bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Alfalfa on the Nitrogen and Phosphorus Requirements of Crops
Authors: Carlson C. W. , Grunes D. L. , Haise H. R. , Alessi J.
Published: July 2010

The effect of N and P fertilization on crop yields under irrigation was evaluated in a nonlegume rotation (barley, corn, potatoes), and in a legume rotation (barley, alfalfa, alfalfa, alfalfa, corn, potatoes), on Gardena loam at Upharn, N. Dak. In the nonlegume rotation all crops responded to N. Phosphorus alone decreased yields of corn forage. However, with adequate N, P increased yields of barley, corn and potatoes.

In the legume rotation, the major effect of alfalfa was to supply available N. Added N fertilizer increased the yields of all nonlegume crops, but P additions increased yields of all crops. Phosphorus was available to potatoes 5 years after it had been added on the barley crop.

Yields of barley and corn tended to be higher in the legume rotation than in the nonlegume rotation, regardless of the fertilizer treatment. At the highest N fertilizer rate, yields of potatoes were similar in the two rotations. Higher yields in the legume rotation resulted mainly from the available N contributed by the alfalfa, but other factors also appear to be involved. Alfalfa, grown only in the establishing year, contributed available N to the succeeding corn crop in an amount comparable to alfalfa grown for a longer time.
Use of Soil Management Groups and Related Information in Evaluation of Farmlands and Their Utilization
Authors: Priest T. W. , Whiteside E. P. , Heneberry W. H.
Published: July 2010

Soil management groups and related information were used in Eaton County, Michigan to arrive at equitable evaluations of farmlands. These values were then compared with values determined by assessors, another appraisal procedure, and with farmers' estimated land values. This method of farmland evaluation avoids the common tendency of assessors to overvalue low‐valued properties. The computed land values averaged 112% of the other appraised values and averaged 97% of the farmers' estimated land values. Other uses of this method and the need for land classification in addition to soil classification are discussed.
Age and Properties of Peorian Loess and Buried Paleosols in Southwestern Wisconsin
Authors: Hogan J. D. , Beatty M. T.
Published: July 2010

Seaton silt loam in southwestern Wisconsin was found to have formed in the coarser textured windward portions of the same loess deposit as have Fayette and Tama silt loams. This loess is as much as 19 feet thick on ridge crests and is underlain by two paleosols at some localities. The upper paleosol is a silt loam which resembles Farmdale loess or silt both in morphology and in stratigraphy, and which contains fragments of spruce charcoal with a radiocarbon age of 29,400 ± 700 years before present. The lower paleosol is truncated and the B horizons which remain are reddish clays underlain by dolomite. The dense uppermost B horizon contained 7.82% free Fe2O3 and the lower B possessed strongly developed fine angular blocky structure. Mass wasting has occurred extensively on ridge flanks.

X‐ray diffraction analyses show the silt loam upper paleosol to be more highly weathered than the overlying calcareous loess, and the lower paleosol to be more vermiculitic than residual clay derived from the same bedrock formation at other localities.

The radiocarbon date of the spruce charcoal is somewhat older than dates obtained from Farmdale deposits in Illinois or Iowa, and is also older than ages of overlying loess calculated by G. H. Robinson from depth of carbonate leaching.
Characterization of Soil Temperature Distribution from Various Tillage‐Induced Microreliefs
Authors: Burrows W. C.
Published: July 2010

Soil temperature was measured where three tillage systems produced a ridge and furrow microrelief and a smooth soil surface. Corn was planted on ridges, in furrows, and on a smooth surface and with rows running in an east‐west or north‐south direction. During early growth, corn seedlings were in the warmest soil when the seed was placed in ridges running in an east‐west direction and in coolest soil when the seed was placed in a furrow such as that produced by a listing tillage system.
Potassium Uptake by Cation‐Exchange Resin Amberlite IR‐120 from Fithian Illite
Authors: Kalovoulos J. M. , Paxinos S. A.
Published: July 2010

The rate of K uptake by the hydrogen form of Amberlite IR‐120 from Fithian illite was studied. Resin‐illite ratio, time in contact of illite with the resin, temperature, and repeated treatment effect on the release of K were investigated. The amount of released K increased as the resin‐illite ratio, time in contact, and temperature increased. It seems probable that amberlite IR‐120 attacks mainly the surface parallel to the c‐axis of illite crystals. Thus, even after a long treatment of illite with the hydrogen form of amberlite, illite keeps its cation‐exchange capacity value, crystal structure, and almost all of its K content. X‐ray graphs of the resin‐treated illite samples after their Mg saturation and ethylene glycol solvation do not present any clear evidence of alteration of illite to expanding lattice type clay minerals.
Mineralogy of Soil Separates and Alkali‐Ion Exchange‐Sorption
Authors: le Roux F. H. , Cady J. G. , Coleman N. T.
Published: July 2010

X‐ray and petrographic examination of a number of California soils derived from granite‐diorite sedimentary material showed the presence of biotite weathering products which appeared to include slightly altered biotite, vermiculite, and a regularly interstratified biotite‐vermiculite. Magnetic and specific gravity separations of fine sand‐ and silt‐size material from a Hanford soil yielded relatively pure minerals giving rational series of X‐ray reflections from 25, 14.48, or 10Å. spacings when Mg‐saturated; 23.5, 12.25, or 10Å, when Na‐saturated; and 10Å. when K‐saturated. Cation‐exchange capacities of vermiculite, hydrobiotite, and biotite separated from 100‐ to 200‐mesh material were 0.95, 0.40, and 0.15 me. per g., respectively. Tagged rubidium sorbed on exchange sites was displaced by 0.1N NaCl to the extent of 10% from vermiculite, 20% from hydrobiotite, and 42% from biotite fractions. Soil vermiculite and hydrobiotite had smaller cation‐exchange capacities than similar separates from the Libby, Montana, vermiculite deposit, and the reversibility of the Rb‐sorption reaction was less for the soil minerals.

Vermiculite‐hydrobiotite‐biotite appeared to be the predominant clay mineral in all size fractions from the Hanford soil except the < 0.5µ clay. Cation‐exchange capacities of coarse clay and silt were relatively large (0.35 to 0.0067 me. per g.) and sorbed Rb was only around 50% exchanged by 0.1N NaCl. Rubidium could be almost completely displaced from < 0.5µ clay. It is concluded that vermiculite and hydrobiotite in the coarse clay, silt, and fine sand fractions account for around 40% of the cation‐exchange capacity of the soil and for essentially all of its capacity to sorb Rb or K irreversibly.
Effect of Fumigants on the Soil Status and Plant Uptake of Certain Elements
Authors: Smith Donald H.
Published: July 2010

Fumigants commonly used or studied in relation to pineapple production in Hawaii are D‐D, EBD, BBC (1,2‐dibromo‐3‐chloropropane), and methyl bromide. These fumigants sometimes increase and sometimes decrease the quantity of iron that may be extracted from the soil. Use of D‐D and methyl bromide appears to improve the utilization of iron within the plant but not the uptake of iron by the plant. Fumigants sometimes lower the oxidation‐reduction potential in otherwise unamended soil. When combined with easily decomposable organic matter, they very markedly reduce this potential. The effect of fumigants in increasing availability of maganese in the soil and to the plant may be large, and may persist for many months. Fumigants frequently increase the phosphorus content of soil extracts, and D‐D has increased the phosphorus “A value” in greenhouse tests, but use of D‐D or methyl bromide in the field consistently results in reduced phosphorus uptake by the plant.
Clay Mineral Characterization of Modal Soil Profiles in Several Pennsylvania Counties
Authors: Johnson L. J. , Matelski R. P. , Engle C. F.
Published: July 2010

As part of the detailed soil survey of Pennsylvania, clay mineral types in modal soil profiles are being identified to determine: (1) weathering trends within profiles, (2) the distribution of clay types, and (3) the utility of clay mineral data for soil correlation. The clay mineral data is summarized on triangular diagrams which graphically illustrate the distribution of clay mineral types among horizons within a profile and between profiles of the same soil type. Differences in distribution of clay types between profiles of the same type are very common. The major change with increasing depth within the profiles studied is the increase in illite and the decrease in vermiculite and/or aluminum interlayered vermiculite. Kaolin minerals are relatively constant with increasing depth. Montmorillonite is generally associated with poor drainage and high organic matter content. It is concluded that soil correlation with clay mineral data is helpful but only of restricted application. Weathering is manifested by the sequence illite to vermiculite to aluminum interlayered vermiculite. Parent material controls the occurrence of kaolin and trioctahedral chlorite.
Residual Effects of Perennial Grass Sod on the Physical Properties of a Chernozem Soil
Authors: Mazurak Andrew P. , Ramig Robert E.
Published: July 2010

Residual effects of perennial grass sod on a Chernozem soil were studied in two experiments. In the first experiment, two cool‐season grasses were in sod for 2, 4, 6, and 8 years in the second 10‐year cycle of a 20‐year study. Sod was plowed and then cropped to a fallow‐wheat sequence for 4 years. In the second experiment, seven cool‐season and four warm‐season grasses were in sod for 7 years. Sod was plowed and then cropped to a fallow‐wheat sequence for 6 years. In both experiments the plots were split or paired and one‐half of each plot or one of each pair of plots received nitrogen fertilizer.

In the first experiment the residual effects of grasses on the rates of water entry into soil and on the water stability of aggregates were evident 4 years after plowing sod. The degree of residual effect increased as the years in sod prior to plowing increased. Residual effect of grasses augmented the yields of wheat. Similarly in the second experiment, favorable effects of cool‐ and warm‐season grasses were noted on the rate of water entry into soil.
Threshold Gradient for Water Flow in Clay Systems
Authors: Miller Raymond J. , Low Philip F.
Published: July 2010

In this work the presence of a threshold gradient for water flow in clays was established. The threshold gradient is the hydraulic gradient below which no flow occurs. The threshold gradient decreased with decreasing clay concentration and increasing temperature. At gradients above the threshold gradient, the flow rate‐gradient relationship was essentially linear, except at low gradients, for the concentrated clay systems but curvilinear for the less‐concentrated clay systems. These results were explained on the basis of a quasi‐crystalline water structure which developed in the clay‐water systems as a result of water‐surface interaction.
Solubility of Gypsum and Dicalcium Phosphate Dihydrate in the System CaO‐P2O5‐SO3‐H2)O and in Soils
Authors: Moreno E. C. , Osborn G.
Published: July 2010

The solubility isotherm (25°C.) for gypsum was determined in the concentration range from 1.5 × 10‐2 to 6.0 × 10‐2 mols of S per liter by equilibrating CaSO4 · 2H2O with H2SO4 solutions of varying concentrations. The solubility product of gypsum calculated from these data was 2.45 × 10‐5. The effect of gypsum upon the solubility of dicalcium phosphate dihydrate (DCPD) was related to the pH. The percentage of calcium in solution which was derived from DCPD was 80% and 3% at pH 3.6 and 6.3, respectively. The data from exchange resin and solubility studies are consistent with a hypothesized complex in solution of the form Ca(H2PO4)+. Equilibrations of DCPD and gypsum in soil systems indicated that apparent supersaturation with respect to both salts was obtained at pH values above 5.8. This anomalous behavior was explained by the complexing of Ca by soluble organic matter. The research findings are discussed in the light of soil and fertilizer chemistry.
Diffusion of Phosphorus as Related to Soil Texture and Plant Uptake
Authors: Olsen S. R. , Watanabe F. S.
Published: July 2010

Differences in the diffusion coefficients of phosphorus (P) between sandy and clay soils were applied to explain variations in rates of P uptake by corn seedlings from equal initial concentrations of P in the soil solution. The relation between labile P of the solid phase and P concentration in solution or the phosphate capacity, also varies with the clay content. An equation relating uptake of P by plant roots to the diffusion coefficient and the phosphate capacity showed that the rate of uptake was proportional to where Dp is the diffusion coefficient and b is the slope of the line relating labile P to concentration of P in solution or the phosphate capacity, when other factors are constant. The equation predicts that the rate of uptake of P will be one‐third as much from the sandy soil as from the clay soil at equal concentrations of P in the soil solution. Actual measurement of the rate of P uptake by corn seedlings agreed closely with the predicted values from the equation for P concentrations < 0.2 ppm. As the clay content of three soils increased from 17 to 51%, the diffusion coefficient for P increased from 1.1 × 10‐7 to 6.7 × 10‐7 cm.2 per sec. and the b value increased from 110 to 178.
Influence of Straw Mulch on Soil Moisture, Soil Temperature and the Growth of Corn
Authors: Moody J. E. , Jones J. N. , Lillard J. H.
Published: July 2010

In a 3‐year study, corn was grown on plots treated with 3 tons of wheat straw per acre, either placed on the surface or plowed under, and with two rates of N. Soil temperature, soil moisture, plant height and weight, N and K content of the plant and yields were obtained. Soil temperature at the 4‐inch depth was lower throughout the growing season under mulch conditions. The low temperature under mulch was associated with a temporary depression of growth during the early growing season. A significant increase in growth of mulched over unmulched corn, beginning in late June, was attributed to the greater moisture under mulch during the period of high plant requirements. Mulched corn was 64 cm. taller at tasseling and produced 42 bushels per acre more grain than corn which had the straw plowed down. Runoff was seven times greater from the unmulched plots.
Pressure Dependence of the Relative Vapor Pressure of Water in Soil
Authors: Richards L. A. , Low P. F. , Decker D. L.
Published: July 2010

The equation ∂ ln (p/po)/∂P = (v̄ − vo)/RT, expressing pressure dependence of the relative vapor pressure in terms of the difference between the partial molar volume v̄ of the water in the system and the molar volume of pure water vo, was derived and was used in interpreting the experiments. A thermocouple psychrometer (TP) was calibrated at 25°C. using 0.10 and 0.20 molal KCl solutions at several air pressures in the sample chamber, ranging up to 15 bar. The TP reading for a sample of soil, when referred to the measurement for an appropriate sample of KCl solution, did not change significantly as the air pressure in the soil chamber was increased by 5‐bar steps up to 15 bar. The total suction of water in soil is directly related to the relative vapor pressure p/po of the soil water and for our test sample the total suction was 6.44 bar at atmospheric pressure. The values of the standard deviation of total suction corresponding to the standard deviation of the TP readings were calculated to be 0.053, 0.084, and 0.109 bar for pressure increases of 5, 10, and 15 bar. Decreases in total suction greater than these amounts were not found.
Entrapped Air Content and Hydraulic Conductivity of Quartz Sand During Prolonged Liquid Flow
Authors: Gupta Rajinder P. , Swartzendruber Dale
Published: July 2010

Boiled deionized water, with and without 0.1% phenol, was passed through permeameters filled with several types of quartz sand. In addition to measurements of hydraulic conductivity, the sand‐water system inside the permeameters was periodically subjected to a static gauge pressure ΔP, and the resulting volume change Δv was recorded by the movement of a mercury droplet in a capillary tube. The quantity Δv/ΔP was found to be a highly sensitive indicator of the air entrapped within the wet sand. For sand wetted at atmospheric pressure, Δv/ΔP was found to be high initially, and then to decline sharply as flow proceeded. When the hydraulic conductivity reached its maximum value, the decrease in Δv/ΔP flattened out abruptly, but a slow decline persisted as flow continued. When the sand was wetted under vacuum, the high initial value and subsequent rapid decline in Δv/ΔP were eliminated.

Since Δv/ΔP was always observed to decline with continued flow, even when the hydraulic conductivity was undergoing a drastic decrease, it was concluded that flow‐associated reductions in hydraulic conductivity, observed in the present and in previous similar experiments, were not caused by an accumulation of entrapped air originating from dissolved air released by the flowing liquid.
Toxic Factors in Acid Soils: II. Differential Aluminum Tolerance of Plant Species
Authors: Foy C. D. , Brown J. C.
Published: July 2010

Differential Al tolerance of plant species in nutrient solution and in acid Bladen soil was closely associated with the ability of plants to absorb and utilize P in the presence of excess Al.

Chelating agent (EDDHA), added to the nutrient solution portion of a split medium, increased the solubility of Al but decreased its toxicity to Al‐sensitive plants. EDDHA at 1/4 the molarity of the Al added gave near‐maximum yields for Al‐tolerant buckwheat. For Al‐sensitive barley, EDDHA at twice the molarity of the Al was required for normal growth. The beneficial effects of EDDHA on Al‐sensitive barley in nutrient solution were associated with marked increases in the solubility of P and with increased uptake of P by plants.
The Dissolution of Calcium Aluminum Phosphate, CaAlH(PO4)2·6H2O
Authors: Taylor A. W. , Gurney E. L.
Published: July 2010

The solubility product of CaAlH(PO4)2·6H2O is not less than 10‐39. Although the salt is formed readily by reaction of gibbsite with concentrated calcium phosphate solution, it is unstable in dilute solutions and hydrolyzes to amorphous aluminum phosphate.
The Effect of Root Aeration on Plant Growth
Authors: Williamson R. E.
Published: July 2010

Rates of oxygen diffusion were measured in soil contained in 3‐foot‐cube lysimeters in field installations. Water tables were maintained by subsurface watering at 6‐ to 30‐inch depths below the soil surface. Some lysimeters were sheltered from rain. Soybeans, cabbage, grain sorghum, sweet corn, and dwarf field corn were grown in these lysimeters.

The highest yields were obtained at oxygen diffusion rates of approximately 15 g. X 10‐8 per cm.2 per minute. The maximum yields were high in comparison with yields obtained in most field experiments. Oxygen diffusion rates at 6‐inch water table depths were below 5 g. X 10‐8 per cm.2 per minute. Under these conditions of extremely poor aeration, yields of grain sorghum, soybeans, cabbage, sweet corn, and dwarf field corn were reduced 25, 35, 40, 65, and 75%, respectively.
Soil Water Diffusivity and Hysteresis Data from Radial Flow Pressure Cells
Authors: Klute A. , Whisler F. D. , Scott E. J.
Published: July 2010

The theory and advantages of radial flow geometry for the determination of soil water diffusivity are discussed. A description is given of a cylindrical pressure cell in which this theory is applied. Values of the soil water diffusivity, D, were obtained from a comparison of the experimental volume outflow or inflow‐time curves with the theoretical relationship between volume outflow or inflow and the factor Dt where t is time. Diffusivities were measured in the pressure range up to 1 ½ atmospheres on two porous media. The diffusivity‐water content hysteresis function was observed to be composed of crossed‐curve segments forming a skewed and distorted “bowtie.”
Water Vapor Diffusion in Relatively Dry Soil: I. Theoretical Considerations and Sorption Experiments
Authors: Jackson Ray D.
Published: July 2010

Water transfer was measured in three soil materials at water content ranges corresponding to a relative pressure range of 0.97 to about 0.05. At these water contents vapor flow is probably the predominant transfer mechanism. The data were obtained from a transient sorption experiment and diffusion coefficients were calculated from analyses of water content distribution curves. The evaporation‐condensation reaction between the liquid and vapor phases was treated by using simultaneous diffusion‐reaction theory. Within the water content ranges used the diffusion coefficients increase and then decrease with increasing water content.
Sorption and Fixation of Microquantities of Cesium by Clay Minerals: Effect of Saturating Cations
Authors: Sawhney B. L.
Published: July 2010

Sorption and fixation of microquantities of Cs by six minerals, as affected by the saturating cations, were studied. Micas and vermiculite sorbed more Cs in the presence of Ca and similar divalent cations than in the presence of K and similar monovalent cations. Montmorillonite and kaolinite, on the other hand, sorbed more Cs in the presence of K than in the presence of Ca. While micas and vermiculite fixed large proportion of the Cs sorbed, mont‐morillonite and kaolinite did not fix significant amounts of Cs against replacement by neutral salts. Thus, whereas Cs‐sorption by montmorillonite and kaolinite appeared to be largely electrostatic, the sorption and fixation of Cs by micas and vermiculite was governed by the size and hydration, rather than valence, of the competing cation. Micas particularly exhibited a large fixation of Cs. It is suggested that the fixation of Cs by micas occurs at the crystal edges where Cs may replace K and thus become a part of the stable mica structure.
Cobalt Content of New England Soils in Relation to Cobalt Levels in Forages for Ruminant Animals
Authors: Kubota Joe
Published: July 2010

The Co content of soils and common forage plants was low and related to reported areas of Co deficiency in ruminant animals in two extensive areas of granitic drift deposits in New England. One of the areas extends from southestern Maine to southeastern New Hampshire, encompassing an area mantled by granitic drifts from the White Mountains. The other area occurs in southeastern Massachusetts and includes Cape Cod. The low Co soils within these areas are Podzols, Brown Podzolic soils and Ground‐Water Podzols of sand to fine sandy loam textures. These soils have 5 ppm. or less Co, and legumes grown in them have 0.07 ppm. or less Co. Similar soils outside of the areas noted and soils of loam, silt loam and clay surface textures have sufficient Co to produce legumes with adequate amounts of Co. Grasses with very few exceptions had low amounts of Co irrespective of soil.
Ammonia and Ammonium Reactions with Some Pacific Northwest Soils
Authors: Young J. L.
Published: July 2010

Retention and fixation of NH3 and NH4+ by 76 horizon samples from 20 different Pacific Northwest soils were investigated using aqua and anhydrous NH3, NH4Cl, and different degassing and fixing conditions.

Retention of NH3 by ammoniated air‐dry samples was approximately 0.7 me. N per each me. of soil cation‐exchange capacity. In the surface horizons, retention of NH3 was roughly 0.3 and 2.6 me. N per 100g. of soil for each percent clay and organic carbon, respectively.

Ratios of “NH3 retained by air‐dry ammoniated samples” to “H2O retained by the air‐dry samples prior to ammoniation” ranged from 0.03 to 0.19 but were generally < 0.1.

As with expandable lattice minerals, vacuum degassing increased NH3 retention substantially beyond that of free diffusion degassed samples open to moisture of the atmosphere. Loss of retained NH3 by diffusion and/or water vapor displacement continued at a slow rate for many weeks and while total retention was decreasing, mineral‐fixed values were generally increasing.

Infrared absorption patterns were completely dominated by the soil mineral fraction thereby nullifying possible determination of sites or functional groups reactive in NH3 fixation. An absorption band peaking near 7µ appeared most closely correlated with mineral‐fixed NH4+.

Generally, three‐fourths or more of the retained anhydrous NH3 was KCl leachable. Of the fixed NH3 (that not leachable with KCl) the major part was associated with the organic fraction except in most subsurface horizons of the recent silty alluvial and water‐deposited silt soils wherein the major part was fixed by the mineral fraction.

Comparative NH3/NH44 fixation revealed widely variable behavior, suggesting that a considerable gradation of mineral structures may be involved in soil NH3/NH4+ reactions and that a correspondingly broad range in availability of fixed NH3/NH4+ is to be expected. A number of the minerals giving significant fixation exhibited characteristics intermediate between specimen montmorillonites and vermiculites, implicating beidellitic and/or expanding vermiculite‐like structures.
Ammonium Sorption and Release from Rocks and Minerals
Authors: Adams R. S. , Stevenson F. J.
Published: July 2010

Some igneous rocks and primary silicate minerals were found to retain added NH4+ against extraction with 1.0N KCl. The amounts ranged from 15 to 244 ppm., and were 3 to 15 times the quantity of NH4+ in the original rock or mineral. At least two types of reactions were involved, namely, sorption at particle surface and intraparticle penetration. In contrast to the NH4+ held in difficultly exchangeable forms by soils and secondary silicate (clay) minerals, part of the nonexchangeable NH4+ in rocks and primary silicate minerals was released readily with hot 1.0N KOH. The micas were primarily responsible for NH4+ fixation by igneous rocks.
Retention of Cu and Zn by H‐Montmorillonite
Authors: Bingham F. T. , Page A. L. , Sims J. R.
Published: July 2010

Studies were conducted on the retention of Cu and Zn by H‐montmorillonite in relation to associated anion, salt concentration reaction time, pH of the equilibrium solution, and techniques.

Under conditions where the pH of the equilibrium solution was too acid for formation of Cu(OH)2, the amounts of Cu and Zn retained were similar for Cl, NO3, and SO4 salts and equal to the cation‐exchange capacity (CEC) as measured with NH4+. Detailed studies of metal retention in relation to pH of equilibrium solutions for Cl systems revealed no retention of Cu or Zn in excess of the CEC provided the pH of the system was below 5.5 to 6.5. The exact pH favoring excess retention varied according to salt concentration and the metal in question. Retention of the metals in excess of the CEC was explained in terms of precipitation of Cu(OH)2 and Zn(OH)2 in the clay systems.

In the acetate systems, Cu and Zn retention was usually greater than the CEC even under acid conditions. As the pH of the systems increased, metal retention increased. In addition to metal retention, acetate retention was measured. Acetate retention was found to be related to the concentration of acetate and essentially independent of the quantity of metal retained.
Calcium Uptake and Transport by Wheat Seedlings as Affected by Aluminum
Authors: Johnson Ray E. , Jackson W. A.
Published: July 2010

Uptake and distribution of Ca was studied with excised roots and intact seedlings of wheat. Patterns characteristic of inorganic ion uptake by roots were obtained, namely a rapid initial adsorption phase followed by a linear rate of accumulation. The former was relatively large compared to the latter. It also was reduced to a greater extent by increasing acidity from pH 6 to pH 4. The Ca accumulation phase was reduced by modest restrictions in aerobic metabolism. Treatments resulting in severe reductions in metabolism produced a loss of internal inorganic cations and an increase in influx of external Ca indicating serious objections to the sole use of isotopic procedures for ion uptake studies under such extreme conditions.

Aluminum treatments reduced both the adsorption and accumulation phases of Ca uptake. The reduction in the accumulation phase could not be overcome by supplying additional Ca. Increasing the Al concentration from 10‐4N to 10‐3N at constant Ca did not alter the extent of inhibition, suggesting that a portion of the Ca accumulation mechanism was inactivated completely by Al at 10‐4N or less.

Transport of Ca to shoots of intact seedlings also was restricted by Al although appreciable transport still occurred when root uptake was inhibited completely.
The Effect of Gamma and Neutron Irradiation of Soil on the Yield and Nutrient Uptake of Rye
Authors: Cummins D. G. , McCreery R. A.
Published: July 2010

Cecil sandy loam and Lakeland sand with 6 fertility treatments, at field capacity and air dry, were subjected to 3 rates of mixed gamma and neutron radiation from an airshielded 10 megawatts thermal reactor. Rye was grown as a test crop on these soils in the greenhouse. Forage yield and uptake of N, P, K, Ca, Mg, and Na by rye were used to evaluate irradiation effects. Yields of rye on Cecil soil were increased as a result of irradiation when N was limiting, probably as a result of increased mineral N from dead organisms. The uptake of P, K, Ca, Mg, and Na was not affected by irradiation, except where influenced by an increased yield due to N. Soil moisture at irradiation time did not influence irradiation effects on rye yields.
Evaluation of Calcium Ammonium and Calcium Potassium Pyrophosphates as Fertilizers
Authors: Lehr James R. , Engelstad Orvis P. , Brown Earl H.
Published: July 2010

Six calcium ammonium and calcium potassium pyrophosphates were tested in the greenhouse as sources of P and N or K for two successive crops of corn forage on limed and unlimed Hartsells fine sandy loam. The fertilizers were applied as powders and as pellet‐granules; the residues of the granules were examined petrographically after harvest of the second crop.

The granules were much less effective than the powders as sources of P and N for the first crop, but only slightly less effective as sources of K. The powders were nearly as effective as superphosphate as sources of P and one of the ammonium compounds was nearly as effective as (NH4)2SO4 as a source of N, but none of the K compounds was as effective as K2SO4 as a source of K.

The chemical alterations of the pyrophosphates in the soil were much like those of the same compounds in water, and all the observed alteration products were pyrophosphates. Some of the pyrophosphates show promise as long‐term, slow‐release sources of P and N or K.
Aspects of Catenary and Depth Distribution of Opal Phytoliths in Illinois Soils
Authors: Jones Robert L. , Beavers A. H.
Published: July 2010

Soil opal phytolith content is intimately related to internal soil drainage; highest opal contents occur in the middle of the drainage sequence. Soil productivity is invoked to explain the catenary opal distribution. Phytoliths are concentrated in the surface horizon of Planosols but distributed downward to 20 inches in Brunizem and Gray‐Brown Podzolic soils. Differences in chemical and catenary milieu, soil fauna, or loess depositional pattern are possible causes for depth distribution differences.
Direct Interception of Cloud Water on Lanaihale, Hawaii
Authors: Ekern Paul C.
Published: July 2010

Lanai, a relatively dry island, lies in the trade wind flow downstream from Maui and Molokai and is peculiarly adapted to a demonstration of the amount of water that can be gathered by direct interception from clouds. An observation station was established at the 2,750‐foot level on Lanaihale in July 1955, and maintained for 3 years. The water collected over the 3 years by a network of rain gauges set beneath a Norfolk Island pine tree averaged 391 inches while rainfall in the open was only 149 inches. Since the tree also intercepted some rainfall, a net of 30 inches is suggested as the annual gain from cloud water interception. A wire harp kept oriented into the wind by a vane gathered 1,706 inches of water while rainfall alone was 97 inches. The harp had a vertical silhouette 27.5 times the area of the standard rain gauge in which the catch was measured. A 15‐ to 20‐inch gain per unit vertical area exposed is suggested as the annual direct cloud interception by the harp. Identical catchers of aluminum louver mounted at several elevations up to 30 feet above the ground gave an increased catch greater than the increase of wind with elevation.
Water Storage Characteristics of Several Peats in situ
Authors: Boelter D. H.
Published: July 2010

Water storage characteristics of the various horizons in a northern Minnesota bog were found to vary considerably with peat type. Surface horizons of sphagnum moss peat contain 0.020 g. per cc. of dry material and 95 to nearly 100% water by volume at saturation. Its total porosity consisted primarily of large pores which released 0.80 cc. of water per cc. between saturation and 0.1 bar suction.

Decomposed and herbaceous peats from horizons below 25 cm. had water‐holding properties strikingly different from those of the moss peats. These materials had bulk densities of 0.24 and 0.14 g. per cc., respectively, and they contained between 80 and 90% water by volume at saturation. Their porosity, though high, consisted primarily of many small pores which are not easily drained at low suctions. They retained 65 to 75% water by volume at 0.1‐bar suction.

These data show that a specific change in water table elevation in the horizons containing loose, porous, undecomposed moss peat would involve a great deal more water than the same change in horizons of more dense decomposed and herbaceous peats. Thus, the hydrologic role of any bog or bog area in a watershed will depend on the type of peat found in the organic soil profile.
The Effects of Wash Solvents on Cation‐Exchange Capacity Measurements
Authors: Frink C. R.
Published: July 2010

The CEC of a strong acid‐exchange resin, four clays, and several soils was determined using various cations for saturation and a wide variety of solvents for removal of the excess electrolyte. Precipitation of the salts in the solvents was avoided by using the more soluble acetates of the monovalent ions and the chlorides of the polyvalent ions, and by diluting the occluded volume of salt solution once with water to reduce its concentration to 0.1N. The CEC of the resin could then be determined equally well by Na, Ca, or Al, using water or any of eight nonaqueous solvents. The CEC of montmorillonite was found to be more dependent on the solvent used: low results with solvents of high dielectric constant could only be prevented by high speed centrifugation, while high results were obtained with acetone, t‐butanol, and dioxane owing to salt retention even after extensive washing. No evidence was found for the loss of adsorbed ions due to hydrolysis, or for the formation of basic exchange ions. One additional complication was found with soils: the NH4+ CEC was found to vary owing to the variable solubility of some ammoniated organic matter complex. A method is proposed in which the samples are washed with 0.001N solutions of the salts used for saturation. While high speed centrifugation is required, the introduction of a nonaqueous solvent is avoided, and a clay of known ionic composition results.
Contribution of Organic Matter and Clay to Soil Cation‐Exchange Capacity as Affected by the pH of the Saturating Solution
Authors: Helling Charles S. , Chesters G. , Corey R. B.
Published: July 2010

The effect of pH of the buffered saturating solution on the cation‐exchange capacity (CEC) of 60 Wisconsin soils was determined within the pH range 2.5 to 8.0. The relative contributions of clay and organic matter to total CEC were measured using multiple regression analyses; the independent variables were clay and organic matter contents and the dependent variables, CEC at pH 2.5, 3.5, 5.0, 6.0, 7.0, and 8.0. The average CEC of the organic matter at each pH value was 36, 73, 127, 131, 163, and 213 me. per 100 g., respectively; while that of the clay was 38, 46, 54, 56, 60, and 64 me. per 100 g. Within the limits of the standard errors of the regression coefficients, CEC of both clay and organic matter increased linearly with pH. The regression equations indicated that the mean relative contribution of organic matter to total soil CEC in this group of soils varied from 19% at pH 2.5 to 45% at pH 8.0; the mean organic matter and clay contents of the soils studied were 3.28% and 13.3% respectively. Coefficients of multiple correlation varied from 0.927 at pH 3.5 to 0.959 at pH 8.0.
Pyrolysis of Soil Organic Matter
Authors: Schnitzer M. , Hoffman I.
Published: July 2010

Organic matter extracted from O2 and Bh horizons of a Podzol soil was pyrolyzed between room temperature and 540°C. Samples were withdrawn at regular temperature intervals and analyzed by chemical and spectroscopic methods.

The carbon content of the chars increased with temperature accompanied by a simultaneous decrease in oxygen. The chars of both organic matter preparations heated to 540°C. contained identical percentages of carbon and hydrogen but no oxygen. Some of the nitrogen and sulfur in the original organic matter was very stable and was recovered in the chars heated to the highest temperature.

Phenolic OH groups were more stable than COOH groups but both were eliminated between 250° and 400°C. Both types of functional groups were more stable in the Bh horizon organic matter than in O2 horizon organic matter, apparently because the former was more aromatic.

The infrared spectra of the chars were in general agreement with the chemical data. On the basis of the analytical data the low temperature peaks in the DTG curves of both organic matter preparations were due mainly to the elimination of functional groups, whereas the high‐temperature maxima resulted from decomposition of the nuclei.

Using the graphical‐statistical method of Van Krevelen, the main reactions governing the pyrolysis of O2 horizon organic matter were found to be: (a) dehydrogenation (up to 200°C.); (b) a combination of decarboxylation and dehydration (between 200 and 250°C.); and (c) continuous dehydration. The main reaction determining the pyrolysis of Bh horizon organic matter was dehydration.
Mechanisms Involved in Soil Aggregate Stabilization by Fungi and Bacteria
Authors: Harris R. F. , Chesters G. , Allen O. N. , Attoe O. J.
Published: July 2010

Microbial mechanisms of soil aggregate stabilization were investigated as a function of microbiological and water‐stability changes of incubated artificial aggregates, 2 to 4.76 mm. in size composed of soil particles < 0.5 mm., prepared from Waupun silt loam. Aggregate water‐stability was determined by wet‐sieving and expressed as the percentage of soil material bound into water‐stable aggregates 0.5 to 1 mm., 1 to 2 mm. and > 2 mm. in size. Microbial development was investigated by dilution plate and microscopic methods.

Aggregate stabilization was a function more of microbial synthesis of soil‐binding substances than of numbers of microorganisms. Extensive production of mycelium and spores in soil aggregates by a fungus known to be capable of aggregate stabilization, did not, necessarily, result in an increase in the stability of the aggregates. Stabilization of aggregates by Mucor silvaticus involved the binding of soil particles into > 2 mm. water‐stable aggregates at all stages of incubation. Aggregates stabilized under anaerobic conditions exhibited a high percentage contribution of 0.5‐ to 1‐mm. and 1‐ to 2‐mm. aggregates to total stability in the early stages of incubation. A relatively high proportion of the total water‐stability of sucrose‐amended aggregates possessing the indigenous mixed microflora was attributable to stable 0.5‐ to 2‐mm. aggregates in the early stages of aerobic incubation, an indication that bacteria were more important than fungi in the initial stabilization of these aggregates.
Partially Acidulated Rock Phosphate as a Source of Phosphorus to Plants: I. Growth Chamber Studies
Authors: McLean E. O. , Wheeler R. W.
Published: July 2010

Rock phosphate was acidulated with H3PO4 at 0, 10, 20, 50, and 100% of that required to convert the rock phosphate to triple superphosphate. These materials plus a check (0 P) and H3PO4 alone were established as treatments on an acid soil (AB‐38) in 1‐gallon containers in a growth chamber. Representative treatments were also made to a Miami (County) soil. The phosphate treatments were applied both in bands and mixed with the soil. In general, German millet and alfalfa yielded about as much and contained as much P in the tissue from 10% acidulated phosphate as from 100% acidulated.

Corn seedlings took up P in proportion to the relative solubilities of rock phosphate, FePO4, AlPO4, Ca3(PO4)2, and KH2PO4 in sand. Yet they took up much less P when the phosphates were added to the soil, the amount being nearly constant regardless of the phosphate source added. This seems to be evidence for depression by common‐ion action of the availability of P in comparatively insoluble phosphates whether added to or formed in the soil.

Plant response to the partially acidulated phosphates and to H3PO4 was discussed in the light of recent reports on phosphate reaction products in the soil. This led to the suggestion that detrimental effects of the common ion may be minimized by the partial acidulation treatments such that the environment for the soluble phosphate may be largely defined by the unreacted rock phosphate.

The comparatively favorable plant response to the partially acidulated material and the economy of its production make partial acidulation appear to have very promising practical applications.
Soil Nitrogen Loss as a Result of Alternate Submergence and Drying
Authors: Patrick Wm. H. , Wyatt Ronald
Published: July 2010

Successive cycles of submergence and drying resulted in the loss of 15 to 20% of the total soil nitrogen. Nitrogen was nitrified during the aerated portion of the cycle and lost when the soil was submerged. Most of the loss occurred during the first three cycles of submergence and drying. The soil oxidation‐reduction potential decreased rapidly after the initial submergence. The more times the soil had been submerged and dried, the slower the oxidation‐reduction potential decreased when the soil was again submerged. Carbon and nitrogen were lost in approximately the same ratio that they occurred in the soil.
Effects of Liming on Yields and Composition of Heavily Fertilized Grasses and on Soil Properties Under Humid Tropical Conditions
Authors: Abruña Fernando , Vicente‐Chandler José , Pearson Robert W.
Published: July 2010

Heavily fertilized tropical grasses responded strongly to liming on two typical soils of the Humid Tropics. Liming increased the Ca and decreased the Mn content but did not affect the phosphorus or Mg content of the grasses. Surface applications of limestone were as effective as mixing limestone with the surface soil and one application was as effective as two applications at 2‐year intervals.

Exchangeable Al and Mn content of the soils was sharply increased by fertilization alone but was decreased by liming. Base content at all depths sampled was decreased by fertilization alone but was increased by surface liming followed by heavy fertilization. Yields of grasses increased markedly with pH of the upper 6 inches to about 4.8, with bases to 8.0 me. per 100 g. of soil and with decreasing exchangeable Al to 2 me. per 100 g. of soil.

Heavy fertilization of grasses over a 4‐year period without liming greatly depressed yields of subsequently planted tobacco and this effect was only partly compensated by reliming prior to planting the tobacco.
Soil and Plant Potassium as Affected by Soil Temperature Under Controlled Environment
Authors: Weber J. B. , Caldwell A. C.
Published: July 2010

Studies on the effect of soil temperature and moisture on the K‐supplying power of two soils were carried out in a growth chamber. Air temperature and lighting were programmed to follow a constant daily cycle, while soil temperature was kept constant with an insulated water bath assembly. Soil and plant K determinations were made at each of five stages of growth. Regression and correlation analyses were performed to describe the various response curves. Correlations were also made to describe the relationships between the plant and soil K measurements.

Results obtained from these studies showed soil temperature to have a tremendous effect on the K‐supplying power of a Floyd soil and much less of an effect on a Milaca soil. Plant yields were increased similarly on both soils with increased soil temperature, but K yields on the Floyd soil were increased from two to three times those of the Milaca soil. A significant response to applied K was obtained on both soils at low soil temperatures, but only the Milaca soil showed a substantial response at the high soil temperature. Correlations between plant and soil K measurements indicated that plants on the Milaca soil utilized exchangeable K at both low and high soil temperatures, whereas those on the Floyd soil utilized exchangeable K at low soil temperatures, and both exchangeable and nonexchangeable forms at high soil temperatures. Both soils fixed substantial amounts of applied K, but temperature effects on the two soils were very different and it appeared as though different fixation processes were involved. It was concluded from these studies that the erratic response to K fertilization on the Floyd soil in different years can be attributed primarily to differences in soil temperatures. Yield increases from K applications were obtained on this soil at low temperatures but not at high temperatures.
Morley and Blount Soils: A Statistical Summary of Certain Physical and Chemical Properties of Some Selected Profiles from Ohio
Authors: Wilding L. P. , Schafer George M. , Jones R. B.
Published: July 2010

Statistics including the mean, range, coefficient of variation, and standard deviation are reported for particlesize distribution, organic matter content, calcium carbonate equivalent, pH, depth of leaching, soil color, grade of soil structure, horizon thickness, and depth to mottling for 21 Morley and 38 Blount soil profiles sampled in Ohio. Of these properties, composite horizon thickness, hue and value variables of color, depth of leaching of free carbonates, silt content, and total clay content are least variable. The number of profile samples required to estimate the population mean of the above parameters within ± 10% using a .95 confidence interval was also computed. Cation‐exchange data are also presented for representative Morley and Blount profiles.
Soil Water Measurement with Gamma Attenuation
Authors: Reginato R. J. , van Bavel C. H. M.
Published: July 2010

Gamma‐ray attenuation measurements of wet density were made with a 5‐mc. Cs137 source over a pathlength of about 30 cm. Data were obtained for glass‐and‐water systems as well as for soil materials of varying water content. The equipment was designed for use in the measurement of water content of soil in situ in 1‐cm. increments, without any collimation of the beam.

Experimental results verify theoretical considerations on the use of gamma attenuation for soil water measurement. For equipment calibration, the unattenuated beam intensity and the attenuation coefficients for oven‐dry soil and water need be determined to make use of the exponential inverse square law for calculating the water content, given the dry density. The data demonstrate that the difference in the attenuation coefficients of dry soil and water must be taken into account.

Accuracy of the method, for a total count of 20,000, is 0.010 g. cm.‐3 for water contents from 0.050 to 0.400 g. cm.‐3 at a dry density of 1.300 g. cm.‐3. For the same total count, a precision of 0.006 g. cm.‐3 is demonstrated.