bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Simulated Rainfall on the Retention of Sludge Heavy Metals by the Leaves of Forage Crops
Authors: Jones S. G. , Brown K. W. , Deuel L. E. , Donnelly K. C. 
Published: July 2010

AbstractThe land disposal of municipal liquid digested sludge by surface application to a growing forage crop may cause foliage to become coated with sludge. The ingestion of foliage contaminated with sludge could be detrimental to the health of grazing animals, since municipal sludges often contain potentially toxic amounts of various heavy metals. The influence of simulated rainfall, leaf morphology, and sludge solids concentration on the retention of sludge heavy metals by the foliage of grasses was evaluated.Liquid digested sludges, containing 2 and 4% solids, were applied to greenhouse flats of common bermudagrass (Cynodon dactylon L.) and Bell rhodesgrass (Chloris gayana Kunth.), equivalent to depths of 2.50 and 1.25 cm, respectively. Sludge‐treated grasses were subjected to simulated rainfall equivalent to 2.5 cm/hour either immediately following sludge treatments or after 24 hours of drying. Additional flats receiving the sludge treatments were sampled at regular intervals over a 2‐week period to determine the foliar retention of sludge in the absence of rainfall.The foliage of both grasses was visibly contaminated with sludge following application. The foliar concentrations of Cd, Cu, Pb, and Zn were measured for each sludge treatment. There appeared to be no preferential retention of any particular heavy metal. Bell rhodesgrass retained more sludge than common bermudagrass because of its larger leaf blades and overlapping sheathes. The sludge containing 4% solids was retained by the foliage to a greater extent than sludge containing 2% solids.Sludge that was not allowed to dry on the leaves was removed by 1.25 cm of simulated rainfall, regardless of the grass species or sludge solids concentration. Sludge that was allowed to dry on the leaves, however, was not removed by 2.50 cm of simualted rainfall.
Waste Wood Fiber as a Soil Amendment
Authors: King Larry D. 
Published: July 2010

AbstractByproducts from wood processing have been used as soil amendments for many years. This study was conducted to determine the effects of a relatively new wood byproduct on plant growth and soil properties. Waste wood fiber containing 2% N (mainly as urea‐formaldehyde used as a binding agent in fiberboard production) was applied to sandy loam and clay loam soil materials in a greenhouse study. Single applications of 2,4, and 6% by weight of fiber were compared over a 2‐year period to six applications of 25, 50, and 100 ppm of fertilizer N to soils receiving no fiber.Fiber did not increase yields of fescue grass (Festuca arundinacea Schreb.) at the first harvest but did increase yields for 8 to 10 mo thereafter. By the seventh harvest the single application of 4% fiber (supplying 800 ppm N) produced a cumulative yield equal to the yield with six 50‐ppm N applications. Yields with the 6% fiber rate (supplying 1,200 ppm N) were 80% of the yields obtained from six 100 ppm N applications. Fiber additions increased available soil moisture (between 0.1 and 15 bars), cation exchange capacity, organic matter, and total N, and lowered bulk density.
An Extended Version of a Conceptual Model for Evaluating Annual Nitrogen Leaching Losses from Croplands
Authors: Tanji K. K. , Broadbent F. E. , Mehran M. , Fried M. 
Published: July 2010

AbstractPreviously, a steady‐state conceptual N model was applied to corn (Zea mays L.) field trials at two University of California Field Stations. That model examined only the inputs and outputs of N into a soil‐plant‐water system without considerations of carryover inorganic soil N and mineralization of organic soil N. It predicted N leaching losses reasonably well in the corn plots at the Kearney site where residual soil N was low, but not for the Davis site where considerable mineralization of soil organic N occurs.This steady state model was extended so that it would be applicable to the transient conditions prevailing at the Davis site. The revisions included provisions for the presence of residual inorganic soil N and the mineralization of organic soil N as well as inputs of organic N such as manures and sewage sludges and their mineralization rates. The original water submodel was not modified. The model is described in the appendix and required input parameters with examples are listed.The revised model was tested with 2 years of corn field trials at Davis which consisted of four (NH4)2SO4 rates (0, 90, 180, and 360 kg N/ha) and three irrigation regimes (1/3, 3/3, and 5/3 of the corn evapotranspiration). Sensitivity analysis evaluated the importance of the harvested crop coefficient, the denitrification coefficient, and the mineralization rate constant for organic soil N, and aided in estimating the latter two experimentally unmeasured parameters.Computed results compared favorably with measured N content in the harvested (grain and stover) crop, the residual inorganic soil N after harvest, and the average annual N concentration in the soil solution beneath the root zone at the 3‐m depth. There was no leaching of N in the 1/3 ET treatment; from 0.5 to 12 kg N/ha per year N leaching losses in the 3/3 ET treatment; and from 13 to 144 kg N/ha N leaching losses in the 5/3 ET treatments. Some differences were noted in the annual leaching losses between the 1975 and 1976 corn crops in the 5/3 and 3/3 ET treatments mainly due to differences in seepage out of the root zone.It is concluded that the applicability and utility of this expanded model have been significantly enhanced over that of the previous steady‐state model.
Programmed Impacts of Environmental Restraints Applied to U.S. Agriculture
Authors: Heady Earl O. , Vocke Gary 
Published: July 2010

AbstractA national and interregional programming model is developed to evaluate the impact of potential restraints for soil loss and nitrogen on land use, crop production patterns, interregional competition, and economic variables. The model includes 105 producing regions with 5 land classes in each, 51 water supply regions, and 28 market regions. Crop and soil loss activities are defined for each land class in each producing region. The soil loss restraints would reduce gross soil loss through use of more contouring, strip cropping, terracing, and minimum tillage. Interregional reorganizations of agriculture are predicted to occur. Regions with greater rainfall and hilly land, particularly the southeastern U.S., would sacrifice in cropping share and farm income. Regions of level lands and less rainfall, particularly the Great Plains and part of the Corn Belt, would gain in cropping intensity and income. Under nitrogen restrictions more hectares of crops would be grown and pesticide expenditures would increase. Under all environmental alternatives analyzed, U.S. agriculture could meet U.S. food needs with small increases in the supply prices of food.
Hydrology and Chemical Quality of Flow from Small Pastured Watersheds: I. Hydrology
Authors: Van Keuren R. W. , Mc Guinness J. L. , Chichester F. W. 
Published: July 2010

AbstractSurface runoff, soil loss, and subsurface flow were measured from four rotationally grazed summer pastures. One of these pastures was also used as a winter‐feeding area. Surface runoff volumes and peak rates from the three pastures used only for summer grazing were generally less as compared with values for earlier years when the fields were in meadow and fight pasturing; however, runoff from the winterfeeding area was markedly increased. Both before and after the initiation of grazing, the areas used only for summer grazing had but a trace of soil loss. More soil was lost from the winter‐feeding area, particularly during the dormant season. Water‐balance studies indicated that during the growing season surface runoff and subsurface outflow were higher and evapotranspiration (ET) was less from the winter‐feeding area than from areas summer‐grazed only. During the dormant season, surface runoff was higher and subsurface outflow was lower from the winter‐feeding area than from the summer‐grazed areas, whereas ET was similar.
Statistical Considerations and Survey of Plutonium Concentration Variability in Some Terrestrial Ecosystem Components
Authors: White Gary C. , Hakonson Thomas E. 
Published: July 2010

AbstractStatistical aspects of the use of the coefficient of variation (c) in the design of environmental plutonium studies are considered. Small sample properties of the estimate of c are studied for both normal and log‐normal populations with Monte Carlo simulations. A minimum sample size of 50 is necessary to estimate c with much precision, and an estimate of c from a sample size of less than 5 is nearly worthless. The difficulty of achieving good estimates of c increases as the true value of c increases.In addition, some of the available data on the variability of plutonium concentrations in terrestrial ecosystem components is summarized. The data were pooled to achieve better estimates of the coefficient of variation than might be available from individual studies. Pooled estimates of c are: soils, 1.35; vegetation, 0.70; and rodent tissues, 1.10. The estimates of c presented should be useful in designing a field sampling program for plutonium.
Occurrence and Stability of Calcite in the Maumee River
Authors: Green Dan B. , Smeck Neil E. 
Published: July 2010

AbstractThe occurrence of secondary (precipitated) calcite and the concentrations of parameters controlling calcite dissolution‐precipitation were monitored at six sites in the Maumee River drainage system during 1975–76. Secondary calcite was identified on the basis of calcite/dolomite ratios as determined by X‐ray diffraction and a volumetric procedure employing the Chittick apparatus. Additional evidence for the occurrence of secondary calcite as well as crystal morphology was obtained by optical microscopy. A positive correlation between nigh calcium concentrations and the occurrence of secondary calcite could not be established; however a relationship between algal blooms and calcite formation was noted. It is concluded that a reduction in the CO2 content of the stream due to algal biomass production is the factor responsible for initiating calcite precipitation in the Maumee River system. Calcite equilibria in the stream is quite dynamic with secondary calcite appearing and disappearing in relatively short periods of time.
Extent and Distribution of Soil Heavy Metal Contamination near a Nickel Smelter at Coniston, Ontario
Authors: Rutherford G. K. , Bray C. R. 
Published: July 2010

AbstractThe extent of contamination in surface soils and profiles by sulphur compounds and the heavy metals nickel, copper, zinc, and iron up to a distance of 3.5 km in the southeast quadrant from the smelter at Coniston, Ontario, has been examined. Total and sulphate sulphur were measured, as well as total, available, and exchange heavy metals. Strong contamination by Ni, Cu, total S, and sulphate, and mild contamination by Zn and Fe, was recorded for the upper Soil horizons. The Mean pH value for these soils is about 3.7.The distribution of contaminants in surface soil was examined by use of a site‐specific soil classification and by analyses of site variables using linear regression and SYMAP. Site variables of most import were: distance from the smelter, exposure of the site with respect to the smelter, and soil drainage status.
Solute Movement from Fluidized Bed Combustion Waste in Acid Soil and Mine Spoil Columns
Authors: Sidle R. C. , Stout W. L. , Hern J. L. , Bennett O. L. 
Published: July 2010

AbstractFluidized bed combustion waste (FBCW), a by‐product from a specialized coal‐fired power plant, was used as a liming source to determine its impact on solute transport in the soil. The upper 10 cm of 60‐cm‐long acid silt loam soil (pH 4.6) and strip mine spoil (pH 4.1) columns was treated with enough FBCW to raise the pH of the two media to 5.0 and 6.0, and 4.6 and 6.0, respectively. Loadings of Ca, S, and Mg in the upper 10 cm of the pH 6 mine spoil treated were 1,132, 309, and 46 µg/g soil, respectively. Approximately twice these loadings were applied to the upper 10 cm of the acid soil columns. Heavy metal loading rates were very low in all treatments. Columns were leached with 10 cm of water at 10‐day intervals 7 and 14 times. Percolate samples collected from mine spoil columns treated with FBCW showed no evidence of enhanced levels of Al, B, Ca, Cd, Cr, F−, Cu, Fe, Mg, Mn, Ni, P, Pb, SO42‐, Sr, and Zn after 14 leachings. Acid soil columns, containing higher levels of organic matter, had percolate concentrations of Ca, Mg, Mn, and SO42‐ that increased with increasing FBCW liming applications. None of the analyzed constituents showed any evidence of downward migration in mine spoil matrix and only Ca moved downward into the 10‐ to 15‐cm depth of the soil matrix.
The Influence of Anion Mobility on Ionic Retention in Waste Water‐irrigated Soils
Authors: Johnson D. W. , Breuer D. W. , Cole D. W. 
Published: July 2010

AbstractThe concept of anion mobility as a determinant of soil leaching rate was illustrated in a waste water irrigation study. Anion adsorption appeared to affect the leaching of H2PO4− and SO42‐, but not Cl−, which percolated freely through the soil. The mobility of NO3− was primarily regulated by nitrification and plant uptake. The most pronounced change in solution chemistry was an alkalinity decrease of approximately 80% as waste water entered the soil due to lowering of pH (7.5 to ca. 6.5), and to gaseous CO2 loss from solution. This alkalinity decrease accounted for most of the total ionic retention in the soil which ranged from 40–60% of waste water input.
Concentrations of Coumestrol and 4′ ,7‐dihydroxyflavone in Four Alfalfa Cultivars after Exposure to Ozone
Authors: Skärby L. , Pell E. J. 
Published: July 2010

AbstractOzone can induce increases of 4′ ,7‐dihydroxyflavone (4′ ,7‐DHF) but not coumestrol in the ‘Buffalo’ alfalfa cultivar. This study was designed to determine whether these responses were unique to ‘Buffalo’ or characteristic of other alfalfa cultivars. Seven‐week‐old seedlings of ‘Ladak,’ ‘Sonora,’ ‘Moapa,’ and ‘Vernal’ alfalfa cultivars were exposed to 773 µg/m3 (0.40 ppm) ozone for 3 hours. Forty‐eight hours after exposure, all foliage exhibiting chiorosis to extensive necrosis were harvested. Similar‐aged foliage from non‐ozonized control plants was also harvested. Methanolic extracts of the tissue were prepared and the presence and quantity of coumestroi and 4′,7‐DHF determined. Coumestrol was not detected in control or ozonized tissue. Nonozonized tissue was free of detectable 4′,7‐DHF. Injured foliage of all four cultivars contained elevated levels of 4′,7‐DHF as high as 91 ppm. There were no significant differences in concentrations of 4′,7‐DHF when concentrations were compared in four ozonized cultivars.
Kinetics of the Reaction Between Orthophosphate Ions and Muskegon Dune Sand
Authors: Novak L. T. , Petschauer F. J. 
Published: July 2010

AbstractThis paper presents data on the kinetics of orthophosphate adsorption on Muskegon dune sand. The data was obtained using batch experiments with shaken flasks followed by centrifuging and standard techniques for orthophosphate determination. Data is also presented for orthophosphate breakthrough from packed columns of dune sand.Three mechanistic kinetic models were evaluated against the batch adsorption data over the 0‐ to 24‐hour period: (i) LPDF model for interparticle mass transfer followed by a first order irreversible surface reaction; (ii) Langmuir kinetics followed by a first order irreversible surface reaction; and (iii) solid phase diffusion model for intraparticle mass transfer. Both models (i) and (ii) describe the fast and flow reactions occurring over the 24 hours studied. Model (ii) is favored partly because the sum of the square error in model (i) is 41% greater than the same for model (ii). Model (iii) does not describe the adsorption data during the 24‐hour period studied.Based on dune sand chemical composition data, and the length of the fast reaction period, it appears that the major reaction occurring during orthophosphate adsorption may involve calcite. Model (ii) is shown to be consistent with the general theory of orthophosphate calcite adsorption proposed by W. Stumm and J. O. Leckie (1970).
Sand Filtration of Poultry‐Processing Lagoon Effluent
Authors: Whitehead W. K. 
Published: July 2010

AbstractAbout 100 poultry processing plants in the United States have private waste treatment systems—predominantly stabilization ponds or lagoons. To meet the proposed USEPA regulations for waste discharges, the effluent from many of these systems must be improved. Pilot‐scale, gravity‐flow sand filters were tested as a means of further treating poultry processing lagoon effluent. Waste water application rates ranged from 0.23 o 1.40 m3/m2 per day. Average BOD5 reductions varied from 57 to 27% and average suspended solids were reduced from 52 to 37%. Effluents from the 0.23‐ and 0.47‐m3/m2 per day filters were in compliance with proposed 1983 EPA regulations for BOD5 and suspended solids during the summer and fall months. Filters with waste water applied at rates of 0.23, 0.47, and 0.94 m3/m2 per day performed for over 1 year without being cleaned.
Growth of Rye Grass and Fescue as Affected by Lead‐Cadmium‐Fertilizer Interaction
Authors: Carlson Roger W. , Rolfe Gary L. 
Published: July 2010

AbstractRye grass (Lolium perenne L.) and red fescue (Festuca rubra L.) were grown from seed in fertilized (NPK, 12:6:6) and unfertilized Flanagan silt loam soil treated with Pb (0, 10, 100, 1,000, 5,000, 10,000 µg g−1), Cd (0, 0.1, 1, 10, 50, 100 µg g−1), or a combination of Pb plus Cd at a ratio of 100 Pb:1 Cd. Plant growth and heavy metal content of plants were measured at the end of three, consecutive, 10‐day periods. Growth of Pb‐treated plants did not begin to decrease until treatment concentrations reached 1,000 µg g−1 Pb or above. Above a treatment concentration of 1,000 µg g−1 Pb with or without added Cd, growth was reduced sharply in a log‐linear fashion with increasing treatment concentrations. Some reduction in growth of plants treated with Cd alone occurred for fertilized rescue above 10 µg g−1 Cd but not for rye until treatments above 50 µg g−1. No reduction in growth was found for nonfertilized plants treated with Cd alone at the highest soil concentration (100 µg g−1). Reduction in growth for plants treated with Pb + Cd was no lower than that of plants treated with Pb alone. While fertilization stimulated growth at treatment concentrations < 1,000 µg g−1, it did not ameliorate the effects of Pb at higher concentrations. Fertilization reduced Pb content and uptake in rye (P < 0.001) but not in fescue. The Cd content of fertilized plants was greater (P < 0.05) than that of nonfertilized plants. Cadmium content of plants treated with Pb + Cd was greater (P < 0.05) than that of plants treated with Cd alone, while there was no difference in Pb content between Pb and Pb + Cd treatments.
An Ecosystem Approach to the Treatment of Waste Waters
Authors: Lakshman G. 
Published: July 2010

AbstractAquatic plants such as bulrush (Scirpus spp) and cattail (Typha spp) were used to purify untreated municipal sewage in experimental tanks in a growth chamber measuring 5.5 by 3.7 by 3.7 m high. Initial concentrations of total phosphorus (TP) and total Kjeldahl nitrogen (TKN) before treatment ranged from 3.9 to 29.0 ppm for TP and from 10.3 to 44.0 ppm for TKN. Rates of removal of phosphorus and Kjeldahl nitrogen by the plants were monitored and compared with a control without plants. Generally, the concentrations of TP and TKN decreased exponentially in the treatment trays during the individual experimental runs. High rates of purification, up to 98%, were achieved in <20 days. During the 20 experimental runs lasting >500 days the plants showed unabated ability to remove nutrients while the control achieved a saturated condition.Rates of nutrient uptake by the experimental plants increased with the ambient concentration and were much faster than the rates predicted by Michaelis‐Menten kinetics. Above‐water biomass obtained by periodic harvesting showed that the plants contained high levels of digestible organic matter (DOM) and crude protein comparable to the values obtainable from alfalfa. Experimental data have been used to develop equations for large‐scale in situ applications. Data presented here show that aquatic plants have considerable potential in the purification of municipal waste waters within reasonably short periods.
Metabolism of Carbofuran in Rice Straw‐amended and Unamended Rice Soils
Authors: Venkateswarlu K. , Sethunathan N. 
Published: July 2010

AbstractDegradation of carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl N‐methylcarbamate) in rice straw‐amended flooded soil under alternate anaerobic‐aerobic conditions and 14CO2 evolution from ring‐ and carbonyl‐labeled 14C‐carbofuran in flooded soil were studied. The addition of rice straw accelerated the hydrolysis of carbofuran to carbofuran phenol (2,3‐dihydro‐2,2‐dimethyl‐7‐hydroxy benzofuran) in predominantly anaerobic flooded soil. Carbofuran phenol appeared to accumulate under continued anaerobiosis and was readily decomposed with the significant formation of unextractable (“soil bound”) residues when the system was returned to aerobic conditions. Interestingly, 14CO2 evolution from the aromatic ring in carbofuran was almost negligible, accounting for <0.3% of ring‐14C even after 40 days of flooding as compared to 27% released from carbonyl‐14C.
Injury and Yield Responses of Spinach Cultivars to Chronic Doses of Ozone in Open‐Top Field Chambers
Authors: Heagle A. S. , Philbeck R. B. , Letchworth M. B. 
Published: July 2010

AbstractSpinach (Spinacia oleracea L.) cultivars were exposed continuously during growth to carbon‐filtered air or nonfiltered ambient air in open‐top field chambers. Constant low concentrations of ozone (O3) were added to the varying ambient concentrations in the nonfiltered‐air chambers for 7 hours (0920 to 1620 EDT) per day. There were significant differences in the amount of foliar injury and shoot growth decrease among 11 spinach cultivars exposed for 7 hours/day to 0.13 ppm of O3; America, Winter Bloomsdale, and Seven‐R were less sensitive to foliar injury than Chesapeake, Hybrid‐612, and Dixie Market. Shoot growth of America and Viroflay was affected less and Hybrid‐612 and Dark Green Bloomsdale more than that of most other cultivars. The cultivars America, Winter Bloomsdale, Hybrid 7, and Viroflay were exposed for 38 days to determine threshold doses of O3 for injury and yield effects. The threshold 7‐hour/day mean O3 concentration for foliar injury was between 0.02 and 0.06 ppm. The threshold for a significant decrease in shoot growth of most spinach cultivars was between 0.06 and 0.10 ppm. Shoot fresh weights of plants grown in the ground at 0.06, 0.10, and 0.13 ppm were 18, 37 and 69% less, respectively, than plants grown at 0.02 ppm. Comparative values for potted plants grown in a 1:1:1 mixture of sand/soil/Pro‐Mix BX were 4, 25, and 65%, respectively.