bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partially Acidulated Rock Phosphate as a Source of Phosphorus to Plants: II. Growth Chamber and Field Corn Studies
Authors: McLean E. O. , Wheeler R. W. , Watson J. D. 
Published: July 2010

AbstractPartially acidulated rock phosphate (with H3PO4) was studied using additional soils, application rates and preparation methods under growth chamber and field conditions. The yields and P contents of German millet and alfalfa in the growth chamber increased to a maximum at 66 pp2m P application and 20% acidulation on one group of soils and continued to increase with application rate and acidulation degree in another group. No appreciable difference was obtained with three methods of preparation of 20% acidulated material. Average field corn yield on five soils was highest with 20% acidulated material resulting in marked economic advantage of this material.
Aggregate Size Distribution in the Row Zone of Tillage Experiments
Authors: Allmaras R. R. , Burwell R. E. , Voorhees W. B. , Larson W. E. 
Published: July 2010

AbstractA sampling procedure was developed to measure the distribution of soil aggregate diameters in the row zone of row‐cropped corn. At each of 31 locations, 4 preplant tillage treatments were used to obtain different soil conditions in the row zone. Undisturbed soil cores were taken from the 0‐ to 3‐ and 3‐ to 6‐inch layer. Dry aggregate‐diameter distribution and dry bulk density (DB) were measured for the 0‐ to 3‐inch layer (DB only in the 3‐ to 6‐inch layer). Within 6 weeks after planting DB increased, but the logarithm of geometric mean diameter (log GMD) and the dispersion of aggregate diameters (σlog d) changed differently depending on tillage treatment and year of study. DB in the 3‐ to 6‐inch layer did not change. Large differences in these measurements were observed among tillage treatments, but within a year of field trials no treatment × location interaction occurred. Some comparisons of measurements were consistent between years and others were not.DB of the 0‐ to 3‐inch layer increased among tillage treatments as σlog d increased, but decreased less as the log GMD increased. A similar relation was shown in the laboratory using mixtures of aggregate‐diameter separates. These changes in DB were mainly due to modification of the interaggregate void space. In the laboratory an increase in weight fraction of water was observed from increasing σlog d. Hence, both log GMD and σlog d are measurable parameters of soil conditions in beds of aggregates, and may help to explain soil water retention and movement, evaporation losses, seed‐soil contact, and root‐soil contact.
Mechanism of Reaction of Neutral Fluoride Solution with Layer Silicates and Oxides of Soils
Authors: Huang P. M. , Jackson M. L. 
Published: July 2010

AbstractThe rate of HCl titrable OH formed and reaction mechanism of layer silicates, oxides of Al and Fe, and soils in neutral 1n KF solution were investigated with reference to the possible stoichiometric relationships to mineral bonded fluoride, extracted aluminum and iron, and titrable acidity in the residue. With vermiculite, montmorillonite, kaolinite, halloysite, allophane, chlorite, gibbsite, hematite, goethite, Dodge soil, Cookeville soil and Alberni soil, the formation of HCl titrable OH was rapid initially but approached an apparent equilibrium after 24 hours. The rate of reaction was again rapid upon removal of the reaction products and renewal of the extractant. The amount of titrable OH per unit weight of sample increased with increasing the ratio of fluoride solution volume to sample weight. The hydroxyl formed ranged from 10 meq/100 g of Dodge soil B2 horizon to 281 meq/100 g of halloysite and was not accompanied by any detectable amount of mineral bonded fluoride in the water‐ethanol washed residue. The amounts of aluminum or iron released in neutral 1n NH4F, for example, 20 meq/100 g of hematite and 129 meq/100 g of Alberni soil, were nearly stoichiometric to the OH formed (19 to 131 meq/100 g, respectively) in neutral 1n KF extract. This strongly indicated that the fluoride complexing reaction primarily with Al and secondarily Fe from the minerals was the reaction mechanism. The increase in the potentiometric NaOH titer, to the inflection point at pH 7.5 to 8, of the solid phase after fluoride treatment and washing was in general proportional to the amount of OH formed in the KF solution. For example, for montmorillonite these values were 32 and 37 meq/100 g, respectively. This gives evidence that the mineral surfaces were disrupted (a conclusion confirmed electronoscopically) by reaction in fluoride solutions, yielding NaOH titrable groups in the mineral where Al and Fe had been removed. Ground quartz (<0.5µ) was rather inert toward the neutral fluoride solutions.
Effect of Fertilizer Nitrogen on the Release of Soil Nitrogen
Authors: Broadbent F. E. 
Published: July 2010

AbstractSome explanations which have been suggested to account for the stimulating effect of inorganic fertilizer nitrogen on the mineralization of organic soil nitrogen are examined; and new experimental evidence pertinent to their evaluation is presented.Ionic exchange between fixed and exchangeable ammonium, and between exchangeable ammonium and amino‐N was shown to be negligible. Rates of exchange resulting from biological activity were increased as a result of increasing the level of fertilizer N applied.The stimulating effect was observed in soils receiving no organic amendment and in which no plants were grown indicating that it cannot be attributed solely to the activity of rhizosphere microflora. Osmotic effects appear to be a contributing factor.
Dark Colored, Acid, Forest Soils of Western Oregon
Authors: Knox E. G. , Corliss J. F. , Williams J. M. 
Published: July 2010

AbstractVery acid, strongly leached soils of the Cascade and Coast Ranges of Oregon have been called Brown Latosols, Yellowish Brown Lateritic soils, and Sols Bruns Acides. These soils are in an area of relatively high precipitation and relatively uniform temperatures under coniferous forest and dense understory vegetation. The A horizons are dark colored and have strong granular or subangular blocky structure. The B horizons are commonly dark yellowish brown and have weak or moderate subangular blocky structure. The clay content increases from A to B in some cases, but clay skins are not evident in thin sections. These soils are high in organic carbon, low in bulk density, and low in base saturation. They are Haplumbrepts according to the 7th Approximation.
Nitrogen Recovery from Decomposing Tree Leaf Tissue and Forest Humus
Authors: Voigt G. K. 
Published: July 2010

AbstractRecovery of N from decomposing leaf litter of alder (Alnus rugosa [Du Rois] Spring.), dogwood (Corus florida L.), tulip poplar (Liriodendron tulipifera L.), hemlock (Tsuga canadensis [L.] Carr.), eastern redcedar (Juniperus virginiana L.), and red pine (Pinus resinosa Ait.) was studied under laboratory and greenhouse conditions. Weight loss and N deficits in decomposing tissue were more marked in hardwoods than in conifers. There was no pronounced species correlation between Ca concentration of the leaf litter and either weight loss or N deficit, but N deficit was increased in some cases by addition of CaCO3. Considerable variation in availability of N to Douglas‐fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings was observed in soil cultures where N originated from decomposing leaf tissue or from humus samples collected under the aforementioned species. Recovery of N ranged from about 60 to over 90% of the original N content.
A Tool for Removing Neutron Probe Access Tubes from the Soil
Authors: Campbell Ralph E. 
Published: July 2010

AbstractThe tool which is described consists of a tapered shaft jacketed in a split sleeve with matching taper. As the shaft is pulled, it slips in the sleeve causing the sleeve to expand against the inner wall of the access tube. Friction between the sleeve and the tube wall holds the puller in place as the tube is drawn from the soil.
A Comparison of Several Methods of Determining Lime Requirements of Soils
Authors: McLean E. O. , Dumford S. W. , Coronel F. 
Published: July 2010

AbstractBuffer‐indicated lime requirements of four groups of soils using several buffer methods were related to CaCO2 incubation‐measured lime requirements through regression analysis. Salt accumulated during the incubation period had marked effect on the amount of lime required to bring the soils to pH 6.5. Results from all buffer methods were highly correlated with incubation‐measured values. Slopes and intercepts of regression lines revealed the marked tendency for the Woodruff buffer to indicate too much at low lime requirement levels and too little at high levels. The Mehlich buffer at pH 8.1 indicated approximately the correct amount for soils of high lime requirement but too much for those at low levels. Peech alterations of the Mehlich and the regular Mehlich method gave the same results. The Shoemaker, McLean, and Pratt method was found to be relatively rapid, accurate, and especially well adapted for soils requiring >4,000 lb of lime per acre, having <pH 5.8, containing <10% organic matter, and having apprecitable quantities of soluble Al.
Phosphate—Ammonium—Moisture Relationships in Soils: I. Ion Concentrations in Static Fertilizer Zones and Effects on Plants
Authors: Blanchar R. W. , Caldwell A. C. 
Published: July 2010

AbstractMCP (monocalcium phosphate monohydrate), MCP + NH4Cl, and MCP + KCl pellets were reacted with a Nicollet soil for 2 weeks. The soil was sampled at various distances from the pellet, analyzed for chemical constituents, and used in plant growth studies. Results of chemical determinations showed that pH was reduced in the zone 0 to 3 cm. from the MCP alone pellet. With MCP plus either NH4Cl or KCl the pH was lower than with MCP alone in all samples 0 to 7 cm from the pellet. Calcium diffused 2 to 3 cm from MCP pellets, but the addition of either NH4Cl or KCl increased calcium diffusion to 7 cm. Phosphorus did not move more than 4 cm regardless of whether NH4Cl or KCl was added with MCP. Results of plant growth studies showed that plant roots would grow to within 2, 6, and 8 cm of MCP, MCP + KCl, and MCP + NH4Cl pellets, respectively.
Fixation of Isotopic Nitrogen on a Semiarid Soil by Algal Crust Organisms
Authors: Mayland H. F. , McIntosh T. H. , Fuller W. H. 
Published: July 2010

AbstractSemiarid desert algal crust organisms were found to fix N2 when exposed to an atomosphere which contained isotopically enriched N. Significant quantities of the N isotope were detected in the total crust N after 3 days of incubation under field‐simulated conditions.Net N2 fixation rates by the algal crust organisms were 0.16 and 0.10 lb of N/acre of crust surface per day under continuous wet and cycling wet‐dry conditions, respectively. Net fixation of N under field‐simulated conditions adequately compensated for the removal of N by livestock. The rate of N2 fixation under field‐simulated conditions increased linearly for at least 520 days. The amount of N in the algal crust was doubled during this time. No net N change was observed in dry crusts.Growing algal crusts contained 1% to 2% of the total N as extracellular NH4‐N. Excretion of some fixed nitrogen was suggested by the isotopic enrichment of the extracellular N fraction and uptake of labeled N by grass seedlings (Artemesia sp.) growing on incubated crusts.
The Lime Potential and Percent Base Saturation of Some Representative Podzolic and Brunisolic Soils in Canada
Authors: Clark J. S. 
Published: July 2010

AbstractThe pH, corrected lime potential, and percent base saturation values of a number of representative forest soils were determined. There was generally close agreement between the theoretical base saturation estimated from the corrected lime potential and the value calculated from ions extracted from soils with 2n NaCl.The Gray Brown Podzolic, Gray Wooded, Brown Wooded, and many of the Acid Brown Wooded soils were highly base saturated with values over about 90%. Only soils with well‐developed Podzol features and a Gray Wooded soil developed from acid shale had base saturation values below about 50%. The upper horizons of some Brown Podzolic and some weakly developed Podzols had intermediate base saturation values. Base saturation values obtained by techniques used in this study appeared to be related to the classification of the soils, thus providing a pedogenically significant means of characterizing soils.
Water Transmission by Various Ceramic, Cellulose, Glass, and Steel Membranes
Authors: Wiegand C. L. , Swanson W. A. 
Published: July 2010

AbstractWater transmission characteristics were determined for several steel, ceramic, cellulose, and glass porous materials having pore diameters ranging from 0.5 to 15µ and air bubbling pressures ranging from 0.1 to 2.2 bars. Flow rates ranged from 0 to 1,500 ml hr‐1 cm‐2 m‐1 water suction. The flow rate through materials that transmitted water faster than 15 ml hr‐1 cm‐2 m‐1 water suction decreased slightly per unit suction as suction was increased from 1 to 8 m of water. Water transmission by materials with very low flow rates (< 0.3 ml hr‐1 cm‐2 m‐1 suction) increased rapidly as suction increased. The results of this study offer a good comparison of the different materials under the same test conditions and indicate that the water transmission rate may be estimated from the bubbling pressure. However, the water transmission characteristics of particular porous material specimens must be determined individually if their flow characteristics must be known precisely.
Miscible Displacement Patterns on Disturbed and Undisturbed Soil Cores
Authors: Elrick D. E. , French L. K. 
Published: July 2010

AbstractA new apparatus has been developed for studying miscible displacement processes in soils. Within ranges, both the moisture content and the flow rate through the soil can be regulated. The difference between Cl‐ breakthrough curves on undisturbed cores (taken vertically) and cores packed with air‐dried, 2‐mm sieved soil at moisture contents near saturation was attributed to vertical pathways established in natural soils. At the lower moisture contents of approximately 0.4 cm3/cm3 there was little difference in the breakthrough patterns.
Exchange and Absorption of Cations by Excised Roots
Authors: Franklin R. E. 
Published: July 2010

AbstractBarley (Hordeum Vulgare) corn (zea Mays L.), and soybeans (Glycline max) were given pretreatments which were designed to alter the root cation‐exchange capacity. The amounts of Ca and K absorbed by the excised roots after a 1 hour uptake period in 10‐3N chloride solution were displaced by a series of successive rinses ranging in pH from 2 to 12. There was a significant linear correlation between uptake of both Ca and K and the exchangeable Ca and K in several of the rinses, particularly with the exchangeable ions which were not removed by the first acid rinse but which were removed with subsequent rinses. Multiple correlation coefficients for these relationships ranged from 0.79 to 0.96. The method of fractionating the adsorbed ions showed promise for studying exchange properties of plant roots.
Fractionation of Copper in Neutron Activated Soils
Authors: Kline J. R. , Rust R. H. 
Published: July 2010

AbstractCopper in surface and subsurface horizons of six soils was fractionated by chemical methods after irradiation of the samples with thermal neutrons. The first fraction was obtained by a process of self diffusion in which soil Cu was allowed to diffuse into dilute CuSO4 solutions. The second was obtained by extracting the soils in hot solutions of dilute CuSO4 which were 0.1M in HCl after removal of the diffusible Cu. The third consisted of the residual Cu after the first two increments had been removed. Determinations were done using a 400 channel gamma ray spectrometer. From 35 to 70% of the total Cu in these soils was found to be freely diffusible. Self diffusion took place as readily in calcareous soils as in noncalcareous soils. Extractions in 0.5M NaOH released amounts of Cu similar to those released by diffusion which suggests that much of the freely diffusible Cu is of organic origin. Copper released by acidic CuSO4 ranged from 20 to 40% of the total and residual Cu ranged from 4 to 40% of the total.
Decomposition Products of Carbon‐14 Labelled Rye Tissue in a Peat Profile
Authors: Chahal K. S. , Mortensen J. L. , Himes F. L. 
Published: July 2010

AbstractAfter rye (Secale Ceerale) tissue, labelled with C14, had been incubated with a peat soil, the soil was extracted with various solvents. One fractionation procedure was the proximate analysis method according to Waksman and Stevens (15). The other procedure was a comparison of the components extracted by 0.1m Na4P2O7, 0.5n NaOH, and 6n HCl.In the proximate analysis, the distribution of total carbon in benzene‐methano (10:1), 2% HCl, 80% H2SO4, and insoluble portion was 1.9, 30.8, 17.2, and 50.1%, respectively. The respective distribution of C‐14 was 40.3, 20.5, 13.4, and 25.8%. The fraction containing the smallest proportion of carbon had the largest proportion of C‐14.The 6N HCl extract was separated into more discrete fractions by gel infiltration than the extracts of 0.1M Na4P2O7 and 0.5n NaOH. However, the NaOH removed a greater proportion of the radioactive materials.
Growth and Nitrogen Distribution Patterns in Bean Plants (Phaseolus vulgaris L.) Subjected to Ammonium Nutrition: I. Effects of Carbonates and Acidity Control
Authors: Barker A. V. , Volk R. J. , Jackson W. A. 
Published: July 2010

AbstractGrowth of bean plants was limited when nitrogen was supplied as (NH4)2SO4 in sand culture in comparison to the growth of plants receiving nitrate nitrogen. Mixing relatively insoluble carbonates with the sand, using (NH4)2CO3 instead of (NH4)2SO4 or maintaining the pH of the nutrient solution near neutrality with NaOH all prolonged the life and increased the growth of plants. Experiments in which C13‐labeled carbonate was used revealed no absorption or incorporation of C13 into the plant tissues. The changes in mineral element contents of plant tissue induced by the treatments did not account for the increased growth.In the absence of pH control, ammonium, amide, and amino acid accumulation was very high in the leaves. Maintaining the pH of the nutrient solution near neutrality stimulated N assimilation in roots, especially the synthesis of amino acids and amides. Acidity control thus prevented the accumulation of ammonium in the tops and hence lessened the possibility of toxic effects from ammonium. The increased conversion of ammonium to nontoxic metabolites in roots is considered to be thedominant process by which acidity control improved the growth of plants on ammonium nutrition.
Response of Snap Beans (Phaseolus vulgaris L.) to Soil Temperature and Phosphorus Fertilization on Five Western Oregon Soils
Authors: Mack H. J. , Fang S. C. , Apple S. B. 
Published: July 2010

AbstractDry weight and P content of snap bean plants were determined for 2 levels of P fertilizer on 5 western Oregon soils at soil temperatures of 54, 62, 70, and 78 F. “A” values for P were also calculated.Significant differences in dry weights and P content were found when means of soil temperature (T), P levels (P), and soils (S) were compared. The interactions of S × P, S × T, P × T, and S × P × T were also significant. Dry weights and P content were increased significantly as soil temperatures were increased from 54 to 78 F. Generally, the largest increment of increase in dry weights occurred when soil temperature was increased from 54 to 62 F, while the largest percentage increase in P content of plants was found when soil temperature was increased from 62 to 70 F. Smallest increases in dry weights and P content associated with P fertilization were at 54 F and on soils highest in available P. Percentage of P in plants on the 5 soils (temperatures and P levels combined) ranked in the same order as initial soil analysis values for P and was as follows: Labish Peat, Willamette, Chehalis, Olympic, and Quillayute. “A” values were affected by soil temperatures and were usually highest at 78 F.
Soil Phosphorus in South Dakota: I. Inorganic Phosphorus Fractions of Some Soil Series
Authors: Westin F. C. , Buntley G. J. 
Published: July 2010

AbstractThe inorganic soil phosphorus of the upper three horizons of 16 profiles was fractionated. The soils were selected to provide for a comparison of four kinds of parent materials and two great soil groups.The data show that, in general, the four glacial parent materials had similar proportional amounts of the inorganic P fractions. Climate, as expressed through great soil group, did affect the proportional amounts of two of these fractions, however. Among Chernozem soils the Fe‐P fraction makes up a proportionally larger amount, and the Ca‐P fraction a proportionally smaller amount, than they each do in Chestnut soils. Neither parent material nor climate alters the proportional amount of Al‐P present in these soil series.
The Thermal Release of Ammonium Nitrogen from Ammonium Chloride‐Treated and Nontreated Soils
Authors: Porter L. K. , Stewart B. A. 
Published: July 2010

AbstractComparisons were made of the thermal release of NH4+‐N from soils and NH4+‐saturated soils. Fixed NH4+‐N was lost from untreated and NH4Cl‐treated soil samples when the samples were subjected to temperatures above 400C. A treatment of 800C for 5 min generally released more than 85% of the fixed NH4+‐N. However, small amounts of indigenous fixed NH4+‐N, 25 to 30 ppm N, may be retained by some soils when they were subjected to a temperature treatment of 1,000C for 5 min.Release of exchangeable NH4+‐N was essentially completed when samples were subjected to a treatment of 500C for 5 min. The nontreated surface soils exhibited sharp increases, three‐ to sixfold, in their exchangeable NH4+‐N when samples were heated at 250 or 300C for 5 min. It is suggested that these increases were derived from NH4+‐N being released as soil organic matter decomposed.
Forest Floors in Douglas‐Fir Forests: I. Dry Weight and Chemical Properties
Authors: Youngberg C. T. 
Published: July 2010

AbstractVarious types of understory plant communities occur in association with Douglas‐fir (Pseudotsuga menziesii [Mirb] Franco) forest in western Oregon. Dry weight and chemical properties were determined for 9 forest floor types from the Oregon Coast Range.Dry weight of forest floors varied considerably within stands. Between‐stands values ranged from 20,000 to 76,000 lb/acre. Volatile matter ranged from 69 to 86%. Ranges in values for other factors were: pH, 4.0–6.0; available P, 36–146 ppm; exchangeable K, 1.5–5.4 meq/100g; Ca, 6.5–23.5 meq/100g; Mg, 5–12.8 meq/100g; CEC, 54–76 meq/100g; total N, 0.71–1.52%; total P, 0.089–0.211%; total K, 0.115–0.323%; total Ca, 0.325–1.05%; total Mg, 0.157–0.334%; and total S, 0.081–0.163%. The types having the lowest content of metallic cations were from areas of high precipitation and soils with low base saturation. There was no apparent relationship between levels of exchangeable cations and percentage of these elements in the forest floor.
A Hydraulically Powered Brush for Cleaning Soil‐Coring Tubes
Authors: Runge E. C. A. 
Published: July 2010

AbstractA hydraulically powered brush for cleaning inaccessible soil‐coring tubes is discussed and shown. The brush is driven by hydraulic power already available on the soil‐coring machine. The power brush and power anchor (reference given) allows for maximum use of light weight soil‐coring machines in humid regions.