bluuebunny/crossref_metadata_2025 huggingface dataset:
Subirrigation and Plant Nutrition: II. Utilization of Phosphorus by Alfalfa from the Soil Surface to the Water Table
Authors: Lipps R. C. , Fox R. L.
Published: July 2010

Utilization of phosphorus by subirrigated alfalfa from the soil surface to the water table has been studied. Total and available phosphorus content of soils from adjacent fields, one cropped intensively to alfalfa and the other having little or no alfalfa history, were compared.

Long time alfalfa culture resulted in substantial reductions of total and available phosphorus to a depth of 11 feet. Phosphorus utilization by subirrigated alfalfa has been correlated with available moisture in soils. Soils with shallow water tables (10 feet or less) have water at relatively low tension throughout their profiles. Root activity is concentrated mainly in the surface soil gradually decreasing with depth. Intense root activity in the surface 3 feet of soils having relatively deep water tables (10 to 20 feet) appears to be associated with moisture from precipitation which is usually available for only a part of the growing season. Less intense but more constant root activity is to be expected in the region of capillary moisture above the water table. Decreased phosphorus utilization between these two regions coincides with a relatively dry area with consequent low root activity.

Surface and subsoil depletion of phosphorus by subirrigated alfalfa indicates that phosphate fertilization will be needed in the future if continued high yields are to be maintained.

The availability of nutrients in the substratum of subirrigated soils must be evaluated before reasonable fertilizer recommendations can be made for legumes.
Effects of Soil Moisture Tensions and of Chloride and Sulfate Treatments upon the Yield, Composition, and Bacterial Soft Rot of Irish Potatoes
Authors: Harward M. E. , Jackson W. A. , Nielson L. W. , Piland J. R. , Mason D. D.
Published: July 2010

Greenhouse experiments were conducted over a period of 2 years to determine the effects of soil moisture and of the chloride and sulfate ions upon the growth and quality of potato tubers.

Irish cobbler potatoes were grown in a soil mixture containing equal weights of Bladen fine sandy loam and 18‐mesh quartz sand. The anion variables consisted of KCl or K2SO4 applied at the rate of 180 pounds K2O per acre. The different moisture levels consisted of resaturating the soil when tensions of approximately 300, 800, 2,000 and 10,000 cm. of water were obtained. Measurements of yield, chemical composition, dry matter, specific gravity of tubers, and susceptibility of tubers to bacterial soft rot were made at or after harvest.

The yields of U. S. No. 1 tubers from the SO4‐treated plots were greater than those receiving Cl. There were some suggestions that the response to high levels of soil moisture may have been related to the source of potassium. Greater vine yields were obtained with the chloride treatments than with the sulfate. A reversal in the curve for growth of tops occurred at the lowest level of soil moisture. The use of chloride as compared to sulfate increased the content of Ca and Mg in the leaves and stems and decreased the content of Mg in the tubers. The K contents of tubers were greater with the SO4 than with the Cl treatments but no differences in K content of leaves were associated with source of potassium. Applications of SO4 as compared to Cl at all moisture levels resulted in increased contents of N in the leaves, stems, and tubers. No significant differences in the specific gravity of tubers as related to Cl and SO4 treatments were found after 6 weeks storage. The mean specific gravities of U. S. No. 1 tubers increased with increasing levels of soil moisture. The dry matter contents of leaves and stems were greater from the sulfate treated plants than from the chloride. Wound infection by bacterial soft rot organisms was less for tubers grown under low soil moisture tensions, than those grown under high tensions. The rate of bacterial decay of tubers grown under low moisture tensions was greater than for those grown under the limiting conditions of low soil moisture.
A Study of the Effect of Mineral Phosphates Upon the Organic Phosphorus Content of Organic Soil
Authors: McCall W. W. , Davis J. F. , Lawton K.
Published: July 2010

Laboratory studies were conducted to investigate the effect of mineral phosphates upon the organic phosphorus content of eight organic soils. Soil types represented were Carlisle muck, Everglades peat, Houghton muck, Istopoka peat, and Rifle peat. Six of the samples were obtained in Michigan and two from Florida. Monocalcium phosphate was applied to each soil at the following rates; 12.5, 25, 50, 100 and 200 ppm. of phosphorus. Unphosphated samples were left as controls. To determine if mineralization was as extensive as shown by analyses for organic phosphorus, available soil phosphorus was determined before and after a 4‐month incubation period. The effect of sterilization, temperature and moisture upon the mineralization of organic phosphorus in Houghton muck was also determined.

Samples were incubated for a period of 4 months and the amount of organic phosphorus determined, at the end of 2, 3, and 4 months.

No “fixation” of mineral phosphate as organic phosphorus occurred, but mineralization of the original organic phosphorus did occur. In general, the trend was toward more complete mineralization of the soil organic phosphorus, with increasing rates of added monocalcium phosphate, over a period of 4 months. Generally, the rate of mineralization was rapid the first 2 months and somewhat slower during the last 2 months of the incubation period.

The percentage increase in available phosphorus after 4 months incubation ranged from 31.1 to 292.0%.

Temperature and moisture were shown to be two factors affecting mineralization of organic phosphorus.
Effect of VAMA and HPAN Soil Conditioners on Aggregation, Surface Crusting, and Moisture Retention in Alkali Soils
Authors: Allison L. E. , Moore D. C.
Published: July 2010

A laboratory study was made to determine the relative effectiveness of VAMA and HPAN polymers at 6 rates of application in producing high water‐stable aggregation. Nine alkali soils and two nonalkali soils, obtained from experimental sites in six Western States, were used in this investigation.

VAMA conditioner proved appreciably more effective than HPAN conditioner, within the rates of application of 0.025 to 0.20%, for 8 of the 11 soils studied. For 3 soils, there appeared to be no significant difference between these 2 kinds of conditioners at any of the rates used.

The rate of application of polymers necessary for effective structure stabilization was found to be directly related to both the specific surface and the clay content of soil. Because of its simplicity, the determination of clay content by any satisfactory method is recommended as a guide to rate of polymer treatment for maximum aggregation.

As determined by modulus of rupture measurements, both types of conditioners were effective in ameliorating soil hardness, or the crusting tendency, of high‐sodium soils. However, neither conditioner exhibited an appreciable effect on soil‐moisture retention.
Immobilization and Mineralization Rates of Nitrogen during Decomposition of Plant Residues in Soil
Authors: Stojanovic B. J. , Broadbent F. E.
Published: July 2010

Two well drained New York soils of the Gray‐Brown Podzolic group, Ontario loam and Honeoye silt loam, were incubated under controlled temperature, moisture, and aeration. Soils were treated with either wheat straw or corn leaves, and inorganic nitrogen (ammonia or nitrate). Samples were taken at 2, 4, 6, 10 and 18‐day intervals. Ammonia and nitrate nitrogen were determined. Enriched nitrogen was employed for computing mineralization and immobilization rates.

Recovery data indicate that rapid immobilization took place when wheat straw was added in combination with either ammonia or nitrate nitrogen. Immobilization of added ammonia occurred when corn leaves were added with ammonia nitrogen. Reduction of nitrate was negligible in treatments where corn leaves plus nitrate nitrogen were added.

Mineralization and immobilization data indicate that a substantial amount of nitrogen is turned over in the presence of available energy material. It has been further observed that immobilization is of significant magnitude even in the decomposition of a high nitrogen‐containing material such as corn leaves. For example, in the case of wheat straw plus nitrate, during the 2 to 6‐day interval, the equivalent of 56 pounds of nitrogen per acre per day was immobilized. Maximum turn over occurred in the 0 to 2‐day interval with corn leaves. In the latter case the maximum microbial activity would be attained earlier since the energy material was more available.
A Study of the Origin and Distribution of Loess in Southern Indiana
Authors: Caldwell R. E. , White J. L.
Published: July 2010

Soil profile studies were made along two traverses extending from the Wabash River in a southeasterly direction across southern Indiana for the purpose of determining the distribution of loess in this area. The variation in thickness of the loess mantle with distance from the Wabash River, the assumed source, was measured, and equations of the curves showing the relationship were calculated. X‐ray diffraction studies were made of the medium and fine silt fractions of the A2 horizon of 10 profiles along the southern traverse. The ratio of the quartz/feldspar intensities was determined using sodium fluoride as an internal standard. The calcium, sodium, and potassium content of the medium silt fractions of these 10 horizons was determined by flame photometry. The equation for the curve fitted to points plotted along the northern traverse was Y = 122 − 47 log X, where Y is the depth of the loess in inches and X is the distance from the Wabash River in miles. The equation for the southern traverse was Y = 125 − 53 log X. The X‐ray diffraction studies indicate that the quartz/feldspar ratio may be used as an index of weathering. The correlation coefficients for the relationship between the quartz/feldspar ratio and distance from the Wabash River were 0.95 and 0.96 for the medium and fine silts, respectively. The results of the chemical determinations substantiated the findings of the X‐ray diffraction studies. It is concluded that loess was transported across southern Indiana for a distance of about 90 miles.
Tillage Studies with Corn on an Ohio Lakebed Clay Soil
Authors: Taylor George S. , Johnson W. H.
Published: July 2010

A 3‐year tillage study with corn was conducted on Hoytville silty clay, an extensive soil in the old glacial lakebed which covers portions of Ohio, Indiana, and Michigan. The treatments were fall plowing, spring plowing at shallow and normal plow depths, spring plowing of wet soils, and surface tillage after spring plowing which gave two degrees of seedbed “fineness”.

Treatment brought about a wide range of surface conditions on plots following alfalfa or corn. Fall and shallow plowing have usually resulted in fine seedbed and in rapid emergence. Coarse seedbeds and less rapid emergence were obtained by spring plowing at normal plow depths. Shallow and wet plowing resulted in lowest soil moisture contents. The treatments resulted in significant differences in soil porosities and nitrogen contents following alfalfa but not following corn. Following alfalfa, spring plowing at normal plow depths brought about highest soil porosities and greatest leaf nitrogen contents; while fall, wet, and shallow plowing were associated with lower porosities and nitrogen. The treatments had no effect on phosphorus contents and affected potassium contents only during a drouthy season.

Corn yields were reduced during a drouthy season by spring plowing with maximum seedbed fitting, and by shallow and wet plowing. Lowest yields were obtained from the treatments which result in lowest soil moisture contents. There were no significant yield differences during 2 years of better rainfall distribution.
Thermodynamics of Zinc Adsorption on Calcite, Dolomite and Magnesite‐Type Minerals
Authors: Jurinak J. J. , Bauer Norman
Published: July 2010

The adsorption of zinc chloride on calcite, dolomite and Casubstituted magnesite crystals from aqueous solution is treated theoretically; and a standard adsorption process is thereby rigorously defined. The thermodynamic characteristics Δ F0θ, Δ H0θ and Δ S0θ are determined for this process by means of adsorption isotherm data at various temperatures with crystals of measured surface area.

It is found that about 10% of the adsorption sites probably available on calcite are occupied by zinc when the equilibrium Zn++aq concentration is 0.90 × 10‐6 M at 25.1° C. The Ca‐magnesite shows a somewhat greater affinity for zinc ion than calcite, while dolomite is intermediate. The temperature coefficients of Δ F0θ are opposite in sign for calcite and the other two minerals. The resulting endothermic heats of adsorption of Zn++aq on the dolomite and the Ca‐magnesite (Δ H0θ = 8.21 ± 2.4 and 22.7 ± 5.9 kcal/mole at about 27° C, respectively), as well as the corresponding very large positive entropies of adsorption (Δ S0θ = 56 ± 8 and 106 ± 20 cal/deg × mole at about 27° C, respectively) indicate that Zn++aq is dehydrated when adsorbed by these two minerals. The known compatability of Zn++ with the MgCO3 crystal lattice is suggested as the reason for the strong interaction of this ion with the dolomite and Ca‐magnesite, relative to calcite.
Surface Reactions of Clay Minerals
Authors: Mortland M. M. , Erickson A. E.
Published: July 2010

The effects of particle size of various clay minerals on the properties of cation exchange capacity, ethylene glycol retention, and gas adsorption were determined. The particle size of the clays was varied by limited ball‐milling procedures. Kind of exchangeable cation did not greatly affect the ethylene glycol retention by non‐expanding clays, but cations capable of undergoing fixation did affect the retention by montmorillonite. This indicated the effect of exchangeable cations, capable of fixation reactions, was to prevent solvation of the inner‐layer spaces of montmorillonite rather than a differential association between the cations and ethylene glycol. Ethylene glycol retention was not found to be a function of cation exchange capacity. Specific surface figures determined by ethylene glycol retention and by B.E.T. analysis, using ammonia adsorption, agreed fairly well for non‐expanding clay minerals but differed considerably for montmorillonite.
Availability of Nitrogen from Crop Residues during the First and Second Seasons After Application
Authors: Fribourg H. A. , Bartholomew W. V.
Published: July 2010

The availabilities of nitrogen in alfalfa tops, red clover tops, soybean straw, and oat hulls were compared at different rates of application with the availability of nitrogen from ammonium nitrate. The initial applications were made and evaluated on corn but the carry‐over effects in the second cropping season were measured with an indicator crop of oats.

During the first cropping season, freshly cut alfalfa tops were more efficient in increasing corn yield than equivalent rates of application of red clover. Soybean straw had little or no influence on corn yield and oat hulls tied up soil nitrogen and resulted in decreases in corn yield. On the basis of pounds per acre of nitrogen applied, the mean efficiency of alfalfa in supplying nitrogen to the corn crop was only about 34% of that of ammonium nitrate.

Nitrogen availability from the residues during the second growing season was not more than 7.5% of that originally contained in alfalfa and 3.5% of that contained in red clover. About 2% of the original nitrogen from soybean straw appeared to be available during the second cropping season, but none of the nitrogen from the oat hull applications. Only where large amounts of residue had been applied to corn the first season were the carry‐over effects measurable during the second season.
Soil Reactions at Various Depths as Influenced by Time Since Application and Amounts of Limestone
Authors: Brown B. A. , Munsell R. I. , Holt R. F. , King A. V.
Published: July 2010

Limestone at 2, 4, 8, and 16 tons on the surface of grassland in 1930, increased the pH to depths of 6, 12, 15, and 24 inches, respectively, by 1939. By 1953, the pH had increased to depths of 8, 10, 24, and 30 inches, respectively. The soil was a fine sandy loam, with 50% clay plus silt and had not been tilled since about 1895.

The results 2 years after adding the limestone show that even the unusually high rates of limestone had not affected the pH values of the soil nearly as deeply as had much less limestone after longer lapses of time.

The surface inch of soil had increased in acidity again 5 years after liming in the 1‐, 2‐, and 4‐ton plots, and 9 years after liming in the 8‐ and 16‐ton plots.

The lime requirement and exchangeable base determinations corroborate the pH data.

The results clearly show that it is possible to decrease the acidity of soils to depths far below where liming materials are actually placed. For a given soil and climate, rates and final depths of such penetrative effects depend on the amount of lime applied and on the lapse of time.
Correlation Between Plant Analyses and Soil Tests in New Mexico
Authors: Pack M. R. , Gomez R. S.
Published: July 2010

As part of a plant nutrient survey of New Mexico, samples of cotton leaves and alfalfa were collected from a wide variety of soils throughout the state. The soil was also sampled at each location. Within each set of samples (cotton and alfalfa) the following comparisons were made by means of correlation analysis: plant P with CO2‐soluble soil P, NaHCO3‐soluble soil P, H2O‐soluble soil P, and Bray's adsorbed soil P; plant N with total soil N and soil organic matter; and plant K with CO2‐soluble soil K. Significant positive correlations were found in all comparisons except those involving N. The degree of correlation was used as a basis for evaluating the different soil testing procedures.

Of the four P tests that were tried, H2O‐soluble soil P showed the best correlation with plant P. There was a better correlation between the H2O‐soluble soil P and the NaHCO3‐soluble soil P than between the results of any other two of the soil P tests. Apparently, neither total soil N nor soil organic matter gives a reliable indication of the available N in New Mexico soils. The correlation between plant K and CO2‐soluble soil K was fair.
Salt Concentration a Factor in the Availability of Phosphorus from Rock Phosphate as Revealed by the Growth and Composition of Alfalfa
Authors: Howe D. O. , Graham E. R.
Published: July 2010

A study of the availability of phosphorus held in rock phosphate in relation to the soluble salt content of sandclay cultures was made. An effort was made to relate the availability of the phosphorus to the relative bonding energies of Putnam clay for calcium, magnesium, potassium, and hydrogen. Alfalfa was grown as the test crop. The less than 0.2 µ Putnam clay was brought to desired cation saturation by making the system unsaturated by treating the Na suspended clay with hydrogen‐Amberlite (IR‐120), electrodialyzing to reconcentrate, and then adding carbonates or hydroxides of Ca, Mg, and K. Trace elements and nitrogen as ammonium nitrate were added in small amounts. Phosphorus was added as either rock phosphate or phosphoric acid. Calcium, magnesium, potassium, and sodium salts were added. Calcium and magnesium salts were added in series at 0.010, 0.020, 0.041, 0.081, and 0.163 moles per liter and potassium and sodium salts at 0.020, 0.041, 0.081, and 0.163 moles per liter of soil water.

The results showed all salts influenced the availability of phosphorus held in rock phosphate. However, calcium salts reduced phosphorus uptake with small reduction in plant yields. Variable effects on plant yields and phosphorus uptake resulted when magnesium salts were used. Potassium salts of different anions produced different degrees of response, with the first increments of the carbonate and sulfate giving a positive yield response while the chloride depressed growth and phosphorus uptake. Sodium sulfate gave a reduction in crop yields and phosphorus uptake indicating an influence of excessive sodium.
Potassium Release Characteristics of Several Soils from Ohio and New York
Authors: Garman William L.
Published: July 2010

Seventeen Ohio surface soils, 25 New York surface soils, and 21 New York subsoils were investigated. Potassium release characteristics were determined by continuous cropping and by four different chemical methods. A continuous leaching method employing the use of 0.01 N HCl gave the highest correlations with continuous cropping. Cumulative amounts of potassium removed by this leaching technique were plotted to produce a family of curves with specific characteristics for each great soil group. A measure of the rate of release of K from structural positions is indicated by the slope of the line drawn between the points plotted from 5 to 10 liters of leachate.

Potassium release from both surface and subsoils followed the order of Brown Forest>Gray‐Brown Podzolic>Brown Podzolic>Podzol. The average K concentration in the last 5 liters (10 liters total) of leaching solution from surface soils was as follows: Brown Forest 0.31 ppm., Gray‐Brown Podzolic 0.12 ppm., Brown Podzolic 0.05 ppm., and Podzol 0.04 ppm.
An Investigation of Some of the Relationships between Copper, Iron, and Molybdenum in the Growth and Nutrition of Lettuce: I. Experimental Design and Statistical Methods for Characterizing the Response Surface
Authors: Hader R. J. , Harward M. E. , Mason D. D. , Moore D. P.
Published: July 2010

In studies involving the experimental determination of critical levels of plant nutrients and optimum rates of fertilizer application, the need for the consideration of joint effects of other nutrients has long been realized. Where such joint effects or interactions exist, characterization of the response surface is essential for the realistic evaluation of the responses. The use of the complete factorial experiment provides a means of estimating the response surface; but the number of treatment combinations required, especially where more than two nutrients or factors are involved, has often prohibited their use in field and greenhouse research.

Where a polynomial model may be used to approximate a response surface, new experimental designs, known as the composite and rotatable designs, have been developed by Box and Hunter. In these designs, the treatment combinations are selected to allow estimation of the parameters of the model. These designs use considerably fewer treatment combinations for the experiment than required by the complete factorial arrangement. Other important advantages of those designs are discussed.

The basis of construction of these designs is briefly discussed and some examples are presented. The details of statistical analysis are illustrated by the use of experimental data from a greenhouse experiment with lettuce.
Production of Sugar Beets Following Winter Green Manure Cropping in California: I. Nitrogen Nutrition, Yield, Disease, and Pest Status of Sugar Beets
Authors: Williams W. A. , Ririe David
Published: July 2010

Leguminous and nonleguminous winter green manure crops were grown in two field experiments and followed by sugar beets as a test crop. The latter were fertilized with several levels of nitrogen. The legume, purple vetch, made approximately 80 pounds of nitrogen per acre available to the succeeding crop as indicated by the response in sugar production and beet petiole analysis for nitratenitrogen. The nonlegume, barley, depressed sugar production from unfertilized sugar beets by making some soil nitrogen unavailable. The trend of the petiole nitrate‐nitrogen content as influenced by the green manures and fertilization was observed through the season and was found to be closely related to the sucrose content of the beets at harvest.
The Distribution of Nonextractable Phosphorus in Some Gray‐Brown Podzolic, Brunizem, and Planosol Soil Profiles
Authors: Bauwin George R. , Tyner Edward H.
Published: July 2010

Substantial amounts of phosphorus, which resists solution in conventional phosphorus fractionation solvents, are found in many soils. In this report, the insoluble phosphorus fraction is termed nonextractable phosphorus.

The distribution of nonextractable phosphorus in the horizons of four Illinois soil‐type sequences developed on Peorian loess was studied. The relative proportion of the total soil phosphorus occurring in nonextractable form in the various soil horizons was B > A > C.

The very low content of nonextractable phosphorus found in the parent loessial C horizons, and the greater and variable nonextractable phosphorus contents found in the A and B horizons of soils developed on Peorian loess, suggested that the synthesis of nonextractable phosphorus forms in soils was related to weathering and soil development processes. No relation between degree of soil maturity and level of nonextractable phosphorus was apparent for the A horizons; however, a very significant increase in the nonextractable phosphorus content of the B horizons was found to occur with increasing soil maturity, particularly from the early through the medial stages of development. It was concluded that the accumulations of nonextractable phosphorus observed were associated with soil development processes.
The Use of Aqua Ammonia in the Hawaiian Sugar Industry: II. Injection Studies
Authors: Humbert R. P. , Ayres A. S.
Published: July 2010

The shift from solid forms of nitrogen fertilizer to aqua ammonia has resulted in an annual saving to the Hawaiian sugar industry in excess of $1,000,000. Where reasonably good water distribution is obtained, aqua is successfully applied in the irrigation stream. Results of 35 tests show an average decrease in nitrogen content of 21% as ammoniated irrigation water flows from the head to the tail of 200‐foot furrows. About 20% of the decrease was found by tests in plastic lined furrows to be due to volatilization. Ammonia applied in the irrigation water is retained in the top few inches of soil. It is rapidly nitrified, and is then carried downward by subsequent irrigation.

Laboratory studies of aqua ammonia applied directly to the surface of acid soils showed losses up to 15%. In alkaline soils where application rates exceed the ammonia saturation capacity of the soil, volatilization losses can exceed 50% even when placed at depths of 4 inches.

On the unirrigated plantations, aqua is applied by injection at rates of 60 to 200 pounds of N per acre either with the seed at planting, or near the stools at ratooning. Laboratory and field studies show, that at the high concentrations of ammonia obtained by injection, nitrification is retarded. This minimizes loss by leaching and results in effective utilization of the applied nitrogen.
Fragipan Horizons in New York Soils: I. General Characteristics and Distribution
Authors: Carlisle F. J. , Knox E. G. , Grossman R. B.
Published: July 2010

Fragipans are dense, brittle subsoil horizons that appear to be indurated when dry, but the apparent induration disappears upon moistening. They are genetic soil horizons that have developed from many different parent materials. Fragipans have a wide geographic distribution, and they have been found below A‐B horizon sequences characteristic of several great soil groups, and as a component of Low Humic Gley profiles. Properties of fragipans are closely related to texture of the soil material and the natural drainage of the soil. Fragipans are generally less permeable to water than the horizons above or below. Root penetration into these pans is very limited.
Relationships between Rigidity and Particle Size Distribution
Authors: Grossman Robert B. , Cline Marlin G.
Published: July 2010

Twenty‐four fragipan horizons were studied to determine the relationships between rigidity and particle size distribution. Objective consistence measurements, using relatively unaltered clods, were related to various textural components. Fourteen of the horizons were relatively sandy (sandy loams and light loams) and 10 were silty (silt loams).

The measurement of consistence involved: (1) shaping clods by hand into rough cylinders approximately 40 mm. long and 25 mm. in diameter; (2) encasing the upper and lower surfaces of each clod in plaster of paris to form smooth, parallel bearing surfaces; and (3) crushing the clods by the slow application of an axial stress and recording the maximum stress withstood per unit of crosssectional area over which the stress was applied. Mean values of 25 to 40 clods from each horizon were used in analyses of the data.

Rigidity was found to be highly correlated with percent total clay. It was concluded that clay was a principle bonding agent among primary particles, that very fine sand or silt may be equally effective as a matrix within which such clay bonding may occur, and that clay may act either as a bonding agent or as an agent of structural development and consequent weakness, depending upon its amount and distribution within the soil mass. The data do not suggest a special role for ultra‐fine clay.
Field and Laboratory Studies of the Lufkin Soil, a Planosol
Authors: Kunze G. W. , Oakes H.
Published: July 2010

The Lufkin soil is an extreme type of clay pan Planosol found in a warm‐temperature humid climate and is developed in moderately clayey sediments of deltaic and marine origin. It occupies mainly, smooth erosional upland with gradients dominantly less than 2%. The solum is composed of a relatively thin A1 horizon with an erratically developed thin, vesicular A2 resting abruptly on a dense subsoil of clay loam to clay texture.

Analyses were made on four profiles for particle size distribution, pH, organic matter, cation‐exchange capacities, exchangeable cations, surface area, and mineral composition.

The < 2µ fraction in the B21 horizons was found to range from 35 to 48%. The largest amount of fine clay (< 0.2µ) occurred in the B21 horizons. Montmorillonite dominated the clay raction in all profiles investigated. Relatively large amounts of exchangeable sodium and magnesium are reported for the lower portions of each soil profile.

It is believed that eluviation of the fine clay from the A horizons with subsequent accumulation in the B horizon (illuviation) and clay formation in combination with the relatively large amounts of exchangeable sodium and possibly magnesium, plus a swelling type clay, are responsible for development of the clay pan, but which was the more important is not known.
Influence of Continuous Cropping on the Fixation and Release of Potassium in Three Pennsylvania Soils
Authors: Grissinger E. , Jeffries C. D.
Published: July 2010

The fixation and release of potassium by three Pennsylvania soils was studied under greenhouse conditions using ryegrass as the indicator crop. The soils studied were representative of the two types of clay mineral distributions determined by a previous mineralogical survey of the soils of Pennsylvania.

The potassium fixed by the soils during the greenhouse experiment was measured two ways: the fixation of exchangeable potassium as nonexchangeable, and the fixation of acid soluble potassium as acid insoluble. The amounts of potassium fixed as nonexchangeable and as acid insoluble potassium were approximately the same. The potassium fixed under moist greenhouse conditions was less than that fixed by repeated wetting and drying the soils at 75°C. The difference in the potassium fixation capacities of the soils was related to the physical characteristics of the vermiculite contained in the respective soils.

The release of potassium by the soils during the greenhouse experiment was again measured two ways: the release of acid insoluble potassium as acid soluble, and the release of acid soluble potassium as exchangeable. The best indicator of the rate of release of potassium was the acid soluble potassium. The different rates of release of potassium by the soils were related to the hydrous mica content and were responsible for the significant differences in the ryegrass yield of the three soils.
Green Manuring and Crop Residue Management in Rice Production
Authors: Williams W. A. , Finfrock D. C. , Davis L. L. , Mikkelsen D. S.
Published: July 2010

A series of field experiments were conducted to determine the nature of the effects of green manures and rice crop residue management on lowland rice production. Winter leguminous green manure was determined to be an inexpensive, efficient source of nitrogen which fits in well with continuous rice culture in the Mediterranean type climate of California. The marked response of rice to leguminous green manure was duplicated, for the most part, by inorganic nitrogen applications when properly placed in the reducing zone of the rice soil.

Leguminous green manure served to add nitrogen to the highly carbonaceous rice crop residues. This permits decomposition to proceed without tying‐up nitrogen needed by the subsequent crop, and provides a satisfactory alternative to the deleterious practice of burning the residues.
Effect of Tile Spacing on Crop Yield and Water Table Level in a Planosol Soil
Authors: Schwab G. O. , Kirkham Don , Johnson H. P.
Published: July 2010

Six years of data are presented on the effect of tile drainage in a Planosol soil (claypan soils of flat lands) at spacings of 15, 30, and 60 feet. Corn, oats, and hay yields were obtained as well as water table levels, rainfall, tile outflow, soil texture, and soil hydraulic conductivity measurements. Corn and oat yields on the 15‐ and 30‐foot spacings varied from 3.4 to 9.1 bu. per acre higher (significant at 99% probability) than the yields on the 60‐foot spacings. Water table, outflow, and hydraulic conductivity measurements seem to indicate that water movement to the tile is largely through the more permeable backfill over the drains. The initial water table midway between the drains a few hours after a rain is lower for the narrower spacings; subsequently, the rate of drop is nearly the same for all spacings. After the first day following rainfall, evapotranspiration and other losses appear to influence the rate of drop more than the tile. Between the drains the water table is nearly flat. After the soil is saturated, tile outflow increases rapidly within a few minutes after the rain starts and reaches a peak in 2 to 4 hours. Several peak flows of over 1 inch per day were recorded. The maximum tile outflow volume measured for a given storm was 55% of the rainfall; however, this percentage is influenced greatly by antecedent moisture conditions.
Hydrodynamic Dispersion of Solutes in the Soil Moisture Stream
Authors: Day Paul R. , Forsythe Warren M.
Published: July 2010

The soil moisture stream is characterized, even in the simplest cases, by a heterogeneous velocity pattern that affects the movement of dissolved solutes. The solutes are carried by the moving stream at diverse rates, causing a spreading action whose amount depends upon the detailed pattern of the flow.

The amount of dispersion (σd) in unidirectional flow is proportional to the square root of the linear displacement of fluid. The proportionality constant is a characteristic of the flow system and can be determined experimentally. The amount of dispersion obtained for a given amount of linear displacement is theoretically independent of the velocity of flow. Experiments supporting this conclusion are cited.

The experiments with ion exchange resin described herein indicate that the free ions are translocated in accordance with Scheidegger's probability theory. One concludes that the movement of dissolved solutes in the soil moisture stream cannot be determined adequately from the average fluid velocity unless the hydrodynamic dispersion effect is taken into account.
Soil Potassium‐Moisture Relations: I. Potassium Release Observed on Drying Iowa Soils With Added Salts or HCl
Authors: Scott A. D. , Hanway J. J. , Stickney E. M.
Published: July 2010

Increments of salts or HCl were added to field‐moist samples of selected Iowa soils. The soils were then dried and extracted with neutral 1N NH4Ac to determine the K released under these conditions.

When no salt or HCl was added, there was a continuous increase in K release when the moist soils were first dried at room temperature and then at progressively higher temperatures. The release of K at elevated temperatures appears to be part of the same extractable K‐moisture relationship that has been observed when soils are airdried.

Soils that normally released K on drying showed a continuous net fixation of K on drying when enough KCl was added to the moist soil. When lesser amounts of KCl were added both fixation and release were observed in the same drying sequence. The release of K was reduced when NH4Cl, NaCl, or HCl was added to the soil prior to drying. The NH4Cl additions were particularly effective. CaCl2 additions had little or no effect on the K released by drying.
Soil Potassium‐Moisture Relations: II. Profile Distribution of Exchangeable K in Iowa Soils as Influenced by Drying and Rewetting
Authors: Hanway J. J. , Scott A. D.
Published: July 2010

Exchangeable K was determined in “moist,” air‐dry, and oven‐dry samples from profiles of different Iowa soils. All moist subsoil samples contained low amounts of exchangeable K. Drying increased the exchangeable K in all of the samples, but in general, the subsoils released more K on drying than the surface soils. Thus, the profile distribution of exchangeable K depended upon the moisture content of the soil samples at the time of extraction.

No relation existed between the amount of K released on drying and the amount of released K that reverted to fixed form when the soils were subsequently stored under moist conditions. There was more reversion of K to fixed form in the Marshall profile samples and in samples from below 3 feet deep in the Carrington, Fayette, and Edina profiles than in samples from the upper 3 feet of these profiles. This indicates that greater reversion occurs in the least weathered material. In some cases reversion occurred in the oven‐dried samples but not in the air‐dried samples.
The Weathering of Some Boron‐Bearing Materials
Authors: Graham E. R.
Published: July 2010

The weathering properties of several boron‐containing minerals and materials were studied for their solubilities and reactions in water and their exchange reactions in contact with clay.

The amounts of boron released from the minerals Howlite, Bakerite, Colemanite, Tourmaline, and boron frits, 176‐E and 176‐F, some commercial preparations, were investigated by treating these materials with distilled water at room temperature, hot distilled water as in a Soxlet extraction, hydrogen‐saturated IR‐120 amberlite, Putnam clay, and sodium EDTA. The bakerite and tourmaline minerals were studied for the availability of the mineral‐held boron as demonstrated by growing alfalfa plants in sand‐clay cultures that had received treatments of these minerals as a source of boron.

The amount of boron released was related to the nature of the mineral and to the type of weathering agent employed. The calcium borosilicates, Howlite and Bakerite, were weathered most highly by the weathering agents with high calcium‐bonding energies such as amberlite IR‐120 and EDTA. They were moderately weathered by hot water extraction, and weathered least by distilled water. The calcium borate, Colemanite, and the two boron frit compounds released the largest amount of boron when treated with the hydrogen‐saturated IR‐120. The Tourmaline released only traces of boron, regardless of the weathering treatments.

The plant root study of the availability of boron revealed the Bakerite mineral as an actively available source of boron, even such that it released excess amounts. The boron held in Tourmaline is unavailable to the plants.
The Availability of Phosphorus in Various Sources of Rock Phosphate as Shown by Greenhouse Studies
Authors: Bennett O. L. , Ensminger L. E. , Pearson R. W.
Published: July 2010

Greenhouse studies were carried out to determine the value of seven sources of rock phosphate as compared with superphosphate for production of Sudangrass and Ladino clover on two soils with and without lime. A significant difference was found in the amount of phosphorus available to plants from the various sources of rock phosphate as shown by yields and phosphorus uptake by Sundangrass and Ladino clover. The availability of the seven sources of rock phosphate was affected by both lime and soil type; however, source of rock phosphate was more important than either.

In general, the foreign sources of rock phosphate tested, which included Tunis, Morocco, and Curacao Island, were superior to all of the domestic sources of rock phosphate except that of South Carolina. Rock from the latter state was as available as any of the foreign sources of rock phosphate tested.

No correlation was found between fluorine content or specific surface of the sources of rock phosphate and their availability to plants. Chemical solubility was a better measure of availability than fluorine content or specific surface.
A Microscopic Method for the Detection of Alkaline Earth Carbonates in Soils
Authors: Matelski R. P.
Published: July 2010

A microscopic method for the detection and estimation of alkaline earth carbonates in soils is described. Essentially, the method consists of adding 10.7N sulfuric acid to soil on a glass slide and estimating microscopically the carbonates from the number of needle‐like crystals of calcium or magnesium sulfate that develop. Trace amounts of carbonates can be estimated. The method is also useful in the determination of the relative number of fragments or coatings of carbonates in soils. Data indicate that soils differ in the thickness of the carbonate coating on minerals and in the presence of concretions or rock fragments.
Factors Affecting Calcium Nutrition of Celery, Tomato, and Pepper
Authors: Geraldson C. M.
Published: July 2010

All of the factors most frequently associated with the prevalence and severity of blackheart of celery and blossom‐end rot of tomatoes and peppers can be placed into two categories according to the mechanisms by which they affect calcium nutrition.

Mechanism A.—Excessive soluble ammonium, potassium, magnesium, or sodium or a deficiency of soluble calcium (low calcium ratio) cause a decreased calcium uptake and increased incidence of the physiological disorders. On an equivalent basis, ammonium decreases calcium uptake of tomatoes to the greatest degree; sodium the least.

Mechanism B.—Excess total salts can cause a calcium deficiency and has frequently been associated with the prevalence of these disorders even when the measurable calcium ratio is considered high or adequate.

A deficiency of boron was of minor importance in affecting the calcium nutrition, but high calcium ratios severely accentuated a boron deficiency.

A favorable calcium ratio should be maintained to the best degree possible by (1) supplying larger amounts of soluble calcium salts, and (2) avoiding, as much as possible, excesses of soluble ammonium, potassium, magnesium, or sodium salts as well as excess total soluble salts.

Periodic calcium sprays are recommended as a source of calcium supplementary to that supplied by the soil as a means of maintaining an adequate supply of calcium to meet the plant requirement at all times.
Genesis of Some Thick‐Surfaced Brunizemic Soils of Eastern Oklahoma
Authors: Brengle K. G. , Gray Fenton , Galloway Harry
Published: July 2010

Thick‐surfaced Brunizemic soils, Taloka silt loam, occur in eastern Oklahoma and adjoining states. A Taloka silt loam profile consists of (1) a dark grayish brown A1 horizon 10 to 20 inches thick; (2) a brown to light brownish gray, soft floury A2 horizon 10 to 14 inches thick containing some black concretions and slightly mottled in the lower part; (3) a dark grayish brown, mottled B21 horizon with dark clay film on peds, blocky, containing some small black concretions, becoming less dark but more clayey below; and (4) mottled, grayish brown, yellowish brown, and strong brown very firm and very slowly permeable clay (C).

The following analyses are reported on (1) each of the several horizons of two profiles of typical Taloka silt loam, and (2) the major horizons of an adjoining Teller fine sandy loam: particle size distribution, bulk density, percent organic matter, percent total nitrogen, and pH. Base‐exchange capacity was determined for the < 2µ fractions of each horizon. Heavy, medium, and light mineral determinations were made on the very fine sand and coarse silt fractions of each horizon.

The physical, chemical, and mineralogical measurements indicate that the Taloka silt loams possess more than one solum. The data show that the upper and more silty horizons have undergone horizon differentiation under a different regime of soil development than the more clayey and lower horizons.
Retention of Organic Matter and Nitrogen by the Silt and Clay Fractions and by the Whole Soil as Affected by Lime and Organic Residues
Authors: Laws W. Derby
Published: July 2010

The experiment was conducted in glazed 3‐gallon pots in the greenhouse, using Kirvin clay soil, limed and not limed, treated with red clover, wheat straw, and Juniper wood residues. An application of 59.5 mg. of nitrogen per 100 g. of soil was made at the beginning, and again after 15 months. Soil samples were taken from each treatment before planting the first crop, after 15 months, and again after 48 months. Ten crops were grown during the 4‐year period.

There was a marked loss of nitrogen from all soils during the experiment, but loss from limed soil was greater than from unlimed soil. The highly carbonaceous materials retarded nitrogen loss. There was a tendency for nitrogen to accumulate in the silt fraction, especially in unlimed soil.

The amount of organic matter retained by the soil was not affected by lime content and there was no difference in organic matter and total nitrogen contents of the wheat straw and red clover treatments after 48 months, although the organic matter/nitrogen ratio was 21.0 for the red clover treatment and 34.4 for the wheat straw treatment when the experiment started.

Only the Juniper wood had a significant effect on aggregate stability after 48 months.
Use of Density Gradients for Size Distribution Analysis
Authors: Beavers A. H.
Published: July 2010

A linear‐density gradient tube, sensitive to 0.00001 g./ml., was prepared from mixtures of kerosene and bromobenzene and used to measure the specific gravity of small drops of clay and/or soil suspensions.

A small drop of suspension (0.005 ml.) was transferred with a micropipette at the required depth from the soil or clay suspension and placed in the density gradient. The drop seeks a level in the tube according to its density which depends upon the concentration of solids. The level is read with a cathetometer and compared to the level of standards of known density and weights.

The method is especially suited for the size distribution analysis of material < 0.002 mm. in diameter. Since only 0.005 ml. of suspension is required for a determination, a high‐speed centrifuge that accommodates small tubes can be employed.

The density gradient technique is more reproducible than the standard pipette method and lends itself more readily for the size distribution analysis of the clay size materials. It is as accurate for the 0.002‐mm.‐diameter clay and up to the 0.02‐mm.‐diameter silt as the standard pipette analysis, and it requires less time for a determination since only a cathetometer reading is necessary.