bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Soil Temperature and Phosphorus Fertilizers of Different Water‐Solubilities on the Yield and Phosphorus Uptake by Oats
Authors: Case V. W. , Brady N. C. , Lathwell D. J. 
Published: July 2010

AbstractThe effect of root zone temperatures of 15°, 20°, and 25°C. and P sources having water‐solubilities of 1, 25, 50, and 100% were evaluated in two greenhouse experiments using oats as a test crop. Oats were grown for 43 days and height, dry weight, and P uptake were determined.Height response to added P was greatest at 15°C. and least at 25°C. The effects of temperature on height were greatest where no P was applied. There was a marked response in forage yields and in P uptake to increasing amounts of applied P and to increasing soil temperature. Root yields and P uptake, however, were highest at 15°C. and lowest at 25°C. In both tops and roots the temperature effect was greater at high rates of P than at low rates of P application.In the winter experiment using ammoniated superphosphates, yields and P uptake by oat forage decreased as the percentage of water‐soluble P decreased, except at the lowest percentage of water‐soluble P where yield and P uptake were not related to water‐solubility of P. In the fall experiment where mixtures of MCP and DCP were used, the source of P had little effect on yield and P uptake.
Carbonate Clay: Measurement and Relationship to Clay Distribution and Cation‐Exchange Capacity
Authors: Shields L. G. , Meyer M. W. 
Published: July 2010

AbstractA method for the determination of carbonate clay as an integral part of the pipette method for particle‐size analysis is given. Carbonate clay is calculated by measuring the gravimetric loss of CO2 from a 50‐ml. aliquot of the clay (< 2µ) fraction.For some calcareous soil materials a substantial proportion of the clay fraction consists of carbonate. A survey is given of the proportion of carbonate that is claysize. Five kinds of clay percentages for calcareous soil materials are discussed. The application of carbonate clay data to the interpretations of clay distribution curves is presented.Evidence is presented that carbonate, including carbonate clay, has negligible cation‐exchange capacity. The effect of the presence of carbonate clay on the calculated cation‐exchange capacity of the clay fraction is discussed.
Extraction of Clay‐Water Systems
Authors: Lagerwerff J. V. 
Published: July 2010

AbstractExperimental data on suspensions of Na‐montmorillonite in solutions of various NaCl concentrations quantitatively confirm existing theory which predicts a gradual decrease in the extract concentration during pressure extraction (salt exclusion). This decrease is preceded by a maximum in extract concentration when salt is retained in the suspension (salt sieving). The theoretical descriptions imply a constant salt‐sieving factor. A coarser filter was found to be associated with stronger salt sieving. The extract from mixed Na‐Ca suspensions in chloride solutions shows an increasing concentration of Na relative to Ca during protracted extraction. Practical implications of the results are discussed.
Effects of Supplemental Irrigation with Saline Water on Soil Composition and on Yields and Cation Content of Forage Crops
Authors: Lunin J. , Gallatin M. H. , Batchelder A. R. 
Published: July 2010

AbstractDilutions of synthetic sea water were used for supplemental irrigation on small plots containing alfalfa, Kentucky 31 Fescue, orchardgrass, and ladino clover. One treatment irrigated with nonsaline water and a nonirrigated control were also included. Significant increases in yield due to irrigation were obtained in only a few instances during the second through fourth year of study, but during the first year two of the four cuttings of all four crops responded to supplemental irrigation. Where several irrigations were applied, yields tended to decrease with increasing salinity, with ladino clover being the most sensitive of the four crops tested. Soil salinity increased to ECe values as high as 15.4 mmho. per cm. (electrical conductivity of the saturation extract) as a result of saline irrigation. The Ca, Mg, and K content of all four crops were relatively unaffected by soil salinity. The Na content of all plants tended to increase with increasing salinity, with the greatest accumulation occurring in the ladino clover. Exchangeable Ca decreased and Mg, Na, and K increased with increasing salt concentration of the water applied.
Wheat Stubble Management: I. Influence on Some Physical Properties of a Chernozem Soil
Authors: Ramig Robert E. , Mazurak Andrew P. 
Published: July 2010

AbstractFour methods of wheat stubble management (burn and plow, plow, one‐way disk, and subsurface‐till) in an alternate wheat‐fallow system on a Chernozem soil were studied for 12 years. Plots were split, with one‐half of each plot receiving N fertilizer. Twelve years of subsurface‐tilling or one‐way disking substantially increased the geometric mean diameter of water‐stable aggregrates and decreased the bulk density of the surface soil as compared with plowing or burning and plowing. The ratio of water entry, 10 minutes to 120 minutes, was substantially lower in wheat plots that had been subsurface‐tilled or plowed than where the plots had been burned and plowed or one‐way disked. Application of N fertilizer did not affect the physical properties measured.
Combining Surface Mulches and Periodic Water Applications for Reclaiming Saline Soils
Authors: Carter David L. , Fanning Carl D. 
Published: July 2010

AbstractWater applied by periodic sprinkling of surface‐mulched soil resulted in greater salt removal and higher leaching efficiency than did either flooding or periodic sprinkling of bare soil. Cotton (Gossypium hirsutum) bur and chopped shrubbery mulches were about equally effective. Flooding and sprinkling bare soil decreased salt concentration in the surface 2 feet of the soil profile, but salt accumulated below a depth of 3 feet when compared with check soil that received only rainfall. Similarly, salts were removed from all depths to 5 feet where surface mulches were present. The salt leaching efficiency decreased from above 90% in the surface foot to approximately 33% in the fifth foot of surface‐mulched soil. The higher leaching efficiency for mulched soil was attributed to the probably reduced evaporation under mulches that lessened upward movement of water.
Microrelief Influences in a Saline Area of Ancient Glacial Lake Agassiz: II. On Shallow Ground Water
Authors: Benz L. C. , Sandoval F. M. , Mickelson R. H. , George E. J. 
Published: July 2010

AbstractA study was made of the shallow ground‐water regime in a ridge‐depression microrelief area where high salinity occurred in the ridges compared to low salinity in the depressions. Ground‐water movement was affected by: (a) surface relief, which caused impounding of precipitation in the depressions; (b) greater hydraulic conductivities in the depressions; and (c) differences in moisture use due to greater tree and vegetative growth in the depressions. Water tables fluctuated from above the ground surface to depths of 10 feet. Salt concentrations of ground water were much higher in the ridges than the depressions. These differences occurred to a depth of 20 feet.
Relative Erodibility of Three Loess‐Derived Soils in Southwestern Iowa
Authors: Schmidt B. L. , Shrader W. D. , Moldenhauer W. C. 
Published: July 2010

AbstractMeasurements of original and present surface soil depth, as indicated by slope and erosion field data and organic carbon contents, were used to determine the relative erodibility of the loess‐derived Monona, Marshall, and Sharpsburg soils in southwestern Iowa. These studies indicated decreasing surface soil depths with increasing slope on all three soils, with the Monona soil having the least and Sharpsburg the most surface soil remaining. The difference in average depth to an arbitrary benchmark, 0.90% organic carbon content, in cultivated as compared with virgin profiles of each soil indicated, however, that slightly lower erosion losses due to cultivation over time have occurred on the Monona soil.Laboratory rainfall simulator studies indicated higher infiltration and lower soil loss rates on the Monona soil than on the Marshall and Sharpsburg soils. The formation of a dense surface seal by raindrop impact appeared to be a dominant factor in the erodibility of these soils. Studies on crusted samples indicated slightly lower soil loss and higher infiltration rates on the Monona even with the crust present.
Heat Capacities of Clay and Clay‐Water Mixtures
Authors: Oster J. D. , Low Philip F. 
Published: July 2010

AbstractHeat capacities of mixtures of several homoionic clays with different amounts of water were determined with a Bunsen ice calorimeter. The specific heats of the clays were also determined by the same technique. From the results, the apparent specific heats of the water are calculable. In addition, the partial specific heat of the water associated with each clay at each of several water contents was determined by plotting the heat capacity of the mixture against the water content (in grams of water per gram of clay) and taking the slope of the resulting line at the desired water content. In all cases, the apparent specific heat and the partial specific heat of the water were > 1.0 at low water contents (< 1.0 gram water per gram of clay). At higher water contents the values of these quantities approached unity. The results were interpreted in terms of the contribution of H‐bonding to the specific heat of the water.
Competition of NH3 and H2O for Adsorption Sites on Clay Minerals
Authors: James D. W. , Harward M. E. 
Published: July 2010

AbstractAmmoniation of air‐dry Ca, Mg, and Al montmorillonite and bentonite resulted in dehydration of the exchangeable cations and a change in c‐axis spacing from 15 to 16Å. to 12.6 to 13Å. Ammoniation of a vacuum‐dried Ca system resulted in a change in c‐axis spacing from 10.1 to 12.3Å. On the other hand, NH3 retained by the minerals upon ammoniation was replaced by H2O under controlled conditions of relative humidity. It was postulated that the mutual competition between H2O and NH3 molecules for adsorption sites can be described by the law of mass action. The various theories which have been proposed to describe the mechanism of NH3 chemisorption are discussed.
D2O‐Na24 Method for Tracing Soil Moisture Movement in the Field
Authors: Haskell C. C. , Hawkins R. H. 
Published: July 2010

AbstractA unique method is described for measuring unsaturated flow of water in the field with D2O tracer, a Na24 gamma source, and a slow‐neutron detector. The interaction of gamma radiation of energy greater than 2.23 Mev. and deuterium produces photoneutrons. The Na24 gamma source and the slow‐neutron detector are contained in a modified neutron‐type soil moisture probe. The method successfully measured vertical movement of deuterium tracer in a Gilead sandy loam with the aid of access tubes.
Water Vapor Diffusion in Relatively Dry Soil: IV. Temperature and Pressure Effects on Sorption Diffusion Coefficients
Authors: Jackson Ray D. 
Published: July 2010

AbstractThe temperature and pressure dependence of water transfer coefficients in two relatively dry soil materials were measured. The relative magnitudes of liquid and vapor transfer were obtained from the pressure experiments. The liquid diffusion coefficient for Adelanto loam was 20 to 40% of the total diffusion coefficient, whereas for Pachappa loam the liquid diffusion coefficient was negligible. The temperature dependence of the vapor diffusion coefficient for Adelanto and the total diffusion coefficient in Pachappa can be calculated from published data on the temperature dependence of the water vapor diffusion coefficient in air and the saturated vapor density. The activation energy for the liquid component in Adelanto was calculated by combining the temperature and pressure diffusion data and was found to be about 4.2 kcal mole‐1 for water contents above a monolayer.
Self‐Diffusion Coefficients of Phosphorus in Soil Measured by Transient and Steady‐State Methods
Authors: Olsen S. R. , Kemper W. D. , Van Schaik J. C. 
Published: July 2010

AbstractSelf‐diffusion coefficients of P in soil were measured by two independent methods and by calculating Dp from chloride diffusion. All three methods yielded similar values for Dp at low moisture suctions. On Apishapa silty clay loam, values of Dp ranged from 0.4 × 10‐7 to 15.5 × 10‐7 cm2/sec as the volumetric moisture content increased from 0.22 to 0.55, or as the soil moisture suction decreased from 6 to < 0.1 bar. From these values of Dp a self‐diffusion coefficient for P in bulk solution was calculated, which agreed closely with the experimentally measured value. The transient state method required a separate evaluation of a capacity factor which varied between 100 to 300. If this capacity factor had been omitted, the apparent Dp would have been smaller by 100‐ to 300‐fold. These results demonstrate the necessity of measuring a capacity factor when Dp is to be determined by a transient state method.
Boron Concentration Adjacent to Fertilizer Granules in Soil, and Its Effect on Root Growth
Authors: Mortvedt J. J. , Osborn G. 
Published: July 2010

AbstractRates of dissolution of B from granules of rasorite and three boronated fertilizers in limed Hartsells fine sandy loam decreased in the order: Nitric phosphate (2.2% B) > rasorite (20.2% B) ≫ calcium silicate slag (7.5% B) > calcium metaphosphate (2.1% B). Movement of B from the granules increased with B concentration gradient and soil moisture content.Concentration of hot water‐soluble B in soil near the granules at a given time depended on: (i) B content of the granule, and (ii) the relative rates of B dissolution from the granule and movement of B from the granule site. Concentrations of B near rasorite granules—as high as 80 parts per million (ppm) in a large volume (4 kg of soil in gallon cans) and 385 ppm in thin soil layers (80 g of soil in Petri dishes)—were inversely proportional to the amount of soil affected.Root growth of oats and alfalfa was slightly depressed at soil B concentrations of 2 to 5 ppm, and markedly so at concentrations above 10 ppm B. Thus, high concentrations in soil near some B sources may inhibit root growth. Root injury may be prevented by decreasing the B content per fertilizer granule and by applying less soluble sources or lower amounts of B.
Effects of Climatic Factors on Fruit Volume Increase and Leaf Water Deficit of Citrus in Relation to Soil Suction
Authors: Lombard P. B. , Stolzy L. H. , Garber M. J. , Szuszkiewicz T. E. 
Published: July 2010

AbstractThe primary factors affecting the rate of fruit volume increase and leaf water deficit of navel orange trees were investigated under two irrigation treatments. One treatment was applied when tensiometers in the major root zone indicated 20 cbar soil suction and the other treatment was applied at 100 cbar soil suction. The correlations between either fruit volume increase or leaf water deficit and various environmental conditions were studied by factor analysis to determine possible primary factors affecting the water status of the trees. Soil suction, a primary factor in both treatments, influenced the fruit and the leaf in only the 100 cbar treatment. Rate of water movement through the soil to the plant roots could be the underlying factor. Another factor, evaporation power of the atmosphere during high diurnal transpiration affected the rate of fruit volume increase in only the 100 cbar treatment.
Significance of Extractable Aluminum in Hawaiian Sugarcane Soils
Authors: Ayres A. S. , Hagihara H. H. , Stanford G. 
Published: July 2010

AbstractAluminum was extracted with water and solutions of NH4OAc, pH 4.8, and KCl from Humic, Hydrol Humic, and Humic Ferruginous Latosols (some of which are considered potential commercial sources of Al) as well as from certain less weathered soils. Exchangeable Al appeared to account for only a small fraction of the Al extracted from some of the more highly weathered soils. NH4OAc‐soluble Al increased markedly with degree of weathering of the soil, but this was not true of KCl‐ or water‐soluble Al. Within each great soil group Al, soluble in all three extractants, increased many times with decreasing soil pH. Concentrations of Al in water extracts did not exceed 2.5 ppm; in soils of pH 5.0 or above, concentrations seldom were in excess of 0.1 ppm. The addition of limestone effectively decreased levels of both NH4OAc‐ and water‐soluble Al. These results, coupled with field observations, have led to the conclusion that Al levels in Hawaiian soils are not sufficiently high to repress the growth of sugarcane.
Phosphorus Fixation as a Transfer Controlled Phenomenon
Authors: Avnimelech Y. , Hagin J. 
Published: July 2010

AbstractPhosphorus fixation in various soils was accelerated by: (i) the application of P in solution thus inducing its immediate dispersion in the soil, and (ii) increasing the rate of movement of the P in the soil by changes in the water regime. It was concluded that the dispersion of P in the fertilized soil volume is the rate‐limiting step in the process of its fixation and thus P fixation could be described as a transfer‐controlled process.
Response of Table Beets (Beta vulgaris L.) to Banded Fertilizer Phosphorus and Potassium at Different Levels of Soil Phosphorus and Potassium in a Heavily Fertilized Honeoye Silt Loam Soil
Authors: Peck N. H. , Vittum M. T. , MacDonald G. E. 
Published: July 2010

AbstractResponse of table beets to fertilizer P and K banded at planting time in 1960 was determined on a Honeoye silt loam soil which had received various levels of complete fertilizer from 1945 to 1951, and different levels of broadcast fertilizer P and K from 1954 to 1959. Soil P from previously applied fertilizer accumulated to a greater extent and had a longer residual effect than soil K as measured by soil tests; however, responses of beets to different levels of soil K were greater than they were to different levels of soil P. At high levels of soil P, there was little response to differences in soil P or banded fertilizer P. At medium levels of soil K, there were considerable increases in percentage of K in the leaves, plant size, and yield with increases in soil K and/or banded fertilizer K. Responses to different levels of soil P and K, and banded fertilizer P and K were cumulative and generally independent of each other. Generally, the soil P and K were relatively as important as the banded fertilizer P and K in producing high yields of beets.
Forms of Phosphorus in Soil After Long‐Continued Fertilization
Authors: Manning P. B. , Salomon M. 
Published: July 2010

AbstractThe forms of P in a Bridgehampton silt loam (Brown Podzolic) after more than 65 years of phosphate fertilization were studied by the fractionation methods of Chang and Jackson. The investigation showed that superphosphate treatments increased the aluminum phosphate fractions, and iron and calcium phosphate to a lesser degree. Rock phosphate treatments increased the calcium phosphate fraction. Of particular interest was a manured soil where phosphate followed a similar aluminum bonding as did superphosphate.Occluded and organic phosphate fractions were not greatly affected by various levels and sources of applied phosphate. Summation of the extracted inorganic and organic forms did not equal the total P. This “unextractable” fraction is believed to be tightly bound forms not solubilized by the acid extractions or possibly held as nonexchangeable “lattice” phosphate. There was some indication that lime treatments decreased the amount of aluminum phosphate formed.
The Numerical Analysis of Infiltration, Considering Hysteresis, Into a Vertical Soil Column at Equilibrium Under Gravity
Authors: Whisler F. D. , Klute A. 
Published: July 2010

AbstractA numerical solution of the flow equation for water in soil was obtained for a flow system consisting of a vertical column of soil which had been drained from saturation to equilibrium with a water table. A thin layer of ponded water was assumed to be applied to the top end of the column. This meant that each point in the column wetted up along a different scanning curve of the moisture characteristic curves. The solution of the equation depicts the time and depth distributions of water content and pressure head during the resulting infiltration. The results show that for soils that have water content‐pressure head curves with regions of steep slopes, the wetting front advances as a steep, well‐defined front. In those soils with more gently sloping water content‐pressure head curves, the wetting front was more diffuse. If hysteresis was ignored, the position of the front at any one time was overestimated or underestimated—depending upon whether the drainage or wetting curve was used.
Determination and Isotope‐Ratio Analysis of Different Forms of Nitrogen in Soils: I. Apparatus and Procedure for Distillation and Determination of Ammonium
Authors: Bremner J. M. , Edwards A. P. 
Published: July 2010

AbstractMethods of analysis have been developed which permit both determination and isotope‐ratio analysis of inorganic and organic forms of nitrogen in soils and soil extracts. In each method, the form of nitrogen under analysis is converted to, and estimated as, ammonium, which is readily oxidized to nitrogen gas for mass spectrometer assay of N15. The ammonium is separated by steam distillation, collected in boric and acid‐indicator solution, and determined by titration with standard acid. The apparatus and procedure used for distillation and determination of ammonium are described.
A Technique for Making Thin Sections of Soil with Roots in Place
Authors: Lund Z. F. , Beals H. O. 
Published: July 2010

AbstractA short dehydration series was combined with a plasti‐embedding technique to study cotton roots in place. This was an effort to see if there was much particle orientation at the root surface‐soil interface. A limited number of sections failed to show much orientation but did show a packing effect. The use of colored plastic was investigated. It greatly facilitates thin section work as it makes identification of pore space much easier.
Soil Moisture Effects on Potassium Release Observed on Drying Soils with Organic Additives
Authors: Bates T. E. , Scott A. D. 
Published: July 2010

AbstractA release of 223 ppm K occurred when Marshall subsoil samples were heated for 40 days in a drying oven at 110C. Most of this release can be attributed to the desiccation attained, not the heat, because similar heat treatments without drying increased the exchangeable K level by only 33 ppm.The release of K associated with drying was entirely eliminated by adding organic compounds to the soil samples before they were dried. To attain this control of K release, however, it was necessary to dry the soil under conditions that ensured the presence of the organic compounds throughout the drying period. Otherwise, the effect of organic additives varied with the initial moisture level of the soil and the relative rates at which the water and organic additives were lost. Single additions of compounds with high boiling points were particularly effective in controlling K release, but even ethanol (boiling point 78C) prevented K release when it was maintained in the soil while the soil moisture was removed.A practical method of controlling the release of K associated with drying involves the addition of 20 mmoles dextrose to 10 g soil. This treatment eliminates K release despite the presence of large amounts of water or the use of different drying rates.