bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Oxidation of Elemental Sulfur in Soil
Authors: Li Paulina , Caldwell A. C. 
Published: July 2010

AbstractThe effects of particle size, rate of application, soil pH, temperature, inoculation, and addition of organic matter on the oxidation of elemental S in soil were studied. In general the amount of S oxidized increased with decrease in particle size. Greatest oxidation occurred with particle sizes of < 100 mesh. Oxidation reached a peak at 60 days of incubation time. The amount of S applied to the soil did not seem to affect the fraction oxidized. Little S was oxidized at 4C, some at 10C. Temperatures of 30C and 40C were more effective than 23C and lower. Inoculation accelerated the oxidation. Organic matter increased the rate of oxidation when soil samples were inoculated but did not affect the process when soil samples were not inoculated. Decrease in soil pH was highly correlated with the amount of S oxidation.
Level Pan System for Spreading and Storing Watershed Runoff
Authors: Mickelson Rome H. 
Published: July 2010

AbstractLevel pans were constructed in broad natural waterways to intercept runoff from contributing watersheds for storage and crop use. Stored soil moisture at seeding time in the level pans was as much in a 7‐month period over winter as that stored in unleveled fallow plots during a 19‐ to 21‐month period. Watershed runoff during the growing season provided 3 inches of moisture annually to level pans. The increased moisture supplies in the level pans permitted annual cropping with a 2‐fold or better increase in yields over unleveled dryland areas in either fallow or continuous cropping. Water‐use efficiency of grain and forage sorghums (Sorghum vulgare 'RS‐610 and ‘FS‐22’) increased with increasing moisture supplies.
Coastal Bermudagrass Response to Applications of P and K as Related to P and K Levels in the Soil
Authors: Jordan C. W. , Evans C. E. , Rouse R. D. 
Published: July 2010

AbstractThe response of Coastal bermudagrass (Cynodon dactylon L. Pers.) to applications of P and K as related to P and K levels in the loamy sand and sandy loam soils of the Lakeland‐Norfolk series was studied from 1959 to 1963. The annual rate of 240 lb N/acre was applied in four applications. Effect of treatment on yield, plant content of P, K, Ca, and Mg, and change in soil test values of the surface 24 inches were determined each year.The relationships between yield and soil test P and K were described by curves calculated with a modification of the Mitscherlich equation to the form log (A − y) = log A − bc using data for initial and final years. The curves obtained showed yield response to P at soil test values < 25 ppm P and yield response to K at soil test values < 40 ppm K. Chemical analysis of samples from the surface 2 inches of soil was representative of the P and K fertility.Plant contents above 0.16% P and 1.0% K were adequate for maximum production.A fungal disease apparently associated with K deficiency was observed on plots receiving no K at 10 of the 18 locations in 1961 and subsequent years.
Calcium Deficiency as a Causal Agent of Ammonium Phosphate Injury to Cotton Seedlings
Authors: Adams Fred 
Published: July 2010

AbstractShort‐term experiments were conducted with cotton seedlings (Gossypium hirsutum L.) on a Lakeland loamy sand at different pH levels and at different rates of (NH4)2HPO4 and NH4H2PO4. Seed was planted in a layer of untreated soil that was underlain by treated soil. The primary roots were allowed to grow into the treated soil for 48 hr. Root growth into treated soil was inhibited by several treatments, and apparent death of the primary root was effected by several other treatments. Root growth into the treated soils could not be explained in terms of soil pH, P‐rate, or individual concentrations of soil solution cations. However, if all solution cations were expressed in terms of molar activities, then a striking relationship between root growth and ratio of Ca/total‐cation or NH4/total‐cation in the soil solution became evident. Root growth was inhibited by all NH4‐phosphate treatments that resulted in Ca/total‐cation molar activity ratios in soil solution of less than about 0.15. Apparent death of root was caused by all NH4‐phosphate treatments that resulted in Ca/total‐cation molar activity ratios in soil solution of less than about 0.05. It was concluded that the injurious effect of NH4‐phosphate on cotton seedlings was a Ca deficiency in the ambient soil solution. This resulted from the precipitation of Ca phosphates and from the antagonistic action of NH+4 on Ca absorption by the root.
Soil Moisture Measurement with Ultrasonic Energy
Authors: Mack A. R. , Brach E. J. 
Published: July 2010

AbstractLow energy ultrasonic waves were propagated readily at specific megacycle frequencies through samples of water and moist soil. At these frequencies, the propagated energy varied with the moisture content of the soil. Energy propagated at frequencies near 15.9 and 19.8 Mcycle/sec was sensitive to a change in moisture over a narrow range (0 to 12 g H2O/130 cm3 soil), whereas that propagated near 114 and 142 Mcycle/sec was related to moisture over a wider range (0 to 56 g H2O/130 cm3 soil). Results obtained when salts were added to the soil indicated that ultrasonic waves near 15.9 and 19.8 Mcycle/sec were affected markedly by the ionic concentration of the soil. Waves near 114 and 142 Mcycle/sec were not affected by ionic concentrations of 1 mmhos cm‐1 as measured in 1:5 soil‐water extracts. Change in texture and in organic matter content of 8 soils and 2 other materials had no significant effect on propagation at the higher frequencies (114 and 142 Mcycle/sec). Propagation of energy (114 Mcycle/sec) through moist samples changed little between 0C and about 30C, increased somewhat above 30C and decreased sharply below 0C. These higher ultrasonic frequencies appeared suitable for a nondestructive method of determining moisture content of soils.
Determination and Isotope‐Ratio Analysis of Different Forms of Nitrogen in Soils: 3. Exchangeable Ammonium, Nitrate, and Nitrite by Extraction‐Distillation Methods
Authors: Bremner J. M. , Keeney D. R. 
Published: July 2010

AbstractMethods of determining exchangeable ammonium, nitrate, and nitrite in soils are described. They involve extraction of the soil sample with 2M KCl (10 ml/g of soil) and analysis of the extract by steam‐distillation methods in which magnesium oxide is used for distillation of ammonium, ball‐milled Devarda alloy for reduction of nitrate and nitrite to ammonium, and sulfamic acid for destruction of nitrite. The distillation methods are rapid, accurate, and precise, have high specificity, and are applicable to turbid, colored, and unfiltered soil extracts. They give quantitative recovery of ammonium, nitrate, and nitrite added to soil extracts and permit nitrogen isotope‐ratio analysis of these forms of nitrogen in N15‐tracer studies of nitrogen transformations in soils.
Determination and Isotope‐Ratio Analysis of Different Forms of Nitrogen in Soils: 5. Fixed Ammonium
Authors: Silva J. A. , Bremner J. M. 
Published: July 2010

AbstractA method of determining fixed ammonium in soils is described. The soil sample is treated with alkaline KOBr solution to remove exchangeable ammonium and organic nitrogen compounds, and the residue is washed with 0.5M KCl and shaken with 5N HF:1N HCl for 24 hr, the ammonium released by the HF‐HCl treatment being determined by steam distilling the soil‐acid mixture with KOH. The KOBr treatment effects almost quantitative removal of organic soil nitrogen under conditions which preclude fixation by soil minerals of ammonium released from soil organic matter by this treatment, and evaluation tests indicate that the procedure used to estimate fixed ammonium in the KOBr‐pretreatment residue is satisfactory. The method is simple and precise, and it has none of the observed defects of previous methods of estimating fixed ammonium in soils. It gives higher values than the Dhariwal‐Stevenson, Bremner, and Mogilevkina methods, and lower values than the Rodrigues and Schachtschabel methods. A modification in which the HF‐HCl treatment is performed at 100C for 30 min is described.
A Modified Procedure for the Determination of Total Boron from Soil Fused with Sodium Carbonate
Authors: Gupta Umesh C. 
Published: July 2010

AbstractTotal boron was extracted by 6N HCl and by 6N H2SO4 from a soil fused with Na2CO3. The amount of boron in the resulting extracts was determined directly. It was found that the H2SO4 extraction of soils interfered with the absorbance of the boron carmine complex resulting in high values of boron. No interferences were encountered with the HCl extracts. Further, the resulting extracts from HCl were easily filtered. The percentage recovery of the added boron from the investigated soils, when extracted by 6N HCl was good and the results were reproducible.Heating 6N acid solutions for a period of 2 hr on a hot water bath at 100C resulted in no loss of boron. Carmine reagent was found to be stable for at least 18 days when stored in polyethylene bottles at room temperature.
Genesis, Mineralogy and Related Properties of West Indian Soils: I. Bauxitic Soils of Jamaica
Authors: Ahmad N. , Jones Robert L. , Beavers A. H. 
Published: July 2010

AbstractThe red and brown bauxite soils of Jamaica occurring over hard, pure white limestone are strongly aggregated, freely drained soils of almost pure clay texture. They are of low fertility, nitrogen and potassium being very deficient. The red bauxite is deficient in available phosphate but not responsive to phosphorus fertilization. Phosphorus fractionation data show both soils to be adequately supplied with phosphorus. The brown bauxite is much higher than the red in total phosphate and in aluminum‐ and calcium‐bonded forms. Both soils are very high in iron‐bonded phosphate with the red bauxite having a greater percentage of the total phosphate in reductant soluble form. Chemical analysis shows the soils to be very high in Al2O3 content with little or no difference between the two soils. Silica content is very low. Iron is high and virtually all of it is present in dithionite extractable form. No minerals containing potassium seem to be present in the soils. Mineralogical study shows the Al2O3 to be present as gibbsite and boehmite in a ratio of 2:1 for both soils. The soils had less than 10% kaolinite, the brown bauxite being higher. Traces of chlorite were identified in both soils, and traces of montmorillonite were found in the deeper layers of the brown bauxite. Titanium was present as rutile and anatase in the brown bauxite but only as anatase in the red. The red bauxite is richer in goethite. The low content of silicates in the bauxites is associated with a low SiO2 content of the insoluble residue of the limestone and this is evidence for possible genesis of the bauxites from the underlying limestone.
Growth and Nutrient Uptake of Irrigated Young Ponderosa Pine After Fertilizer Treatments
Authors: Tarrant Robert F. , Silen Roy R. 
Published: July 2010

AbstractAmmonium nitrate and treble superphosphate were applied to irrigated, 7‐year‐old ponderosa pine (Pinus ponderosa Laws.) in a wind break planted on Deschutes sandy loam in central Oregon. Nitrogen was supplied at levels of 0, 200, and 400 lb/acre and P at 0, 100, and 200 lb/acre in a factorial experiment. Fertilizer treatments were repeated two years after initial application.Over a 6‐year period after first fertilizer treatment, tree growth was stimulated in relation to amount of N applied singly. When N and P were applied together in various combinations, growth was in some cases stimulated and in other cases reduced, according to the combination of the two elements. Foliage N concentration was not affected significantly by any treatment, but when P was applied at the 100‐lb rate, addition of N treatments caused a linear increase in foliage N concentration. With P at 200 lb, addition of N caused a linear decrease in foliage N concentration.At the conclusion of the study, N content of soils receiving the heaviest N fertilizer application was only about 11% more than that of the controls. However, under heaviest P treatments soil P was more than five times that of unfertilized soils.
Nickel‐Barium Exchange Selectivity Coefficients for Montmorillonite
Authors: McLean G. W. , Pratt P. F. , Page A. L. 
Published: July 2010

AbstractNickel‐barium exchange selectivity coefficients were determined for a montmorillonite clay by saturating 0.5‐g samples with 0.04N serial concentrations of NiCl2 and BaCl2. The values for the reaction BaZ + Ni2+ ⇄ Niz + Ba2+ ranged from 0.65 to 0.78, indicating a preferential adsorption of barium.
Determination and Isotope‐Ratio Analysis of Different Forms of Nitrogen in Soils: 6. Mineralizable Nitrogen
Authors: Keeney D. R. , Bremner J. M. 
Published: July 2010

AbstractAn incubation method of estimating mineralizable soil nitrogen which does not require preliminary analyses to determine the amount of water required for incubation and is applicable without modification to soils having widely different textures is described. It is based on the finding that the amount of water required for maximal aerobic mineralization of nitrogen during incubation of soils is practically the same for different soils (ca. 0.6 ml/g of soil) if the soil sample is mixed with three times its weight of 30‐ to 60‐mesh quartz sand before incubation. The method involves determination of the (exchangeable ammonium + nitrate + nitrite)‐N produced when 10 g of soil mixed with 30 g of sand are treated with 6 ml of water and incubated at 30C for 14 days under conditions which ensure adequate aeration without loss of water. It is simple and precise, and evaluation tests indicate that it provides a good index of soil nitrogen availability.
Estimation of Dead‐End Pore Volume in Soils from Transient‐ and Steady‐State Diffusion Coefficients
Authors: Jackson R. D. , Klute A. 
Published: July 2010

AbstractA means of estimating dead‐end pore volume in porous materials using transient‐ and steady‐state diffusion coefficients is presented. The few available data indicate that dead‐end pore volume in soils is a small percentage of the total pore volume.
Composition of Dilute‐Acid‐Fluoride (Bray P1) Extracts of Illinois Soils
Authors: Tandon H. L. S. , Motto H. L. , Kurtz L. T. 
Published: July 2010

AbstractThe Bray P1 reagent (0.03N NH4F + 0.025N HCl) is widely used to extract “available P” from soils, but few studies have been made to determine the other elements that it removes with P. Illinois soils differing in pH and P fertilization were extracted with the P1 reagent and also separately with its two components, 0.025N HCl and 0.03N NH4F. These extracts were analyzed for P, Al, Fe, Ca, Mg, Mn, and Si. Phosphorus extracted by the P1 reagent or by 0.03N NH4F was not correlated with soil pH or any of the other elements extracted. Combinations of Al with P in the soil, if they existed, could have been masked since the Al extracted by P1 and by 0.03N NH4F were many times greater than the P extracted. Phosphorus removed by 0.025N HCl was positively correlated with soil pH and with the Ca and Mg in the same extracts. From most soils the P1 reagent removed more P than the sum removed separately by 0.03N NH4F and 0.025N HCl. However, the reverse was true for a soil naturally high in calcium. Removal of the “Al‐P” fraction of Chang and Jackson markedly reduced the P removed in a subsequent extraction with the P1 reagent. Also, very little Al was extracted by P1 after the “Al‐P” fraction had been removed.
Cesium Sorption in Relation to Lattice Spacing and Cation Exchange Capacity of Biotite
Authors: Sawhney B. L. 
Published: July 2010

AbstractInterlayer K from biotite was extracted with sodium tetraphenylboron for varying time intervals. Then, the Cs sorbed from 10‐4N and 10‐6N CsCl solutions by the original biotite and its altered products was determined.The increased removal of K successively increased the vermiculite component with expanded 14A lattice and a larger CEC and decreased biotite with a collapsed 10A lattice and a smaller CEC. Further, the greater the amount of vermiculite and larger the CEC, the more was the Cs sorbed. Obviously, the expanded component with a larger CEC sorbed more Cs than its collapsed counterpart. These sorptions by mixtures of biotite and vermiculite, thus, do not support the contention that Cs is sorbed selectively by minerals with a 10A lattice spacing.
Kaolinization of Biotite as a Result of Coniferous and Deciduous Seedling Growth
Authors: Spyridakis D. E. , Chesters G. , Wilde S. A. 
Published: July 2010

AbstractThe rhizospheric activity of coniferous and deciduous tree seedlings grown for a period of 13 months in sand cultures containing biotite (50 to 2µ) as the only source of K and Mg, effected the transformation of biotite to kaolinite. The identity of the kaolinite was established by means of X‐ray diffraction and electron microscope analyses. The effectiveness of the seedlings in producing kaolinite from biotite was in the order: white cedar > hemlock > white pine > white spruce > red oak > hard maple [(Thuja occidentalis) > (Tsuga canadensis) > (Pinus strobus L.) > (Picea glauca > (Quercus rubra L. (Q. borealis Mich. x.f.) > (Acer saccharum)]. The conditions prevailing in the cultures accelerated the hydrolytic process and removal of K, Mg, and Fe from biotite and their substitution by H3O causing kaolinization. Electron microscope data revealed the characteristic hexagonal crystals of kaolinite forming on the mica surfaces. Monterey pine (P. radiata) grown in sand cultures converted biotite to vermiculite. The formation of vermiculite rather than kaolinite was attributed to the presence of metal cations in the root remains added to the cultures at the outset of the experiment.
Clonal Differences in Yield Response of Populus deltoides to Nitrogen Fertilization
Authors: Curlin James W. 
Published: July 2010

AbstractTrees propagated from cuttings of 22 clones of Populus deltoides were grown under unfertilized and nitrogen‐fertilized conditions. Large increases in growth resulted from fertilization. A strong clone × fertilizer interaction was observed for diameter, height, and volume growth. Wood specific gravity was reduced by fertilization but no interaction between clones and fertilizers was noted for that character after 2 years.The presence of the genotype‐environment interaction indicated that it would be unwise to select eastern cottonwood from a nutritional environment other than the one in which it will ultimately grow. Frequently a clone which performed poorly under unfertilized conditions excelled when fertilized and in several instances the reverse was true. This suggests the possibility that selection can be made specifically for fertilizer response in tree improvement programs. Caution should be exercised when interpreting fertilizer response of experimental populations which might contain genetic bias.
Psychrometric Measurement of Soil Water Potential without Precise Temperature Control
Authors: Rawlins S. L. , Dalton F. N. 
Published: July 2010

AbstractA theoretical analysis shows that by imposing certain boundary conditions it should be possible to eliminate the major effects of temperature fluctuation on psychrometric measurements of soil water potential. Tests on a psychrometer constructed to meet these boundary conditions were carried out on a soil column in a greenhouse. Although diurnal fluctuation of soil temperature was as great as 5C, water potential was measured with an apparent accuracy of ±0.5 bars throughout two irrigation cycles.
‘A’ Values of Potassium Related to Other Indexes of Soil Potassium Availability
Authors: Nuttall W. F. , Warkentin B. P. , Carter A. L. 
Published: July 2010

AbstractA technique was developed to measure ‘A’ values of K with oat (Avena sativa) plants grown in the greenhouse and with the radioactive isotope 42K. The isotope 42K has a short half‐life (12.42 ± .03 hours) and was applied to the soil as KCl (approximately 2 mc of 42K/g of 39K) 14 to 18 days after seeding. Plants were harvested to determine initial quantities of K at the time of tagged fertilizer application. Six days later the fertilized plants were harvested and the activity in the plant tissue was counted in a liquid scintillation spectrometer. For 11 soils the total of exchangeable K plus nonexchangeable K accounted for 56% of the variability in K uptake at the time of tracer application, whereas 92% of the variability in ‘A’ values was accounted for by these measurements. Results from the experiments indicated that both amounts of exchangeable and nonexchangable K should be used as availability indexes.
Interstratification in Vermiculite and Biotite Produced by Potassium Sorption: I. Evaluation by Simple X‐ray Diffraction Pattern Inspection
Authors: Rhoades J. D. , Coleman N. T. 
Published: July 2010

AbstractThe formation of mixed‐layer minerals occurred upon potassium sorption by sodium or magnesium vermiculites with a change in the interlayer cation composition from the homoionic state to one of varying K/Na or K/Mg proportions. The type of mixing occurring in the vermiculites, as deduced by examination of X‐ray diffraction patterns, was similar to that expected for regularly interstratified systems. The same conclusion could not be drawn for the Na‐ or Mg‐biotite material. The effect of particle size on this phenomenon is such that the tendency toward regularity of mixing was greater for the 50 to 74µ than for <2µ materials. It was concluded that it is difficult to distinguish regular from random interstratification in the trioctahedral mica minerals due to coincidence of all but the weakest peaks of the two systems.
Infrared Studies of Hydroxy‐Aluminum Interlayer Material
Authors: Weismiller R. A. , Ahlrichs J. L. , White J. L. 
Published: July 2010

AbstractDifferential infrared spectra of films of Al‐montmorillonite matched with films of Al‐montmorillonite with artificially introduced hydroxy‐aluminum interlayers showed the interlayer to give absorption bands at 3,695 cm‐1 and 3,570 cm‐1 of nearly equal intensity. The pleochroism of the 3,695 cm‐1 band indicated an orientation of many of the hydroxyls normal to the oxygen surface of the montmorillonite. The nonpleochroic nature of the 3,570 cm‐1 band indicated an orientation at a moderate angle to the oxygen surface for the balance of the interlayer hydroxyls. A decrease in frequency from 3,695 cm‐1 to 3,670 cm‐1 and an increase from 3,570 cm‐1 to 3,600 cm‐1 upon drying can be explained by dehydration and by a closer association of the high frequency hydroxyls (3,695cm‐1) with the oxygen surface of the clay. A single ring, six aluminum, polymer lying planar in the interlayer position would be expected to have the structural requirements to satisfy the observations in the 1.5:1 OH/Al interlayer system.