bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Nucleic Acid Components in Soil
Authors: Adams A. P. , Bartholomew W. V. , Clark Francis E.
Published: July 2010

A procedure is described for the quantitative estimation of ribonucleic acid phosphorus in soil. Organic phosphorus was extracted from soil by digestion with 1 N NaOH for 19 hours at 30°C. Acidification of the alkaline extract resulted in precipitation of organic materials or humus. The soluble organic phosphorus in the acid extract was separated from excess salt and concentrated by adsorption on activated alumina. After removal from the alumina, the extract was resolved by anion‐exchange chromatography. Samples of the eluants from chromatographic peaks were analyzed in a spectrophotometer. Techniques were evaluated by the addition of known quantities of nucleic acid to soils and the determination of the extent of nucleotide losses in the several steps involved.

The data showed that a Carrington soil containing 575 ppm. of organic phosphorus, and a Webster soil containing 327 ppm., contained not more than 1 ppm. and 6 ppm., respectively, of ribonucleic acid phosphorus by the above described technique. The large fraction of soil organic phosphorus was not identified, but the evidence was considered adequate that only a small portion of the soil organic phosphorus could be accounted for as nucleic acids. Purine bases were not detected in soil hydrolysates. Paper chromatograms were run on an acid hydrolysate of soil and the migration of the ultraviolet absorbing spots compared with the migration of known purine bases. Under ultraviolet light no migration of the soil hydrolysate could be detected. The absence of detectable quantities of purine bases also indicated that very little nucleic acid exists in the soil.
Phosphorus Needs of Small Grains on a Moderately Saline Soil
Authors: Fine Lawrence O. , Carson P. L.
Published: July 2010

An exploratory study was started in 1950 to evaluate soil amendatory practices which might be used to increase the yield of small grain on mildly saline intrazonal soils of the Chernozem area. Symptoms presently regarded as salt injury are widely observed on barley and oats and are associated with rather striking phosphate responses on the Maple soils. Application of large amounts of phosphate fertilizers, or manure and phosphate, in both the greenhouse and the field increased yields remarkably and alleviated symptoms on oats and barley. Phosphate application with the seed proved to be approximately twice as effective as broadcast applications.

Investigation of the soils revealed a higher total phosphorus content in the saline soil than in surrounding non‐saline soils. However, smaller percentages and absolute amounts of phosphorus were soluble in sulfuric acid extractions of the saline than of the normal soil. In a greenhouse experiment using P32 on the saline and a normal upland soil, it was found that added sodium salts sharply depressed the yield, phosphorus uptake and percent plant phosphorus derived from the fertilizer, whereas added calcium salts only slightly depressed these. These observations appear to the authors to discount the theory that formation of salts of the nature of tricalcium phosphate is responsible for the low phosphorus availability in this soil.
Soil Moisture Studies of Some Great Plains Soils I. Field Capacity and “Minimum Point” as Related to the Moisture Equivalent
Authors: Cole J. S. , Mathews O. R.
Published: July 2010

Field determinations of soil moisture were made on land either continuously cropped to wheat or alternately fallowed and cropped to wheat, to depths up to 6 feet for periods up to 30 years at 31 stations or locations in the Great Plains. These determinations were made at intervals throughout the period of seedbed preparation and the life of the crop.

Two of the major points of interest that developed were the quantity of water that the soil could continue to hold against the pull of gravity, and the portion of it that could not be used by the wheat crop. Late in the 1930's data on these two points were abstracted on all plots — 121 — where enough data were available to make the abstractions reliable. The moisture equivalent was used as an expression of texture in examining these data. The results were assembled but not published. Recently these field determined values have been compared with laboratory vlaues obtained through recently‐developed techniques. (Part II of this paper). Their relation to the moisture equivalent is presented partly as a background for these other studies.

The moisture equivalent had a good but not an exact relationship to the field capacity throughout the range of soils studied. The regression lines established showed that there was a slight reduction in field capacity with depth, probably due to the manner of wetting.

There was a fair agreement between the extent to which wheat reduced the moisture content of the soil, and the moisture equivalent to the depth to which wheat rooted freely. Below a depth of 3 feet the extent to which wheat could remove water was affected by increasingly sparse root development that differed on the several soils. The moisture equivalent served as a means of showing the extent to which actual field reduction fell short of the level established by the soil texture.

The quantity of water between the field capacity and the minimum point for wheat decreased from the surface downward, due to a slight reduction in the field capacity and an increase in the quantity of water that wheat could not remove.

Results are applicable to dry land conditions in the Great Plains and would not apply to soils wetted by irrigation or by a more continuous or adequate water supply.
Some Factors Affecting the Adsorption of Sulfate by Alabama Soils
Authors: Ensminger L. E.
Published: July 2010

The sulfate content of a number of Alabama Soils was determined by extracting with various solutions. The sulfate extracted was measured turbidimetrically. Some factors affecting the adsorption of sulfate by soils were studied.

About the same amount of sulfate was extracted by neutral sodium acetate solution, sodium acetate buffered at pH 4.8, KH2PO4 solution containing 100 ppm. phosphorus, and KH2PO4 solution containing 500 ppm. phosphorus. However, 0.1 N HCl solution extracted little or no sulfate. The samples contained only small quantities of water‐soluble sulfate except where sulfate had been recently applied.

The results show that sulfate is retained to a certain extent by most soils. The subsurface layers usually contain more sulfate and are capable of adsorbing more sulfate than the surface layers. The surface layers of most of the light textured soils did not contain sulfate or show a capacity to adsorb sulfate from solution.

The capacity of soils to adsorb sulfate is affected by certain soil treatments. Increasing amounts of superphosphate applied to a Cecil sandy clay loam resulted in decreasing amounts of soluble sulfate. The data show that superphosphate decreased the capacity of this soil to adsorb sulfate from a CaSO4 solution. Liming also resulted in a decrease in the retention of sulfate.

The sulfate adsorption capacity of a number of materials was determined in an attempt to show what fractions of soils may be responsible for the retention of sulfate. The data show that dehydrated Al2O3 adsorbed much more sulfate than any of the other materials. The iron minerals adsorbed rather small amounts of the sulfate while the Davidson colloid, kaolinite, and bauxite were intermediate.
Variation in the Nitrogen, Phosphorus, and Potassium Contents of Pine Needles with Season, Crown Position, and Sample Treatment
Authors: White Donald P.
Published: July 2010

Important variations occur in potassium, nitrogen, and phosphorus contents of first‐year pine needle tissue depending on the part of the crown sampled, the time of year, and the tissue drying procedure. The primary aim of the study was to provide a basis for standardizing the sampling routine in collecting pine needles for foliar analyses. Several plantations in New York were systematically sampled and analyzed by standard chemical procedures to obtain data on the magnitude of these variations which have been observed by some workers, yet often ignored in tree nutrition studies. The data confirm previous observations of the percentagewise decline of potassium, nitrogen, and phosphorus in needle tissue from an early summer maximum to a fairly constant base level during the winter months. Late fall and winter sampling is recommended for foliar analysis of pine tissue. At this season, the needles are likely to be least affected by confounding physiological changes, and are also more expressive of soil fertility levels and species norms. Mid‐crown positions are recommended as expressive of crown means, whereas aspect is not considered important. Stripping of needles from branches and immediate oven‐drying (70°C.) after collection are necessary. Important dry weight losses in tissue which result in increases in nutrient percentages may occur in material which is allowed to air‐dry.
Soil Type and Land Use Effects on Percolation of Soil Water through Monolith Lysimeters
Authors: Dreibelbis F. R.
Published: July 2010

This paper presents a summary of data on percolation of soil water through monolith lysimeters with an 8‐foot profile covering the period 1938 to 1953. The effects of soil type and land use on percolation are stressed.

Soil type influences amounts and rates of percolation. The Muskingum soils, because of their lighter texture, provide greater opportunity for more rapid soil water movement which is reflected in greater amounts and more rapid rates of percolation than on the heavier Keene soils except under the circumstances noted. When all the lysimeters were in grass, the average annual percolation amounted to 16.0 inches on Muskingum silt loam (sandstone); 9.85 inches on Muskingum silt loam (shale); and 8.26 inches on the Keene silt loam. From 83% to 92% of the total annual percolation is obtained during the first 6 months of the year.

The expression of annual percolation in terms of percent of annual precipitation minus runoff affords a better comparison of land use effects on percolation. In general, percolation is lowest under corn and wheat and highest under first‐year meadow.

Soil conservation practices involving greater crop production have resulted in an appreciable decrease in percolation. This is due largely to the better vegetative cover and growth which removes more water by transpiration thereby leaving a lesser amount of soil water available for percolation.
Ion Exchange Chromatography of the Amino Acids in Soil Hydrolysates
Authors: Stevenson F. J.
Published: July 2010

In this investigation the amino acids present in soil hydrolysates were isolated and determined quantitatively, using the technique of ion exchange chromatography. A preliminary desalting was done by passing the solution through a large column of an ion exchange resin, Amberlite IR‐120, followed by elution analysis on a Dowex 50 exchange column.

Thirty‐two ninhydrin‐reacting compounds were detected in acid hydrolysates from several Flanagan silt loam soils, each of which had received a different manurial and fertilizer addition. The compounds identified were: glucosamine, chrondrosamine, aspartic acid, serine, threonine, glutamic acid, hydroxyproline, glycine, alanine, β‐alanine, γ‐amino‐n‐butyric acid, valine, proline, isoleucine, leucine, tyrosine, lysine, histidine, arginine, and phenylalanine. Twelve other compounds were not identified positively. The presence of acetylated hexosamines was established. Some quantitative differences were noted in the soil as a result of the treatments.
Distribution and Retention of Anhydrous Ammonia in Sandy Soils
Authors: Blue William G. , Eno Charles F.
Published: July 2010

Anhydrous ammonia was applied to several sandy soils which are typical of many soils in Coastal Plain areas. Applications of 58, 115 and 258 pounds per acre of ammonia nitrogen were made at a depth of approximately 5 inches with the injector feet set 13.5 inches apart. Studies were made of the distribution of ammonia around the injection line and of its retention by these soils.

The ammonia was found to be concentrated in zones from 2 to 8 inches wide, depending on the soil moisture content. Most of the ammonia was usually concentrated in a zone 3 inches wide at rates of application as high as 258 pounds per acre of nitrogen. This resulted in a very high concentration of ammonia at the injection line. The retention was somewhat variable, but in only one instance, at the 58 pound per acre rate of application, was nitrogen found which equaled that applied. On several soils, losses were shown even at the 58 pound per acre application of nitrogen.
Determination of Organic Phosphorus in Soils: I. Extraction Method
Authors: Mehta N. C. , Legg J. O. , Goring C. A. I. , Black C. A.
Published: July 2010

A procedure developed for determining organic phosphorus in soils consisted of successive extractions with concentrated HCl and 0.5 N NaOH at room temperature, and 0.5 N NaOH at 90° C. The difference in content of inorganic and total phosphorus in the combined extracts was taken as total organic phosphorus in the soil. In a group of soils, values obtained by the proposed method were higher than those by other methods. Tests indicated that the higher values resulted from the greater accuracy of the proposed method.
Conditions Affecting the Availability of Residual and Applied Manganese in the Organic Soils of the Florida Everglades
Authors: Forsee W. T.
Published: July 2010

Manganese deficiency symptoms are quite prevalent in plants growing on the organic soils of the Florida Everglades. These experiments were conducted in order to determine the effect of soil pH, microbiological populations and sources of applied manganese upon the availability of this essential element in the soil. Greenhouse and field experiments were carried out and the results measured in terms of plant growth, yield, soil analyses and plant analyses. The organic soils show progressively decreasing amounts of available manganese as their pH values increase to 6.0, and beyond this pH they may not have the ability to supply the plant requirements either from residual or applied manganese. Soil sterilization may release large amounts of residual manganese and promote normal growth of plants. Lowering of the soil pH to values slightly below 6.0 will render the fixed manganese more available and will also reduce fixation of applied manganese. Sulfur applications to lower the soil pH have been used with considerable success in commercial plantings, and have resulted in very substantial yield increases, especially with leafy vegetables.
Clay Minerals in Three Podzol Profiles
Authors: Tedrow J. C. F.
Published: July 2010

Clays from well‐developed podzols from gray acid sandstone glacial tills of Kansan, Illinoian, and Wisconsin ages were identified. After removal of the free oxides, the predominant minerals in the clay were interstratified 2:1 layer silicates, quartz, illite, and small quantities of kaolinite. Vermiculite or chlorite was present in the lower horizons of the older tills. The A2 horizons tended to be higher in quartz than the B and C horizons. Wisconsin clays were slightly higher in quartz than Illinoian or Kansan. The clays, while showing slight shifts with age and depth, were basically similar.
Theory of Capillary Flow: II. Experimental Information
Authors: Miller R. D. , Miller E. E.
Published: July 2010

Published results of experiments relating to capillary flow have been examined for data which test the capillary flow theory discussed in Part I. Pertinent information appears to be quite limited.

Kirkham and Feng assembled data showing that linear diffusion theory predicts the time dependence but not the space dependence of water intake by horizontal columns of dry soil. Nonlinear diffusion theory as used by Klute covers both dependences. For this special case of horizontal wetting, the present theory, after change of variables, reduces to Klute's form.

Desorption curves by Nelson and Baver for a series of sieved sand separates coalesce into a single reduced curve when reduced by the particle‐size factor.

Time invariant hysteresis effects are characteristic of the present theory; other theories do not exhibit hysteresis properties. Published data show that hysteresis is severe. Time invariance has been tacitly assumed by those reporting such measurements.

When measurements by Parker of freezing point depressions for three liquids in each of three substrates are converted to potential by the method of Schofield and the result is reduced, the points so obtained coalesce, though rather poorly, into a single curve for each substrate.
Rate of Phosphate Reaction with Soil Minerals and Electron Microscope Observations on the Reaction Mechanism
Authors: Kittrick J. A. , Jackson M. L.
Published: July 2010

The phosphate reaction rate for several soils was found to be very rapid initially, but diminished to lower values in a matter of minutes. For example, the rate of phosphate reaction with a Catalina Latosol after 3 minutes contact was 100 tons of superphosphate per acre per hour but after 1 month the rate of reaction had fallen to about 1 pound per acre per hour. Removal of extractable iron oxides from the Catalina soil greatly diminished the rate of reaction of phosphate with the soil but reaction with the kaolinite portion was nearly half of the total. It was possible to produce colloidal iron oxide and aluminum hydroxide particles analogous to the reactive surfaces responsible for the rapid initial reaction of phosphate with soil minerals. Electron microscope observations of these minerals in contact with phosphate solution disclosed the formation in a few minutes of separate‐phase phosphate crystals by the mechanism of solution‐precipitation. These experiments suggest that the solution‐precipitation mechanism is important in phosphate fixation in soils.
Trace Element Distribution in Virgin Profiles Representing Four Great Soil Groups
Authors: Wright J. R. , Levick R. , Atkinson H. J.
Published: July 2010

The purpose of this investigation was to study the distribution and comparative leaching of several trace elements in virgin profiles of the Podzol, Brown Podzolic, Gray‐Brown Podzolic and Brown Forest great soil groups. Two profiles of each group were analyzed for total Zn, Pb, Cu, Co, Mn and Mo. The results were compared with those for sesquioxides. The distribution of trace elements was more varied in Podzol and Brown Podzolic than in Gray‐Brown Podzolic and Brown Forest profiles.

Lead showed the greatest proportional accumulation and this was most pronounced in the A0 horizons of Podzol and Brown Podzolic profiles. Relative to sesquioxides, zinc accumulated in the A0 and B horizons of Podzol and Brown Podzolic soils and in the A1 horizons of Brown Forest profiles. Accumulations of copper relative to sesquioxides occurred mainly in the A0 horizons of Podzol and Brown Podzolic profiles. Considering all soils, copper was the element most susceptible to leaching. The distribution of cobalt paralleled that of sesquioxides in Gray‐Brown Podzolic and Brown Forest profiles. The profile distribution of manganese was irregular. The molybdenum content was greatest in the B horizon of all profiles. Generally, the sola accumulated molybdenum relative to sesquioxides.

The range in concentration, expressed as ppm., for all samples was: Zn, 10 to 150; Pb, 6 to 108; Cu, 1 to 23; Co, 0.8 to 18.2; Mn, 250 to 1380; Mo, 0.16 to 0.82. The average zinc and lead contents of the C horizons were similar to, but that of cobalt, copper and especially molybdenum were considerably less than, the average values for these elements found in the earth's crust.
Investigations on the Mobilization and Transport of Iron in Forested Soils: I. The Capacities of Leaf Extracts and Leachates to React with Iron
Authors: DeLong W. A. , Schnitzer M.
Published: July 2010

Methods for estimating the capacities of aqueous solutions derived from forest litter and forest canopy to retain iron in solution and to bring the iron of freshly‐precipitated ferric hydroxide into solution (true or colloidal) are described and results presented. It is shown that the amount of iron retained or brought into suspension depends on the source of the solution, the pH and the nature of the dominant cation present, and on the proportion of iron to organic matter in the system.
The Effect of Tractor Logging on Physical Properties of Some Forest Soils in Southwestern Washington
Authors: Steinbrenner E. C. , Gessel S. P.
Published: July 2010

An increase in tractor logging in recent years and resulting concern regarding skid road compaction led to this investigation of the effects of tractor logging on the physical properties of soils in southwestern Washington.

Nine areas of recent tractor logging with adjacent undisturbed mature timber were selected for sampling. Samples were obtained from the undisturbed timber which was used as a control, tractor roads, and tractor cutover on each of these areas. The latter included all of the area not in the major skid road system. The samples consisted of 3‐inch soil cores taken at the surface with a special sampling tool. Soil permeability rate, bulk density and pore space distribution were determined for each sample in the laboratory.

Results showed that the soils from the tractor cutover had a 35% loss in permeability rate, a 2.4% increase in bulk density and a 10% decrease in macroscopic pore space when compared to the timber control. The tractor roads showed a 93% loss in permeability, a 15% increase in bulk density and a 53% loss in macroscopic pore space. The areal extent of the tractor skid roads in this study was found to be 26% of the logged area.
Absorption of Rubidium by Plants from Solution and Soils
Authors: Murphy W. S. , Hunter A. H. , Pratt P. F.
Published: July 2010

The absorption by plants of Rb from soils and sand was measured. The Rb was added to the soil as RbCl, and in the sand culture various ratios of K to Rb were used. Corn was grown in the soils and the distribution in the plant and the soil determined. Beans were grown in the culture solutions, and the distribution of K and Rb measured in the various plant parts.

The percent recovery of Rb by the corn plant from three soils was inversely related to the K in the soil. The K to Rb ratios in the plants showed high correlation with the HNO3‐soluble K. The percent of the added Rb fixed against extraction with NH4OAc or HNO3 during the 11 weeks growing period was small.

Where bean plants were grown in sand culture with various ratios of K and Rb, the molar ratios of K and Rb in the plants differed somewhat from those in the solutions. There was also a significant difference between the K/Rb ratios in the various plant parts. Growth and fruit production in beans were reduced where the molar ratios of K to Rb were less than 5/1.
Residual Soil Phosphorus from Various Fertilizer Phosphates Extracted by Different Solvents
Authors: Salomon Milton , Smith John B.
Published: July 2010

A Bridgehampton silt loam of moderate acidity which had received phosphate from several sources for 48 years followed by 10 years without additional phosphates was analyzed for “extractable” phosphorus by 8 methods. Phosphorus from superphosphate, rock phosphate, Thomas slag, and ground bone, determined by these chemical tests, was correlated with yields of hay, phosphorus uptake, yields of sudangrass, and total soil phosphorus.

Methods using relatively strong acid extracting solutions (Bray's 0.1 HCl + 0.03 N NH4F and Thornton's 0.1 N HCl + (NH4)2 MoO4) and those employing weaker acids with wide soil extracting solution ratios (Peech's CH3COOH + NaC2H3O2 and Truog's 0.002 N H2SO4 + (NH4)2 SO4), gave the most consistent positive correlations. Bray's weaker acid solution (0.025N HCl) distinguished soils receiving rock phosphate from those receiving phosphorus from superphosphate. Alkaline extractants (NaOH and NaHCO3) and Morgan's extracting solution (NaC2H3O2 + CH3COOH), proved least adapted to the soil tested. The Peech and Truog methods, although inconvenient for quick soil tests, gave a better indication in terms of probable crop response to phosphorus than did the Bray (P2) method which, although it reflected the phosphorus status of the soil very well, extracted excessive quantities when compared to the levels of Low, Medium and High phosphorus proposed by Bray as a guide for fertilizer recommendations. The Thornton method extracted somewhat more phosphorus than had been previously established at this station for use in making recommendations based upon rapid soil tests.

Subsoils accumulated less phosphorus than topsoils but there was no correlation between the level of phosphorus in topsoil and the amount recovered from the subsoil.

Total phosphorus accumulation due to treatment was greatest in the rock phosphate plots, and least where triple superphosphate had been added. Residual effects from superphosphate, Thomas slag, and ground bone were intermediate.
Soil Test Summaries for Predicting Fertilizer Ratios and Type of Lime Needed
Authors: Fitts J. W. , Welch C. D. , Nelson W. L.
Published: July 2010

Soil test summaries have been instrumental in preparing general fertilizer recommendations on an area basis rather than for the state as a whole. Results for phosphorus and potassium, when summarized together in a two‐way table, give a good indication of the ratios of these nutrients most needed in fertilizers. The summary tables were blocked off to show the number of pounds of P2O5 and K2O recommended at different fertility levels for the various crops. The percentage of samples in the various categories indicates the proportion of fertilizer ratios needed.

Two‐way summary tables were prepared to determine the relationship of calcium and magnesium in North Carolina soils. Regardless of soil region, crops grown, or the level of calcium and magnesium, the ratio of the two elements remained remarkably constant. In general, the ratio of magnesium to calcium was about 1 to 5 which indicates that most soils throughout the state that need liming should receive a dolomitic limestone.
Crop Response to Deep Tillage with Lime and Fertilizer
Authors: Engelbert L. E. , Truog E.
Published: July 2010

Investigations over a 5‐year period on deep plowing, subsoiling, and deep incorporation of lime and fertilizer were conducted on Almena silt loam (strongly acid and tight subsoil). Subsoil treatments included tillage only, tillage with liming, and tillage with liming and fertilizing. The plow‐layer of all subsoiled plots was limed to pH 6.5 and fertilized uniformly. Plots not subsoiled received varying amounts of fertilizer, equal in several cases to the total applied to both the plow‐layer and subsoil of the subsoiled plots.

Deeper root penetration of alfalfa was promoted by subsoil liming and fertilizing, but not by subsoiling alone. Subsoil liming and fertilizing helped materially in establishing alfalfa during a dry year. Second‐year and especially third‐ and fourth‐year hay yields appeared to be increased (up to one‐half ton per acre in dry years) by subsoil liming and fertilizing, but were not increased by subsoil treatment where the fertilizer was omitted. The potassium content of the alfalfa from subsoil fertilized plots was as much as 1% higher during dry years.

Corn and oats did not appear to respond to these subsoil treatments even in the dry years, and when they followed the alfalfa‐brome grown with subsoil treatments.

In the case of deep plowing with liming and fertilizing, first‐year alfalfa‐brome gave a consistent but small response to this deep treatment; however, second‐year hay yields were increased appreciably when plowing was to a 12‐inch depth. Where the depth of plowing was 9 inches, the response was somewhat less, but still greater than where plowing, liming, and fertilizing was to a 6‐inch depth only.

In no year were the yields of corn and oats increased by deeper plowing, liming, and fertilizing, although increased vigor was noted in some years.
The Effect of Various Rates and Frequencies of Application of Rock and Superphosphate on the Yield and Composition of Forage on a Lake Charles Clay Loam Soil
Authors: Cheaney R. L. , Weihing Ralph M. , Ford R. Norton
Published: July 2010

The effects of various rates and frequencies of application of rock and superphosphate on the yield and chemical composition of pasture forage was studied on a Lake Charles clay loam soil. The amount of P2O5 in pounds per acre from each source and the frequency of fall application of this amount were: 30 lbs. every year, 60 lbs. every 2 years, 120 lbs. every 4 years, 240 lbs. every 8 years, and 480 lbs. every 16 years. The area was seeded to a pasture mixture of Dallisgrass and white, Persian, and hop clovers. Yield and chemical data are reported for the first 4 years, 1950–53. At the end of the fourth year, 4 yearly 30‐pound applications and two 60‐pound applications of P2O5 from superphosphate had equalled and surpassed the production from single applications of 120 and 240 pounds of P2O5 from the same source. There appeared to be a similar trend with rock phosphate; however, the yearly 30‐pound application has not proven very effective to date.
Characteristics of Some Forest Soils from the Gray‐Brown Podzolic‐Podzol Transition Zone in Northeastern Minnesota
Authors: Holt R. F. , McMiller P. R.
Published: July 2010

Gray‐Brown Podzolic soils grade into the Podzols in a relatively narrow belt of soils in Northeastern Minnesota. It is the purpose of this paper to present the properties of soils found in this narrow transition zone.

Podzols and Brown Podzolic soils are found predominantly in the northern part of this zone and Gray‐Brown Podzolic soils predominate to the south. In the narrow belt under consideration there is an intermingling of Podzols, Brown Podzolic, Gray‐Brown Podzolic, and Gray Wooded soils. Influence of climatic and biotic factors on an interlacing of parent materials from several different glacial drifts has given rise to some rather distinctive profile differentiations in this zone.
Degrees of Adoption of Erosion Control Practices in Shelby County, Iowa
Authors: Sutherland W. N. , Shrader W. D.
Published: July 2010

A land use study in Shelby County, Iowa, is used as an example of a procedure for studying the land use status of an area. A land use history was obtained for 1950, 1951, 1952, and 1953 on a 2% statistical sample of the land in the county. Detailed soil survey informatiou was available for the sample. The land use history was tabulated by soil units.

All land was classified as to the intensity of cropping and to the intensity of treatment. When so classified, land use data can be readily compared against any appropriate standard. Comparisons of the land use history of two soil units against two different standards, a soil loss standard and a crop yield standard are given. The degree of compliance on all soil units with the soil loss standard is presented.

It was found that there was no significant difference in the way in which any of the upland soils were being used but there is a wide difference in the degree of compliance with the soil loss standard.
A Method for Study of the Influence of Mechanical Impedance and Aeration on the Growth of Seedling Roots
Authors: Gill William R. , Miller Robert D.
Published: July 2010

Apparatus was developed to permit simultaneous study of the effects of two of the factors regarded as responsible for the poor growth of roots in some compacted soils. The other factors were purposely minimized by the use of glass beads and tap water as the substrate and sterilized, freshly germinated corn seedlings as the plant material. The factors investigated were mechanical impedance and oxygen supply to the root. Although the mechanical impedance imposed could not be precisely stated, the control of the soil atmosphere was excellent. It was found that the rate of growth of unimpeded roots declines when the oxygen content falls below 10% and that the growth of impeded roots is seriously reduced under these conditions. Microscopic examination of roots grown under conditions of severe mechanical restraint have not yet revealed reliable symptoms of impedance other than a distortion of the normal shape.
Reactions of Some Polyamine Polyacetate Iron Chelates in Various Soils
Authors: Lunt O. R. , Hemaidan N. , Wallace A.
Published: July 2010

The solution‐solid phase distribution of Fe supplied as polyamine polyacetate chelates in several soils and clays at various pH levels was studied. In the pH range from 7 to 8, the disappearance of Fe from solution from clays and soils having moderate amounts or more of clays was much more rapid than is the loss of Fe from nutrient solutions in the same pH range. Clays apparently catalyze the hydrolysis reaction by which Fe is fixed in alkaline solutions. With a number of soils and clays, there was considerable loss of Fe from the soil solution under acid conditions. The process by which FeEDTA is fixed in acid soils is obscure, although Fe and EDTA were removed from solution at about the same rate. The rates of reaction indicated that simple surface exchange was not involved. Movement of Fe chelates in fine textured soils is slow. Organic matter content, wetting and drying, microbiological activity, and nominal quantities of salts in soils did not affect the loss of Fe from solution greatly. The recovery of fixed chelated Fe by plants was poor as compared to soluble chelated iron.
Release of Potassium from Nonexchangeable Forms in Relation to Soil Reaction
Authors: Pratt P. F. , Simon R. H. , Volk G. W.
Published: July 2010

Alternate incubations at various pH values and extractions with 0.5 N HCl for a Crosby soil indicated an increase in K release from nonexchangeable forms with increase in pH. Incubations of samples of the same soil with various cations in the exchange complex indicated higher K release from nonexchangeable forms with Ca rather than H as the exchangeable cation. Samples of six soils were extracted with AlCl3 or with HOAc and then incubated in the moist after removal of excess salts and the addition of various quantities of lime. There was about 50% less K release with the AlCl3 treated soils than with the HOAc treated soils. With the AlCl3 soils there was no change in K release with increase in pH. In the HOAc treated soils there was a tendency for K release to increase with increase in pH.
The Effect of Seed Treatment on Yield and Germination of Garden Peas
Authors: Seay William A. , West S. H.
Published: July 2010

The effects of Spergon treatment and Rhizobium inoculation of five varieties of garden pea seed on the yield and germination of peas in the field and on germination of peas in soil at 40°, 45°, and 50° F. in the laboratory were investigated. Although there was a trend towards increased yield due to either Rhizobium or Spergon treatment and the combination of both treatments gave somewhat better yields than either treatment alone, yield increases were not significant. Spergon treatment increased germination whereas Rhizobium inoculation did not affect germination. As the Maury soil employed evidently contained the correct rhizobia (non‐inoculated plants were nodulated), the data presented shed no light on the question of inoculant compatibility with seed treatment.
Isolation and Identification of Some Amino Compounds in Soils
Authors: Stevenson F. J.
Published: July 2010

An isolation experiment was conducted to obtain sufficient amounts of all of the amino acids in a soil hydrolysate to permit their identification. This was done by a selective separation on a large column of Dowex 50, in which elution was carried out by hydrochloric acid. The identification of the various compounds was accomplished by the application of specific tests, by paper partition chromatography, and by ion exchange chromatography on a sodium column of Dowex 50, using the procedure of Moore and Stein.

Twenty‐nine ninhydrin‐reacting compounds were identified positively as products of acid hydrolysis of soils, one compound was identified tentatively, and three others were isolated but not characterized. In addition to the compounds previously verified, the following were confirmed: cysteic acid, N‐acetyl‐D‐glucosamine, methionine sulfone, α, ε‐diaminopimelic acid, α‐amino‐n‐butyric acid, methionine sulfoxide, methionine, cystine, and ornithine. A discussion is given concerning the natural occurrence of these compounds in soils.
Some Effects of Kudzu versus Continuous Corn on Soil Properties and Crop Yields
Authors: Jordan Howard V. , Crockett S. P. , Bardsley Charles E.
Published: July 2010

In a continuing study of means of improving a soil with genetic pan, kudzu, a deep‐rooted perennial legume, was introduced in rotation with corn. Following 4 years of kudzu, the nitrogen, organic carbon, and exchangeable potassium in the 0 to 12‐inch soil were higher than in continuous corn plots. The bulk density was lower, and the porosity, aggregation, and intrinsic permeability were higher on the kudzu plots. Evidence, both from soil moisture studies and from uptake of deeply‐placed radioactive phosphorus, indicated deeper rooting of corn following the kudzu. Corn yields were increased as a result of growing the legume, and, particularly in the absence of the legume, by supplemental nitrogen. Some data on the persistence of these effects are reported.
Cotton Growth and Production as Affected by Moisture, Nitrogen, and Plant Spacing on the Yuma Mesa
Authors: Hamilton J. , Stanberry C. O. , Wootton W. M.
Published: July 2010

Acala 44 cotton was grown near Yuma, Ariz. on irrigated Superstition loamy sand having a steep productivity gradient from one end of the field to the other. Effects of soil moisture, N rate, and plant spacing, each at 3 levels in a factorial experiment, were determined for vegetative growth, fruiting, N uptake, yields, and ginning and fiber characteristics.

Yields were increased substantially by N, and significantly, but less so by moisture and spacing. The spacing effect was limited to the second of 2 pickings. Considering the 4 direct factors which determine cotton yields (total flowers, percent boll‐set, boll size, and percent lint) fertilizer affected 2 and spacing 4 of these factors. The precision of the experiment did not permit a decision as to how moisture increased yields since none of the 4 factors were affected significantly.

Cotton growth and production were unsatisfactory where substantial cuts were made in leveling the field before planting. The range of yields among individual plots varied almost 800% with a maximum of 2.51 bales and a mean of 1.28 bales of lint per acre. In spite of the large productivity gradient and resultant variations in growth and yield, relative response to a given treatment was remarkably consistent.
The Effect of a Dense Soil Layer and Varying Air‐Water Relations on the Growth, Root Development, and Nutrient Uptake of Cotton in Commerce Silt Loam
Authors: Jamison V. C. , Domby C. W.
Published: July 2010

Studies were made of a Commerce silt loam traffic pan soil at St. Joseph, La., to determine the cause of the poor productivity in droughty field areas locally known as “hotspots”. The pan in the problem area was only slightly more dense and less permeable than that of the productive areas. Large cylinders (10 by 24 inches) of soil were cut undisturbed and placed in a covered pit with the surface exposed. Restricted drainage, with a water table maintained at 24 inches, reduced oxygen diffusion and retarded the growth of cotton planted in the cylinders. Supplemental aeration provided by perforating some of the walls of the cylinders had very little effect on oxygen diffusion or plant growth. Reduced oxygen diffusion in this soil was associated with lower nitrogen uptake but had little effect on the uptake of potassium since the soil supply was sufficient to allow for luxury consumption by the cotton plants. It appears that a combination of factors affecting air‐water relationships and root extension are responsible for these problem areas in fields of the lower Mississippi River Delta areas.
Reactions of Some Iron, Zinc, and Manganese Chelates in Various Soils
Authors: Wallace A. , Lunt O. R.
Published: July 2010

Polyamine‐polyacetate chelating agents were previously reported to be fixed on the clay portion of soils. Further studies have been made to characterize the method of fixation on clays. From these studies it has been postulated that ferric iron EDTA can become attached to clay through an Fe‐O‐clay linkage on the edges of clay crystals. Divalent zinc and manganese EDTA chelates did not fix on clays. The degree of fixation in relation to the cation exchange capacity of different clay minerals indicated the fixation occurs principally on the edges of the clay rather than on the basal planes. This theory is supported by X‐ray examination. Some divalent metal chelates other than EDTA fixed readily on clays while others did not. A new chelating agent, APCA, was examined which was extremely stable under alkaline soil conditions. Iron APCA was not adsorbed on clay in the pH range encountered in calcareous soils. Zinc and manganese APCA, in contrast, readily fixed on clay. For certain chelating agents in various soils, there was an isotopic exchange which sometimes was of considerable magnitude between the chelated iron and the natural iron of the soil.
Estimation of Available Zinc in Soils from Yield‐of‐Zinc Curves
Authors: Nearpass D. C.
Published: July 2010

The native soil zinc that is equally as available to plants as is a standard source of zinc supplied as fertilizer, may be estimated from yield‐of‐zinc curves if the total zinc in the aerial portions of the plants is related to the available zinc supply in a soil, and the amount of available native soil zinc is unaffected by the addition of fertilizer zinc.

A logarithmic relationship between zinc in the substrate and zinc in the aerial portions of plants was found when plants were grown in ion exchange resin‐sand‐nutrient cultures. From 88 to 95% of the variation was accounted for by the logarithmic regression equation.

When plants were grown in soils, the yield‐of‐zinc curves obtained were also curvilinear and could be described by logarithmic or parabolic equations. The estimated available native soil zinc values found by solving the logarithmic regression equations were significantly correlated, r being +0.800, with the zinc contents of the control plants. On the other hand, available zinc by parabolic fit and dithizone extractable zinc were also significantly correlated, with a correlation coefficient of +0.847. In further experiments, the soil zinc values found from the yield‐of‐zinc curves obtained by growing millet, were less than those found from the yield‐of‐zinc curves obtained by growing oat and tomato plants.
The Formation of Nitrate from Ammonium Nitrogen in Soils: I. Effect of Temperature
Authors: Frederick Lloyd R.
Published: July 2010

The quantitative relationship between temperature and nitrification rates was determined in four different soils under laboratory conditions. The formation of nitrates took place at all temperatures studied between 2 and 35° C. when other factors were favorable. The rate of nitrification increased with temperature with the greatest increase between 7 and 15° C.

In Genesee silt loam (pH 7.7) nitrate nitrogen was formed at rates of 2, 10, 45, 60, 90, and 120 ppm. per week at 2, 7, 15.5, 21, 27, and 35° C., respectively, until the 200 ppm. ammonium nitrogen (NH4 ‐N) added was oxidized. The maximum rate in the Mellott C horizon (pH 7.8) was nearly equal to that achieved in the Genesee; the rate in the Chalmers silty clay loam (pH 6.2) was intermediate; the slowest rates found occurred in the Clermont silt loam (pH 5.0) which had maximum rates of 0, 0, 25, 30, 30, and 15 ppm. per week at the temperatures from 2 to 35° C. given above. The initial rate in the Mellott C and Clermont was much slower than the maximum rate. After 4 weeks the rate decreased in the Chalmers and Clermont, probably due to increased acidity.

A marked decrease in the rate of nitrification occurred as the pH dropped below neutrality. Change of pH by adding calcium carbonate did not change the temperature range of nitrification in Clermont silt loam. Differences in temperature range existed between the soils as well as differences in the rate of nitrification.

Temperatures fluctuating in a 24‐hour cycle generally resulted in an increased rate of nitrification at temperatures below 15.5° C. and a decreased rate above 15.5° C. in Genesee silt loam.
An Investigation of Some of the Relationships between Copper, Iron, and Molybdenum in the Growth and Nutrition of Lettuce: II. Response Surfaces of Growth and Accumulations of Cu and Fe
Authors: Moore D. P. , Harward M. E. , Mason D. D. , Hader R. J. , Lott W. L. , Jackson W. A.
Published: July 2010

A study was made to determine some of the interrelations of Cu, Fe, and Mo in the growth and nutrition of lettuce. The objectives of this study were: (1) to determine the importance of interactions among Cu, Mo, and Fe; (2) to determine if form of N or source of Fe affects interactions involving Cu; (3) to determine which concentrations of Cu, Mo, and Fe result in the greatest growth; and (4) to determine if levels of Fe and Mo, sources of Fe, or form of N affect the critical level of Cu in the plant.

Solutions with varying concentrations of Cu, Fe, and Mo were imposed on four series of treatments involving combinations of ferrous iron, ferric iron, all nitrate nitrogen, and 1/4 ammonium plus 3/4 nitrate nitrogen. The experiment was conducted using solution culture in a rotatable design. This design permitted calculations of response surfaces from a much smaller number of treatments than would have been necessary with complete factorials.

All of the variables affected growth and accumulation of ions. Illustrations are given for some of the relationships which appear to exist among Cu, Mo, Fe, sources of N, and sources of Fe. Pronounced interactions were obtained between Cu and Fe. The growth of lettuce at any one level of Cu was affected by Fe supply. The reverse relationship was also observed. The Cu content of leaves was affected by Fe supply as was Fe content by Cu supply. The interaction between Cu and Fe on Cu content was affected by source of N and source of Fe. The effects of Cu and Mo on Fe content and the interactions between Cu and Mo, Cu and Fe, and between Fe and Mo were much more pronounced in the series containing all NO3 ‐ nitrogen. Curves of yield vs. Cu content of tops suggested that there is not any single level of Cu in the plant which represents an optimum level. The Cu content corresponding to maximum yield appeared to be influenced by levels of Fe and Mo in solution, source of Fe, and source of N. In general, form of nitrogen had a more pronounced effect on growth and accumulation than did the valence of Fe.

Implications of the relationship suggested by this study and the use of response surfaces as an aid in studying nutrient interactions are discussed.