bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acetylene‐Reduction Assay of Anaerobic Nitrogen Fixation by Sediments of Selected Wisconsin Lakes
Authors: Macgregor A. N. , Keeney D. R. 
Published: July 2010

AbstractSediments from two hardwater and six softwater lakes of varying trophic levels from Wisconsin were incubated under conditions which permitted continued synthesis of methane. Rates of acetylene reduction indicated that, on the average, sediments from hardwater and softwater lakes may fix 37 and 7.7 ng of N, respectively, per gram (dry weight) per day. The rate of acetylene reduction diminished in the presence of nitrogenase inhibitors.
A Study of Factors Influencing the Nitrogen and Phosphorus Contents of Nebraska Waters
Authors: Muir John , Seim Edwin C. , Olson R. A. 
Published: July 2010

AbstractThe purpose of this investigation was to determine magnitude and sources of nutrient N and P in Nebraska waters. Correlation studies reveal little relation between N and P concentrations of the water and agricultural use of fertilizers. Nutrient levels in the water are governed more by human and livestock densities and intensity of irrigation development than by agronomic production factors. Only at sites of intensive irrigation development on very sandy soils and with irrigation of valley positions of shallow water table has fertilizer N contributed substantially to a reduction in ground‐water quality.Nutrient concentrations in streams fluctuate widely with (i) varied time and rate of organic waste intrusions and subsequent biological assimilation and (ii) major runoff events. Reservoirs on streams also have a major modifying action in reducing sediment and fertility load. The observed higher N content of streams during periods of peak flow can be attributed partially to the high N content of precipitation and its direct runoff into streams during periods of high rainfall intensity.
Nitrogen Transformations During Subsurface Disposal of Septic Tank Effluent in Sands: I. Soil Transformations
Authors: Walker W. G. , Bouma J. , Keeney D. R. , Magdoff F. R. 
Published: July 2010

AbstractSoil physical and chemical studies of five subsurface septic tank seepage beds were conducted to determine the biochemical transformations of N and thereby its potential for ground‐water pollution. Effluent was found to be ponded in all the seepage beds examined due to the presence of an impeding layer, a “crust”, at the boundary between the gravel bed and adjacent soil. The crust reduced infiltration rates approximately from 500 to 8 cm/day. Soil atmospheric composition 5 cm below the crust averaged 19.6% O2 and 0.66% CO2. Nitrogen in the septic tank effluent occurred as NH4‐N (80%) and organic N (20%) with virtually no NO3‐N. Organic‐N was largely concentrated in the crust zone. Nitrification of NH4‐N to NO3‐N was essentially complete and commenced in the unsaturated subcrust soil within about 2 cm of the crust. Nitrification did not occur and NH4‐N was absorbed by the soil below a seepage bed that was submerged in the ground water.
The Persistence and Movement of Picloram and 2,4,5‐T in Soils
Authors: Lutz J. F. , Byers G. E. , Sheets T. J. 
Published: July 2010

AbstractThe movement and persistence of picloram (4‐amino‐3,5,6‐trichloropicolinic acid) and 2,4,5‐T (2,4,5‐trichlorophenoxyacetic acid) were studied on a western North Carolina watershed on which extensive agronomic, hydrologic, and climatic data had been accumulated over a period of 18 years. Picloram was more persistent than 2,4,5‐T; approximately 60% of the picloram and 90% of the 2,4,5‐T disappeared in 15 days. There was some penetration into the soil, but a very high percentage of the total amount present at the different sampling periods was in the 0‐ to 7.5‐cm layer. Doubling the application rate (4.48 vs. 2.24 kg/ha) resulted in a twofold increase in the amount of herbicide recovered at each sampling period. Very little downslope movement of either herbicide occurred even though the average slope on the plots was approximately 27%. Practically no herbicide was found more than 0.3 m, and none beyond 1.2 m, downslope. More picloram than 2,4,5‐T moved.
Effect of Soil Treatments on Losses of Two Chloronitrobenzene Fungicides
Authors: Wang C. H. , Broadbent F. E. 
Published: July 2010

AbstractPCNB (pentachloronitrobcnzene) and DCNA (2,6‐dichloro‐4‐nitroaniline) are widely used as soil fungicides and have been found to be quite persistent in soils at field moisture capacity. Laboratory experiments were conducted to determine the effects of flooding, sterilization, addition of organic matter, atmosphere composition, free or combined oxygen, and soil temperature on pesticide decomposition.Known quantities of fungicides were added to three different California soils and analyzed for residual concentrations after incubation under controlled conditions. Samples were extracted with acetone and analyzed by gas‐liquid chromatographic analysis (GLC).Both fungicides were rapidly lost from soils made anaerobic by flooding or exclusion of oxygen. Losses were mainly due to microbial degradation. Loss rates were inversely related to organic matter content. Pentachloroaniline and possibly pentachlorothioanisole were found to be degradation products of PCNB.Organic amendments increased the rate of fungicide loss under flooded conditions, but not at field capacity, Degradation in flooded soils was retarded by free oxygen or combined oxygen in nitrate form. Rates of loss varied directly with temperature from 15 to 35C.
Soil Profile Conditions of Cattle Feedlots
Authors: Mielke Lloyd N. , Swanson Norris P. , McCalla Thomas M. 
Published: July 2010

AbstractCharacterization of the conditions that exist in the feedlot surface and soil profile is important to evaluation of the potentials for soil and water pollution. Cattle action and management activities create a dynamic condition in the feedlot. The organic matter surface causes physical and biochemical changes in the soil that are unlike natural or cultivated soils. The feedlot profile can be described as three layers: the organic matter, the interface, and the underlying soil. Measurable characteristics include bulk density, infiltration, and content of organic matter, water, and nitrate‐N. Generally, the surface 15.2‐cm depth of feedlot soils is compacted and has a high bulk density. Infiltration into the feedlot surface layers is essentially zero. There is no transpiration, and the soilwater content is more uniform through the profile than on cropped land.
Effects of Treated Municipal Wastewater and Commercial Fertilizer on Growth, Fiber, Acid‐Soluble Nucleotides, Protein, and Amino Acid Content in Wheat Hay
Authors: Day A. D. , Rahman Abdul , Katterman F. R. H. , Jensen Varon 
Published: July 2010

AbstractExperiments were conducted at Tucson, Arizona to study effects of treated municipal wastewater on growth, total fiber, acid‐soluble nucleotides, total protein, and amino acids in hay from wheat (Triticum aestivum L.). Plant heights and number of culms per plant for wheat grown with wastewater were similar to plant heights and number of culms per plant when wheat was produced with well water and suggested amounts of N, P, and K and when it was grown with well water plus N, P, and K in amounts equal to those in wastewater. Wheat plants grown with wastewater had culms with a larger diameter and a higher total fiber content than did plants produced with the other treatments. Highest hay yields were obtained when wheat was grown with wastewater, followed by hay produced with well water plus N, P, and K in amounts present in wastewater, and hay grown with well water plus suggested amounts of N,P, and K, in decreasing order. Wheat plants from the three irrigation and fertilizer treatments contained similar amounts of acid‐soluble nucleotides.Wheat grown with well water plus N, P, and K in amounts equal to those in wastewater and hay produced with wastewater alone contained similar amounts of total protein, and more protein than did hay grown With well water plus suggested amounts of N, P, and K. Wheat utilized the N in wastewater more efficiently than it used the N in well water plus N, P, and K equal to wastewater. The amino acids alanine, glycine, phenylalanine, and tyrosine were present in higher concentrations in wheat hay grown with wastewater then in hay produced with the other two treatments. Hay grown with the three irrigation and fertilizer treatments contained similar amounts of leucine, proline, and threonine. When wheat hay was grown with wastewater, none of the observed amino acids were decreased below the levels at which they were present in hay produced with suggested cultural practices. Treated municipal wastewater was an effective source of irrigation water and plant nutrients for the production of high quality hay from wheat in the Southwest.
Nutrients in Subsurface and Runoff Waters of the Holland Marsh, Ontario
Authors: Nicholls Kenneth H. , MacCrimmon Hugh R. 
Published: July 2010

AbstractConcurrent with a limnological investigation of the Holland River, Ontario, an attempt was made to determine relative contributions to the river of nutrients (NO3−‐N, NO2−‐N, total and soluble reactive phosphorus) and total electrolyte (specific conductance) in surface runoff water pumped from both cultivated and uncultivated plots of muck soil within the Holland Marsh. In addition, subsurface water from piezometers installed in both cultivated and uncultivated marsh soil was analyzed throughout the growing season to determine fundamental differences in water chemistry and the extent of leaching of N and P under both cultivated and uncultivated conditions.The present study has shown that the time and amount of rainfall was important in determining nitrate‐N and to a lesser extent, soluble reactive P concentrations in subsurface water beneath the cultivated plot but not beneath the uncultivated plot. The mean concentration (0.75 mg/liter) of inorganic N (NO3−‐N + NO2−‐N + NH3‐N) in subsurface water under the cultivated plot was about 10 times higher than under uncultivated marsh during the growing season.The combined effects of fertilization, drainage and hence oxidizing and nitrifying conditions yielded 4 to 5 times more P (1.56 kg P/ha) and 40 to 50 times more nitrate‐N (4.1 kg N/ha) runoff water from the cultivated over the uncultivated plot. The significance of the loading from the cultivated plot is that the nutrients are lost to the river during a 5 to 6 week pumping period during the spring and that more than 90% of the total P in runoff is in the soluble reactive form (as opposed to only 45% from the uncultivated marsh) and is, therefore, readily available for algae and aquatic plant growth in the lower Holland River and Cook Bay of Lake Simcoe.
An Ecological Interpretation for the Small Mounds in Landscapes of Eastern Oklahoma
Authors: Allgood F. P. , Gray Fenton 
Published: July 2010

AbstractMany hypotheses suggesting the origin of small, oval, slightly domed mounds have been proclaimed but none widely accepted. Mounds typical to eastern Oklahoma were studied by relating climatic influences, patterns, distributions, sizes, shapes, relief, vegetation, and biological evidences to morphological characteristics of soil pedons within the mounds and associated landscape. Laboratory measurements included particle‐size distribution, bulk density, extractable cations, and organic matter extractions.Mounded soils occur in the greater than 102‐cm rainfall belt on landscapes having occasional perched water tables. The pattern of the mounds which consists of sizes, shapes, and distribution is similar in these landscapes.The average yield per hectare of forage was 4,997 kg on the mounds as compared to 3,227 kg in the intermound areas.Evidence of biological activities is highly concentrated in mounds, increasing in the soil horizons where mottlings decrease due to decreasing wetness. Even though soil textures are similar, bulk densities show soils to be more porous in the mound than in the associated intermounds. The surface horizons of the mound soils are apparently continually “fluffed” by organisms and protected by a flourishing growth of vegetation sustained by the high productivity of these soils.Mounds are concluded to be natural phenomena resulting from a soil environmental equilibrium, a condition created by the influence of a complex ecological association of a protective cover of grasses, and organisms of the landscape assembling in selected elevated soils to escape seasonal wet soil conditions.
Nitrate‐Nitrogen and Phosphorus Contents of Streams Draining Small Agricultural Watersheds in Kentucky
Authors: Thomas Grant W. , Crutchfield James D. 
Published: July 2010

AbstractEight streams draining agricultural watersheds in the important physiographic regions of Kentucky were sampled monthly from January through May in both 1971 and 1972. The objective of the study was to determine the effects of land use and geology on the concentrations of nitrate‐N and P in the stream water. The land use ranged from almost completely forested to mostly cultivated. There was not a good relationship between nitrate‐N and land use. Nitrate‐N varied from 6 ppm to zero, with the highest value being found in a stream draining a watershed which was 98% in bluegrass pasture. The P concentrations in the stream water were closely related to local geology and not to land use. A comparison between the 1921 data of McHargue and Peter and 1971–72 data from the same geological areas showed very little change in mean nitrate‐N or P concentrations.
Land Disposal of Waste Gases: I. Flow Analysis of Gas Injection Systems
Authors: Miyamoto S. , Warrick A. W. , Bohn H. L. 
Published: July 2010

AbstractThe steady‐state flow of gases in soils is analyzed mathematically from the view of land disposal of waste gases. Gas injection systems considered include ditches, buried pipes, and wells. The systems are compared on the basis of two criteria (i) how effectively the power is used (power efficiency), and (ii) how uniformly is the gas distributed through soils (uniformity). Often the two criteria are in conflict, and systems giving a high power efficiency result in low uniformity. Gas injection by buried porous pipe appears advantageous over ditch or well systems.
Nitrate Occurrence in Some Soils With and Without Natric Horizons
Authors: Gentzsch E. P. , Runge E. C. A. , Peck T. R. 
Published: July 2010

AbstractThe effect of animal activity and fertilizer practices on the nitrate content in soils with and without natric horizons was investigated in a field study in southern Illinois where excessive ground‐water nitrate levels were reported. Most of these soils are poorly drained. A comparison is provided by the poorly and well‐drained soils without natric horizons observed in central Illinois. The results indicate that soils with natric horizons at shallow depths or dark‐colored poorly drained soils had low levels of nitrate in the profile; all other soils showing increased nitrate levels in the entire profile or below the root zone were related to the amount of fertilizer used or the amount of animal activity. Animal operations resulted in larger amounts of nitrate in similar soil profiles than did fertilizer applications. Increased nitrate content of the ground water, sampled in Washington County, similarly was related to fertilizer practices and animal activity in all soils, except under soils with natric horizons at shallow depths.
Predicting Pesticide Runoff from Agricultural Land: A Conceptual Model
Authors: Bailey G. W. , Swank R. R. , Nicholson H. P. 
Published: July 2010

AbstractA mathematical model of the dynamic, single‐rainfall‐event type is being developed to describe quantitatively pesticide runoff as a function of pesticide and soil properties, agricultural practices, watershed characteristics, and climatic factors. From the model, guidelines governing pesticide use will be derived to prevent or minimize water pollution resulting from runoff from agricultural land.The model described is based on a state‐of‐the‐art approach. Pesticide transport is “piggybacked” on existing hydrologic and soil‐loss models. Both direct mass‐balance and areal averaging‐statistical simulation approaches are being considered for the basic runoff and sediment transport descriptors. The conceptual structure of the overall model includes (i) source term effects (parameters that determine the initial concentration of pesticide available for runoff), e.g., pesticide formulation, physical‐chemical properties, and initial spatial distribution; (ii) loss of pesticide from the surface zone between rainfall events by various attenuation processes (volatilization, microbial, chemical, and photochemical degradation, and organism uptake); and (iii) loss of pesticide from the soil surface during runoff‐producing rainfall events because of mass transfer from soil surface into the moving runoff film and pickup of sediment containing pesticide particulates.The minimum output requirements for the model are the prediction of runoff rate and sediment loading plus the corresponding water and sediment phase pesticide concentrations at a designated boundary (normally a watershed confluence or drainage channel) as a function of time during a runoff event. This output is to be based upon input consisting of the type, formulation, and rate and method of application of the pesticide, and the areal extent, topography, type of soil, cropping characteristic, and rainfall characteristics of the watershed or basin. The model will internally generate and store the appropriate boundary condition changes required to predict sequential rainfall response using between‐event meteorological data as input. In addition, the model structure is to be suitable for scaleup for application to areas approaching basin size parametrically, by use of transfer functions, or by use of executive and routing subroutine additions.
Short‐Term Kinetic Studies on the Inhibition of Photosynthesis by Sulfur Dioxide
Authors: Sij J. W. , Swanson C. A. 
Published: July 2010

AbstractUtilizing infrared gas analysis techniques, the effect of a 1‐hour exposure to 1, 3, or 5 ppm SO2 on apparent photosynthesis in the primary leaf of Pinto bean (Phaseolus vulgaris L. cv. Pinto) was studied as a function of three leaf ages. Generally, photosynthesis was reduced about 15, 70, and 90% for the respective concentrations regardless of leaf age. The initial inhibition of photosynthesis was not due to stomatal closure. Inhibition kinetics observed at 1 and 3 ppm SO2 for Pinto bean (Phaseolus vulgaris L.) were compared with those of SO2‐tolerant corn (Zea mays L.). At 1 ppm SO2, the kinetics of inhibition of photosynthesis for the two species were similar; however, at 3 ppm SO2, apparent photosynthesis in corn was inhibited less than in Pinto bean and recovered to a higher level following removal of SO2.
Nitrogen Release Associated with the Decrease in Soil Organic Matter in Newly Cultivated Soils
Authors: Reinhorn Tova , Avnimelech Yoram 
Published: July 2010

AbstractA marked decrease in soil organic matter occurs during the first years following the cultivation of virgin soils. The purpose of this work is to study the release of nitrogen, associated with this process. Technically, this was achieved by a series of comparisons between cultivated plots and adjacent virgin soils.It was found, that in the area under study, the decrease in soil organic nitrogen was rather fast and a steady state was apparently achieved during the first few years. The amount of nitrogen released during this process are up to 9 tons of N/ha.The amount of nitrogen released is linearily related to the initial organic nitrogen content of the soil.In regions where large areas of newly cultivated fields are found, this process may be a major factor responsible for nitrate enrichment of the drainage water.
Potential Interactions of Aldicarb and Its Metabolites on Nontarget Organisms in the Environment
Authors: Spurr Harvey W. , Sousa A. A. 
Published: July 2010

AbstractLaboratory evaluations were conducted with aldicarb pesticide and its metabolic degradation products to determine their effects on selected plants, insects and microorganisms. Except for aldicarb, aldicarb sulfoxide and aldicarb sulfone, which were toxic to insects and nematodes, none of the aldicarb metabolites were significantly toxic to the test organisms studied. The metabolic utilization of aldicarb by certain microorganisms should increase the rate of detoxification and result in the rapid dissipation of residues. The results imply that the growth of soil microorganisms should not be effected adversely by the concentrations of aldicarb applied for pest control.
Volcanic Air Pollution: Deleterious Effects on Tomatoes
Authors: Kratky B. A. , Fukunaga E. T. , Hylin J. W. , Nakano R. T. 
Published: July 2010

AbstractFrom the winter of 1969–70 to the summer of 1973, severe yield and quality reductions occurred on field grown tomatoes (Lycopersicum esculentum Mill) in the Kona district on the Island of Hawaii. Symptoms of this mysterious disease included blossom drop, poor fruit set, hollow, small, and almost seedless fruits, and a less luxuriant appearance. A definite atmospheric haze appeared at this time, and was apparently caused by fumes from active and degassing vents located 75 km away and associated with Kilauea Volcano since the volcanic eruption period coincided with the appearance of the haze. Tomato plants under plastic rainshelters grew normally. Since rainwater was suspected of causing the symptoms, it was analyzed and found to be acidic (pH 4.0) and to contain appreciable quantities of Cl− and SO42‐ plus 27 detectable organic compounds in the ppb range. When tomato leaf discs were immersed in rainwater samples, more Ca, Mg, and K were leached from these acidic samples than from less acidic rainwater samples and the distilled water controls. In a pollen germination medium containing rainwater, pollen germination and tube lengths decreased as the pH of the rainwater decreased. However, since increasing the pH of the acidic Kona rainwater with NaOH did not increase pollen germination, factors other than pH are suspected to cause poor pollen germination. The pH of rainwater samples from a single heavy rainfall were less acidic than from cumulative samples of lighter rainfalls.
Fungal Populations in the Rumen Associated with Fescue Toxicosis
Authors: Futrell M. C. , Farnell D. R. , Poe W. E. , Watson V. H. , Coats R. E. 
Published: July 2010

AbstractThe fungal population of the rumen of fistulated steers grazing fescue (Festuca arundinacea Schreb.) was studied in 1972 and 1973. Aspergillus terreus Thom was found in 1972 in the rumen shortly after the steers were placed on fescue pastures. Populations of this fungus increased in 6 weeks from 0 to over 1000 propagules per gram of rumen fluid. One month after the steers were placed on this pasture, fescue toxicosis occurred. Aspergillus terreus was not found in the rumen of fistulated steers grazing fescue in 1973, and no fescue toxicosis developed in these steers. Fusarium tricinctum (Cda.) Sacc. and other fungi were found in both years but not in high populations as was A. terreus. In 1972 A. terreus was isolated from fescue in four different counties in Mississippi where fescue toxicosis was found. In 1973 no A. terreus was isolated from these same fields and no fescue toxicosis occurred. Higher numbers of propagules of A. terreus were found in 1972 in fescue growing on low nitrogen. Two out of three fistulated steers artifically dosed with A. terreus and grazing fescue in 1973 developed swollen and tender feet, symptoms of fescue toxicosis. Aspergillus terreus remained viable through the entire digestive tract of these three steers in 1973.