bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Dry Matter Content and Temperature on Ammonia Loss from Surface‐Applied Cattle Slurry
Authors: Sommer S. G. , Olesen J. E. 
Published: July 2010

AbstractEffects of increasing dry matter content in slurry on NH3 loss was measured with a wind tunnel system, whereby parameters affecting the volatilization can be estimated under controlled conditions. The effect of dry matter content on NH3 loss was measured using a slurry adjusted to different contents of dry matter. The slurry was prepared by mixing the fibrous and liquid fractions of a mechanically separated cattle slurry. Slurry was applied to a 5 cm high grass ley (Lolium multiflorum Lam.) and to barley (Hordeum vulgare L.) at a rate of 3 L m−2. The content of dry matter varied from 0.9 to 22%, total N from 2.9 to 4.9 g N L−1, TAN (NH3 + NH−+4) from 1.6 to 3.0 g N L−1 and pH from 7.0 to 7.9. The results indicated that NH3 volatilization increased with increasing slurry dry matter content. The accamuiated 6‐d loss ranged from 19 to 100% of applied TAN from slurries having a dry matter content of 0.9 and 15.6%, respectively. The accumulated NH3 loss after 6 h exposure was linearly related to dry matter content. In the periods of 6 to 12 h, 12 to 24 h and 24 h to 6 d the loss was nonlinearly related to dry matter content. If the results were adjusted for effects of pH and temperature, NH3 loss tended to be sigmoidally related to content of dry matter in all four periods. Therefore, changes in slurry dry matter content on NH3 loss seemed to be small if the dry matter content was higher than 12% or lower than 4%.
Mineralization of Sulfur in Soils Amended with Organic Wastes
Authors: Tabatabai M. A. , Chae Y. M. 
Published: July 2010

AbstractThis study was conducted to compare the mineralization of S in soils amended with various types of sewage sludges, animal manures, and plant materials. Field‐moist soils amended with organic waste materials at a 50‐Mg‐ha−1 rate were mixed with glass beads, packed in leaching columns, leached with 5 mM CaCl2 to remove the mineral S, and incubated at 30 °C. The leaching procedure was repeated every 2 wk for 26 wk. The leachates were analyzed for SO2−4‐S. The rate of SO2−4 release from sewage sludges was rapid during the first 6 wk, followed by a slow linear release. The release of SO2−4 from anhnal manures was linear with time of incubation. With the exception of alfalfa (Medicago sativa L.), which showed a rapid SO2−4 release within the first 2 wk and a subsequent linear release with time up to 26 wk, the addition of all other plant materials resulted in net S immobilization. The total net S mineralized from the organic waste materials varied considerably, depending on the type of soil and the C/N/S ratio of the organic waste material. The amounts of S mineralized in soils amended with sewage sludges and animal manures ranged from 99 to 345 mg S kg−1 and from 32 to 52 mg S kg−1 soil, respectively. The total S mineralized in soils amended with plant materials ranged from 15 to 57 mg S kg−1. Expressed as a percentage of total organic S added to soils, the S mineralized ranged from 41 to 97% for sewage sludges and from −62 to 127% for animal manures. The percentage of organic S mineralized in the plant materials ranged from −510% for cornstalk (Zea mays L.) to 87% for alfalfa. Soil types have marked effects on the mineralizable S (S0) pool and first‐order rate constants (k).
Fate of Heavy Metals in an Abandoned Lead‐Zinc Tailings Pond: I. Vegetation
Authors: Chambers Jeanne C. , Sidle Roy C. 
Published: July 2010

AbstractA 50‐yr‐old abandoned tailings pond from a Pb‐Zn processing mill was studied to determine relationships among depositional processes, physical and chemical properties of surface soils, vegetation development, and plant foliar concentrations of Zn, Cd, Cu, and Pb. Five soil/vegetation types were identified ranging from loamy sand with arid land species and 14% aerial vegetation cover at the upper (north) end of the pond to clay loam with wet meadow species and 61% cover at the lower (south) end of the pond. Foliar concentrations of Cd, Zn, Cu and Pb in blue grama [Bouteloua gracilis (H.B.K) Lag.] and creeping bentgrass (Agrostis stolonifera L.) showed no significant differences among the soil/vegetation types in which they dominated. Concentrations of Cd and Pb in foliage of alkali muhly [Muhlenbergia asperifolia (Nees & Meyen) Parodi], a ubiquitous grass species, were higher at the south than the north end of the pond. Metal concentrations in alkali muhly showed significant linear relationships to soil concentrations of metals in the five soil/vegetation types for total Cd (r2 = 0.97; P ≤ 0.001) and Zn (r2 = 0.70; P ≤ 0.05), but exhibited negative exponential relationships for total Cu (r2 = 0.99; P ≤ 0.001) and Pb (r2 = 0.99; P ≤ 0.001). Lead concentrations in grasses within the lower meadows (37.6–69.0 mg kg−1 dry mass) exceeded levels known to be toxic to plants. The results were evaluated in terms of tailings pond reclamation.
Productivity of Clay Tailings from Phosphate Mining: III. Grain Crops
Authors: Mislevy P. , Blue W.G. , Roessler C.E. , Martin F.G. 
Published: July 2010

AbstractPhosphatic clay is a waste product from the Florida phosphate mining industry presently totaling 41 000 ha. These clays contain no phytotoxic materials, are high in most plant nutrients, and 226Ra and average about 460 g moisture per kilogram. A split‐plot field experiment was conducted to study forage and grain yield, forage quality, plant nutrient concentrations, changes in soil nutrients, and 226Ra contents of four grain crops in various rotations. The crop rotations (i) corn (Zea mays L. ‘Jacques 247’)‐sunflower (Helianthus annuus L. ‘Cargill 205’), (ii) sunflower‐grain sorghum (Sorghum bicolor L. Moench ‘Northrup King Savanna 5’), (iii) soybean (Glycine max L. Merr. ‘Williams 80’)‐grain sorghum, and (iv) grain sorghum‐soybean ‘University of Florida V‐1’) were grown on a dry phosphatic clay with and without a 50‐mm surface layer of quartzsand tailings. Nitrogen was the only fertilizer element applied. Results show that corn and grain sorghum produced highest (P < 0.05) forage yields (15.7 and 13.4 Mg ha–1) and highest grain yields (8955 and 4302 kg ha–1) per harvest, respectively. Soybean harvested for forage (Crop 1) contained the highest crude protein (217 g kg–1) and in vitro organic matter digestibility (736 g kg–1). Concentrations of P, K, Ca, Mg, and Fe in most of the forages were adequate for the diets of beef cattle (Bos taunts), while those of Mn, Cu, and Zn were low. Mehlich I‐extractable soil P (1601 mg kg–1), Ca (4696 mg kg–1), and Mg (1173 mg kg–1) were considered very high and changed little over the 4‐yr production period. Application of 50 mm of sand tailings tended to increase (P < 0.05) Mehlich I‐extractable P, Ca, Mn, Cu, Zn, and Fe. Radium‐226 concentration in the forage of all grain crops averaged 8.5 Bq kg–1, which was about 17 times higher than that in the grain (0.4958 Bq kg–1) of the same crops. Concentrations of 226Ra in the forage (8.288 Bq kg–1) and grain (0.6771 Bq kg–1) were 1.1% and 0.09% of the concentration in clay (761 Bq kg–1) respectively. These data indicate that phosphatic clays can be a valuable resource for the production of corn and sorghum grain that contain low concentrations of 226Ra.
Leaching of Nitrate from Monolith Lysimeters of Different Types of Agricultural Soils
Authors: Bergström L. , Johansson R. 
Published: July 2010

AbstractNitrate leaching was measured in field lysimeters containing undisturbed soils of different texture and organic matter content. Spring barley (Hordeum distichum L.) was sown on each lysimeter and fertilized with 100 kg N ha–1. Each soil type received supplementary watering to simulate either “average” or “worst‐case” precipitation. The largest leaching losses of NO–3, ca. 65 kg N ha–1 yr–1, occurred in a sandy soil that contained little organic matter and in a peat soil. Two loamy soils lost between 25 and 40 kg N ha–1 yr–1. Smallest leaching losses, ca. 20 kg N ha–1 yr–1 or less, occurred in a clay soil and another sandy soil rich in organic matter. With the exception of the clay and peat soils, the watering treatment did not significantly affect the amounts of NO–3 leached, although the temporal distribution of leaching was clearly influenced by weather conditions. The difference in leaching between the two sandy soils was explained by differences in crop growth, whereas leaching differences between soil types were mainly considered to be due to different textural and structural properties. The results show that to make a thorough comparison of NO–3 leaching between different soil types they have to be tested simultaneously at the same site.
Nonequilibrium Sorption and Degradation of Three 2‐Chloro‐s‐Triazine Herbicides in Soil‐Water Systems
Authors: Gamerdinger A. P. , Lemley A. T. , Wagenet R. J. 
Published: July 2010

AbstractMiscible displacement techniques were used for the simultaneous study of nonequilibrium sorption and degradation of atrazine (2‐chloro‐4‐etbylamino‐6‐isopropylamine‐s‐triazine), simazine (2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine), and cyanazine (2‐(4‐chloro‐6‐ethylamino)‐s‐triazine‐2‐ylamino‐2‐proprionitrile) on two central New York soils. A bicontinuum model, which considers sorption in two domains and includes a description of first‐order degradation, was applied to describe experimentally determined breakthrough curves. Values of the equilibrium sorption constant, K, and first‐order degradation rate constant, µ, were independently measured using batch and mass‐balance techniques. Values of the sorption rate coefficient (fitted with a bicontinuum model) were inversely correlated with K, and were dependent on concentration and velocity. Estimates of the rate of atrazine degradation were on the same order, but slower when measured with miscible displacement vs. batch incubation techniques. The techniques presented in this study provide an opportunity to better quantify sorption and degradation parameters that are required in environmental fate models.
Popular Formulations for Modeling Tree Rings from Climate: A Unifying Approach
Authors: Van Deusen P. C. 
Published: July 2010

AbstractThere are several model formulations in current use for predicting tree‐ring widths from climate variables. The results of such studies may aid in predicting past climate or in understanding how trees will respond to future climate change. However, it isn't clear if the results of such investigations depend on the particular modeling strategy selected. In an effort to answer this question, a general formulation is presented that includes the most commonly used models as special cases. The general formulation and selected special cases are then fit to the same tree ring dataset. Procedures are demonstrated for choosing among the various formulations based on information criteria and evaluating Kalman filter prediction errors.
Soil Chemistry and Nutrition of North American Spruce‐Fir Stands: Evidence for Recent Change
Authors: Joslin J.D. , Kelly J.M. , Van Miegroet H. 
Published: July 2010

AbstractOne set of hypotheses offered to explain the decline of red spruce (Picea rubens Sarg.) in eastern North America focuses on the effect of acidic deposition on soil chemistry changes that may affect nutrient availability and root function. Long‐term soils data suggest that soil acidification has occurred in some spruce stands over the past 50 yr, with plant uptake and cation leaching both contributing to the loss of cations. Studies of tree ring chemistry also have indicated changes in Ca/Al and Mg/Al ratios in red spruce wood, suggesting increases in the ionic strength of soil solution. Irrigation studies using strong acid inputs have demonstrated accelerated displacement of base cations from upper horizons. Spruce‐fir (Abies spp.) nutrient budgets indicate that current net Ca and Mg leaching loss rates are of the same order of magnitude as losses to whole tree harvest removals, spread out over a 50‐yr rotation. For most cations, red spruce foliar nutrient levels decline with elevation, but it is difficult to assess the contribution of the elevational gradient in atmospheric deposition to this pattern. Compared to northeastern sites, spruce‐fir soil solutions in the southern Appalachians have higher nitrate levels and higher Al concentrations, which at times approach the Al toxicity threshold for red spruce seedlings and frequently are at levels known to interfere with cation uptake. There is little evidence that either nutrient deficiencies or Al toxicity are primary causes of red spruce decline in the Northeast, though both may play a role in the Southeast. Major factors that could affect soil chemistry in spruce‐fir stands in the future are (i) changes in S and N deposition, (ii) climate changes affecting soil organic matter decomposition and nutrient uptake, and (iii) tree mortality and physical disturbances to soils resulting in soil nitrate release.
Desorption and Unavailability of Aged Simazine Residues in Soil from a Continuous Corn Field
Authors: Scribner Stephen L. , Benzing Thomas R. , Sun Shaobai , Boyd Stephen A. 
Published: July 2010

AbstractThe sorption/desorption behavior of field weathered (aged) simazine (2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine) residues from a 20‐year continuous corn (Zea mays L.) field was compared to that of 14C‐simazine recently added to the same soil. The apparent sorption coefficients of the aged residues determined from 24‐h and 48‐h desorption experiments were approximately 15 times higher than the sorption coefficients of added simazine. Aged simazine residues were also shown to be biologically unavailable to sugarbeet (Beta vulgaris L.) and to microbial degraders, whereas recently added simazine showed herbicidal damage to sugarbeet and was substantially (ca. 48%) degraded during a 34‐d incubation in soil. Apparently, the process of pesticide aging results in simazine residues that are less bioavailable, as shown by their resistance to plant uptake and microbial degradation, and that desorb slowly into soil solution. The concentration of simazine in water from field soil‐samples (C) was monitored throughout a growing season, and compared to the equilibrium aqueous phase concentration (Cc) predicted from the laboratory determined sorption coefficient (Koc of added 14C‐simazine. The fractional equilibrium values (C/Ce.) were approximately 1 at the time of simazine application in May but fell to 0.05 during July and August. These results show that the concentration of simazine in water contacting field soil is likely to be substantially lower than that predicted from laboratory determined sorption coefficients, except immediately following application.
Selective‐Placement Burial of Drilling Fluids: II. Effects on Buffalograss and Fourwing Saltbush
Authors: McFarland Mark L. , Ueckert Darrell N. , Hons Frank M. , Hartmann Steve 
Published: July 2010

AbstractSurface disposal of spent drilling fluids used in petroleum and natural gas exploration causes surface soil contamination that severely inhibits secondary plant succession and artificial revegetation efforts. Selective‐placement burial was evaluated at two locations in western Texas for on‐site disposal of drilling fluids in arid and semiarid regions. Establishment, yield, and chemical composition of fourwing saltbush [Atriplex canescens (Pursh) Nutt.] and buffalograss [Buchloe dactyloides (Nutt.) Engelm.] transplants on undisturbed soils and plots with spent drilling fluids and cuttings buried 30, 90 (with and without a 30‐cm coarse limestone and capillary barrier) and 150 cm were compared. Survival of boths pecies was 97 to 100% 17 months after planting on plots with buried drilling wastes. Canopy cover and aboveground biomass of fourwing saltbush were greater over buried drilling wastes than on untreated plots, whereas canopy cover and aboveground biomass of buffalograss were not affected by the treatments. Significant increases in Na, K, and Mg concentrations in buffalograss after 17 months on plots with drilling fluids buried 30 cm deep at one location indicated plant uptake of some drilling fluid constituents. Elevated Zn concentrations in fourwing saltbush indicated that a portion of the Zn in the drilling fluids was available for plant uptake, while no evidence of plant accumulation of Ba, Cr, Cu, or Ni from drilling fluids was detected. Selective‐placement burial of drilling fluids offers an environmentally sound technique that will enhance revegetation efforts.
Estimating the Percent Aromatic Carbon in Soil and Aquatic Humic Substances Using Ultraviolet Absorbance Spectrometry
Authors: Novak J. M. , Mills G. L. , Bertsch P. M. 
Published: July 2010

AbstractThe aromatic C content of humic substances is an important chemical property that can be used to explain formation, source, and potential interactions of the humic substances with pesticides and other contaminant organics. The relationship between the UV absorptivity at 272, 254, and 205 nm of six aquatic fulvic acids, eight soil fulvic acids, and four water soluble organic C (WSOC) fractions, and their aromatic C content, as determined by 13C cross‐polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy was evaluated. The percent aromatic C (determined by NMR) for the pooled soil and aquatic fulvic acids and WSOC fractions data was poorly correlated (r < 0.7) with the UV absorptivity measurements at all three wavelengths. When the soil fulvic acid was considered individually, however, a relatively high correlation (r = 0.80 to 0.85, P < 0.05) resulted for the prediction of aromatic C content using UV absorptivity. Poor correlations were found for the other individual fractions. Our data suggest that the prediction of aromatic C content using UV absorptivity was applicable only for base‐extracted soil fulvic acids and not for the aquatic fulvic acids and soil WSOC fractions used in this study.
Soil Science for Environmental Quality—How Do We Know What We Know?
Authors: Warkentin B.P. 
Published: July 2010

AbstractIt is argued that the soils information we have available to apply to environmental issues has depended on the kinds of questions we have asked in soil science. Four periods are identified in the last 150 yr when we asked different kinds of questions. The last period brings us back to some of the same questions asked in the first period. The characteristics of these periods are discussed to give us a perspective as our thinking is now changing from soils as an input into crop production to include a greater emphasis on soil processes that mediate global changes.
Accumulation of Some Metals by Legumes and Their Extractability from Acid Mine Spoils
Authors: Taylor R.W. , Ibeabuchi I.O. , Sistani K.R. , Shuford J.W. 
Published: July 2010

AbstractA greenhouse study was conducted to investigate the growth (dry matter yield) of selected legume cover crops; phytoaccumulation of metals such as Zn, Mn, Pb, Cu, Ni, and Al; and extractability of heavy metals from three different Alabama acid mine spoils. The spoils were amended based on soil test recommended levels of N, P, K, Ca, and Mg prior to plant growth. Metals were extracted by three extractants (Mehlich 1, DTPA, and 0.1 M HCl) and values correlated with their accumulation by the selected legumes. Among the cover crops, kobe lespedeza [Lespedeza striata (Thung.) Hook & Arn.], sericea lespedeza [Lespedeza cuneata (Dum.) G. Don], and red clover (Trifolium pratense L.) did not survive the stressful conditions of the spoils. However, cowpea (Vigna unguiculata L.) followed by ‘Bragg’ soybean [Glycine max (L.) Merr.] generally produced the highest dry matter yield while accumulating the largest quantity of metals, except Al, from spoils. The extractability of most metals from the spoils was generally in the order of: 0.1 M HCl > Mehlich 1 > DTPA. Mehlich 1 did not extract Pb and 0.1 M HCl did not extract Ni, whereas DTPA extracted all the metals in a smaller amount relative to HCl and Mehlich 1. All the extractants were quite effective in removing plant‐available Zn from the spoils. In general, the extractants' ability to predict plant‐available metals depended on the crop species, spoil type, and extractant used.
Distribution and Partitioning of Trace Metals in Contaminated Soils near Leadville, Colorado
Authors: Levy D.B. , Barbarick K.A. , Siemer E.G. , Sommers L.E. 
Published: July 2010

AbstractMountain meadows near Leadville, CO, were contaminated with trace metals through the deposition of hydraulically transported mine tailings in the early 1900s. A study was conducted to: (i) characterize the physical and chemical properties of contaminated soils, (ii) determine the soil depth distribution of total, organically bound, oxide‐bound, exchangeable, and water‐soluble metals, and (iii) evaluate trace metals in forages grown in contaminated meadows. One uncontaminated and four contaminated locations in a north‐south transect were studied. Total soil metals ranged from: Cu, 14 to 1200 mg kg−1; Cd, 3 to 110 mg kg−1; Pb, 46 to 49000 mg kg−1; and Zn, 44 to 12000 mg kg−1. The greatest concentrations of total metals were found either in the surface horizons or in hydraulically deposited sand layers that were buried at three locations. Copper was predominantly associated with the organic fraction at four of the five locations, while Cd, Pb, and Zn were mainly bound to Fe and Mn oxides at all locations. The concentrations of Cd, Pb, and Zn in forages were significantly related to various fractions of soil metals and were found to be potentially detrimental to livestock health and plant growth.
The Effects of Herbicides on Development of Myriophyllum spicatum L. Cultured In Vitro
Authors: Christopher Susan V. , Bird Kimon T. 
Published: July 2010

AbstractTissue cultures of the aquatic plant, Myriophyllun spicatum L., were used to evaluate the effects of four different herbicides and a leaf defoliant on development. The developmental parameters used were the production of new axillary buds, leaves, roots and branches. Production of new branches was the most sensitive measure. The order of developmental inhibition was: 2,4‐dichlorophenoxyacetic acid > atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) > glyphosate [N‐(phosphonomethyl)glycine] > thidiazuron (N‐phenyl‐N′‐1,2,3‐thiadiazol‐5‐ylurea). The herbicide linuron [8‐(3,4‐dichlorophenyl)‐1‐methoxy‐1‐methyl urea] showed no statistically significant toxic effects below 100 mg L−1. This bioassay system provided a quick, sensitive measure of herbicide effects on aquatic plant development. The short time period of only 5 d permits more rapid bioassays than conventional whole plant bioassays.
Photosynthesis and Growth Response of Almond to Increased Atmospheric Ozone Partial Pressures
Authors: Retzlaff W.A. , DeJong T.M. , Williams L.E. 
Published: July 2010

AbstractUniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, ev. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domestica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O3) partial pressures. The trees were planted in open‐top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O3 partial pressures (charcoal filtered air, ambient air, or ambient air + O3) lasted from 1 June to 2 Nov. 1989. The mean 12‐h [0800–2000 h Pacific Daylight Time (PDT)] O3 partial pressures measured in the open‐top chambers during the experimental period were 0.038, 0.060, and 0.112 µPa Pa−1 O3 in the charcoal filtered, ambient, and ambient + O3 treatments, respectively. Leaf net CO2 assimilation, trunk cross‐sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O3 partial pressures. Mission was unaffected by O3 and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O3 treatments. The results indicate that there are almond cultivars that are sensitive to O3 exposure.