bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Property Changes Associated with Crop Residue Management in a Wheat‐Fallow Rotation
Authors: Black A. L. 
Published: July 2010

AbstractWheat (Triticum aestivum L.) straw‐mulch rates of 0, 1,680, 3,360, and 6,730 kg/ha were established in the spring on fallow in alternate spring wheat‐fallow blocks in three replications on a Dooley sandy loam. Subplot fertilizer treatments applied before seeding were as follows: None (check), P, N, and N‐P. Both N and P were applied at a rate of 34 kg/ha; N was applied each crop year, and P was applied initially and every other crop year thereafter. Fertilizer and surface residue remaining after fallow were incorporated at seeding time with a tandem disk. Initially and after four crop‐fallow cycles, selected soil depths were sampled and various chemical and physical soil properties were determined.As residue levels increased, soil organic matter, N, C, and C/N ratio increased significantly in the 0‐ to 7.6‐ and 7.6‐ to 15‐cm soil depths after four crop‐fallow cycles; no changes occurred below 15 cm. Following 1 year of fallow, NaHCO3‐soluble P in the 0‐ to 15‐cm soil depth increased as residue levels increased, independent of P fertilization. Soils obtained during fallow from the 0‐ to 15‐cm soil depth in each field subplot in 1970 were subjected to an 8‐week incubation period with added N rates of 0, 20, and 60 ppm in three replications. Total soil NO3‐N accumulation increased significantly as residue levels increased, regardless of N rate applied before incubation. However, residue levels had the greatest positive effect on NO3‐N accumulation when N was added both in the field and before incubation. Regardless of field fertilizer treatments, exchangeable K increased, Ca decreased, and Mg and Na were not influenced significantly by residue treatments in the 0‐ to 7.6‐cm soil depth after four crop‐fallow cycles. The nonerodible soil fraction (>0.84 mm) increased progressively in the 0‐ to 5‐cm soil depth as residue levels increased. Each 1,100 kg/ha of straw incorporated during the period reduced the erodible soil fraction about 8%. Bulk density of the 0‐ to 7.6‐cm soil depth decreased significantly as residue levels increased.Changes in the chemical and physical soil properties measured were proportionate to the quantity of crop residue added over time. The data obtained provide information about the longtime influence of crop residue management systems on some chemical and physical soil properties.
Effect of Sulfur Deficiency on Yield and Nitrogen Content in Bitterbrush (Purshia tridentata) Seedlings on Granitic Soils
Authors: Klemmedson J. O. , Ferguson R. B. 
Published: July 2010

AbstractPrevious studies by the authors have shown that addition of N (in the presence of P, K, and S) to an infertile soil derived from a granitic parent material may depress the yield of bitterbrush [Purshia tridentata (Pursh) DC.] seedlings and increase the concentration of plant N. The study presented here was conducted to determine the separate effects that added K or S would have on yield and N content of bitterbrush when applied together with N and P to the soils in question. Bioassay using both bitterbrush and barley (Hordeum vulgare L.) revealed an S deficiency in the soils that ranged from slight to strong. Bitterbrush seedlings growing on the S deficient (NPK‐treated) soils weighed significantly less than those growing on NPS‐ and NPKS‐treated soils and averaged 2.07% total N compared to only 1.15% total N for plants from all other treatments. Yield and N content of barley on the NPK‐treated soils were strongly affected only on the soil that was most deficient in available S. The results for bitterbrush were confirmed in subsequent experiments where bitterbrush was fertilized with three rates of N with and without S. In this test, the bitterbrush seedlings that received 224 kg/ha of N without S accumulated significantly more inorganic N than the seedlings that received S. Ammonium‐N accumulation was about 4.5 times higher than that of (nitrate + nitrite)‐N and was highest in roots and lowest in leaves. Reduced yield of affected seedlings may result from inhibitory effects of accumulated inorganic N or inhibition of S‐amino acid formation caused by S deficiency.
Vacuum Extractors to Assess Deep Percolation Losses and Chemical Constitutents of Soil Water
Authors: Duke H. R. , Haise H. R. 
Published: July 2010

AbstractA vacuum extractor, consisting of a porous ceramic tube within a sheet‐metal trough, has been developed to provide a quantitative measure of soil water lost by deep percolation and to provide a water sample for chemical analysis. Several of these extractors have been installed in the field and preliminary field performance is reported. Detailed laboratory evaluation is in progress.
Gravity Correction Due to a Variation of Pressure Head Within a Cavity
Authors: Parlange Jean‐Yves 
Published: July 2010

AbstractThe infiltration of water from small cavities filled with water is affected by gravity, both within and without the cavity and these two effects are of the same order. The effect within the cavity is assessed quantitatively for small spherical cavities that are entirely or partially buried in the soil. As an example, the case of a cavity entirely buried in the soil is discussed in detail.
Kinetics of Phosphate Adsorption and Desorption by Lake Sediments
Authors: Kuo S. , Lotse E. G. 
Published: July 2010

AbstractThe objectives of the present investigation were to gain information on the rate and extent of phosphate adsorption and desorption and the energy of phosphate adsorption by lake sediments, and to evaluate the influence of the sediments on the phosphorus status of lake waters. While phosphate adsorption by sediments from Sebasticook Lake, Maine, could be described by the Freundlich equation over a large phosphorus concentration range, the Langmuir equation provided a good fit to the experimental data only at low phosphorus concentrations. The deviation from the Langmuir isotherm at high phosphorus concentrations was explained by an increase in total negative potential of the surface due to phosphorus adsorption and increased interaction between adsorbate molecules. The rate of phosphorus adsorption by the sediments could be described by the equation X = KC0t1/m. The calculated activation energy was 2.7 kcal/mole.The desorption of phosphorus from minerals and sediments was dependent on the anionic species present in the solution. The replacing power of the anions appeared to be related to their ionic potential and complexing ability. The rate of phosphorus desorption could be described by the proposed kinetic equation.
Transformation of Iron in a Waterlogged Soil as Influenced by Redox Potential and pH
Authors: Gotoh S. , Patrick W. H. 
Published: July 2010

AbstractThe distribution of different forms of iron in a waterlogged soil was studied over a wide range of closely controlled redox potential and pH conditions. Increases in water soluble and exchangeable iron were favored by a decrease in both redox potential and pH. The critical redox potentials for iron reduction and consequent dissolution was between +300 mV and +100 mV at pH 6 and 7, and −100 mV at pH 8, while at pH 5 appreciable reduction occurred at +300 mV. The distribution between water soluble and exchangeable iron fractions was highly pH dependent with a decrease in pH at a given redox potential increasing the relative amount of ferrous iron in the soil solution at the expense of that on the exchange complex. A thermodynamic approach to the equilibria between solid phase ferric oxyhydroxide and a water soluble species of iron (Fe2+) indicated that it was largely governed by the Fe2+ − Fe(OH)3 system in which the ferric oxyhydroxide was a mixture of goethite and amorphous material.
Variation in the Natural Nitrogen‐15 Abundance in Nitrate Mineralized During Incubation of Several Illinois Soils
Authors: Feigin Amos , Kohl Daniel H. , Shearer Georgia , Commoner Barry 
Published: July 2010

AbstractSamples of the surface layer of soil (0–30 cm) were collected from five sites in central Illinois. The soils were incubated under controlled conditions for an extended period of time in an effort to determine the 15N/14N ratio of the mineralizable nitrogen.The results show that the 15N/14N ratio of the nitrate released from the soils tested was approximately constant with time of incubation after about 5 weeks. During the first weeks of incubation, the 15N/14N ratio of the nitrate released increased from an initially low value in four of the five soils tested. The constant values of δ15N (per mill enrichment) for these soils were about +7.6 to +10. We conclude that these values represent the 15N enrichment of the mineralizable pool of organic N in these soils which include major soil associations of the central Illinois Corn Belt.
Mineral Nitrogen Movement into Subsoils Following Continued Annual Fertilization for Corn
Authors: MacGregor J. M. , Blake G. R. , Evans S. D. 
Published: July 2010

AbstractTwo clay loam soils were fertilized for corn (Zea mays L.) at planting for 10 or 15 growing seasons at annual rates of 0, 44.8, or 268.8 kg N/ha as NH4NO3. After 10 growing seasons, little NO3‐N remained below drainage tile depth in Le Sueur clay loam. After 11 growing seasons on untiled Forman clay loam, considerable NO3‐N was found at depths to 6 or 7 meters. After 15 years, appreciable nitrate occurred to at least the 10‐m depth. The average rates of movement of the NO3 front for the 10 and the 15‐year periods were 1.7 and 1.9 mm/day, respectively. Concentrations of ammonium N were similar under all fertilizer treatments.Annual N additions failed to significantly increase corn grain yields on Le Sueur clay loam but significantly increased yields on Forman clay loam.
A Comparison of Hydraulic Conductivities Calculated with Morphometric and Physical Methods
Authors: Bouma J. , Denning J. L. 
Published: July 2010

AbstractHydraulic conductivity of coarse porous media with packing pores could be calculated not only with accepted physical, but also with morphometric techniques if matching factors were used. Morphometric K curves were closest to physical curves derived from moisture adsorption characteristics. The morphometric technique can be applied exclusively to small or fragile homogeneous soil materials that cannot be sampled for moisture retention determinations in the laboratory. The pore interaction model of Marshall overestimated Ksat when morphometric r‐values were used. Moisture retention curves, calculated with morphometric data, agreed well in coarse porous media with physical adsorption curves.
Field Measurement of Evaporation from Soil Shrinkage Cracks
Authors: Ritchie J. T. , Adams J. E. 
Published: July 2010

AbstractWeighing lysimetry was used to determine evaporative fluxes from a natural shrinkage crack and from an artificially induced soil shrinkage crack. Evaporation from the soil surface, except at the crack opening, was prevented by covering the lysimeter with plastic film. Evaporation rates from the natural and induced crack averaged about 0.6 mm/day computed on the basis of the surface area of the lysimeter. The horizontal soil water flux in the liquid phase to the crack wall was quite low, indicating that most of the measured evaporation resulted from vapor transport from some distance in the soil pores to the crack walls. Diurnal variations in evaporation rates were closely related to diurnal changes in vapor pressure deficit of the atmosphere above the soil surface. Evaporation rates from the natural/crack experiment were practically the same when the crack and soil surface were exposed to the atmosphere as when only the crack opening was exposed. Therefore, most evaporation from cracked, dry clay soil occurs because of the presence of shrinkage cracks. The results suggest a possibility for conserving water by partially filling the shrinkage cracks with dry soil or mulch to reduce evaporation. The low evaporation rates measured, however, make the feasibility of such a practice doubtful.
Loss‐on‐Ignition as an Estimate of Soil Organic Matter
Authors: Davies Brian E. 
Published: July 2010

AbstractLoss‐on‐ignition at 430C of calcareous and noncalcareous soils has been compared with organic matter contents estimated by a wet oxidation method. The presence of CaCO3 did not affect the magnitude of the ignition‐loss and the gravimetric method provides both a reliable and simple estimation of soil organic matter.
Fixation of Zinc by Clay Minerals
Authors: Reddy M. R. , Perkins H. F. 
Published: July 2010

AbstractSamples of bentonite, illite, and kaolinite clays were studied for their Zn fixation properties under various pH levels, alternate wetting and drying conditions, and incubation at moisture saturation. Bentonite and illite fixed significant quantities of Zn under wetting and drying. Fixation was directly related to pH and the amount of Zn added. Incubation of treated samples at moisture saturation resulted in approximately half the amount of Zn fixed as when subjected to repeated wetting and drying. Kaolinite fixed relatively small amounts of Zn as compared to bentonite and illite regardless of treatment.Since X‐ray and DTA did not reveal mineralogical change, it is concluded that Zn was fixed as a result of precipitation, physical entrapment in clay lattice wedge zones, and/or strongly adsorbed at the exchange sites. Cation exchange capacity (CEC) values were inversely related to Zn fixation.
A Comparison of 15N‐Depleted and 15N‐Enriched Fertilizers as Tracers
Authors: Starr J. L. , Broadbent F. E. , Stout P. R. 
Published: July 2010

Abstract(14NH4)2SO4 from which virtually all 15N had been removed was compared as a tracer with (NH4)2SO4 containing 8.95% 15N excess in a plant uptake experiment using soil columns maintained at ⅓ bar tension and conventional greenhouse pots. Uptake of fertilizer nitrogen in three cuttings of ryegrass (Lolium Perenne L.) was identical with the two fertilizers.Estimates of residual fertilizer N in the pots agreed less closely, owing to the high dilution factor.
Nitrogen Transformations in Soil During Leaching: III. Nitrae Reduction in Soil Columns
Authors: Misra C. , Nielsen D. R. , Biggar J. W. 
Published: July 2010

AbstractNitrate reduction in water‐unsaturated Columbia silt loam columns was examined at 19.5C and 34.5C with three levels of oxygen (0.5, 5, and 20%) in an aerating gas passing through the soil. Following a continuous application of NH4+ solution, a pulse of a NO3‐ solution was leached through these columns. After the decay of the pulse, a continuous application of NO3‐ solution allowed mathematical analysis leading to ascertaining NO3‐ reduction rate coefficients. The temperature dependence of these constants as a function of oxygen composition was discussed and the need for microbial population and activity analysis is emphasized.
Mineralization of Carbon and Nitrogen in Soil Amended with Carbon‐13 and Nitrogen‐15 Labeled Plant Material
Authors: Broadbent F. E. , Nakashima T. 
Published: July 2010

AbstractDoubly labeled barley (Hordeum vulgare L.) plants were grown in a closed chamber containing 13C‐enriched CO2 and 15N‐enriched nutrient solution. Tops and roots were separated, ground, and added to Columbia fine sandy loam in fritted glass filter tubes. Soil samples were incubated with continuous flow aeration for 5 years. Evolved CO2 was trapped for 22 weeks. Mineral nitrogen was leached from the samples at intervals throughout the 5‐year period. After 5 years, only 12% of the carbon from tops and 16% of that from roots remained in soil, compared with 38% of the nitrogen in tops and 57% of the root nitrogen. Average annual losses of carbon from soil organic matter were 6.1–6.8%; annual turnover of nitrogen varied from 6.3 to 7.4%. Availability ratios for nitrogen decreased as a function of time from about 2.5 initially to 1.2 at the end of the incubation period. Unaccounted‐for losses of nitrogen from barley tops and from soil organic matter were 15–17%, but only 2% from roots.
Recovery of Corn Yield on Gardena Subsoil as Related to Leaf and Soil Analysis
Authors: Follett R. F. , Grunes D. L. , Reichman G. A. , Carlson C. W. 
Published: July 2010

AbstractOur objective was to determine the relationship of leaf N and P and soil P (NaHCO3‐soluble) in exposed subsoils to forage yield restoration resulting from fertilizer treatment. Corn (Zea mays L.) was grown on a Gardena fine sandy loam. Fertilizer treatments consisted of NH4NO3, concentrated superphosphate, and manure. Half of the plots had 30 cm of topsoil removed (cut area), the rest had no topsoil removed (undisturbed area). Cut area treatments were evaluated against corresponding undisturbed area treatments as follows
urn:x-wiley:03615995:saj2sssaj197403615995003800020032x:equation:saj2sssaj197403615995003800020032x-math-0001A coefficient of multiple determination (R2) of 0.82 resulted when the data was fitted to the following equation
urn:x-wiley:03615995:saj2sssaj197403615995003800020032x:equation:saj2sssaj197403615995003800020032x-math-0002If leaf N was 2.9%, 90% yield recovery was obtained when leaf P was 0.27%. A leaf N level near 2.9% or more could be obtained by the addition of inorganic fertilizer N. However, high N and P rates or N and P plus manure were required to obtain 0.27% leaf P. Leaf P values from cut areas never equalled those obtained from the corresponding undisturbed area treatment. Leaf P on the cut area was closely related to soil P only if leaf N was also considered. These results indicate that a combination of plant and soil analysis is needed to identify fertilizer requirements. The potential for restoring subsoil yields was excellent and full recovery was accomplished the first year with a combination of N, P, and manure.
On the Interaction of Water and Heat Transport in Frozen and Unfrozen Soils: II. The Liquid Phase
Authors: Groenevelt P. H. , Kay B. D. 
Published: July 2010

AbstractA theory is presented for the transport in porous media of water in response to a temperature gradient and the transport of heat in response to a water pressure gradient. The fundamentals have been discussed in a previous paper. This second paper is concerned with the coupled flow processes occurring in the liquid phase. The cause of these processes is found to be the existence of the heat of wetting and the heat of fusion. Expressions for and relations between the transport coefficients are developed. Their magnitude is estimated by model calculations.
Copper (II) Interactions with Montmorillonite: Evidence from Physical Methods
Authors: McBride M. B. , Mortland M. M. 
Published: July 2010

AbstractInteraction of exchangeable copper(II) with montmorillonite was studied by means of infrared and electron spin resonance spectroscopy supported by X‐ray diffraction, magnetic susceptibility measurements, and determination of CEC values. The solvation properties of the clays after heat treatment are found to be much different with ethanol than with water. Dehydration of exchangeable Cu(II) allows these ions to become imbedded in hexagonal cavities of the silicate structure, or penetrate into the empty octahedral positions and lower the layer charge. Resolvation allow the Cu(II) ions to move out of the hexagonal holes; however, Cu(II) ions that have migrated to the octahedral layer are not exchangeable. No evidence for specific adsorption was found. The results indicate that the properties of Cu(II) on clay surfaces are dependent largely on its strongly held ligand water, and the ion behaves much like other divalent ions on clays.
Fission Particle Tracks in Micas and Micaceous Vermiculites as Related to Chemical Weathering and Cation Exchange Properties
Authors: Lee S. Y. , Jackson M. L. , Sachs I. B. 
Published: July 2010

AbstractFission particle tracks from 238U impurities in natural micas and micaceous vermiculites were observed by scanning electron microscopy after hydrofluoric acid etching. Track frequency was increased by neutron activation in a thermal nuclear reactor. Without HF etching, the average rate of interlayer K+ released from micas saturated with UO22+ and activated, during 6 days depletion in 0.5N Mg(OAc)2 solutions at pH 7 renewed every few min, were 40 to 50% higher than that from nonactivated samples. Activated UO22+ saturated micaceous vermiculites from Colorado (CO) and Wisconsin (WI) liberated more K, Fe, and Si(OH)4 compared to that from the controls, in 0.5N Mg(OAc)2 at pH 4, renewed frequently. Weathering of micaceous minerals in nature would thus be accelerated by the additional diffusion of interlayer and structural cations through the natural fission particle tracks. The cation exchange capacity (CEC) of the activated micaceous vermiculites after UO22+ saturation increased from 16 to 25 meq/100g (CO) and from 6 to 12 meq/100g (WI) after the extensive salt treatments involved in CEC measurement, while negligible change in CEC occurred in the CO Na controls and one‐third as much change occurred in the WI Na control. The observed higher K+ selectivity (relative to Ca2+) of the activated samples (0.86 for CO and 1.39 for WI), compared to the controls (0.43 and 1.21, respectively), indicates that activation provided an increase in edge wedge sites for the selective adsorption of fixing cations including the fission product 137Cs+.
The Use of Radiocarbon Dating of Organic Matter in the Study of Soil Genesis
Authors: Martel Y. A. , Paul E. A. 
Published: July 2010

AbstractRadiocarbon dating was used to study the nature and the stability of the organic matter in a range of Chernozemic soils (Borolls) from Saskatchewan. Two catenas, one cultivated, the other not, were studied in detail; the bottom soils of the uncultivated catena contained buried horizons.From the crest of the knoll to the depression, the mean residence time of the surface horizon of the cultivated catena decreased from 545 years before present (B.P.) to modern, the organic matter content increased and the percentage of hydrolyzable carbon decreased. The content of organic matter decreased but the mean residence time increased by 700 to 4,000 years in the B horizons. Two buried horizons located at different depths underneath the lower members of the uncultivated catena showed mean residence times of 5,950 and 8,410 years B.P. indicating that mass movement of soil had periodically occurred since the last glaciation.The 14C content of a field soil, measured by radiocarbon dating, was compared with the 14C distribution in fractions of another sample of the same soil after amendment with 14C‐acetate and 350 days incubation in the laboratory. The artificially labelled soil accumulated more of the tracer in the acid hydrolyzable fractions than was found by radiocarbon dating the field soil. In turn, the distribution of soil nitrogen was more closely associated with the 14C than with the unlabelled carbon of the soil.
Influence of Antecedent Soil Moisture Suction on Saturated Hydraulic Conductivity of Soils
Authors: Gerard C. J. 
Published: July 2010

AbstractStudies were conducted to evaluate influences of antecedent soil moisture suction on saturated hydraulic conductivities of soils. These studies revealed that saturated hydraulic conductivity of a soil is a dynamic property which is markedly influenced by antecedent soil moisture suction. Antecedent soil moisture of ≤ 0.33 bar suction, such as is often practiced with trickle irrigation, caused marked reduction in the ability of soil to conduct water. Gases produced by microorganisms at low suction, their subsequent entrapment, and their influence on soil macrovoids are largely responsible for reduction in ability of soil to conduct water. Reduction of effective soil macrovoids by microbial growth, flowing water, and/or soil moisture suction can also reduce soil permeability. These findings indicate that soil moisture suction and management such as trickle irrigation can influence the ability of soil to conduct water.