded. The time involved in numerical calculations is greatly reduced by the use of Laplace transforms of heat flux density and rise of temperature. The heat flux into the soil under natural conditions can be calculated from the temperature recorded in the absence of the heat flux plate using the thermal conductivity as it has been determined. The method is applied to a sand soil and to a peat mulch on sand, which were at uniform initial temperature. Theory is emphasized. A discussion of some experimental problems, met in in situ determinations, will be given in a subsequent paper.
Water Vapor Diffusion in Relatively Dry Soil: III. Steady‐State Experiments
Authors: Jackson Ray D.
Published: July 2010

Steady‐state water vapor diffusion coefficients were measured for sorption and desorption on Adelanto loam and Pachappa loam at 27°C. The sorption diffusivities for both soil materials increase, and then decrease, with increasing water content. The desorption diffusivities for Adelanto loam are constant throughout the water content range studied, whereas the desorption diffusivities for the Pachappa loam exhibit a maximum similar to the sorption diffusivities. For both soil materials the transient and the steady‐state diffusivity‐water content curves have nearly the same shape and magnitude. Diffusivities calculated from adsorption isotherm data are similar to the measured diffusivities. Comparison of data from the three methods indicates that liquid diffusion becomes noticeable at water contents corresponding to relative pressures of 0.5 to 0.7 for Adelanto and 0.8 to 0.9 for Pachappa.
Influence of Sorbed Hydroxyl and Sulfate on Neutralization of Soil Acidity
Authors: Mehlich A.
Published: July 2010

Soils of varying clay mineral characteristics were treated with anion‐exchange resin to obtain systems containing either sorbed OH‐ or SO42‐. They were then equilibrated with Ca(OH)2, and the neutralization of acidity consisting of permanent charge (Hp), variable charge (Hv) and anion‐exchange (Han, principally SO42‐ absorbed) evaluated. The order of neutralization was Hp (consisting principally of Al3+ except in the case of the muck) first, followed virtually simultaneously by Hv and Han. Sorbed SO42‐ resulted in more strongly acidic systems. Hv is postulated to arise from covalently‐bonded H of aquo groups in the coordination sphere of hydrated Al (or possibly Fe3+ atoms). The source of Han is postulated to be acid radicals substituted for OH groups, likewise in the coordination sphere of Al and Fe3+ associated with clay surfaces or in hydrous oxide crystals. The magnitude of Han, the soil acidity due to sorbed acid radical anions, may be an appreciable part of the total acidity of Red‐Yellow Podzolic and Reddish‐Brown Lateritic soils.
Respiration Studies on Soil Treated with Some Hydrocarbons
Authors: Dobson Ann L. , Wilson H. A.
Published: July 2010

Respiration studies, as measured by the uptake of O2, were made upon oil‐free and oil‐impregnated soils. A modified Haldane apparatus was used. Composite soil samples of oil‐impregnated soil obtained around oil wells showed greater biological activity than samples of oil‐free soil. The respiration rate was greater, however, in oil‐free soil cores than with oil‐impregnated soil cores. Crude oil, kerosene, and mineral oil were added at 2, 10, and 20% on a volume‐weight basis levels to a soil. Each percentage addition resulted in its own biological activity pattern but in general the trends were similar. In all cases, the soil with added hydrocarbon had a greater respiration rate than the untreated soil.
Effects of Ridges on Erosion of Soil by Wind
Authors: Armbrust D. V. , Chepil W. S. , Siddoway F. H.
Published: July 2010

The effect of ridges on soil erosion by wind was studied under laboratory conditions with wind tunnels. Smoothed soil surface and 1.3, 2.5, 5.1, 10.2, and 20.3 cm. high ridges constructed of dune sand and three simulated cultivated soils were exposed to six wind velocities ranging from 47 to 83 miles per hour. Ridges 5.1 to 10.2 cm. high eroded little due to trapping of soil particles between ridges and average wind velocity decrease. Ridges less than 5.1 cm. high were not as effective in trapping soil particles and reducing wind velocities. Extensive erosion on ridges higher than 10.2 cm. resulted from higher wind velocities at the ridge crests and increased wind eddying.
Physical Artifices and Formulas for Approximating Water Table Fall in Tile‐Drained Land
Authors: Kirkham Don
Published: July 2010

Two physical artifices are used to simplify the mathematics of the falling water table in tile‐drained land. One artifice is to insert in the soil rigid frictionless, infinitesimally thin, impervious membranes along the natural soilwater seepage streamlines, or along approximate streamlines. The second artifice [one used previously by the author (4)] is to replace soil by gravel in the region above the level of the drain tube centers. The gravel is subsequently, for final derived formulas, replaced by soil. The formulas are shown, theoretically, to be “on the safe side” for drainage design. The formulas agree with experimental data.
Soil Water Relations During Rain Infiltration: III. Water Uptake at Incipient Ponding
Authors: Rubin J. , Steinhardt R.
Published: July 2010

Rain‐induced ponding onset was analyzed theoretically, by using a diffusion‐type equation of soil moisture flow and was investigated experimentally, by employing laboratory columns of a sandy soil. Equations for the lower and upper bounds of water uptakes at incipient ponding were derived. These expressions seemed to represent well the experimentally established relation between rain intensity R and cumulative rain uptake by a soil on the surface of which isolated puddles just started to form. In every case observed, such an uptake was significantly smaller than one of a flood‐wetted column which reached an infiltration rate equal to R. On the other hand, at identical water entry fluxes, similar uptakes were exhibited by flooded columns and rain‐wetted soil which had just become completely covered by a mantle of ponded rain‐water.
The Effect of Soil Moisture Tension on Carbon Dioxide Evolution, Nitrification, and Nitrogen Mineralization
Authors: Miller Richard D. , Johnson D. D.
Published: July 2010

Four soils were incubated at 30°C. for 14 days under soil moisture conditions varying from zero tension to airdry soil after which NO3‐N and NH4‐N were measured. Carbon dioxide evolved from the soils was collected continuously and measured at the end of the 1, 2, 3, 7, and 14 days. Carbon dioxide production during the first day increased from a minimum in air‐dry soil to a maximum at tensions of from 0.50 to 0.15 bars, and then decreased with further increase in soil moisture. At the end of the incubation period there was little difference in the CO2 evolved in the tension range from zero to 0.15 bar. Maximum nitrification occurred in the tension range of 0.50 to 0.15 bars. There was a peak in both N mineralized and N nitrified in this tension range followed by a decline in NH4‐N and NO3‐N to about zero tension where there was another peak in N mineralization. Nitrification was shown to proceed at tensions above 15 bars tension but at a very slow rate. Ammonification took place at a faster rate at both high and low tensions, indicating that NH4‐N can accumulate in soil at high tensions (up to air‐dry) and low tensions (near zero bars).
Effect of Cultivation on the Nitrogen Distribution in Soils
Authors: Keeney D. R. , Bremner J. M.
Published: July 2010

The effect of cultivation on the nitrogen distribution in soils was studied by determining total N, nonexchangeable ammonium N, nonhydrolyzable N, and hydrolyzable (total, ammonium, hexosamine, amino acid, unidentified) N in 10 virgin soils and their cultivated analogues.

Cultivation led to a marked decrease in all forms of N, excepting nonexchangeable ammonium N, but, on the average, had little effect on the percentage distribution of N. The average percent loss of total N on cultivation was 36.2%, and the average losses of different forms of N, calculated as percentages of the loss in total N, decreased in the order: hydrolyzable N (70.5%) > amino acid N (29.8%) > nonhdrolyzable N (29.5%) > unidentified hydrolyzable N (20.0%) > hydrolyzable ammonium N (17.1%) > hexosamine N (3.5%) > nonexchangeable ammonium N (0.5%).

On the average, cultivation led to small increases in the proportions of total N as nonexchangeable ammonium N, Hydrolyzable N, hexosamine N, and hydrolyzable ammonium N, and to small decreases in the proportions as nonhydrolyzable N, amino acid N, and unidentified hydrolyzable N. The average percent losses of different forms of N on cultivation decreased in the order: amino acid N (43.0%) > nonhydrolyzable N (39.4%) > total N (36.2%) > total hydrolyzable N (35.2%) > unidentified hydrolyzable N (34.5%) > hydrolyzable ammonium N (28.6%) > hexosamine N (27.6%) > nonexchangeable ammonium N (0.2%).
Differential Response of Orchardgrass Varieties (Dactylis glomerata L.) to Nitrogen and Phosphorus under Controlled Soil Temperature and Moisture Conditions
Authors: Finn B. J. , Mack A. R.
Published: July 2010

In a greenhouse experiment, the growth and nutrient uptake of four varieties of orchardgrass were differentially affected by soil temperature and moisture. The yield of tops, for all varieties, was increased by a rise in soil temperature from 10°C. to 20°C. and by a rise in soil moisture from 25% to 75% of the available soil moisture capacity. The yield of roots was increased by a decrease in soil temperature from 20°C. to 10°C. when associated with the high soil moisture level. Under warm soil conditions a rise in available soil moisture generally produced similar increases in top yields for all varieties; whereas, under cool soil temperature a rise in soil moisture increased top yields in the following order: Frode > Rideau > S‐143 = Chinook. Under the same moisture and temperature condition root yields were in the order of Frode > Chinook = Rideau.

The influence of N fertilization on herbage yield and on N uptake was only slightly affected by soil temperature and moisture. A rise in soil temperature and soil moisture increased the uptake of soil P and decreased the effect of applied P on yield and P uptake. Under P fertilization the uptake of P by the varieties differed with environment: the order was S‐143 > Frode = Rideau > Chinook at 20°C. and 75% moisture, and Frode = Rideau > S‐143 = Chinook at 10°C. and 25% moisture.
Surfaces of Peds from B Horizons of Illinois Soils
Authors: Grossman R. B. , Odell R. T. , Beavers A. H.
Published: July 2010

Surfaces of peds from B horizons of several Illinois soils were studied. Concepts of “structural specific surface” and of “disparity” between the ped surface and ped interior are presented. The ped surfaces are described in terms of accretive (accumulation) and degradational (removal) alteration classes. Aspects of the moisture regime at the ped surface are discussed.

Ped surfaces were sampled by washing kerosene‐saturated peds with Calgon solution. Clay in the ped surface generally has more fine clay (<0.04µ) and more coarse clay (>0.5µ) than clay from bulked (whole) peds. Collapse from 14Å to 10Å is less complete on heating to 450°C. for the clay from the ped surface. In samples of peds with significant percentages of both montmorillonite and nonexpanding 2:1 lattice clays, the predominantly accretive ped surfaces have more mortmorillonite than the bulked peds, whereas predominantly degradational ped surfaces have less.
Sorption of Cesium from Dilute Solutions
Authors: Sawhney B. L.
Published: July 2010

Sorption of Cs by a synthetic cation‐exchange resin and by several clay minerals, over a range of low Cs concentrations, was studied in the presence of different counter‐ions. An ionexchange equation was used to predict the sorption of Cs from dilute solutions. Exchange isotherms showed that the sorption of Cs by the resin followed these predictions: Exchange isotherms were straight lines with unit slope. Sorption of Cs by clay minerals, however, did not follow these predictions except when K+ was the competing cation. When Ca2+ and Al3+ were the competing cations, the exchange isotherms for montmorillonite were straight lines with less than unit slope, showing that a larger proportion of Cs was sorbed with decreased Cs concentrations. The exchange isotherms of illite and vermiculite, on the other hand, had at least two distinct slopes suggesting that more than one type of exchange site is involved in the sorption of Cs by these minerals. These conclusions were also supported by estimates of the equilibrium constants calculated from Vanselow's equation.
Extraction of Potassium from Soils with Sodium Tetraphenylboron
Authors: Schulte E. E. , Corey R. B.
Published: July 2010

The amounts of K extracted from several soils of different K supplying power with solutions containing NaTPB were compared with the amounts taken up by intensive greenhouse cropping and with the amounts extracted with 1N NH4OAc (exchangeable K). The best estimate of plant available K was the amount of K extracted from 2‐g samples of nondried soil with 10 ml of 0.3N NaTPB in 15 min (r = 0.991). The decrease in the amount of K extracted by the same reagent in 16 hours, as a result of cropping, likewise was closely correlated with available K (r = 0.984). Exchangeable K determined in nondried soil samples was more closely correlated with available K (r = 0.971) than was exchangeable K determined in dried soil samples (r = 0.788).
Studies on the High Pressure Hydrogenolysis of the Organic Matter from a Muck Soil
Authors: Felbeck George T.
Published: July 2010

About 80% (on the basis of C content) of the organic matter from a muck soil was degraded by a combination of acid hydrolysis and high pressure hydrogenolysis. Approximately 31% of the total organic C was dissolved by hydrolysis with dilute H2SO4 at 90 C. Hydrogenolysis rendered 47% of the total organic C soluble in benzene, with the remainder either converted to a gaseous form (1%) or to an insoluble residue (21%). Particular interest was given to the fraction soluble in benzene as it was thought to represent the breakdown products of the skeletal structure of the nonhydrolyzable fraction of the organic matter.

A normal hydrocarbon of about C25 length, representing 1.2% of the total organic matter carbon, was isolated from the hydrogenation products.

From these observations and other data it is suggested that part of the nonhydrolyzable organic fraction of a muck soil representing the source of the normal C25 hydrocarbon consisted of chains of unsaturated, O‐containing heterocyclic compounds connected by a‐a′ C‐C bonds. Part of the nonhydrolyzable N in the organic matter possibly exists in the tertiary amine state, and it is probably protected from attack by steric hindrance.
Plant Recovery of Immobilized Nitrogen in Greenhouse Experiments
Authors: Broadbent F. E. , Nakashima T.
Published: July 2010

A series of greenhouse pot experiments was conducted to measure plant uptake of fertilizer N in the presence and absence of straw. Soils were incubated with straw for periods up to 12 weeks to overcome the depressing effect of straw and then cropped. Two or more crops were evaluated for each treatment. In spite of preincubation, plant recovery of N was invariably lower where straw had been added, even when the level of fertilizer N added was equivalent to 2.5% of the weight of straw.

The presence of growing plants on the soil during the period immediately following application of fertilizer N resulted in more efficient utilization of fertilizer than where planting was delayed several weeks after fertilizer application. This was true whether straw was added or not.

A tracer experiment lasting nearly 2 years indicated progressive stabilization of fertilizer N after incorporation into the soil organic fraction.
Phosphorus Fertilizer Residual Effects on Irrigated Crops in Rotation
Authors: Campbell R. E.
Published: July 2010

Residual effects for 8 years of 0, 26, 52, 105, and 210 lb of P per acre applied for barley were measured in a 6‐year rotation of barley, alfalfa (3 years), corn, and sugar beets grown on Thurlow clay loam. Amounts of P removed by crops in 9 years totaled 96, 109, 124, 136, and 179 lb, respectively. Corresponding recoveries of applied P were 49, 54, 38, and 40%. Most of the 26 pounds of P was used in 4 years. Residual response over the entire period increased with higher rates.

Residual P soluble in NaHCO3 decreased with continued crop removal of applied P.

The results of this experiment which was located in Montana agreed well with similar experiments run concurrently in New Mexico, Oregon, and South Dakota. The differences among them can be reconciled on the basis of soil textural differences as they affect P adsorption and availability.
Sulfur in Plant Materials by Digestion with Nitric and Perchloric Acid
Authors: Blanchar R. W. , Rehm George , Caldwell A. C.
Published: July 2010

A method for the determination of S in plant materials is described. The material is oxidized by nitric and perchloric acid using a heating block to reduce perchloric acid loss. The SO4 content of the solution is determined turbidimetrically as BaSO4. The proposed method has been found to be more accurate and rapid than the conventional dry ashing procedures for the determination of S in plant material.
Accumulation and Decline of Available Phosphorus and Potassium in a Heavily Fertilized Honeoye Silt Loam Soil
Authors: Peck N. H. , MacDonald G. E. , Vittum M. T. , Lathwell D. J.
Published: July 2010

Seven years of different rates of fertilizer application on vegetable crops were followed by 2 years when only N was applied. Fertilizer P and K treatments were then superimposed for the next 6 years.

During years of application of fertilizer P and K, residual soil P and K accumulated in available forms as measured by soil test. The higher the rate of application of fertilizer P and K, the higher was the accumulation of available soil P and K. After application of fertilizer P and K was discontinued, there was a rapid decline in residual available soil P and K. After 8 years without application of fertilizer P and K, there was still a highly significant residual soil P effect, and a significant residual soil K effect in one of the two fields.
Soil Individuals and Soil Classification
Authors: Knox Ellis G.
Published: July 2010

The standing of 8 kinds of soil bodies as soil individuals was evaluated in the light of the following principles, derived from an analysis of basic ideas: 1) Classes are abstract fields, not groups of individuals. 2) Artificial individuals of continuous universes are different from natural individuals of particulate universes. 3) Classes in continuous universes are independent of individuals. 4) Artificial individuals are memberbodies of minimum size. Soil particles, soil horizons, soil landscape units (including polypedons), and delineated soil bodies are natural individuals, but only within nonsoil universes. The universes of soil resulting from any of the common concepts of soil as an isotropic material or an anisotropic body are continuous, and contain hand specimens, soil profiles taken as bodies, “individuals”, and pedons as artificial individuals. These may be regarded as soil individuals. There is need for a concept of soil corresponding to some kind of soil landscape unit.
The Characterization of Some Soils Developed from Mixed Brown and Gray Tills in Central Minnesota
Authors: Grimes Myron F. , Arneman Harold F.
Published: July 2010

Superposition and interbedding of various glacial drifts of the Wisconsin age are common in central Minnesota.

Morphological characteristics of soils developed from calcareous gray till (Hayden series), noncalcareous brown till (Flak), and from mixed tills (Holdingford) are shown in the profile descriptions. The series were characterized in the laboratory by pebble identification, particle size distribution, bulk density, moisture holding capacity, total exchangeable cations, exchangeable calcium, magnesium, and hydrogen, percent base saturation, pH, and C/N ratio.

The characterization of the profiles studied showed definite morphological, physical, and chemical differences between the soils developed from the mixed tills and those from the unmixed modal brown or gray tills. The study shows the need for a series separation between these soils.
Unsaturated Flow Phenomena in Panoche Sandy Clay Loam as Indicated by Leaching of Chloride and Nitrate Ions
Authors: Dyer Kenneth L.
Published: July 2010

Moisture suctions greater than 15 atmospheres are a common occurrence in the subsoils and substrata underlying unirrigated soils of the Panoche series. One such soil which contained appreciable quantities of Cl‐ and NO3‐ was taken from the field at a moisture suction of 16 atmospheres and packed into a column measuring 117 inches in height. This column was partially leached under unsaturated flow conditions with a saturated gypsum solution. Subsequent analyses indicated that about half the original soil moisture was not displaced downward with the dissolved Cl‐ and NO3‐. The Cl‐ and NO3‐ concentrations contained in the displaced portion of the soil solution were about double those in the original soil solution existing at 16 atmospheres suction.
Deviations from Darcy's Law in Saturated Clays
Authors: Olsen Harold W.
Published: July 2010

Atmospheric contamination causes an error in the conventional use of air‐water menisci and air bubbles in capillary tubes for measuring flow rates through clays. This error gives rise to spurious deviations from the conventional criterion for Darcy's law. Data are presented which show the error can be of sufficient magnitude to account for the deviations from Darcy's law in much of the published data on confined clay samples. The error is negligible compared with the deviations in the published data on unconfined clay and sandstone samples.
Simultaneous Flow of Water and Salt Through Unsaturated Porous Media: I. Rate Equations
Authors: Abd‐el‐Aziz Mahmoud H. , Taylor S. A.
Published: July 2010

The thermodynamic theory of irreversible proceses was used as a basis in developing two rate equations for the simultaneous movement of potassium chloride and water through porous media under isothermal conditions. The two rate equations are
urn:x-wiley:03615995:saj2sssaj196503615995002900020010x:equation:saj2sssaj196503615995002900020010x-math-0001 where T is Kelvin temperature, Jw and Js are flux of water and salt, ΔP and ΔCs are the pressure and salt concentration differences across the sample, C̄s is the mean salt concentration, r is the concentration ratio, v̄w is the partial molar or specific volume of matric water, depending upon units selected for measuring Jw and R, Lww and Lss are the direct transfer coefficients for water and salt, and Lsw and Lws are the interaction or linked transfer coefficients. The equations were tested under conditions of flow through unsaturated kaolinite and Millville silt loam at constant temperatures of 15, 25, 35C. The results showed that the interaction coefficients, Lws and Lsw, were equal, suggesting that the Onsager theorem was met in both kaolinite and soil systems at the temperatures, pressure, and concentrations used.
Quartz, Feldspar, and Mica Determination for Soils by Sodium Pyrosulfate Fusion
Authors: Kiely P. V. , Jackson M. L.
Published: July 2010

Soil fractions are treated with the J. Lawrence Smith Na2S2O7 fusion which is shown to decompose micas and other layer silicates common in soils. The layer silicate relics are dissolved by washing with 3n HCl and hot 0.5n NaOH for 2.5 min leaving quartz and feldspar in the residue. Recovery of quartz after the treatment ranged from 99.4% in the 50 to 20µ fraction to 96.6% in the 2 to 0.2µ fraction; correction factors are applied to the respective fractions accordingly.

Recovery of K feldspar ranged from 96.5% in the 500 to 50µ fraction to 64% in the 2 to 0.2µ fraction; Na feldspar recovery varied from 95% in the 500 to 50µ fraction to 68% in the 2 to 0.2µ fraction. Highly calcic feldspars (bytownite, An 70–90, and anorthite) were completely dissolved in the finer fractions but such feldspars are uncommon in soils. Labradorite (An 50–70) is determinable in fractions coarser than 5µ. Feldspars are determined by allocation of residue K, Na and Ca to their equivalent endmember feldspars, with suitable correction factors for mineral solubility and for increase of Na from pyrosulfate in K and Ca feldspars. The remainder of the residue is allocated to quartz. Mica K2O is obtained as the difference of total K2O less feldspar K2O in the residue, a differentiation important to soil fertility.

Quartz is almost invariably present with layer silicates in soil clays. As much as 15% quartz frequently is undetectable in X‐ray diffractograms in the presence of appreciable mica, because of the coincidence of the 3.35A peak of quartz with the 3.33A peak of micas and because the 4.26A quartz peak is relatively weak. The quartz present can be determined by the proposed method to within ± 1% in samples low in feldspars.
Mineralogical Changes Associated with Ammonium and Potassium Fixation in Soil Clays
Authors: Rich C. I. , Lutz J. A.
Published: July 2010

Ammonium and potassium fixation by the 2 to 0.2µ fraction of 14 surface soils, mainly from Southeastern United States, was related to both the decrease in intensity (ΔI) of the 14A X‐ray diffraction peak and its shifting (Δd) toward 10A.

A statistical study of the relationship of X‐ray diffraction characteristics with K and NH4 fixation showed that in the case of NH4 fixation, 82% of the variation in fixation could be attributed the two factors, ΔI and Δd. The determination of K fixation apparently was confounded by release of native K.

The relationship of NH4 and K fixation to interstratification and interlayering is discussed.

Fixation on a unit weight basis increased with decrease in particle size, but, because of its abundance as well as high fixing ability, the 2 to 0.2µ fraction was generally the most important.
Development of the Tetraphenylboron Method for the Determination of Extractable Soil Potassium
Authors: Bennett Allison C. , Reed Robert M.
Published: July 2010

Many county and small commercial laboratories make quick tests on soil samples. These laboratories need a simple precise analytical procedure for extractable soil potassium. A turbidimetric method, using sodium tetraphenylboron, proposed by Sunderman and Sunderman was modified and further developed. Six Oklahoma soils were collected for this investigation. Sodium acetate and sodium nitrate at three concentrations (0.1, 0.5, and 3.0n) were used as extractants. Three extractant‐soil ratios (5:1, 7:1 and 10:1) were also employed. The most suitable extractant was 0.1n sodium nitrate at an extractant‐soil ratio of 5:1. Injection of sodium tetraphenylboron with a hypodermic syringe was the most satisfactory method. For maximum flocculation, there was a time‐temperature interaction. Ammonium ion concentrations of 3 ppm or less were complexed by formaldehyde. Calcium and magnesium interferences were alleviated by EDTA.
Fertilizer Needs for Restoring Productivity on Pullman Silty Clay Loam After Various Degrees of Soil Removal
Authors: Eck H. V. , Hauser V. L. , Ford R. H.
Published: July 2010

Greenhouse and field studies were conducted on Pullman silty clay loam to assess the relative productivities of its genetic horizons and permissible depth of cut in land leveling. German millet was grown in the greenhouse experiment. Without fertilizer, the 0‐ to 5‐inch horizon produced highest yields. Under high N and P levels, only the 13‐ to 19‐inch depth produced yields lower than the surface soil. The 28‐ to 38‐inch horizon produced yields equivalent to the 0‐ to 5‐inch horizon and greater than all other nonsurface depths studied. Trends in N and P uptake were generally similar to those in dry matter yields.

In the field experiment, N was required for maximum yields of grain sorghum on undisturbed soil and on all degrees of cut. Nitrogen and P were required when 4 or more inches of top‐soil was removed and restored yields where up to 12 inches of topsoil was removed. Yields on heavily fertilized 16‐inch cuts were 80% of those on similarly fertilized, undisturbed soil.
Composition and Precision of Classification of Several Mapping Units of the Appling, Cecil, and Lloyd Series in Walton County, Georgia
Authors: Powell James C. , Springer M. E.
Published: July 2010

Soils of the Appling, Cecil, and Lloyd series comprise about 80% of Walton County, Ga., according to a medium‐intensity soil survey completed in 1962. To study the composition and precision of classification of mapping units of these series, straight‐line transects using the point‐intercept method were made along diagonal lines across 16 randomly selected 160‐acre blocks of land. The soil was checked every 33 paces along these transects on mapping units of the Appling, Cecil, and Lloyd series. Slope was mapped correctly at 91% of the 518 stops; texture of surface layer, 82%; erosion, 77%; soil series, 74%; soil type, 64%; and all of these, together, were correct at 59% of the stops. All but one of the 19 mapping units studied contain more than 15% of inclusions of other soils. The mapping, however, is highly reliable from the standpoint of grouping pedons that can be interpreted similarly. Only a small proportion of included soils would behave differently from the dominant soil in each mapping unit.
Conductance of Frozen Bentonite Suspensions
Authors: Hoekstra Pieter
Published: July 2010

The conductance of frozen Wyoming bentonite suspensions was measured. The magnitude of the observed conductance was consistent with an expression derived from the assumption that the films of unfrozen water on the clay particle surfaces are continuous through the frozen soil matrix. For the range of water contents used, the conductance per gram of clay was found independent of water content in the frozen suspensions. There was a large difference in conductance between frozen and unfrozen soil; this difference was larger for Na than for Ca‐bentonite.
Detection and Determination of Gypsum in Soils
Authors: Lagerwerff J. V. , Akin G. W. , Moses S. W.
Published: July 2010

A rapid, semiquantitative method (I) and a quantitative method (II) are proposed for the determination of gypsum in soils. Method I involves the determination of the degree of gypsum‐unsaturation of an aqueous soil extract nearly saturated with gypsum, i.e., sufficiently dilute to dissolve all gypsum initially present. The unsaturation is determined by electrical conductivity (EC) measurements before and after saturating the extract with reagent CaSO4·2H2O. Increasing the water content of the soil in preparation of the dilute soil extract causes an exchange of adsorbed cations for Ca2+ from gypsum, and the formation of an equivalent amount of sulfate salts of cations other than Ca2+ (“exchange error”). The error is equal to the difference between the observed and calculated contents of salts‐other‐than‐gypsum in the dilute extract. It has been estimated from EC measurements.

Method II is a modification of an existing method, where gypsum is precipitated in the dilute soil extract by acetone. The exchange error is avoided by determining gypsum on the basis of sulfate associated with calcium. The method minimizes several potential errors, such as those due to acetone and ions occluded in the gypsum precipitate.

For a group of gypsiferous soils, errors due to Ca2+‐exchange and acetone occlusion averaged about −22% and −3%, respectively. Gypsum contents, and recovery of added amounts of gypsum, as determined independently by Methods I and II, compare favorably for the soils studied.
A Comparative Study of Developmental Color in a Chestnut‐Chernozem‐Brunizem Soil Climosequence
Authors: Buntley G. J. , Westin F. C.
Published: July 2010

A comparative study was made of the function of the interaction of the hue and chroma color components on the genetic or developmental color in seven well‐drained soil profiles arrayed across a Chestnut‐Chernozem‐Brunizem soil climosequence. Earlier attempts to assess the aspect of developmental color associated with hue and chroma on the basis of hue alone or chroma alone have not proven satisfactory, especially in grassland soils. The numerical method used in this study involves the interaction of the hue and chroma components. Quantitative numerical color‐development equivalents were obtained for the individual horizons in each profile studied. This made possible the graphic portrayal of the color‐development profile which in turn facilitated the direct comparison of the distribution and magnitude of the developmental color in the profiles in the climosequence. Among the profiles studied, characteristic color‐development curves were obtained for the Chestnut, Chernozem, and Brunizem profiles as well as for the intergradational profiles. The curves obtained appear to comprise an evolutionary sequence of color development across the climosequence of the grassland soils used in this study.
Water Movement Through Acrylic Plastic
Authors: Willis W. O. , Nielsen D. R. , Biggar J. W.
Published: July 2010

Water movement through acrylic plastic was quantitatively determined. Measurements showed an average diffusion coefficient of 8 × 10‐6 cm2/sec for water through 0.053‐, 0.129‐, and 0.250‐inch thick acrylic plastic. This amount of water movement through plastic is considered significant for some experimental work.
Ion Diffusion: III. The Effect of Soil Compaction on Self Diffusion of Rubidium‐86 and Strontium‐89
Authors: Phillips R. E. , Brown D. A.
Published: July 2010

Self diffusion coefficients of Rb80 and Sr89 diffusing in Dundee silt loam soil and of Sr80 diffusing in Sharkey clay soil were measured at several soil bulk densities. The relationship between soil bulk density and self diffusion coefficients was found to be curvilinear. The soils were prepared as homoionic systems and the exchange complex was saturated with one symmetry value of either Rb or Sr and washed free of salts. Maximum self diffusion coefficients occurred at soil bulk densities of 1.58 and 1.31 g/cc for Sr89 self diffusing in Dundee silt loam and Sharkey clay, respectively, and a bulk density of 1.30 g/cc for Rb80 self diffusing in Dundee silt loam. The ratio of the maximum to the minimum self diffusion coefficients were 1.40, 1.25, and 1.17 for Sr89 and Rb80 diffusing in Dundee silt loam and Sr89 diffusing in Sharkey clay, respectively. The magnitude of self diffusion coefficients measured in soil which was compacted, saturated with water, and then drained to a given volumetric water content were approximately one‐half those determined in soil which at the time of compaction contained the same volumetric water content and which received no further treatment prior to the determination of the self diffusion coefficients.
Test of an Ascorbic Acid Method for Determining Phosphorus in Water and NaHCO3 Extracts from Soil
Authors: Watanabe F. S. , Olsen S. R.
Published: July 2010

Murphy and Riley proposed use of a single reagent for determining P. The method was found to be accurate for determining P in soil extracts. This method is based on reduction of the ammonium molybdiphosphate complex by ascorbic acid in the presence of antimony. The color produced is stable for 24 hours. It is less subject to interfering substances than are methods involving reduction by SnCl2.
Sulfur Dioxide as a Source of Sulfur for Wheat
Authors: Roberts S. , Koehler F. E.
Published: July 2010

Sulfur dioxide was injected into the soil as a source of S for wheat in greenhouse and field studies with S‐deficient Athena and Palouse silt loam soils. Yields were approximately doubled when SO2 was applied at a rate of 2.5 ppm S in the greenhouse. Higher rates of SO2 up to 500 ppm S gave little additional growth. Plant growth responses to SO2 and gypsum at 10 ppm S were almost identical. In greenhouse experiments SO2 applied at 2,500 ppm S greatly reduced plant growth, and 5,000 ppm S proved lethal to the plants soon after emergence. Concentration of S in plants was directly related to rate of S application. In field trials, SO2 was applied at rates of 8, 16, 32, and 64 lb S/acre. No adverse effects were noted at the higher rates of application. Sulfur dioxide compared favorably with gypsum as a source of S with respect to plant growth response, total sulfur uptake and wheat yield in the greenhouse, and with respect to total S uptake in the field.
Characteristics and Genesis of a Gravelly Brunizemic Regosol
Authors: Gaikawad S. T. , Hole F. D.
Published: July 2010

A Rodman gravelly, cobbly sandy loam profile was sampled in Wisconsin in a prairie “oak opening” at the crest of an eskerkame ridge of Woodfordian (Cary) age largely composed of gravel and cobbles of dolomitic limestone. Laboratory analyses reveal a shallow profile resembling a Brunizem soil with respect to distribution of organic matter. Distributions of pedogenic calcium carbonate and clay somewhat resemble those in the upper horizons of calcareous parent materials of some soil profiles in the North Central Region of the USA. The slight concentration of silt and clay near the surface of the Rodman soil may be largely aeolian in origin. The weathering mean of this shallow soil profile is 5.6 on the basis of the entire clay and 7.8 on the basis of noncarbonate clay. A depth function is suggested by the slight concentration of weathered ferromagnesian sand particles near the surface. Distribution and character of the carbonate crusts on the under surfaces of coarse particles exhibit a pronounced depth function by volume but not with respect to content of noncarbonate silt and clay.
Nitrifying Organisms Affected by Climatic Region in Western United States
Authors: Mahendrappa M. K. , Smith R. L. , Christiansen A. T.
Published: July 2010

Nitrification of ammoniacal (NH4+) N added as (NH4)2SO4 to different soils of western USA and incubated at 20, 25, 35 and 40C with moisture at 0.3 bar moisture tension was investigated. In all soils from northern regions, nitrification was faster at 20 and 25C than at 35 and 40C. The reverse was true in the case of the southern soils which nitrified fastest at 35C. Nitrites accumulated in larger quantities under the temperature conditions less favorable for nitrification.
A Thermogravimetric Approach to the Classification of Organic Soils
Authors: Schnitzer M. , Hoffman I.
Published: July 2010

The thermogravimetric method is shown to offer a simple but valid and meaningful method for assessing the degree of humification of organic soils. Heights of the 280C maxima in the differential thermogravimetric (DTG) curves of 22 organic soil samples, ranging from peats, mucky peats, peaty mucks to mucks, were inversely proportional to the degree of humification as determined by pyrophosphate solubility. Highly significant negative correlations were found between peak height at 280C and (i) solubility in 0.025m sodium pyrophosphate solution, (ii) percent ash, and (iii) percent moisture. The analytical data were fitted by the method of least squares to polynomials of various degrees on an IBM 1620 computer. The thermogravimetric technique offers a new approach to the classification of organic soils and should also find wide application in humification studies.
Parent Material‐Clay Relations in Some Northern Utah Soils
Authors: Southard A. R. , Miller R. W.
Published: July 2010

It is frequently stated that soils with well‐developed A and B horizons are sufficiently weathered that their clays will reflect strongly the influence of the climatic environment. Studies of three profiles developed from sedimentary rock materials in northern Utah show a high association between parent material, kind of clay in each parent material, and kind of clay in the soil derived from the rock materials.

Soil derived from a calcareous, red matrixed conglomerate (Wasatch) contains 20 to 50% of clay as kaolinite. Soil formed from a particular and distinctly calcareous tuffaceous deposit has dominantly montmorillonite clays, with no evidence of kaolinite even in horizons lying adjacent to soil layers developed from Wasatch conglomerate. Where a particular limestone is the main parent rock, the soil contains some kaolinite and montmorillonite, but the proportions of different clays are little changed at different depths. These data and other observations not reported here strongly support the concept that clays in soils of the northern Utah area developed since Pleistocene times or even longer are mostly a result of heredity, if the soils are derived from sedimentary parent rock. Climate is a subordinate factor in altering the kinds of clays found in these soils.
Interspersed Salt‐Affected and Unaffected Dryland Soils of the Lower Rio Grande Valley: II. Occurrence of Salinity in Relation to Infiltration Rates and Profile Characteristics
Authors: Wiegand C. L. , Lyles Leon , Carter D. L.
Published: July 2010

Thirteen variables including chemical and physical characteristics, topographical features, and water table depth measurements were statistically analyzed for differences between seven saline and adjacent nonsaline soil profiles of Lower Rio Grande Valley salt‐affected dryland soils. Cumulative intake and final intake rate, electrical conductivity of soil saturation extract, exchangeable sodium percentage, clay percentage, relative elevation, sand percentage, soil surface slope, and cation‐exchange capacity were the variables most consistently different between saline and nonsaline soils. Profile salinity and water intake were both significantly correlated with profile sand and clay content and with soil surface elevation, In addition water infiltration was a function of profile salinity. Consideration of the effects of clay content, ground surface elevation, and soil slope on the processes of runoff and infiltration lead to the conclusion that the observed salinity pattern is due to differential infiltration of rainfall which results in differences in leaching between saline and nonsaline areas.
Influence of Mulches on Runoff, Erosion, and Soil Moisture Depletion
Authors: Adams John E.
Published: July 2010

A 3‐year study was conducted on Austin clay at Temple, Texas, to determine the effect of mulches of straw, gravel, and soil treated with dioctadecyl dimethyl ammonium chloride (DDAC) on runoff, erosion, and evaporation. Mulches were applied to 0.01‐acre plots on a 4% slope. Plots were fallowed 2 years and planted in grain sorghum (Sorghum vulgare) the third year. Runoff and erosion were greater from DDAC‐treated soil than from bare‐check soil. A surface cover of straw or gravel reduced runoff significantly and essentially eliminated erosion. Both the 2‐inch straw mulch and the bare DDAC‐treated soil reduced evaporation significantly from the 0‐ to 6‐inch depth during a hot, rainless 10‐day period. Straw, gravel, and DDAC‐treated soil mulches were about equally effective in evaporation control over periods of a month or more. During high rainfall periods, straw and gravel mulches increased infiltration and movement of excess water below 54 inches. The effect of chemical treatments on runoff and erosion should be considered in addition to their ability to reduce evaporation of soil moisture.
Response of Corn to Zinc as Affected by Nitrogen and Phosphorus Fertilizers
Authors: Terman G. L. , Allen S. E. , Bradford B. N.
Published: July 2010

Response of 2 successive crops of corn (Zea mays L.) forage to fine zinc sulfate mixed with 2 soils was measured in greenhouse pot experiments. Zinc sulfate was also incorporated into −9 + 16‐mesh granules of each of four phosphates, ammonium nitrate (AN), and ammonium sulfate (AS) fertilizers. Large amounts of fine dicalcium phosphate (DCP), concentrated superphosphate (CSP), monoammonium phosphate (MAP), and ammonium polyphosphate (APP) depressed the pH of Hartsells fine sandy loam (limed to pH 7.1) increasingly in the order listed. Depression in soil pH was closely related to response of corn to 6 and 12 mg of applied Zn per pot (2 and 4 ppm of Zn). In Nolichucky sandy clay loam (pH 7.3) and Hartsells soil limed heavily to pH 8.0, soil pH remained high and response to Zn with the APP, MAP, and CSP sources of P was similar and greater than with DCP. Forage yields and uptake of Zn were in the order: Zn mixed alone with the soil > Zn in AN or AS granules > Zn in phosphate granules > no applied Zn. Results with Zn in DCP granules were poorest. Reciprocal Relationships between concentrations of P and Zn in the corn were largely related to yield levels dependent on sufficiency of Zn.
Surface Tension and Water Contamination as Related to the Selection of Flow System Components
Authors: Topp G. C.
Published: July 2010

The changes in air‐water interfacial tensions caused by contaminants leached from 16 different materials were measured. This was an attempt to find noncontaminating components for a water flow system. A modification of the Wilhelmy slide method using a small volume of water was adopted to measure surface tensions. Only seven of the materials tested showed no measureable effect on the surface tension of the water. In addition to a reduced surface tension caused by the nine remaining materials there was an increased contact angle.
Validity of the Transect Method for Estimating Compositions of Soil‐Map Areas
Authors: White Everett M.
Published: July 2010

The large number of transects needed to estimate accurately the quantities of different soils in a soil map area precludes the method from routine use. If map area compositions can not be estimated by landscape relationships, the area probably should be considered a land type or an association.
Porosity of Surface Soil Aggregates at Various Moisture Contents
Authors: Voorhees W. B. , Allmaras R. R. , Larson W. E.
Published: July 2010

Porosity of individual surface soil aggregates at moisture contents ranging from saturation to air‐dry was determined by glass bead displacement. Measurements were made on aggregates having a diameter range from 0.5 to 10 mm at air‐dry moisture content and 2.0 to 10 mm at suctions ≤ 15 bars. The coefficient of variation for a determination of aggregate density (g cm‐3) ranged from 1 to 11% depending on diameter and moisture content. The major contributor to precision loss was heterogeneity of soil aggregates and not precision errors of the method.

More than a 50% decrease in specific total pore volume (cm3 g‐1 of oven‐dry aggregate) upon desorption from saturation to air‐dry was found for three aggregate sizes each from a Chernozem and a Chestnut soil. In both soils, the percentage of pores having diameters > 29 µ increased as aggregate diameter increased. The volume fraction of air at a given moisture content increased as the diameter of aggregate increased. For all aggregate sizes, the volume fraction of air was ≥ 0.10 at 0.33 bar suction. The two soils exhibited different types of shrinkage curves.