bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crop Response to Soil Acidity Factors in Ultisols and Oxisols: I. Tobacco
Authors: Abruña‐Rodríguez Fernando , Vicente‐Chandler José , Pearson Robert W. , Silva Servando 
Published: July 2010

AbstractYields of tobacco (Nicotiana tabacum L.) on three Ultisols in Puerto Rico increased with liming up to about pH 5.0. There was a highly significant inverse relationship between yield and exchangeable Al. Maximum yield was generally reached as exchangeable Al approached 0 and at base saturation values of around 60%. Yields on an Oxisol increased with liming to about the same pH and base saturation level, although only traces of exchangeable Al were found. Leaf analysis indicated that Mn toxicity was a probable factor in the Oxisol. Tobacco root growth, studied in one of the Ultisols, was directly affected by low soil pH. Al toxicity appeared to be the chief cause of restricted growth but Ca deficiency was a possible contributing factor.
Some Relations Among Coastal Plain Soils and Geomorphic Surfaces in North Carolina
Authors: Daniels R. B. , Gamble E. E. , Cady J. G. 
Published: July 2010

AbstractSoils on the upper and middle Coastal Plain surfaces in North Carolina have been exposed to surface weathering for about 3‐ to 10‐million years. This makes it possible to evaluate the effect of soil formation of long duration on soil properties. Solum thickness, percentage of soils with plinthite, and gibbsite content increase from the youngest to the oldest surface, but kaolinite content and percentage of soils with Be bodies decrease in this direction. Solum thickness, percent of soils with plinthite, gibbsite and kaolinite content and percentage of soils with Be bodies have a curvilinear change with time. Soil properties are not always related to the total time of subaerial weathering because some soil processes do not begin for a million or more years after weathering starts. Changing internal soil environments produced by changing water‐table regimes is a major factor influencing soil formation in these soils. Changing water‐table regimes probably are produced largely by landscape evolution.
Effects of Added Nitrogen on the Availability of Phosphorus to Slash Pine on Two Lower Coastal Plain Soils
Authors: Maftoun M. , Pritchett W. L. 
Published: July 2010

AbstractApplications of 50 to 400 ppm N as NaNO3 or (NH4)2SO4 suppressed growth, total P uptake, and recovery of fertilizer P by young slash pine (Pinus elliottii var. elliottii Engelm.) in two P‐deficient coastal plain soils. At the higher N rates (200 and 400 ppm) growth was limited severely by (NH4)2SO4 and all seedlings were killed by these rates of NaNO3 in pot experiments. Growth suppressions following N fertilization were associated with reductions in P availability, as measured by total P uptake.Reducations in total P uptake apparently were not a result of anion antagonism, as there were only small differences in P uptake associated with the two N sources. Incubation studies indicated very low rates of nitrifications in these soils and N applications did not increase microbial activity (CO2 production), which could have temporarily reduced P availability.Root development was restricted by the N fertilizers to a greater extent than was top growth. The root suppression evidently resulted from increased concentrations of Na or total salts in the soil. Although it appeared from these studies that Na was involved in the reduction in P uptake by the seedlings, it was not clear whether the small suppressions following N fertilization were associated with reductions in P uptake.
Equations for Approximating Vertical Nonsteady‐State Drainage of Soil Columns
Authors: Jackson Ray D. , Whisler Frank D. 
Published: July 2010

AbstractEquations are derived, from a capillary tube model, that predict vertical nonsteady‐state drainage from soil columns over the entire time of drainage for which experimental data are available. The model assumes that a soil column is a bundle of capillaries of various radii with the effective conductivity of the column decreasing as drainage progresses. The conductivity is first considered to be a linear function of the average water level in the column, and then considered to be a quadratic function of the water level. Both resulting equations predict drainage reasonably well when particular values are assigned to the ratio of the average height of capillary rise to the column length. A simplified expression is obtained by neglecting an insignificant term and assigning values to constants in the equation in which the conductivity was taken as a quadratic function of the average water level. The equations are compared with experimental data.
Crystalline Phosphates Produced By Interaction of Orthophosphate Fertilizers With Slightly Acid and Alkaline Soils
Authors: Bell L. C. , Black C. A. 
Published: July 2010

AbstractPetrographic and X‐ray diffraction methods were used to identify the phosphates formed when Ca(H2PO4)2 · H2O, NH4H2PO4, and (NH4)2HPO4 were allowed to move individually into columns of slightly acid and alkaline soils from a layer of the solid phosphate salt placed at the bottom. The soil columns were examined after 4, 16, and 48 weeks of incubation. With Ca(H2PO4)2 · H2O as the fertilizer, the dominant phosphate identified in all soils was CaHPO4 · 2H2O. Minor amounts of CaHPO4 were found in the soils within 2 mm of the fertilizer. With NH4H2PO4 as the fertilizer, CaHPO4 · 2H2O was again the dominant phosphate identified in all soils, the amount increasing with the amount of calcium present initially in exchangeable and carbonate forms. No CaHPO4 was found. In one soil containing 12 meq of exchangeable magnesium per 100 g, the CaHPO4 · 2H2O was accompanied by MgNH4PO4 · 6H2O, which, with time, dissolved to form Mg3(PO4)2 · 22H2O. With (NH4)2HPO4 as the fertilizer, the amounts of crystalline phosphates found were smaller, but the number of different phosphates was larger than with the other fertilizers. Phosphates identified were Ca(NH4)2(HPO4)2 · H2O (dimorph B), Ca8H2(PO4)6 · 5H2O, CaHPO4 · 2H2O, and MgNH4PO4 · 6H2O, but no one phosphate was identified in all soils. CaHPO4 · 2H2O was the dominant phosphate in high‐calcium soils (except for a highly calcareous soil in which only Ca8H2(PO4)6 · 5H2O was identified), but was present only in traces in low‐calcium soils. Ca(NH4)2(HPO4)2 · H2O (dimorph B) was identified in most soils at 4 weeks; it disappeared with time, leaving a residue of CaHPO4 · 2H2O. MgNH4PO4 · 6H2O occurred at 4 weeks in a soil high in exchangeable magnesium; only a trace remained at 48 weeks. Ca8H2(PO4)6 · 5H2O occurred as an initial product in a soil containing 22% CaCO3 equivalent and as a product of alteration of CaHPO4 · 2H2O in a number of soils with pH values of 6.3 or higher. Once formed, it seemed stable with time.
Effect of Clod Size in the Seedbed on Development and Yield of Sugarcane
Authors: Jain N. K. , Agrawal J. P. 
Published: July 2010

AbstractTopsoil was replaced to a depth of 22.8 cm with clod separates, to correspond to Yoder's pulverization moduli, in an experiment conducted with sugarcane (Saccharum officinarum L.) during 1965–1966 and 1966–1967 at the Government Agricultural College, Kanpur, India. Soil bulk density, used as a measure of soil pore space, was lowest at pulverization modulus 2 which represented a clod size of 3.2 to 6.4 mm. Increased pore space at this pulverization modulus resulted in a higher germination percentage, increased the number of shoot roots, enhanced the uptake of nitrogen and, consequently, benefited all measured indices of sugarcane crop response. These included plant height, number of tillers, number of millable canes, and cane yield. To some extent, juice quality of sugarcane was also improved by optimum soil preparation. Deviation from an optimum to a coarser seedbed was less harmful than deviation to a finer seedbed.
Nitrate Volatilization from Soils
Authors: Thomas G. W. , Kissel D. E. 
Published: July 2010

AbstractNitrate losses from several soils were studied with regard to soil acidity, temperature, and time of heating. Much higher losses of NO3 were observed from soils containing KCl‐exchangeable Al3+ + H+ than from those with no replaceable acidity. Losses at 85 and 110C were much higher than at lower temperatures, suggesting that losses in the field would be moderate. There was a general increase in NO3 loss with time of heating.The reaction explaining most of the loss was thought to be:
urn:x-wiley:03615995:saj2sssaj197003615995003400050043x:equation:saj2sssaj197003615995003400050043x-math-0001 However, there was an additional small loss of NO3 from all soils used which could not be explained by the above reaction.
A Variable‐Intensity Sprinkling Infiltrometer
Authors: Amerman C. R. , Hillel D. I. , Peterson A. E. 
Published: July 2010

AbstractA rotating disk with four open, adjustable slots was mounted on a portable single‐nozzle sprinkling infiltrometer. When spun at about 60 rpm, essentially uninterrupted artificial precipitation reached the ground surface. At intensities ranging from 1 mm/hr to more than 150 mm/hr, uniformity coefficients were little different from those achieved by the nozzle itself.
Miscible Displacement Measurements within Laboratory Columns Using the Gamma‐photoneutron Method
Authors: Corey J. C. , Hawkins R. H. , Overman R. F. , Green R. E. 
Published: July 2010

AbstractWhen fluid in a porous medium is displaced by a second fluid that is miscible with the first, a transition zone exists between the two. The length and location of this transition zone in a soil column is difficult to measure in situ. When one of the fluids contains D2O as the major component, a new procedure, the gamma‐photoneutron method, readily measures this transition zone. This method permits precise measurements of the average concentration of heavy water (D2O) at selected locations in a soil column. The utility of the method is illustrated by two experiments; the downward displacement of D2O (specific gravity of 1.105 g/cm3) by H2O, and the downward displacement of H2O by D2O + NaNO3 (specific gravity of 1.291 g/cm3). The mathematical model which describes the shape of the transition zone between the miscible fluids requires the apparent diffusion coefficients to be constant. The experiment showed the apparent diffusion coefficient was not constant as the zone moved through a 100‐cm column. Unstable flow due to viscosity differences between fluids was probably responsible for increases in the apparent diffusion coefficient when H2O displaced D2O.
Sources of Phosphorus for Plants Grown in Soils with Differing Phosphorus Fixation Tendencies
Authors: McLean E. O. , Logan T. J. 
Published: July 2010

AbstractSeveral phosphates of varying water solubilities were evaluated as sources of P for plants grown in soils with different degrees of P fixation. With relatively low fixation, P content of corn (Zea mays) seedlings increased in direct proportion to water solubility of “available” P. With high fixation, P content decreased with increased water solubility of P. Under the latter conditions, liming the soil or banding the P decreased P fixation; but the amounts were small relative to total P fixed. On slightly acid soils (pH 5.6 to 6.5) where response was obtained to applied P by six crops (corn, alfalfa, German millet, buck‐wheat, wheat, or rice under both field and growth chamber conditions) 20% acidulated material was superior to 100% acidulated material in 16 cases, equal to 100% acidulated material in 55 cases, and inferior to 100% acidulated in only 17 cases. Where yields from the two materials differed significantly, differences were also observed in the effect of added P on soil available P (Bray P‐1). Since the efficiency of solubilization of P in rock phosphate by H3PO4 decreases with rate of acidulation, and the unreacted rock phosphate evidently enhances plant recovery of soluble P, partially (20%) acidulated rock phosphate is a reasonable choice for soils of high P fixing tendency.
Soils and Stratigraphy of a Portion of the Gola River Fan of Uttar Pradesh, India
Authors: Hurelbrink Richard L. , Fehrenbacher J. B. 
Published: July 2010

AbstractThe Gola River fan, formed at the base of the Himalayan Mountains in Nainital District of Uttar Pradesh, India, is composed of strongly to moderately sloping, thin, coarse‐textured sediments over stony layers near the foothills and gently sloping, moderately thick to thick, medium‐textured sediments over sand and gravel beyond some 8 to 10 km below the foothills. The two portions of the fan are separated by a spring line.The soils of the upper portion of the fan, which is known as the bhabar, are thin and drouthy. Soils of the lower portion of the fan, which is called the tarai, have good moisture storage capacity and are highly productive. All soils are weakly developed with high pH values and high base saturation. Some leaching of bases, translocation of iron, and formation of structure has taken place in these soils, but clay movement has been very slight. Mineral alteration has not been great, the high chlorite and mica clay mineral content being inherited from the soil parent materials. Most of the soils in the tarai have mollic epipedons and cambic horizons and are Mollisols. Soils in the bhabar tend to have thinner, dark‐colored surface horizons than those in the tarai, and those near the apex of the fan and the foothills are Inceptisols and Entisols.
Adsorption of Boron by Ferromagnesian Minerals and Magnesium Hydroxide
Authors: Rhoades J. D. , Ingvalson R. D. , Hatcher J. T. 
Published: July 2010

AbstractArid‐zone soils are found to have appreciable boron‐sorption capacities in their silt and sand fractions. The site of this sorption is hypothesized to be magnesium‐hydroxy clusters and coatings that exist on the weathering surfaces of ferromagnesian minerals such as olivine, enstatite, diopside, augite, tremolite, and hornblende as well as micaceous layer‐silicate minerals.
Photoelectric Tachometer for Precise Centrifuge Speed Determination
Authors: Fisher H. D. , Brown M. J. 
Published: July 2010

AbstractCertain chemical and physical investigations such as the mechanical analysis of soils by centrifugation require that the speed of rotation of the centrifuge be precisely determined. For a cost of approximately $40.00, when used with instrumentation normally available in research laboratories, the system outlined provides a vivid, unambiguous indication of the speed of rotation, the accuracy of which is limited only by the frequency standard used.
Soil Hydraulic Conductivity Measurement by Field Monoliths
Authors: Stibbe Ehud , Thiel T. J. , Taylor G. S. 
Published: July 2010

AbstractA method is described for evaluating the saturated hydraulic conductivity (K) of field soils. Vertical water flow in relatively large, in situ monoliths provides K values that are reproducible and agree well with other techniques for evaluating K.
The Diffusion and Consumption of Oxygen in Submerged Soils
Authors: Howeler R. H. , Bouldin D. R. 
Published: July 2010

AbstractSix O2 diffusion models, which included several oxygen consumption processes, were evaluated by measuring O2 consumption rates under conditions which approached the steady state and under transient‐state conditions. Consumption rates under approximately steady‐state conditions were determined by placing undisturbed lake‐bottom cores in water and measuring the decrease in O2 concentration of the water. Transient‐state consumption rates were determined from the amount of O2 gas that had to be injected above an initially reduced soil to maintain a constant O2 concentration at the soil surface. The distribution of extractable Fe in the cores was obtained by sectioning frozen soil cores and extracting the sections with NaOAc at pH 2.8 and with dithionite in EDTA.Considerable amounts of Fe2+ were found to diffuse from the reduced zone to the oxidized zone where it accumulated as precipitated Fe3+. The oxygen consumption was best described by models which included consumption by microbial respiration in the aerobic zone and oxidation of mobile and nonmobile reductants such as Fe2+. The latter components of oxygen consumption accounted for about 50% of the consumption by cores after 11 days when the cores were initially uniformly reduced.
Wheat Straw Decomposition in the Field
Authors: Smith J. H. , Douglas C. L. 
Published: July 2010

AbstractWheat (Triticum aestivum) varieties ‘Nugaines’ and ‘Lemhi’ were grown on Portneuf silt loam soil with three nitrogen and three irrigation treatments in 1967. After harvest, 84 kg N/ha was applied to half of each plot before plowing. Uniform straw samples were enclosed in fiberglass cloth bags and buried in the plots September 7. The straw placed in N‐treated plots received sufficient N in solution to increase the straw N from about 0.29 to 1.5%. Straw samples were recovered November 15, after the soil had cooled below 4C, and at three later sampling dates to October 3, 1968, after a bean crop (Phaseolus spp.) was harvested. Weight loss and total N were determined on all samplings and total C on the first sampling. Decomposition was greater with N than without it for the November sampling and the March sampling for Nugaines but not at other samplings for both varieties. The weight of N in both N‐treated straw varieties decreased 55% by November 15, while in the non‐N‐treated Nugaines and Lemhi straw, N weight increased 12 and 32%, respectively, by March 22. Later, N moved out of all the straw samples when the N percentages were much lower than the theoretical equilibrium value.
Chemical and Physical Stability of Microbially Stabilized Aggregates
Authors: Aspiras R. B. , Allen O. N. , Chesters G. , Harris R. F. 
Published: July 2010

AbstractChemical properties of microbially bound aggregates were determined by organic solvent extraction and by the rate of sonic dispersion of the aggregates. Seven fungi, six streptomycetes, and four bacteria, produced in situ chemically different binding agents which conferred different chemical and physical properties on soil aggregates. A. tenuis, S. atra, and two species of Penicillium apparently bound soil aggregates by the production of humic‐like binding materials. Six streptomycetes and two Aspergillus species obtained their effectiveness by production of a combination of humic‐like components and polysaccharides. Components of lignin‐like character were involved in the stabilization of aggregates bound by two Aspergillus species. B. polymyxa, R. trifolii, and two species of Agrobacterium bound soil aggregates largely by NaIO4‐oxidizable polysaccharide gums. M. hiemalis was the only organism that bound aggregates by waxy or fatty components.Microorganisms differ widely in their ability to affect mechanical stability of water‐stable soil aggregates. The ability of each microorganism to bind mechanically stable aggregates varied between soil types. Aggregates bound by A. tenuis and S. atra, B. polymyxa, and A. radiobacter were more stable than those bound by other microorganisms, as evidenced by the longer exposure time required for sonic dispersion. The aggregates produced by S. purpurascens and S. coelicolor were less resistant to sonic dispersion. Aggregates of three soils bound by A. zonatus and M. hiemalis were destroyed easily by sonication. Microbially‐bound Kewaunee clay aggregates were generally the most resistant to sonic dispersion.
Ionic Effect of Salts on Mineral Nitrogen Release in an Allophanic Soil
Authors: Agarwal A. S. , Singh B. R. , Kanehiro Y. 
Published: July 2010

AbstractA comparison of the effects of sulfate and chloride salts on N release and microbial activity in Akaka soil showed that only sulfate salts at low concentrations increased CO2 evolution. The chlorides were more effective than sulfates in effecting NH4‐N release in the soil. The addition of CaCl2·2H2O resulted in the greatest NH4‐N release, followed by that of KCl and NaCl. Among sulfates, K2SO4 ranked first, followed by Na2SO4 and CaSO4 · 2H2O. The idea that certain chemical reactions and/or processes are involved in splitting NH4‐N from organo‐inorganic complexes of a soil and that NH4+ ions are subsequently exchanged with cations in the surrounding soil solution was further substantiated by results of this investigation. The exchange reaction was noted to depend on the nature and valence of the cation, concentration in the soil solution, length of reaction, and the anionic species associated with the cation. The capacity of the cations for releasing NH4‐N decreased in the order Ca > K > Na for the chloride series.Unlike the NH4‐N release pattern, sulfates were more effective than chlorides in promoting nitrification. In general, all salts, excepting CaSO4 · 2H2O, at higher concentrations curtailed nitrification. The results indicated a real participation of anions in soil N release. Two salts containing the same cation but different anions released different magnitudes of N at an equivalent concentration. Thus, the results of this investigation provide further support for the role of cations in soil N release and, in addition, furnish reasonable evidence of the participation of anionic species. A consideration of the overall values of NH4‐ and NO3‐N at various salt concentrations led to the series, CaCl2 · 2H2O > KCl > NaCl > K2SO4 > Na2SO4 > CaSO4 · 2H2O, in order of decreasing N release power.
Phosphorus Adsorption and Movement in Some Sandy Forest Soils
Authors: Humphreys F. R. , Pritchett W. L. 
Published: July 2010

AbstractSeven to 11 years after rock or superphosphate was applied to young slash pine (Pinus elliottii Engelm. var. elliottii) plantations on seven soils of the Lower Coastal Plains, significant growth responses were evident in five of the seven tests. However, there were indications that the effect of the fertilizer was diminishing in certain soils. Foliage P, soil P intensity measurements, P sorption characteristics, and the Chang and Jackson sequential extraction procedure were used to ascertain the present availability of fertilizer residues at different soil depths. Little or no residual P from superphosphate remained in the top 20 cm of soils with no P sorption or buffering capacity, such as Leon fine sand. However, almost all of the superphosphate remained in an available form in the rooting zone in soils with a low P sorption and buffering capacity. In a soil with a high P sorption and buffering capacity most of the added P was retained in the surface horizon in a poorly available form. Little rock phosphate had been leached from any of the soils. Some transformation of P to adsorbed forms, as with superphosphate, had occurred, but availability was very high in each case. Some observations are made concerning the types and amounts of phosphate fertilizers suitable for these and similar soils.
Testing Sodium Hazard Predictions
Authors: O'Connor G. A. 
Published: July 2010

AbstractGreenhouse data were used to test a series of equations developed by Rhoades to predict the sodium hazard of irrigation waters. Two equations used to calculate values of LRSAR were found to successfully predict excess sodium accumulation in treatments where LF < LRSAR. Equations used to calculate SARdw values gave good quantitative agreement for systems apparently in equilibrium when the soil‐mineral weathering coefficient was assumed to be 0.65.