bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of the Salt Burden of Irrigation Drainage Waters
Authors: Jury W. A. , Pratt P. F. 
Published: July 2010

AbstractThe problem of predicting salt concentrations and mass emissions below irrigated fields is studied with three models, ranging from an inert proportional model frequently used by water quality regulatory agencies, to steady state and transient models which include chemical reactions as well as salt transport. Calculations of salt movement are made for four waters and three leaching fractions, for depths up to 450 cm below the surface.Results suggest that the proportional model will overestimate salt burden for waters which tend to precipitate Ca2+‐salts and will underestimate the salt burden of waters which tend to dissolve native CaCO3 in the soil. The extent of the error is a function of the leaching fraction (LF) and the irrigation water composition. The steady state model, which does not consider ion exchange, predicts a greater tendency toward mineral dissolution than occurs when Ca2+ ions are brought into solution through ion exchange, but calculates a more accurate salt balance than the proportional model. For instance, with a saline irrigation water at a LF = 0.1, the steady state and transient model mass emission predictions were 22 and 36% less, respectively, than the estimates of the proportional model. At the other extreme, with a high‐quality irrigation water at a LF = 0.4, the mass emission predictions of these two models were 198 and 201% higher, respectively, than the predictions of the proportional model.The transient stage of salt movement was found to persist until Mg2+ had reached steady state, which required about 12 years/m at a moderate leaching fraction of 0.25. It was concluded that the steady‐state and proportional models are not appropriate for estimating the salt burden of irrigated fields on underlying ground water.
Coastal Bermudagrass Yield and Soil Properties as Affected by Surface‐Applied Dairy Manure and its Residue
Authors: Lund Zane F. , Doss Basil D. 
Published: July 2010

AbstractLand spreading of animal manure is a common practice for waste disposal and plant nutrient utilization, but it may cause problems by polluting runoff and ground water. Field experiments were conducted on two soils: Dothan loamy sand (Plinthic Paleudults) and Lucedale fine sandy loam (Rhodic Paleudults). Dairy manure was surface‐applied for 3 years as a solid at rates of 45 and 90 metric tons ha−1 year−1 and as a liquid at rates of 45, 90, and 135 metric tons ha−1 year−1, dry wt basis. Check plots received N, P, and K at the rates of 470, 225, and 470 kg ha−1 year−1 from mineral fertilizer. The effects of manure on soil properties and on period of time coastal bermudagrass [Cynodon dactylon (L.) Pers.] responds to residue were determined. Residue from the manure 3 years after the final manure application with no additional fertilizer was still producing considerably higher yields of coastal bermudagrass on both soils than on the check plots at the beginning of the residual phase of study. Yields were higher the third year on the Dothan than on the Lucedale soil, but organic N was higher in the forage from the Lucedale soil. Nitrogen was one of the most limiting factors of production on both soils by the end of three cropping seasons.Additions of manure increased K, Mg, and pH in the subsoil, and the increase was still evident after three cropping seasons. There was also some downward movement of P, but less than there was of the other elements. There was more movement of all ions in the sandier Dothan soil than in the Lucedale soil.Projection of the loss of organic N in the surface soil indicated that residue would be negligible 45 to 55 months after applications ceased.
Effect of Antibiotics in Beef Cattle Feces on Nitrogen and Carbon Mineralization in Soil and on Plant Growth and Composition
Authors: Patten D. K. , Wolf D. C. , Kunkle W. E. , Douglass L. W. 
Published: July 2010

AbstractThe potential human health hazard associated with the use of antibiotics in animal feeds is currently being reevaluated by the Food and Drug Administration. This study was conducted to investigate the impact of the addition of antibiotic‐containing feces on soil biological activity. A total of nine beef cattle were placed on either a control feed, or a feed supplemented with chlortetracycline (CTC) or oxytetracycline (OTC) for a period of 10 days. Feces from these cattle were collected and analyzed for chemical, physical, and microbiological properties. Samples of the feces were added to an Evesboro sandy loam at rates equivalent to 0, 9.4, and 18.8 dry metric tons/ha (0, 20, and 40 wet tons [U.S.]/acre). Carbon and nitrogen mineralization were studied in the soil‐feces system. Analyses of the feces indicated antibiotic‐related changes in several properties. Total nitrogen in the feces of cattle receiving OTC was, at 1.50%, significantly lower than the 1.74% level found in the feces of CTC fed cattle. Feces from cattle receiving OTC contained a higher concentration of potassium, more fungi, and fewer volatile solids than did wastes from control animals. Antibiotics in the feed had no effect on number of total bacteria, total and fecal coliforms, or fecal streptococci; concentration of NH4‐N, NO3‐N, P, Ca, Mg, Na, Zn, Mn, Fe, or Cu; pH; percent moisture; or chemical oxygen demand in the feces. The antibiotics CTC and OTC were found at levels of 5.3 and 11.3 µg/g, respectively, in the feces of cattle receiving the antibiotics. When added to the soil, feces from antibiotic‐fed cattle evolved approximately 20% more carbon than did control feces during a 70‐day period. Nitrogen immobilization occurred for 28 days following feces addition to the soil. No significant differences due to the use of feces from antibiotic‐fed cattle were observed in the rate of nitrogen mineralization in the soil during a 60‐day incubation. Greenhouse experiments using feces from antibiotic‐fed cattle as a soil amendment demonstrated no changes related to the antibiotics in the growth, yield, or elemental composition of 30‐day‐old corn seedlings (Zea mays L.).
Environmental Contamination Through Residual Trace Metal Dispersal from a Derelict Lead‐Zinc Mine
Authors: Johnson M. S. , Eaton J. W. 
Published: July 2010

AbstractStudies of historical and current environmental problems in the vicinity of a derelict Pb‐Zn mine at Parc, near Llanwrst in North Wales, have shown that heavy metal dispersal occurs through contaminated mine drainage waters and episodal erosion of an unstable tailings dam.Since the discontinuation of mining operations an estimated 13,000 metric tons of metalliferous spoil, equivalent to 43 metric tons Pb, 104 metric tons Zn, and 1 metric ton Cd, have been eroded from the main tailings dam. Dispersal by a tributary of the River Conwy and redeposition during flooding events has caused extensive contamination of lowland agricultural pastures. Streamwater pollution by tailings and dissolved metal salts in mine effluent continues to have a pronounced adverse effect on the flora and fauna of the tributary.Under normal discharge conditions mean net transfer of metals into the main Conwy River approximates to 0.27 kg Pb, 15 kg Zn, and 0.1 kg Cd over 24 hours. However, because of the increased particulate load during surface drainage and flooding episodes, net dispersal increases unequally for the different metals, to a rate above that anticipated from discharge‐concentration relationships.With a remaining deposit of 250,000 metric tons of mine tailings, tip stabilization measures have been initiated as a safeguard against further degradation of natural resources in the locality.
Effects of Water Quality on Forage Production
Authors: Zartman R. E , Miller T. D. , Goodin J. R. , Gichuru M. 
Published: July 2010

AbstractField studies were conducted during a 4‐year period to determine the influence of water quality on forage production. Three levels of blow down water (used to cool the electrical generating facility) (EC = 12 mmhos/cm, SAR = 11) and city water (EC = 1.5 mmhos/cm, SAR = 4.3) were used to irrigate alfalfa (Medicago sativa L.) and fourwinged saltbush [Atriplex canescens (Pursh.) Nutt.]. Forage stands were initiated in 1975 on a Friona fine sandy loam which is a fine‐loamy, mixed, thermic, Petrocalcic Paleustoll. Alfalfa yields responded positively to irrigation. The highest yield occurred in the high‐irrigation city water treatment followed by the high‐irrigation blow down water treatment. The medium‐irrigation levels produced intermediate yields, with the dryland production decreasing during the span of the experiment. Atriplex yields were not significantly affected by irrigation. There was no difference in forage production with respect to irrigation with either city or blow down water.The results of this experiment indicate that both alfalfa and Atriplex can utilize blow down water as an irrigation water source. From a forage management perspective, however, there is a difference between the crops. Alfalfa responds to water additions with increased forage production, whereas Atriplex does not under these conditions.
Dye‐Sensitized Photooxidation of Bromacil in Water
Authors: Acher A. J. , Saltzman Sarina 
Published: July 2010

AbstractIrradiation of an aerated bromacil (3‐sec‐butyl‐5‐bromo‐6‐methyluracil) aqueous solution (250 ppm), by exposure to direct solar radiation in the presence of different dye‐sensitizers and an appropriate pH, led to complete and fast photodecomposition of the title compound. The photoreaction mixture spotted on TLC showed one major intermediate, 3‐sec‐butyl‐2‐acetyl‐2‐hydroxy‐hydantoin. GLC showed another, minor, intermediate, the 5,5′‐dimer photo‐product of 3‐sec‐butyl‐6‐methyluracil. The most effective dye sensitizers checked were riboflavin (10 ppm) and methylene blue (2 to 5 ppm). Less effective were rose bengal (5 ppm), humic acids (20 ppm), and chlorophyll (20 ppm). The rate of reaction was pH dependent, being faster at alkaline pH and almost negligible in acidic solutions. Under optimal experimental conditions the photooxidation was completed after about 1 hour, and further irradiation resulted in the decomposition of the intermediate products and the formation of unidentified polar products.
Mineralization of Soil‐Incorporated Tomato Solid Waste
Authors: Timm H. , Flocker W. J. , Akesson N. B. , O'Brien M. 
Published: July 2010

AbstractSolid waste from the processing of tomatoes (Lycopersicum esculentum Mill.) consisting primarily of fruit peels and seeds was incorporated into Yolo sandy loam soil, wetted, and incubated at 10, 20, or 30°C for 32 weeks. At 2‐week intervals the soil was analyzed for NO3‐N, PO4‐P, SO4‐S, Cl, total N, organic C, and exchangeable Ca, Mg, K, and Na. Soil pH and electrical conductivity were measured at the beginning of the study and after 32 weeks.With each increment of dried tomato waste applied at rates of 2.5, 5.0, and 10.0% of air‐dry soil, the total organic C and N content of the soil increased. The amount of NO3‐N released from 2.5% rate of waste at 20°C soil temperature was similar to that released from 60 ppm N applied as (NH4)2SO4. Nitrogen released from waste applied at rates of 5.0 and 10.0% air‐dry soil exceeded the level of N usually applied for crop production at about 76 kg N/ha.Significant interactions occurred on NO3‐N release among waste application rates, soil temperatures, and times. At 10°C, there was an increase in NO3‐N released with each increase in waste application. At 20°C, a NO3‐N increase occurred at 2.5 and 5.0% waste application rates, but the increase was less at 10.0 than at 5.0%. At 30°C, a marked reduction of NO3‐N release occurred between 16 and 32 weeks of incubation at all rates of waste application, but was more acute at 10.0% than at lower rates. A similar response, but of lesser magnitude, occurred with release of PO4‐P. Variability in release of NO3‐N and PO4‐P was attributable to the composition of tomato waste and to microbiological activity.Release of SO4‐S was a function of waste loading rate and time. Essentially, all Cl was released within the first week of incubation. An appreciable increase of K, slight increase of Ca, minimal increase of Na, and no change of Mg was found in the soil after 32 weeks of incubation. Although tomato waste is acidic, soil pH decreased only at the highest loading rate after 32 weeks of incubation.
Use of Interfaced Gas Chromatography‐Mass Spectrometry for Detection of Concurrent Mineralization and Denitrification in Soil
Authors: Focht D. D. , Valoras N. , Letey J. 
Published: July 2010

AbstractA method using an interfaced gas chromatograph‐mass spectrometer (GC‐MS) is described for measuring the amount of N2O and N2 derived during denitrification from tagged 15NO3− and from 14NO3−, the latter of which is produced during mineralization of soil organic matter. More mineralization and less denitrification was noted with the respective order related to air‐filled pore content: 10%, 5%, 0 (saturated). Denitrification measured directly from the cumulative emissions of N2O and N2 was considerably underestimated by comparison to measuring denitrification by loss of 15NO3−.
Gas Diffusion as a Factor in Laboratory Incubation Studies on Denitrification
Authors: Letey J. , Jury W. A. , Hadas Aviva , Valoras N. 
Published: July 2010

AbstractLack of nitrogen balance has been frequently observed in laboratory incubation studies on denitrification. Equations were developed for nitrogeneous gas diffusion from incubated soil cores. Calculations using the developed equations indicate that only a fraction of the produced nitrogeneous gases in the soil core diffuses into the incubation container and is measured. The fraction diffusing from the soil core increases as the soil air‐filled porosity increases and the adsorption coefficient between the gas and soil decreases. Under saturated soil conditions, only about 30% of the produced N2O is calculated to be evolved even if adsorption is zero for soil cores 2.5 cm deep. Furthermore, several days are required for produced N2O to evolve from the core after production ceases under saturated conditions. Similar results are calcualted for N2. Thus, nitrogen deficits can be explained by diffusion analysis which eliminates the need for a postulated unknown intermediate compound. In a comparison between calculated and measured N2O evolution, 34% evolution was calculated and 24% was observed for the experimental conditions. The assumptions used in developing the equations lead to a slight overprediction of evolved gases.
A Simple Chamber Technique for Field Measurement of Emissions of Nitrous Oxide from Soils
Authors: Matthias A. D. , Blackmer A. M. , Bremner J. M. 
Published: July 2010

AbstractA simple technique for field measurement of the rate of emission of nitrous oxide (N2O) from soil is described. It involves placement of an insulated cylindrical metal chamber over the soil surface for 20 min and removal of air samples from the chamber at 5‐min intervals for N2O analysis by a sensitive gas chromatographic technique that permits use of the xenon in air as an internal standard. The rate of N2O emission is calculated from the rate of increase in the concentration of N 2O in the air within the chamber. This technique is sensitive and precise, and it has the important advantages that it does not significantly disturb the structure or environment of the soil under study and is not limited in use to sites where electricity or special equipment is available. The chamber described is inexpensive and easy to fabricate, transport, and use, and it is well suited for an extensive program of research on N2O emissions from soils.
Seepage Vs. Terrace Density in Reclaimed Mineland Soil
Authors: Prunty Lyle , Kirkham Don 
Published: July 2010

AbstractThe seepage pattern of infiltrated water through hillside mine overburden materials is of concern because of the possible pollution hazard presented by leachates.Here detailed seepage patterns as found by Gram‐Schmidt analysis are presented for (i) a uniform‐slope topography, (ii) a four‐terrace topography, and (iii) a one‐terrace topography. The aspect ratio (depth/width of the mine pit) of 1:40 and average slope of 5% are the same for each topography and correspond approximately to the aspect ratio and slope of an actual research coal mine. The volume of overburden is also the same for each topography.Saturation of the overburden is assumed. The results, therefore, depict the maximum possible seepage condition for each topography, not average or normally expected conditions. A plot of the total relative seepage rate as a function of the reciprocal of the terrace density (number of terraces) is presented. The total seepage rate for the four‐terrace topography is 10 times greater than for the uniform‐slope topography.
Nitrate Reduction in an Organic Soil‐Water System
Authors: Reddy K. R. , Sacco P. D. , Graetz D. A. 
Published: July 2010

AbstractFlooded organic soil as a treatment system for nitrate‐nitrogen (NO3‐N) removal from agricultural drainage water was evaluated under controlled conditions. Nitrate‐N reduction rates in the flood water (agricultural drainage water) and in the underlying organic soil column were measured as a function of NO3‐N concentration (10, 25, and 50 µg NO3‐N/ml), energy source, and temperature (8, 18, and 28°C). Labeled NO3‐N was used to differentiate between denitrification and NO3‐N reduction to ammonium‐N (NH4‐N) or organic N.Nitrate‐N reduction rates in the soil column incubated at 28°C with no excess flood water were best described by first‐order kinetics with an average rate constant (k) of 0.751 day−1. Flood water NO3‐N removal rates were also described by first‐order kinetics. Nitrate removal rates from low oxygen‐demand flood water (expressed as first‐order rate constants) with an underlying soil column were 0.038, 0.750 day−1 for an incubation temperature of 8, 18, and 28°C, respec‐ 28°C, respectively. In soil columns incubated with high oxygen‐demand flood water, most of the added NO3‐N disappeared before it reached the underlying soil column, with k values of 0.172, 0.292, and 0.790 day−1 for an incubation temperature of 8, 18, and 28°C, respectively. In all treatments, denitrification was the dominant process in the removal of flood water NO3‐N. At low temperature (8°C), a greater portion of 15NO3‐N was reduced to 15NH4‐N and organic N. Most of the immobilized 15NO3‐N appeared as soluble organic N. At 8°C, flood water NO3‐N diffused deeper into the soil column as compared to the flooded soil columns incubated at 28°C.The results obtained in this study indicate that flooded organic soil can function as an effective sink for reducing NO3‐N levels of agricultural drainage waters.
A Study of a Method for Displacing Soil Solution by Centrifuging with an Immiscible Liquid
Authors: Whelan B. R. , Barrow N. J. 
Published: July 2010

AbstractSoil solution can be effectively displaced by centrifuging at 170,000 m s−2 for 30 min with tetrachloroethylene. The solution collects at the top of the dense, organic liquid and can be separated from it by pouring through phase‐separating paper. Suspended material is removed by passing through a membrane filter after which the solution may be analyzed. Tetrachloroethylene was preferred because of its lower toxicity than carbon tetrachloride. The technique is well suited to the study of the movement of water‐soluble pollutants through soil and was used to study phosphate movement below the discharge from a septic tank.
Release Characteristics of Starch Xanthide Herbicide Formulations
Authors: Baur J. R. 
Published: July 2010

AbstractA laboratory procedure was developed using a cucumber (Cucumis sativus ‘Straight Eight’) root‐length bioassay to measure the relative rate of release of herbicides entrapped in various starch xanthide (SX) matrices. SX herbicide formulations placed in vials containing deionized water were decanted periodically and evaluated by bioassay to examine herbicide released into the water. In leaching experiments, fractions of effluent were collected from glass columns containing SX herbicide formulations applied to a glass‐wool pad resting on a sand bed. Collected aqueous fractions were bioassayed. The herbicides examined were salt and ester formulations of picloram (4‐amino‐3,5,6‐trichloropicolinic acid), ester formulations of 2,4‐D [(2,4‐dichlorophenoxy)acetic acid], and salt formulations of dicamba (3,6‐dichloro‐o‐anisic acid). Comparison of salt and ester starch xanthide formulations of picloram indicated that the ester formulation had a release rate three to five times slower than that of the salt formulation. Differences were noted between starch xanthide formulations of salt herbicides designated as fast and slow releases.
Chemical Characterization of Fly Ash Aqueous Systems
Authors: Elseewi Ahmed A. , Page A. L. , Grimm Sabine R. 
Published: July 2010

AbstractAqueous chemistry of fly ash from a western coal‐fired power plant was characterized through measurements of solubility of Ca, Mg, Na, K, OH, CO3, HCO3, Cl, SO4, and B in filtrates from water and electrolyte suspensions of the fly ash obtained at various dilution ratios. Acid titrations of dilute suspensions of the fly ash were also characterized. The study also examined the quantitative relationship between electrical conductivity of the filtrates and their total ionic composition. Relative concentrations of Ca and OH ions in solution and the nature of the acid titration curves suggest that solutions of fly ash are nearly saturated in Ca(OH2). Elements of low to moderate solubility, such as Ca, Mg, SO4, and B, showed greater dissolution as the fly ash suspensions were diluted. Ammonium acetate (NH4OAc‐HOAc) solutions (pH ≅ 5) were found to extract essentially all Ca and S and > 50% of Mg in the fly ash. Substantial fractions of total B in the fly ash were extracted in water (27%) and in an initially acidified (pH = 3) 0.01N NaCl (41.4%). Positive and highly significant correlations were found between total ionic concentration and electrical conductivity of the solution. The slope of the straight‐line relationship was, however, considerably less than that commonly used in describing soil salinity. It is concluded that aqueous systems of fly ash do not represent a true equilibrium and that there is a need to standardize methods of salinity and base analyses in fly ash.
Use of Fermentation Residue from Citric Acid Production as a Soil Amendment
Authors: King Larry D. 
Published: July 2010

AbstractFermentation is used in the production of pharmaceutical chemicals, alcoholic beverages, food supplements, and organic acids. After removal of the desired product, the fermentation residue must be disposed of properly. Since these residues contain organic matter and plant nutrients, they may be useful as soil amendments.Presscake residue from citric acid production was applied to Coastal bermudagrass (Cynodon dactylon L. Pers) which was overseeded with rye (Secale cereale L.) each fall. Presscake supplied appreciable quantities of N, P, Ca, and S. Although all plots received identical rates of supplemental inorganic P and K, single spring applications of presscake at rates up to 76 metric tons/ha (1,500 kg N/ha) were not as effective in increasing bermudagrass yields as were five periodic applications of 112 kg N/ha as NH4NO3. Higher rye yields were obtained with application of 38 metric tons/ha of presscake (375 kg N/ha) than with 180 kg/ha of inorganic N. Residual effect of presscake the year after application produced bermudagrass yields that were about 75% of first year yields.Over a 2‐year period, repeated applications of presscake supplying 224 kg N/ha per application produced identical total yields of bermudagrass and rye as did the same number of applications of 112 kg N/ha from NH4NO3. Presscake rates supplying 224 and 448 kg N/ha per application resulted in an accumulation of excess nitrate in the soil profile. Over the 3‐year study period, presscake N was approximately 50% as efficient as NH4NO3 in increasing forage yields. Supplementing presscake with inorganic P did not increase forage yield.