bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient Balance Involving Phosphorus, Iron, and Zinc
Authors: Watanabe F. S. , Lindsay W. L. , Olsen S. R.
Published: July 2010

Corn (Zea mays L.) and pinto beans (Phaseolus vulgaris) were used as test crops to study the interactions between P, Fe, and Zn in a calcareous solution culture. The addition of Zn to the intermediate Fe level accentuated Fe deficiency symptoms and depressed the yield of corn. This adverse effect on yield was not related to the Fe concentration in the plant but was associated with a decreased Fe/Zn ratio. In this study the antagonistic effect of Zn on Fe was manifested by reduced yields as the ratio of Fe/Zn in the tissue decreased below 1.5. Addition of Fe corrected this adverse effect on yield.

By increasing the P at the intermediate Fe level the yield first increased; then P‐induced Fe deficiency symptoms appeared, accompanied by a depression in yield. This phenomenon was not associated with change in Fe concentration but was related to high P concentration in the plant tissue, which resulted in a P/Fe ratio > 60. The addition of Fe did not change the Fe concentration but corrected the depression in yield. A P/Zn concentration ratio > 300 resulted in a slight depression in yield in the presence of an adequate supply of Fe. The depression in yield associated with the antagonistic effect of Zn on Fe and P on Fe and Zn, although manifested on corn, was not found with pinto bean at the concentration levels studied.
Loess Distribution in Southeastern Illinois and Southwestern Indiana
Authors: Fehrenbacher J. B. , White J. L. , Ulrich H. P. , Odell R. T.
Published: July 2010

Total loess (predominantly Peorian loess) thickness in southeastern Illinois and southwestern Indiana ranged from somewhat less than 40 inches to more than 300 inches, and the thinning rate of the loess was a linear function of the logarithm of the distance from the source. Peorian loess was present throughout the area, but Farmdale loess was present in significant amounts only in extreme southern Illinois and in extreme southwestern Indiana. Loveland loess was present sporadically beyond the limit of Illinoian glaciation. In the Wabash basin, loess thickens to the south as the valley becomes wider, the loess‐receiving landscapes become older, and the sediments in the valley become more silty. West‐northwest winds were important in the loess deposition of this region, but deposition of loess by easterly and southwesterly winds in the lower Wabash and Ohio river basins was shown to be more important than has been previously noted.
A Comparison of the Characteristics of the Ped Faces and Ped Interiors in the B Horizon of a Chestnut Soil
Authors: Heil R. D. , Buntley G. J.
Published: July 2010

The structure units or peds, within the B horizon of the Chestnut soil studied, appear to be centers around which the differential distribution of many of the morphologic, chemical, and physical characteristics are oriented. The differential distribution of organic carbon, total nitrogen, particle size, clay skins, free calcium carbonate, and soluble and extractable cations on the ped faces and in the ped interiors, suggest that the ped faces comprise a profile developing under a microclimate that is somewhat more humid than is the macroclimate of the profile site, while the peds interiors comprise a profile developing under a microclimate that is somewhat more arid than is the macroclimate of the profile site. These relationships seem to indicate that the profile of the ped faces represents a higher stage in the known developmental sequence of soils than does that of the profile of the ped interiors. The ped face profile appears to be diagnostic of the direction of genetic intergradation within the macroprofiles. The results of this study suggest that the peds function as “unit cells” of soil genesis in the profile studied.
Requirements for Achieving and Maintaining Uniformly Low Salt in a Saline Soil
Authors: Robinson C. W. , Kemper W. D. , Golus H. M. , Schumaker G. , Pugh W. J.
Published: July 2010

The amount of irrigation necessary to limit salinity in the plant root zone to concentrations equal to or less than 8 mmho/cm was computed from the consumptive use, rainfall, and salinity of the irrigation water, assuming completely homogeneous plots. Heterogeneity of infiltration rates within plots required that the amount of water applied be 10 to 20% higher than in the theoretical homogeneous case in order to maintain adequate salt removal. Irrigation at 30% higher than the need for the homogeneous case resulted in reduced yields and reduced N content of wheatgrass in areas of high infiltration within the plots. Irrigation at 6% higher than necessary for the homogeneous case resulted in accumulation of salts in areas of low infiltration.
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

Partially 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

A 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

The 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

Some 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

Very 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

Recovery 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

The 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

Buffer‐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

MCP (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

Semiarid 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

The 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

Water 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

A 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

Barley (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

Copper 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

After 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

Growth 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

Dry 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

The 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

Comparisons 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

Various 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

A 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.
Transfer of Fallout Cesium‐137 from Soil to Dairy Cattle Feeds
Authors: Johnson James E. , Wilson Daniel W. , Lindsay Willard L.
Published: July 2010

Corn (Sorghum vulgare) seedlings were grown in a greenhouse in the upper 5 cm of soil taken from a permanent pasture containing a cumulative fallout deposition of Cs137 of 80,000 pc/m2. No detectable Cs137 (< 10 pc/kg) was found in the plants. On the other hand, corn plants growing in local fields contained 1,500 pc/kg of Cs137. It was concluded from these studies that the Cs137 content of dairy cattle feeds resulted largely from direct foliar contamination, and that uptake from the soil reservoir was unimportant. Further, the comparable alfalfa hay crops in years since 1963 have been decreasing in Cs137 level, while the top soil Cs137 concentration has increased steadily during this period.
Determination of Mg with 1‐azo‐2‐hydroxy‐3‐(2,4‐dimethylcarboxanilido)‐naphthalene‐1′‐(2‐hydroxybenzene)
Authors: Peaslee D. E.
Published: July 2010

The reagent 1‐azo‐2‐hydroxy‐3‐(2,4‐dimethylcarboxanilido)‐naphthalene‐1′‐(2‐hydroxybenzene forms a soluble red complex with Mg and tolerates high concentrations of Ca. These properties suggested its usefulness as a reagent for determining Mg in soil extracts. Successful masking of interferences due to Al, Fe, Mn, and Cu permitted its use in precise spectrophotometric and rapid colorimetric determination of Mg.

The spectrophotometric method will determine 1–10 µg of Mg and tolerates the following µg quantities of diverse ions: Ca+, 1,000; Al4+3 100; Mn2+, 150; Fe3+, 150; Zn2+, 65; Cu2+, 10; 10 µg P as PO43‐ plus 300 µg N as NH4+. Analyses of soil extracts had a coefficient of variation of 1.5%. The colorimetric procedure is designed for soil extracts containing 5–85 µg Mg/ml and tolerates the following concentrations of diverse ions expressed as µg/ml in the extract: Ca2+, 1,000; Al3+, 150; Mn2+, 60; Fe3+, 15; Fe2+, 15; Zn2+, 65; Cu2+, 15. These methods have the advantages of sensitivity, stability, and freedom from interferences compared to most “lake” and titration methods. A semiquantitative spot test is also described.
The Relationship Between Soil Tests for Available Nitrogen and Nitrogen Uptake by Various Irrigated Crops in the Western States
Authors: Spencer W. F. , MacKenzie A. J. , Viets F. G.
Published: July 2010

Soil tests for available N were evaluated by determining the relationship between N uptake from a non‐N fertilized plot, as a direct measure of the amount of N available to a crop, and available N as measured by various laboratory methods. Field experiments were conducted with four irrigated crops, corn (Zea mays), sugar beets (Beta vulgaris L.), sorghum (Sorghum vulgare), and cotton (Gossypium hirsutum) on neutral to calcareous soils in California, Nebraska, or Washington. Initial nitrate N, nitrifiable N released on incubation for 2‐ and 4‐week periods, and total N in soil samples from 0‐ to 6‐ and 6‐ to 12‐inch depths were combined to give 14 measures of available N for correlation with N uptake.

Highly significant correlations were obtained between N uptake from no‐N plots and all soil test values, with the exception of NO3‐N released on incubation for 4 weeks. Nitrogen uptake by corn was most highly correlated with initial NO3‐N, 6–12 inches; initial NO3‐N plus N released on incubation for 2 weeks; and total N, 0–12 inches. The coefficient of determination for these relationships indicated that variations in soil test values were associated with approximately 50% of the variation in N uptake from no‐N plots. Combining the effects of initial NO3‐N and total N in a multiple‐regression analyses slightly improved the prediction of N uptake by corn and sugar beets growing in Nebraska. With cotton growing on desert soils low in organic matter, initial NO3‐N, 0–12 inches, was most highly correlated with N uptake, and combining the effect of initial NO3‐N and total N did not improve the prediction of N uptake.

The data for corn indicated that N test correlations for crops following legumes should be established separately.
Effect of Surface Coatings on the Dissolution Rate of Limestone Particles
Authors: Barrows Harold L.
Published: July 2010

High‐purity, 12‐ to 14‐mesh calcitic limestone was mixed into acid soils containing relatively large amounts of either P, Al, or Mn. These mixtures were equilibrated for 12 months, undergoing wetting and partial drying cycles. Samples of each mixture were withdrawn periodically and the limestone particles were recovered, examined, and their rates of solution determined. The surface of the particles equilibrated in the high‐P soil developed a porous, white granular coating that was associated with a 31% reduction in the dissolution rate.

Limestone and calcite crystals were treated in the laboratory with solutions containing Fe, Al, and P. Particles treated with phosphate solutions developed visible coatings, and their average dissolution rates were reduced by 27%.

It was concluded that limestone particles react with phosphates in the soil solution, resulting in the formation of a coating on the surface of the particle. This coating reduces the efficiency of the limestone by reducing the rate of dissolution of the particles.
Weathering in Surface Horizons of Illinois Soils
Authors: Jones Robert L. , Beavers A. H.
Published: July 2010

Lines analogous to isohyets were drawn with respect to molar ratios of CaO, K2O, and Fe2O3 to ZrO2. The resulting maps demonstrate the close relationship of loess thickness to intensity of soil development and identify a north‐south band of soils in southern Illinois that are the most intensely weathered soils in the state. The youngest or least developed soils identified by the lines occur in thick loess deposits of extreme northwestern Illinois. Isoweathering lines cannot be drawn in the area of Wisconsin drift because of the penecontemporaneity of loess on the drift and many local sources within the drift sheet area.
Exchangeable Potassium as Affected by Mica Specific Surface in Some Soils of North Central United States
Authors: Milford M. H. , Jackson M. L.
Published: July 2010

Mineralogical analyses of samples from 16 surface soil horizons and 9 subsoil horizons, representing 15 soil series, revealed that differences in the content of clay sized mica were closely related to the wide differences in the content of exchangeable K in ovendried samples before and after cropping. The specific surface of mica in the clay fraction was significantly correlated with the content of exchangeable K in oven‐dried samples before cropping (r = 0.63), after cropping (r = 0.74), and after fertilization and cropping (r = 0.68). After being cropped and oven dried, for example, a sample of Wabash silt loam surface soil contained 466 pp2m exchangeable K, but a sample of Bates silt loam surface soil contained only 78 pp2m exchangeable K. These samples had 3.3 m2/g and 0.5 m2/g, respectively, of mica specific surface area. No significant relationship occurred between the content of exchangeable K in field moist samples and the content of mica in the soils.

The wedge‐zone concept of mica weathering in crystal edges and in crystallographic (hk0) fractures normal to (001) crystal faces was used to explain the relationships between specific surface of mica and content of exchangeable K in oven‐dried samples. The existence of an equilibrium between exchangeable K in the open part of the wedge with nonexchangeable K at the mica weathering side of the wedge was indicated.
Stability of Chlorite in Dilute Acid Solutions
Authors: Brydon J. E. , Ross G. J.
Published: July 2010

Six chlorites representing 5 species were suspended in 0.01M MgCl2 solutions with different concentrations of HCl. In 10‐4N HCl solutions a final steady pH of 8 to 9 was reached quickly with the Mg‐rich chlorites and more slowly with Fe‐rich species. The evidence showed that Mg‐Al and Mg‐Fe double hydroxides controlled the pH in these suspensions.

In 10‐2N HCl solutions, the chlorites remained at pH values of 3 to 4 for periods up to 6 months. On the basis of direct titrations it was concluded that precipitation of Fe‐ and Al‐hydroxides buffered the pH at 3 to 5 and that the precipitate impeded H uptake and Mg release.
Chemical Properties of the Coastal Alluvial Soils of the Republic of Guinea
Authors: Horn M. E. , Hall V. L. , Chapman S. L. , Wiggins M. M.
Published: July 2010

Tides along the coast of the Republic of Guinea in West Africa and in estuaries, have influenced most coastal soils by salt water intrusion. The soils are mostly clays and poor drainage is general. Some leaching of salts from surface layers occurs during wet seasons in higher‐lying soils while in lower areas fresh‐water flooding causes surface flushing or dilution of saline ground water. Laboratory studies of 129 samples representing 34 soil profiles show wide ranges in salinity (electrical conductivities of < 1 to > 50 mmhos/cm). Acid‐sulfate or “cat‐clay soils” occur that have pH values of 2.6 to 4.0, and up to more than 500 ppm KCl‐extractable Al. Their subsoils contain segregations of a yellowish Fe‐S compound (identified as a mixture of jarosite and natrojarosite). High organic matter and S contents combined with low Ca contents in some unreclaimed soils point to potentially severe acidity upon drainage.
A Casting Method for the Preparation of Sintered Glass Plates
Authors: Ripple Charles D. , Day Paul R.
Published: July 2010

Sintered glass plates, as usually prepared in the laboratory, are frequently inhomogeneous and require machining to the desired final dimensions. A new method makes it possible to produce homogeneous plates which require little or no machining. Water and two additives are mixed with the glass beads, the resulting mixture is cast, and then dried. The product is a coherent, homogeneous glass bead sheet. This sheet may be easily carved to the desired size and shape before sintering. Alternatively, complex shapes may be cast directly. Refractory materials other than glass beads may also be used.
Temperature Effects in a Tensiometer‐Pressure Transducer System
Authors: Watson K. K. , Jackson R. D.
Published: July 2010

A tensiometer‐pressure transducer system using nylon hydraulic leads was found to be sensitive to small temperature fluctuations. A suitable model to describe the effect was developed, and the appropriate differential equation was solved in terms of the pressure variation occurring in the system for a sinusoidal pattern of temperature change. Experiments are described in which the measuring system is subjected to a sinusoidal temperature variation and the induced pressure changes recorded. From such records the amplitude and phase shift of the pressure are determined and compared with those obtained from the model solution.
Forms of Occurrence of Inorganic Phosphorus and Its Chemical Availability in the Limestone Soils of Barbados
Authors: Ahmad N. , Jones Robert L.
Published: July 2010

In the coral island of Barbados the soils at higher elevations where there is greater rainfall are like Terra Rossas and those in lower and drier parts are like Grumusols. There are also soils formed from lagoonal deposits on coral at low elevations which have properties similar to Grumusols. The soils do not respond to phosphorus fertilization. They have about the same level of total phosphorus on the surface, although the level for the Grumusols is slightly higher. In the Terra Rossas total P decreases sharply with depth to less than half the surface values; in comparison there is an increase with depth in the Grumusols.

All the soils are alkaline but the Terra Rossas have many times more free Fe2O3 than the grumuso's and this difference seems to determine the chemical forms in which phosphorus occurs. The Terra Rossas have most of the inorganic phosphorus associated with iron, the reductant‐soluble fraction being greater than the alkali‐extractable fraction; in this respect they resemble highly weathered tropical soils. The Grumusols have most of their phosphorus bonded by calcium and aluminum.

Four chemical methods were used to estimate available phosphorus. Troug's and Bray's reagents were found to be unsuitable since they dissolved free CaCO3 releasing associated phosphorus, thus giving a false indication of availability. For the Grumusols and soils high in CaCO3 but low in iron oxides, Morgan's reagent is recommended; for the Terra Rossas where iron phosphates are important, Olsen's method appears to be more suitable. As a result of this study no immediate phosphate fertilization is suggested for the Grumusols but for the Terra Rossas fertilization should be practiced if only to the extent of replacing losses by the crop. Strict antierosion measures are also recommended since most of the soil phosphorus is concentrated on the surface.
Utilization of Soil and Fertilizer N by Oats in Relation to the Available N Status of Soils
Authors: Legg J. O. , Stanford George
Published: July 2010

Effects of rates of NaN15 O3 on the amounts of N derived by plants from soil and fertilizer in relation to the N and organic matter status of soils were determined. The 12 soils ranged more than fourfold in relative capacity to supply N to the crops. A values, with few exceptions, were independent of N level applied and were highly correlated with dry matter yields (r = 0.939) and total N uptake (r = 0.981) from zero‐N pots. The uptake of soil N increased with level of N applied. This was attributed primarily to reactions involving rhizosphere microorganisms.
Characterization and Genesis of a Sharpsburg‐Wymore Soil Sequence in Southeastern Nebraska
Authors: Al‐Janabi Abdul M. , Drew James V.
Published: July 2010

Major belts of Sharpsburg and Wymore soils in southeastern Nebraska are related to a gradient of loess which varies from a continuous mantle adjacent to the Missouri river valley to a thin, discontinuoan mantle with increasing distance toward the southwest. Sharpsburg with a silty clay loam subsoil occurs where loess is relatively continuous, whereas Wymore with a silty clay subsoil occurs in thin and discontinuous loess farther from the river valley. Within these belts, soils with well‐developed sub‐soils frequently occupy high, relatively stable positions on interfluves, whereas soils with less well‐developed subsoils occur on the beveled, younger surfaces of interfluve slopes.

In a transition zone between major belts of Sharpsburg and Wymore, however, a reverse situation exists. Here Sharpsburg occurs on the highest positions of interfluves and gives way to Wymore on beveled slopes at lower elevations. Morphological, particle size, and mineralogical data indicate that a sequence of soils within this transition zone increases in degree of development from the top to the side of an interfluve in the order Sharpsburg‐Wymore. Hypotheses presented to explain the distribution of these soils on the landscape involve differences in soil moisture regime or rate of loess accumulation as influenced by slope characteristics.
Gibbsite‐Kaolinite Equilibria
Authors: Kittrick J. A.
Published: July 2010

In order to help determine if the equilibria reached by soil mineral mixtures is that predicted on the basis of single minerals, two kaolinite samples were equilibrated individually and also with gibbsite of known stability. One set of samples was equilibrated from undersaturation, the other from supersaturation. Samples were analyzed periodically and equilibrium values obtained by extrapolation to infinite time. The solution ion compositions found were those predicted on the basis of the solubilities of the individual minerals.
Uses of Metalizable Dyes to Minimize the Phosphate Sorption of Cecil Soil
Authors: LaFleur K. S. , Craddock G. R.
Published: July 2010

Native phosphate and added water‐soluble phosphate are “immobilized” to a high degree by Cecil soil. Addition of high‐affinity anions (e.g., citrate and humate ions) which compete with the phosphate anion for cationic soil sites reduces the amount of phosphate immobilized by Cecil soil and increases the amount of phosphate in the soil solution.

Quercetin, Gallein, and Mordant Violet 39 (anionic metalizable dyes) are more effective competing agents for Cecil soil sites than either citrate or humate. They are particularly effective phosphate freeing compounds when used at molar concentrations 10 to 20 times that of added phosphate. Under comparable conditions, Quercetin, Gallein, and Mordant Violet 39 appear to have higher affinity than phosphate for Cecil soil. Mordant Violet 39 is sorbed more rapidly than phosphate by Cecil surface soil.

The hypothesis which arises from these sorption‐desorption experiments is that addition of a high‐affinity, metalizable anionic dye to Cecil soil should make soil phosphate more available for plant consumption.
Sulfate Movement, Adsorption, and Desorption in Three Costa Rican Soils
Authors: Bornemisza E. , Llanos R.
Published: July 2010

The movement, adsorption, and desorption of sulfate was studied, using samples from the A and B horizons of three soils from Costa Rica. Water, equivalent to 509 mm, was applied to small lysimeters and the distribution of radiosulfate in the columns was determined for untreated soils and samples previously incubated with one of the following substances: (NH4)2SO4, K2SO4, simple, or triple superphosphate. Little sulfate movement was observed. This was enhanced slightly by phosphates.

Sulfate adsorption from solutions containing 100 to 1,000 ppm sulfate fit Freundlich isotherms. Very concentration‐dependent adsorption was indicated for alluvial soils but little concentration‐dependent adsorption was noted for latosols. Sulfate desorption by water depended greatly on soil type but was less variable when phosphate solutions were used as desorbants. Higher phosphate concentration increased desorption but the latosols retained appreciable sulfate amounts even against extraction by a 1,000‐ppm phosphate solution. Some hydroxyl displacement on sulfate adsorption occurs as shown by higher pH values for K2SO4, soil suspensions in comparison with soil suspensions in KCl of equal normality.
Cation Exchange Reactions of Soil and Specimen Vermiculites
Authors: Rhoades J. D.
Published: July 2010

Magnesium‐calcium and sodium‐calcium ion‐exchange isotherms and potassium‐sorption properties were determined for two vermiculitic materials isolated from soils as well as for three specimen vermiculites and four montmorillonitic materials. The soil vermiculites differed considerably from the specimen vermiculites in their ion‐exchange and K‐sorption properties. The soil vermiculites did not demonstrate the strong preference for Mg over Ca, the tendency to form interstratified layers upon K‐sorption, as marked a temperature dependence in their exchangeable sodium ratio—sodium absorption ratio (ESR‐SAR) relations, or as great an affinity for Na as was observed for specimen vermiculites. Their behavior deviated considerably from the ESR‐SAR relation commonly used as a reference for Na‐Ca, Mg exchange in soils. Soil montmorillonites, on the other hand, reacted the same as specimen montmorillonites in the ion‐exchange reactions studied and followed the usual ESR‐SAR relation quite closely.
Nitrogen Gradients and Nitrification Associated with Decomposing Corn Plants and Barley Straw in Soil
Authors: Smith J. H.
Published: July 2010

Ammonia, nitrite, and nitrate concentrations and pH were measured in 5‐mm increments of soil over a 50‐mm distance from decomposing layers of corn plants (Zea mays L.) and barley straw (Hordeum vulgare L.) that contained from 1.00 to 2.10% N. During 16 days of incubation, corn plants containing 2.05% N produced an ammonia concentration of 1.3 meq/100 g of soil in the layer near the plant material and inhibited nitrification. At 1.78% N the maximum ammonia concentration was approximately 0.55 meq/100 g of soil and nitrification proceeded almost without inhibition. At 1.27% N, a nitrogen deficiency existed and nitrate moved from the soil into the plant material. Similar gradients of a lesser magnitude were found in soil near decomposing layers of barley straw. Plant materials with the higher N contents increased adjacent soil pH, whereas those with lower N contents had less influence.