bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Isokinetic Sampler for Wind Erosible Silt and Clay Particle Measurement
Authors: Arkin Gerald F. , Perrier Eugene R. 
Published: July 2010

AbstractThe general theory, design details, and soil particle concentration data for an isokinetic fine particulate sampler for soil erosion studies are presented. This isokinetic sampler enables rapid measurement of a totally representative profile distribution of soil particles entrained in a turbulent boundary layer within a wind tunnel test section. Differences between mass flux, soil particle concentration, and particle size distribution measured at the sampling point and in the air stream are minimized by isokinetic sampling.
Count‐Rate Instability in Gamma‐Ray Transmission Equipment
Authors: Reginato Robert J. 
Published: July 2010

AbstractSignificant errors in measuring the bulk density and water content of soils can result from a procedure commonly used with gamma‐ray transmission equipment. The detector probe can be exposed directly to the unattenuated gamma‐ray source when moving from a standard absorber to the soil. Under this high‐exposure condition, 20 to 30 min may be required before the system will stabilize and reliable count rates can be taken. To avoid this difficulty, three alternative techniques are suggested. The alternative found most desirable for existing conditions was to take a standard count rate in the soil pedon where the bulk density remained constant, thus eliminating the necessity of exposing the detector to the unattenuated gamma‐ray source.
Influence of Organic Nitrogen on Soil Nitrogen, Nodulation, Nitrogen Fixation, and Yield of Soybeans
Authors: Bezdicek D. F. , Mulford R. F. , Magee B. H. 
Published: July 2010

AbstractNitrogen was applied on a previous rye (Secale Cereale L.) cover crop for later determination of the effect of organic N on soybean (Glycine max L.) N2‐fixation rate, plant dry matter, N uptake, and yield. Nitrogen was applied at 0, 56, 112, and 224 kg N/ha as NH4NO3 or urea either on rye in mid‐March or at soybean planting time in a 4 × 2 × 2 factorial design. In both years of study, N2‐fixation rate as estimated from acetylene reduction was reduced throughout the season by increased fertilization rate. For 1 year, interactions showed that N2‐fixation rate and nodule mass were stimulated late in the season from increased N fertilizer applied to the rye but not at soybean planting. Interactions between NH4NO3 and urea and time of application showed that NH4NO3 as compared with urea applied on rye significantly increased soybean dry matter, N uptake, and yield. Urea applied at planting increased these parameters in comparison with NH4NO3. The observed increases in dry matter, N uptake and yield from rye‐applied NH4NO3 were not accompanied by a corresponding increase in N2‐fixation rate or nodule mass. This would suggest that the N2 fixing system was not responsible for the increase of dry matter, N uptake, and yield. Soil organic N was not measurably influenced by the treatments imposed.
Afforestation Alters Prairie Soil Nitrogen Status
Authors: Fisher R. F. , Eastburn R. P. 
Published: July 2010

AbstractTwo prairie soils were examined after 20‐years of occupancy by four tree species to determine what alterations had occurred. Bulk density, exchangeable bases, pH, and organic carbon had not changed in the 0 to 10‐cm soil layer. Red pine (Pinus resinosa) and Japanese larch (Larix leptolepis) caused significant increases in total N and a change in N form. Tulip tree (Liriodendron tulipifera) caused a significant change in N form while basswood (Tilia americana) caused no significant alteration. From this we conclude that alteration in soil N form is one of the first changes to occur following afforestation.
Insolubilization of Inorganic Phosphate by Anoxic Lake Sediment
Authors: Norvell W. A. 
Published: July 2010

AbstractThe insolubilization of soluble phosphate by anoxic lake sediments was studied at 4 to 5C under oxygen‐free conditions. After 3 to 4 weeks of reaction between added phosphate and two sediments, samples of the interstitial solution were recovered and analyzed. Sediment samples were extracted to determine exchangeable cations, CEC, and readily soluble phosphate. Insolubilization of added phosphate was accompanied by decreases in the concentrations of all major cations in the interstitial solution. Soluble cations and phosphate were lost in essentially charge‐equivalent amounts. Calcium, iron, and manganese were lost from both soluble and exchangeable forms. Soluble Mg, Na, K, and NH4 decreased also but only because these cations occupied exchange sites vacated by Ca, Fe, and Mn. The fraction of soluble and exchangeable Mn lost was greater than for any other cation. No significant changes in pH, CEC, or concentrations of indigenous anions were found at any level of added phosphate. Essentially all insolubilized phosphate was recovered as inorganic phosphate by mild extractants suggesting that inorganic chemical reactions were responsible for the losses of added phosphate. The results suggest that phosphate compounds of Ca, Fe, and Mn were precipitated.
Soil Temperatures in Selected Southeastern Idaho Soils: I. Evaluation of Sampling Techniques and Classification of Soils
Authors: McDole Robert E. , Fosberg Maynard A. 
Published: July 2010

AbstractAn intensive 2‐year study of mean annual soil temperatures (MAST) was conducted in an attempt to more accurately classify the soils of the Fort Hall Area, Idaho, Soil Survey into the new Soil Taxonomy. Temperature data was obtained from 21 sites partly from deep samplings (7 to 9 m) with an extension auger and partly from monthly readings taken at depths of 0.6, 0.9, 1.2, and 1.5 m.Sites were selected under native vegetation to include a range in elevations (1,330 to 1,860 m), drainage, soil texture, and slope. Drainage classes ranged from excessively drained to very poorly drained; textures ranged from loamy coarse sand to silt loam with one site a peat; slopes were nearly level with one 11% south slope and a 20% north slope.Soils having MAST less than 8C (47F) occurred only above 1,830 m (6,000 ft) elevation or only under very poorly drained conditions. MAST was generally 2.5 to 3C (4.5 to 5.5F) warmer than the mean annual air temperature in the study area except where influenced by slope, texture, or drainage.Mean summer soil temperature (MSST) of all well‐drained soils was above 15C.
Soil Temperatures in Selected Southeastern Idaho Soils: II. Relation to Soil and Site Characteristics
Authors: McDole Robert E. , Fosberg Maynard A. 
Published: July 2010

AbstractDevelopment of the new Soil Taxonomy (Soils Survey Staff, 1970) and classification of soils in the new system has brought about renewed activity in collecting soil temperature data in the past few years. However, little of this data has been published to date.In an attempt to properly classify soils of the Fort Hall Area, Idaho, Soil Survey, an extensive study of soil temperatures was conducted over a 2‐year period. The temperature data collected furnished information on soil temperature as it relates to such characteristics as elevation, slope, texture, drainage, and ground‐water temperature.Mean annual soil temperature (MAST) is strongly influenced by elevation. An increase in elevation of 300 m reduces the MAST by 2.5 to 2.7C. Presence of a water table having an average temperature of 9.6C in the 150‐cm soil profile resulted in lowering the MAST from the 10 to 12C typical of well‐drained soils in the area to a low of 7.5C on a very poorly drained soil. Mean summer soil temperature (MSST) decreases in going from a well‐drained soil to a very poorly drained soil. In contrast, the mean winter soil temperature (MWST) is higher in the more poorly drained soils than in better drained soils.South‐facing slopes and coarse texures give indications of slightly increased MAST over nearly level slopes and medium textures, although results from this study are not conclusive. North‐facing slopes show decreased MAST when compared to nearly level slopes.
Evaluating Penetration Resistance and Wheel Sinkage Response to Soil Water Suction Changes in a Draining Clay Soil
Authors: Steinhardt Reuven 
Published: July 2010

AbstractTo facilitate the development of subsurface drainage design criteria for the reduction of soil compaction, the relation between the bearing capacity of nearly saturated soil and its water suction(s) is analyzed for a cone penetrating into the soil and for a sinking tractor wheel. Approximate equations are developed, from basic soil mechanic theory, for certain soils under a limited range of suction and loading conditions. The main assumptions are attainment of plastic equilibrium during dynamic loading and independence of the soil deformation process and its shear failure pattern of suction. The penetration resistance‐suction model shows that a linear response to suction changes can be expected, characterized by a modified bearing capacity‐suction factor (Ns) which may be estimated from the mechanical and water properties of the soil. The wheel sinkagesuction model predicts the relative change in wheel rut depth in response to loading (inflation pressure) and suction changes, by means of the same Ns parameter. Tests were conducted in plowed (P1) and unplowed (P0) irrigated plots of a clay soil, utilizing a cone penetrometer and a tractor with differentially loaded and differentially inflated rear wheels. Variations in penetration resistance with suction were successfully predicted, assuming local, intermediate, and general shear failure in the subsoil, and in the plow‐layers of P1 and P0, respectively. The relative change in wheel rut depth with suction was found predictable, provided S > Smin. The transition from S > Smin to S < Smin was characterized by an inversion of sinkage response in P0, and by a transition from vertical to horizontal soil compaction or flow in P1.
Soil Water Content: Microwave Oven Method
Authors: Miller R. J. , Smith R. B. , Biggar J. W. 
Published: July 2010

AbstractThe moisture content of two soils was determined rapidly with a microwave technique. Equations were developed for estimating soil drying times for two soils of different texture at different moisture contents and for different sample sizes. Results indicate that drying soil by microwave oven also may have a limited use as a method for soil preparation prior to chemical analyses.
Heating Sample Plate for X‐Ray Diffraction Studies of Clays
Authors: Weed S. B. , Leonard R. A. 
Published: July 2010

AbstractAn inexpensive heating sample plate for X‐ray diffraction studies of clay minerals is described. The plate is supported on a machined massive pyrophyllite base which fits in the sample mount of an X‐ray diffractometer. Temperatures up to 450C are readily attained.
Microbial Growth Rate in Glucose‐Amended Soil
Authors: Behera B. , Wagner G. H. 
Published: July 2010

AbstractMicrobial growth in soil amended with glucose was evaluated. Following the incorporation of glucose into soil, rapid evolution of CO2 occurred and was accompanied by a similar increase in bacterial numbers. It appeared that the amendment was utilized primarily by bacteria and was wholly expended within the first 2 days of incubation. Subsequently fungal growth was noted at the time the bacterial count declined. The developing bacterial population followed the typical sigmoid growth curve and a minimum generation time of 2 hours was obtained during the period 5 to 10 hours after adding the glucose. It was determined that the yield coefficient of bacteria produced relative to substrate consumed was 0.39 g of cell C/g substrate C. The energy expended by the population for functions other than production of new cell material, referred to as specific maintenance, was estimated to be 0.0036 hour‐1.
Utilization of Organic Compounds by Germinating Soybean Seeds
Authors: Zwarun A. A. 
Published: July 2010

AbstractSurface‐sterilized soybean seeds (Glycine max L.) were placed inside sterile vials containing 5 ml of sterile, deionized water and 1µCi amounts of various 14C‐labeled organic compounds. The atmosphere inside the sealed vials was analyzed for 14CO2 every hour for 12 hours. The compounds tested were uniformly labeled glucose, fructose, maltose, lysine, glycerol, and urea; glycine labeled in the 1 or the 2 position; and citric acid labeled in the 1 and 5 positions. All compounds tested were metabolized by germinating soybean seeds as evidenced by 14CO2 evolution. However, with the exception of urea, the amount of 14CO2 produced was small. Urea was metabolized very rapidly and very extensively. It appears that soybean seeds can metabolize external organic molecules within 1 hour of exposure to moisture.
Effect of Macronutrient Ions on the Availability of Iron from a Chelated Source
Authors: Oertli J. J. , Opoku A. A. 
Published: July 2010

AbstractThe uptake of Fe from FeEDDHA [ferric chelate of ethylenediamine di (o‐hydroxyphenylacetic acid)] during periods of 1 to 2 days was studied with 10‐ to 11‐day‐old corn plants (Zea mays L.) grown in nutrient solutions. The Fe in roots and tops was markedly affected by the composition of the nutrient solution. Cations stimulated Fe in plants in the following order: K> Na > Mg > Ca, and anions SO4 > Cl > NO3. The stimulation was the greater the more the pH declined during the absorption experiment; hence it was concluded that the effect of nutrient solution composition on Fe nutrition must be attributed to the imbalance of cation and anion uptake rather than to a specific nutrient. The pH decline and, in general, the associated stimulation of Fe uptake were enhanced by increasing concentrations of the interfering ions and by time. However, when the pH fell toward a value of 4, injury to roots occurred and Fe uptake was reduced in spite of a higher supply. The composition of the nutrient solution was also effective in long‐term experiments in regulating Fe uptake. A decrease in pH resulting from excess cation uptake favors the formation of less dissociated forms of the free ligand, namely of (ligand‐H)3‐, (ligand‐H2)2‐, etc., instead of the reactive ligand, (ligand)4‐ and equilibrium can be maintained only if more FeEDDHA dissociates, liberating Fe3+ for uptake.
Ammonia Volatilization from Surface Applications of Ammonium Compounds on Calcareous Soils: II. Effects of Temperature and Rate of Ammonium Nitrogen Application
Authors: Fenn L. B. , Kissel D. E. 
Published: July 2010

AbstractThe effects of temperature and rate of application on NH3‐N volatilization from NH4+ salts applied to the surface of a calcareous soil were investigated in the laboratory. Total NH3‐N losses were only slightly influenced by temperature over a broad range of NH4+‐N application rates with a precipitate forming NH4+ compound such as (NH4)2SO4 in a calcareous soil. The rates of NH3‐N loss were highly influenced by temperature. High temperatures increased the initial rates of NH3‐N loss although they were proportionally reduced at later stages. The lowest temperature resulted in the lowest initial NH3‐N loss rate but became highest for the last 76 hours. Total ammonia nitrogen losses were dependent on the rate of NH4+‐N application. The quantity of NH3‐N loss varied from 19 to 50% of the applied NH4+‐N at 33 to 550 kg NH4+‐N/ha, respectively.The increasing temperature increased losses of NH3‐N from NH4NO3 which does not form precipitates with CaCO3 or appreciable (NH4)2CO3. In 100 hours, NH4NO3 lost 14, 18, and 26% of the applied NH4+‐N at 12, 22, and 32C, respectively. Both the total 100‐hour NH3‐N losses and rates of NH3‐N loss were increased by increased temperatures; however, the percent of NH3‐N volatilized was unaffected by rates of NH4+‐N application.Ammonium sulfate losses from a noncalcareous Wilson clay loam buffered to the pH of the calcareous soil produced NH3‐N losses equivalent to NH4NO3 at 12C and lower than NH4NO3 at 32C. Ammonia nitrogen losses, both total NH3‐N and rates of NH3‐N loss, were similar to losses of NH4NO3 from the calcareous soils. Therefore in the calcareous Houston Black clay the NH3‐N loss caused by reaction of (NH4)2SO4 with CaCO3 ranged from 0 to 70 or 80%.Regression equations were developed that predict NH3‐N losses at certain temperatures, time, and rate of NH4+‐N application.
Availability of Fertilizer Zinc to Corn in a Calcareous Mineral Soil
Authors: MacGregor J. M. , Sajjapongse A. , Gunderson O. M. 
Published: July 2010

AbstractPowdered ZnSO4 · 7H2O was plowed down for corn (Zea mays L.) in a Zn‐deficient Fieldon silty clay loam at five rates, row banded, or banded at four rates after mixing with NH4NO3. The effect of dusting corn seed with Na2Zn‐EDTA was also compared, using leaf Zn and grain yields for 5 years as criteria. Soil analyses and greenhouse studies with 65Zn, eight years after Zn fertilization, were conducted to determine possible cause(s) of extreme variations in field availability of indigenous soil Zn for corn, and the residual effect remaining where Zn fertilizer was used eight years previously.Plowing down ZnSO4 · 7H2O at higher rates resulted in higher leaf Zn in all 5 years, whereas initially effective lower treatment rates decreased with time. Banded Zn and/or N had little or no effect on leaf Zn. Grain yields were increased by both plow down and band ZnSO4 · 7H2O treatments until the fifth year. Dusting corn seed with Na2Zn‐EDTA had no effect on leaf Zn or on annual grain yield, but increased the 5‐year yield.Soil analyses 8 years after Zn fertilization showed that vegetative Zn‐deficiency symptoms of corn in the field and subsequent low grain yields were significantly related to high extractable P/extractable Zn ratios in the surface 30.5‐cm soil depth. There was no observed effect of temperature, moisture, pH, conductivity, calcium carbonate equivalent, or exchangeable K. More Zn was extracted from the surface soils where Zn had been applied nearly 8 years previously, but “A values” were larger only in soils receiving the heaviest 1962 Zn treatment of 44.8 kg/ha.
A Study of Six “Latosols” from Costa Rica to Elucidate the Problems of Classification, Productivity and Management of Tropical Soils
Authors: Martini J. A. , Macias M. 
Published: July 2010

AbstractSix deep, red, clayey, acid soils from the hot and humid tropics of Costa Rica, previously classified as “Latosols” were studied. Special attention was given to the diagnostic horizons and properties to elucidate the problems of classification, productivity, and management of tropical soils. Physical, chemical and mineralogical properties showed that these soils were as highly weathered as indicated by their morphological properties and other field observations. However, they were predominantly Ultisols and not Oxisols, as it is sometimes assumed, and they did not fully fit C. E. Kellogg's original definition of “Latosol.” Although physical properties were found to be adequate, chemical properties were indicative of poor soil productivity and difficult management.
Difficult Eroded Planting Sites in North Mississippi Evaluated by Discriminant Analysis
Authors: Duffy Paul D. , McClurkin D. C. 
Published: July 2010

AbstractA discriminant analysis of physical and chemical characteristics of the upper 23 cm of the soil was computed for 24 sites where bar‐planted loblolly pines (Pinus taeda L.) had failed and at 15 successful plantations near the fail sites. Screening of 17 soil properties indicated that bulk density is the best variable for classifying sites. A function based only on bulk density correctly classified 74% of the sites as fail or success, regardless of microrelief. On sites where bulk density equaled or exceeded 1.45 g/cm3 bar planting was predicted to fail. Information on a site's proximity to the rim or bottom of a deep gully improved accuracy of classification. Since other soil properties differed relatively little between success and fail sites, results suggest that high bulk density substantially contributed to pine mortality, either through physical impedance of root growth or poor aeration or by interference with proper planting.
A Modified Shop Press for Use in Soil Compaction Studies
Authors: Tanabe M. J. , Murdoch C. L. 
Published: July 2010

AbstractA system was developed at the University of Hawaii for studying effects of compaction on hydraulic conductivity of soil mixtures. A major advantage of this system was the ability of the compacting unit to apply a specific amount of pressure for any desired length of time. The permeameter used also decreased possible error in hydraulic conductivity measurements.
Small Tensiometers for Field and Laboratory Studies
Authors: Rogers J. S. 
Published: July 2010

AbstractA small tensiometer was constructed and used in field and laboratory studies. The units are suitable only for low suctions, but have the fast response time that is desirable for measuring short‐term changes in field and laboratory studies of drainage. Several tensiometers have been in use for over 4 years and continue to perform very satisfactorily.
Predicting Exchangeable Sodium Ratios in Irrigated Tropical Vertisols
Authors: Sinanuwong S. , El‐Swaify S. A. 
Published: July 2010

AbstractBatch equilibrium studies were used to investigate Nadivalent exchange and to derive Gapon constants for three Hawaii Vertisols. Obtained regression coefficient values indicated that a linear relationship exists between exchangeable sodium ratios (ESR) and sodium adsorption ratios (SAR) for tropical Vertisols. ESR values obtained for two of the soils were slightly lower than the values predicted by Bower's equation (3) and higher than those predicted by the U.S. Salinity Laboratory's equation (11). ESR values obtained for the third soil were lower than those predicted by either equation. Generally, the higher preferences of surface than of subsurface horizons for Na was confirmed. Prevailing electrolyte concentration levels were found more important than any other experimental variable in affecting the precision of ESR estimates for a given SAR. Although ESR values were generally higher at 0.1N than at 0.01N, the valence‐dilution effect was reversed for the surface horizon of one Vertisol during Mg‐Na exchange.While little difference was noted between Ca‐Na and Mg‐Na exchange in one of the soils, in the other two significantly smaller ESR values were obtained for the first than for the second reaction. An unexpected type of hysteresis effect was noted, whereby divalent‐soils exhibited greater preference for Na than did Na‐soils. Possible reasons for this effect are discussed.
Nitrogen‐15‐Depleted versus Nitrogen‐15‐Enriched Ammonium Sulfate as Tracers in Nitrogen Uptake Studies
Authors: Edwards A. P. , Hauck R. D. 
Published: July 2010

AbstractFertilizer particles were prepared from ammonium sulfate with a lower (0.031) than natural (0.366) atom percentage of 15N. The 15N‐depleted material was compared with ammonium sulfate of a comparable level of 15N enrichment (0.734 atom %) in a greenhouse pot experiment which measured plant recovery of applied N. There was no statistical difference in N recovery values for five harvests taken over an 18‐week period at three rates of applied tracer N, with on exception. Accurate and precise measurement of tracer N in plant tissue was obtained for both 15N‐depleted and 15N‐enriched materials, using two mass spectrometers with different measurement and rcording systems. A nontracer technique gave lower first harvest and higher combined harvest values of percentage recovery of applied N than either tracer technique.