bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cotton Growth in an Acid Fragipan Subsoil: I. Effects of Physical Soil Properties, Liming, and Fertilization on Root Penetration
Authors: Soileau J. M. , Engelstad O. P. 
Published: July 2010

AbstractRoots of established cotton (Gossypium hirsutum, var. ‘Rex’) seedlings were allowed to grow into undisturbed or laboratory‐prepared cores of an infertile, highly acid, compact fragipan subsoil (Dickson series). A significant positive correlation was found between the number of roots in the subsoil cores and soil moisture. Examination of thin sections revealed a low total porosity and a predominance of small, discontinous planar voids in Dickson fragipan, which apparently contributes to the narrow range of available water in this horizon. The number and dry weight of roots decreased with increase in bulk density; however, the 1.5 g/cm3 bulk density of the fragipan is not considered an important factor for cotton root penetration in this subsoil. Root growth was not consistently related to soil strength as measured with a penetrometer probe. Significantly greater root dry weights and depth of penetration were found in limed than in nonlimed cores, regardless of bulk density, soil strength, or NPK fertilization. Results of this study indicate that adverse chemical or physiological effects related to extreme soil acidity may be dominant over other physical and chemical factors that inhibit root growth in Dickson fragipan subsoil.
Inhibition of Nitrification as a Deterrent to Nitrogen Loss
Authors: Huber D. M. , Murray G. A. , Crane J. M. 
Published: July 2010

AbstractInhibition of nitrification of fall‐applied ammonium sulfate with “N‐Serve”3 prevented movement of applied nitrogen below the 30.5‐cm depth. Yield of wheat (Triticum aestivum L., Cultivar Gaines) fertilized with ammonium sulfate and N‐Serve was increased 37 to 42% compared to no increase in yield with the nitrate form.
Alkaline Permanganate Oxidation of Methylated and Unmethylated Fulvic Acid
Authors: Schnitzer M. , Desjardins J. G. 
Published: July 2010

AbstractThe alkaline permanganate oxidation of humic and fulvic acids yields small amounts of benzene polycarboxylic acids that range from the di‐ to the hexa‐form. Low yields may be due to the presence of electron‐donating substituents, such as OH groups, on aromatic rings. To make the rings less susceptible to destruction by alkaline KMnO4, we attempted to reduce the electron‐donating effect by converting OH groups via methylation to OCH3 groups. The alkaline permanganate oxidation of methylated FA, however, yielded the same types and similar amounts of benzene carboxylic acids as that of the untreated FA. Failure of methylation to increase the variety and yield of oxidation products may be due to inability to either methylate all (phenolic) OH groups or, more likely, to reduce electron‐donating effects sufficiently.
Hydrolysis and Uptake of Pyrophosphate by Plant Roots
Authors: Gilliam J. W. 
Published: July 2010

AbstractPyro‐ and orthophosphate solutions were equally effective in supplying P to P‐deficient wheat (Triticum vulgare), corn (Zea mays L.), and barley (Hordeum vulgare L.). P‐deficient roots absorbed the pyrophosphate ion per se and also rapidly hydrolyzed the pyrophosphate as indicated by 40–55% of the P being present as the ortho form after 24 hours. It was concluded that this hydrolysis was caused by phosphatase present on external portions of the roots. Wheat roots which were P‐ deficient had approximately 1.6 times as much phosphatase activity as non‐deficient roots (per unit weight) as determined by appearance of orthophosphate. Evidence indicated that P‐ deficient wheat roots exposed only to orthophosphate produced significant quantities of pyrophosphate.
Soil Water Evaporation, Isothermal Diffusion, and Heat and Water Transfer
Authors: Fritton D. D. , Kirkham Don , Shaw R. H. 
Published: July 2010

AbstractTemperature and water distribution data were taken for a 9‐ by 11‐ by 20‐cm soil column where wind was the evaporation agent and for a similar soil column where radiation was the evaporation agent. A Webster silty clay loam soil characterized by a soil‐water retention curve and an inflow diffusivity versus water content curve was used in the experiments. The experimental results were compared with results calculated from a solution of the diffusion equation normally used to describe isothermal movement of soil water and from a heat and mass transfer solution which accounted for temperature effects. It was found that the isothermal diffusion equation would describe the cumulative evaporation for the wind and for the radiation treatments. The isothermal diffusion equation did not predict the formation of a surface layer of dry soil, and thus, did not describe the water distributions for the radiation treatment for times greater than 20 hours or for the wind treatment for times greater than 200 hours. A heat and mass transfer equation did predict the development of a dry surface layer and did describe the water distribution where temperature gradients were important.
Effects of Saline Water on the Chemical Properties of Some Tropical Soils
Authors: El‐Swaify S. A. , Swindale L. D. 
Published: July 2010

AbstractSurface and subsurface samples of soils representing the Tropical Red Earths and Tropical Red Deserts were equilibrated with unbuffered salt solutions which had the composition of sea water and ranged in concentration between 0.61N and 0.0061N. The effects of these treatments on soil pH, the concentration of soil solution, and exchangeable sodium percentages were subsequently characterized. The original acidities of these soils were highly resistant to change. Neither soil showed a tendency to accumulate salts by extraction from percolating solutions. Studies of exchangeable sodium percentages at the various concentration levels supported the valance‐dilution principle. At high salt concentrations, however, the observed affinities of these soils for divalent cations were higher than those predicted by the commonly used US Salinity Laboratory regression equation.To eliminate the possible interference by CaCO3 in observed ionic equilibria, Na‐Ca exchange studies were conducted on carbonate‐free soil samples. Isoconcentration isotherms were constructed at electrolyte concentrations of 0.01, 0.1, and 1.0N, compared with isotherms calculated from the US Salinity Laboratory's regression equation. Large discrepancies were observed at 1.0N concentration, particularly for the lowest soil horizons. For that concentration, it was found that predictions of ionic distribution based on the theory of the diffuse double layer can closely describe Na‐Ca equilibrium when large values of surface charge densities are assumed.
Nitrate Transformations in a Column with a Controlled Water Table
Authors: Meek B. D. , Grass L. B. , Willardson L. S. , MacKenzie A. J. 
Published: July 2010

AbstractThe relation of dissolved oxygen, soluble carbon, and redox potential to the movement of nitrate in soil columns and into submerged tile lines was studied. Columns 300 cm long were drained at depths of 180, 240, or 300 cm with the water table in all columns maintained at 175 cm. After adding ammonium nitrate and irrigating, the peak in nitrate concentration moved downward to the 160‐cm depth, but nitrate concentrations decreased at 180 cm and almost disappeared at the 240‐ and 300‐cm depths. The soil solution at 180 cm contained an average of 5.2 ppm nitrate‐nitrogen and a maximum of 16 ppm. In contrast the soil solution at 240 or 300 cm, which had passed through a submerged zone of 65 or 125 cm, averaged 0.5 ppm and had a maximum concentration of 1.1 ppm. Disappearance of nitrate was associated with decreases in redox potential, oxygen content of the soil solution and oxygen levels in the soil atmosphere, and with increases in soluble iron and manganese. Denitrification occurred without submergence if the soil redox potential was sufficiently low. Results of this experiment indicate that nitrate concentrations probably can be reduced in tile effluents by submerging the tile lines.
Hillslope Sedimentation and Soil Formation in Northeastern Iowa
Authors: Kleiss Harold J. 
Published: July 2010

AbstractSystematic investigation of a hillslope from summit to alluvial positions revealed that particle size variations within the soil A horizons are due to sedimentological sorting. The mean particle size in the surficial sediments follows a systematic decrease within two subset systems down the hillslope. Each subset is expressible mathematically. A discordance in the backslope position is caused by truncation of a sand zone within the till underlying the surficial material. Hillslope sedimentation has also influenced accumulation of organic matter, bulk density, and cation exchange capacities in the soils formed at various positions on the slope. Profile characteristics indicate little pedogenic development; rather, many of the soil properties are inherited from the sedimentary nature of the hillslope surficial sediment.
Bulk Density, Aggregate Stability, and Organic Matter Content as Influenced by Two Wheatland Soil Management Practices
Authors: Tanchandrphongs S. , Davidson J. M. 
Published: July 2010

AbstractThe amount of organic matter in the top 15.0–30.5 cm of a Grant silt loam after 11 years of stubble mulching was significantly greater than that in clean tilled (plow) plots on this soil over the same time period. Aggregation under stubble mulching was greater than with clean tillage. Soil compaction was noted by an increase in bulk density at the 23.0–30.5 cm depth in clean tilled plots, but was absent at all depths measured in stubble mulched plots.Annual nitrogen applications gave a significant increase in organic matter content at the 15.0–23.0 cm soil depth. Stubble mulching in an alfalfa (Medicago sativa L.)‐wheat (Triticum aestivum L.) rotation program was shown to influence the soil physical properties more significantly than did stubble mulching in a continuous‐wheat or the clean tillage in an alfalfa‐wheat program.
Effects of Nitrogen and Phosphorus Fertilization on Juvenile Growth of Planted Yellow Poplar on an Eroded Old Field
Authors: Farmer R. E. , Snow E. A. , Curlin J. W. 
Published: July 2010

AbstractIn a yellow poplar (Liriodendron tulipfera L.) plantation, three levels of nitrogen (0, 336, 672 kg/ha) and phosphorus (0, 168, 336 kg/ha) fertilizer applied at planting were tested in factorially arranged experiment with a split plot design. Nitrogen fertilizer was applied in holes near trees by two methods: loose and in perforated plastic bags.Survival after 5 years was 56% and was not influenced by treatment. Both nitrogen and phosphorus stimulated growth during the first 2 years after planting but phosphorus was effective only when combined with nitrogen fertilization. During this period, loose application of nitrogen fertilizer gave better results than bagged application. After 5 years, only nitrogen effects were statistically significant; mean height (2.59 m) of trees in the most effective nitrogen treatment (672 kg/ha) was 80% greater than controls.
Fertilizer Nitrogen and Crop Rotation in Relation to Movement of Nitrate Nitrogen Through Soil Profiles
Authors: Olsen R. J. , Hensler R. F. , Attoe O. J. , Witzel S. A. , Peterson L. A. 
Published: July 2010

AbstractRecovery of fertilizer N by three successive corn (Zea mays L.) crops and as inorganic N in the soil profile following the last crop ranged from 72 to 88%. Total amount of NO3‐N in the soil profiles was directly related to the rate of N application and to the frequency of corn in the rotation. More leaching of NO3‐N generally occurred between fall and spring samplings than during the growing season. The most effective methods indicated for limiting the amounts of NO3‐N passing through the soil profile to the water table include: limiting rates of N fertilizer to approximately that required by the crop, reducing the acreage and frequency of corn or other crops that received fertilizer N in the rotation, and maintaining a crop cover on the land as much of the time as is feasible.
Chemical Differentiation of Selected Wisconsin Histosols
Authors: Isirimah N. O. , Keeney D. R. , Lee G. B. 
Published: July 2010

AbstractSamples of 16 Wisconsin Histosols representing a wide range in botanical composition and in various stages of decomposition were used to evaluate selected chemical criteria which may be useful in classification of histic materials. Chemical parameters which related closely with the relative degree of humification were the organic matter cation exchange capacity, total N content of the organic matter, and C/N ratio. The forms of N soluble in 6N HCl varied widely, and no marked trends existed in the N distribution data with respect to the degree of decomposition of the samples.The amounts of C and N extracted from the samples by NaDowex A‐1 chelating resin bore no relationship to their degree of decomposition. Hot water soluble C and N decreased with increasing degree of decomposition. The absorbance of 0.025M Na‐pyrophosphate extracts of the soils at 340 or 550 mµ was related highly to the amount of organic C in the extracts.Samples were biologically degraded by incubating them under aerobic or waterlogged conditions for 1 year. On the average, Na‐resin and hot water extracted less and Na‐pyrophosphate more of the organic C from the incubated than from the original samples.The results of this investigation indicate that Na‐pyrophosphate solubility is useful in characterizing histic materials and that this extraction procedure can be adapted readily to routine analysis of samples in the laboratory.
Soil Moisture Tension Transients Associated with Evapotranspiration from a Water Table
Authors: Bianchi W. C. , Tovey Rhys 
Published: July 2010

AbstractSoil moisture tensions were recorded continuously in lysimeters containing a loam soil and a controlled water table. Seven strain gauge‐pressure transducer‐tensiometers were spaced from 20 to 110 cm above the 158‐cm water table. The velocity at which the morning and evening soil moisture tension minimum and maximum progressed downward through the root zone and capillary fringe proved inconsistent with soil moisture flow theory. This was interpreted as showing that even at low tensions a decrease in the moisture film continuity between the soil and tensiometer bulb relative to that between the few roots in contact with the bulb, caused the measurement to be biased toward the tensions associated with the root system. When the minimum daily tension exceeded 400 cm of H2O, soil‐bulb continuity was lost and, as a result, the characteristic wave form of daily evaporation (ET) demand was also lost. By placing the tensiometers in the capillary fringe where roots are absent, they could record the changing demands of ET on the capillary fringe. A method was tested for estimating water table uptake from a diffusivity based on the velocity of propagation of tension waves induced into the soil profile by daily ET and associated diurnal gradient changes.
Exhumed Paleosols and Associated Modern Till Soils in Western Illinois
Authors: Bushue L. J. , Fehrenbacher J. B. , Ray B. W. 
Published: July 2010

AbstractExhumed paleosols and modern soils formed in Illinoian and/or Kansan till occur in a complex pattern in many places on the sides of incised valleys in predominantly loess covered regions in western Illinois and adjacent states. The paleosols studied in western Illinois are thicker, finer textured, grayer and more poorly drained, and more impermeable than the modern soils formed during late Pleistocene and Recent weathering. However, the paleosols and modern soils do not differ greatly in chemical properties.The presence of highly contrasting paleosols and modern till soils on the same slope not only cause problems in soil mapping, but because of side‐hill seepage, and the fine texture and poor physical condition of the paleosols, difficult problems in soil management also exist. The use of soil complexes, undifferentiated units, or the inclusion of strongly contrasting soils in given mapping units is necessary to show these soil conditions on many slopes.
Chemical Properties of a Forest Soil Affected by Fertilization and Submergence
Authors: McKee W. H. 
Published: July 2010

AbstractIn samples from the Al horizon of poorly drained flatwoods soils from the Gulf Coastal Plain (Typic glossaqualfs), a combination of lime and phosphorus abruptly increased soil pH after 6 days of laboratory submergence. Treatment with only one of these additives, with other conditions the same, did not influence pH. After submergence for 60 days, pH values were near neutral. Redox values were lowered about 500 mv by waterlogging; they were not altered by lime or phosphorus application.Drying after submergence decreased pH, but effects of waterlogging remained. Submergence reduced levels of exchangeable Al, Ca, and Mg, probably by changing the acid strength of the soil, and shifted Al‐P to Fe‐P. Results of cyclic submergence indicate that effects are slowly reversible.
An Indirect Method for the Measurement of Sulfate by Barium Absorption Spectrophotometry
Authors: Borden F. Yates , McCormick Larry H. 
Published: July 2010

AbstractA method was developed to analyze for aqueous‐solution sulfate by precipitation by barium and measuring the remaining barium by atomic absorption spectrophotometry. The method compared favorably with a turbidimetric and a gravimetric method. Sensitivity was 1.5 ppm S/1% absorption. The method could be used without dilutions for solutions containing up to 150 ppm S.
Cation Exchange Capacity and Component Variations of Soils of Southeastern USA
Authors: Fiskell John G. A. 
Published: July 2010

AbstractSeveral methods for determining CEC were employed for soils selected from southeastern United States to provide a wide range in acidity, clay mineralogy, clay content, and organic matter content. Unbuffered saturation was made with 1N CaCl2, NaCl, NH4Cl, or KCl. Soluble salts were removed by rapid stirring and centrifuging of the soil samples after each of three water and ethanol replacements. Buffered systems were used to measure CEC at pH 4.8, 7.0, and 8.3. Sum of exchangeable bases was not equivalent to values for CEC by unbuffered salts. Increases in CEC from the latter values to those found at pH 7 or pH 8.3 were not identical with corresponding values for titratable soil acidity. Standard deviations of the methods were much lower than differences in CEC between methods. All soils showed less CEC with NH4+ or K+ saturation compared to Ca2+ or Na+ saturation; the difference was attributed chiefly to reaction with expanding phyllosilicates. For CEC measured at pH 7, component CEC of organic matter ranged from 40 to 180 between soil series, with the higher values associated with soils having free carbonate present. Under the same conditions, calculated CEC of clay ranged from 8 to 63 assumingnegligible CEC of the silt component. Apparent pH‐dependent CEC of these soils was mainly attributed to hydroxy‐Al associated with the organic matter and interlayering of expanding phyllosilicates.
Effect of the Separation of Nitrogen and Sulfur Sources on Sulfur Uptake by Corn
Authors: Rehm G. W. , Caldwell A. C. 
Published: July 2010

AbstractThe effect of fertilizer N and S sources on the absorption of S by corn (Zea mays L.) was studied in the greenhouse with the use of 35S. When the N and S sources were separated by a physical barrier, the NH4 ion, when compared to the NO3 ion, produced a significant increase in the S absorption from the fertilizer. The data indicate that the influence of the N source on S absorption is the result of physiological reactions or processes within the plant or the root tissue. The separation of the N and S sources had no significant effect on the total S and total N content of the tissue.
Effects of Stemflow Water on a Miami Soil Under a Beech Tree: II. Chemical Properties
Authors: Gersper P. L. , Holowaychuk N. 
Published: July 2010

AbstractEffects of the stemflow component of the biohydrologic soil forming factor on chemical properties of a Miami soil were investigated. Chemical analyses were made on horizons from soil profiles sampled in radial trenches emanating from the stem of a large American beech tree, at four distances from the stem. Data were subjected to analysis of variance using a two‐way classification with four replications and means were tested with Duncan's Multiple Range Test.A beech tree was selected for the study in order to maximize the intensity of the biohydrologic factor (because of the large amount of stemflow associated with this species). Stemflow water was collected periodically for volume measurements and chemical analyses.Stemflow water from the beech tree had a very high content of organic C; moderately high quantities of Ca and K; small quantities of Na, Mg, and P; and very small quantities of Al, Fe, and Mn. Stemflow water created a much wetter environment, of highly enriched water, in soil contiguous to the stem than that prevailing in soil farther from the stem. This resulted in very pronounced effects on chemical properties of the soil under the tree. In A horizons there were progressive increases inward toward the stem in organic C, total N, exchangeable acidity, exchangeable K, CEC, and free Fe2O3; and progressive inward decreases in pH, exchangeable Ca, exchangeable Mg, and base saturation. In B horizons there were progressive inward decreases in pH, exchangeable Ca, exchangeable Mg, exchangeable K, CEC, base saturation, and free Fe2O3.
The Formation of Mixed Magnesium‐Aluminum Hydroxides In Soil Materials
Authors: Hunsaker V. E. , Pratt P. F. 
Published: July 2010

AbstractPotentiometric titration curves show a buffer region in the vicinity of pH 8.2 to 8.5 when soil materials, which contain reactive forms of Al, are titrated in a Mg solution. This buffering is due to the formation of mixed Mg‐Al hydroxide. The product formed during the titration of gibbsite in 0.2N MgCl2 solution was identified as mixed Mg‐Al hydroxide by X‐ray diffraction analysis. The buffer region also appears when allophane, Al sesquioxide, and clay with exchangeable Al are titrated in Mg solutions. The reaction with exchangeable Al and Al sesquioxide is rapid, but the reaction requires several hours and even days with gibbsite and allophane. It is concluded that soils containing these and possibly other forms of Al, when raised to alkaline pH levels, can remove Mg from the soil solution by precipitation of mixed Mg‐Al hydroxide.
Nitrate and Detergent Recovery in Aerated Soil Columns
Authors: Mansell R. S. , Kirkham Don , Nielsen D. R. 
Published: July 2010

AbstractThe plant nutrient, nitrate, and the surfactant, linear alkylbenzene sulfonate (LAS), were applied in solutions to the surface of aerated columns (93 cm) of layered soil. Distilled water coutaining 0.01N CaSO4 was used to displace the nitrate and LAS through the columns while a steady water flow was maintained through the soil. The columns were water saturated at both extremities but unsaturated throughout most of the column length. Oxygen‐helium mixtures containing 0.2, 5, and 20% oxygen provided three different aeration levels. Recovery of nitrate in the liquid effluent was 73, 81, and 87% of that amount originally applied to the soil surface for the respective three levels of oxygen. Recovery of LAS was 50.4, 50.0, and 48.7% of the surface application for the same oxygen levels. These recovery results show that denitrification in a flowing soil‐air‐water system depended upon the level of oxygen, but the oxidation of LAS was not affected by the oxygen level. Actual times allowed to insure complete displacement of nitrate and LAS from the soil columns were 16.65, 15.42, and 17.67 days, respectively, for the 0.2, 5, and 20% oxygen treatments.