bluuebunny/crossref_metadata_2025_split huggingface dataset:
Movement of Toxaphene and Fluometuron Through Dunbar Soil to Underlying Ground Water
Authors: LaFleur K. S. , Wojeck G. A. , McCaskill W. R. 
Published: July 2010

AbstractOne hundred kilograms per hectare of toxaphene (octachlorocamphene) and 40 kg/ha of fluometuron (3‐[m‐trifluoromethylphenyl‐1,1‐dimethylurea) were applied to Dunbar topsoil in a field plot in the South Carolina Coastal Plain. Loss of both pesticides from the topsoil and accumulation in underlying ground water were monitored for 1 year.Toxaphene loss from topsoil seemed to occur in two stages. The second (major) stage was crudely linear on a log residue vs. log time plot. Half‐residence time in the topsoil was about 100 days.Fluometuron loss from topsoil occurred in one continuous episode that was crudely linear on a log residue vs. linear time plot. Half‐residence time in the topsoil was about 120 days.Toxaphene and fluometuron were found in underlying ground water within 2 months after they were applied to the topsoil. Both pesticides persisted in ground water during the entire year. Overall, concentrations gradually decreased with time.
Nitrogen Transformations During Subsurface Disposal of Septic Tank Effluent in Sands: II. Ground Water Quality
Authors: Walker W. G. , Bouma J. , Keeney D. R. , Olcott P. G. 
Published: July 2010

AbstractGround water observation wells were installed in the immediate vicinity of four septic tank effluent soil disposal systems. Potentiometric maps were constructed from measurements of the groundwater level at each site to establish the direction of movement. Ground‐water samples were pumped from each well to establish patterns of N enrichment in the ground water around the seepage beds and to evaluate the performance of these disposal systems in sands in terms of N removal. Soil disposal systems of septic tank effluent in sands were found to add significant quantities of nitrate (NO3‐N) , formed by nitrification of NH4‐N , the dominant N form in the effluent, to underlying ground water. The data obtained suggest that in sands, the only active mechanism of lowering the NO3‐N content is by dilution with uncontaminated ground water. Relatively large areas of 0.2 ha (0.5 acre) down gradient were needed the studied systems before concentrations in the top layer of the ground water were lower than 10 mg/liter. The average N‐input per person was 8 kg (10 Ib) per year. Essentially complete nitrification in the soil results in addition of approximately 33 kg NO3‐N (73 lb) to the ground water per year for an average family of four.
Mortality Factors Affecting Cotton Insects: I. Resistance of Smooth and Nectariless Characters in Acala Cottons to Heliothis zea, Pectinophora gossypiella, and Trichoplusia ni
Authors: Davis D. D. , Ellington J. J. , Brown J. C. 
Published: July 2010

AbstractHost plant resistance to insects has become a major breeding objective in cotton (Gossypium hirsutum L.), since significant increases in resistance may result simultaneously in yield increases and reduced usage of insecticides. Nectariless ‘Acala’ cotton strains with reduced pubescence are being developed in an attempt to gain significant host plant resistance against harmful Lepidoptera. Extensive studies were undertaken to evaluate the first‐order effects that the nectariless and reduced pubescence plant modifications would have upon oviposition behavior of three key insects. Cage trials with pink bollworms (Pectinophora gossypiella) have been difficult to manage and results are inconclusive. It was found that cabbage loopers (Trichoplusia ni) showed a slight increase in oviposition on nectariless cottons with reduced pubescence. The increase was so small as to be of doubtful economic importance. Paired isolation cage studies conducted over a 4‐year period showed that similar numbers of Heliothis zea moths laid only 45% as many eggs on nectariless Acala strains as on their normally hairy, nectaried companion lines. There was a disturbing reversal in form in certain tests, due to variables not yet clearly understood. However, there was a clear trend indicating that the suppression of oviposition is greatest when environmental conditions are most favorable for a bollworm epidemic. This large reduction of egg numbers at peak oviposition is the strongest confirmation of the value of developing nectariless cottons to minimize Heliothis damage.
Suppression of Oxidant Injury by Benomyl: Effects on Yields of Bean Cultivars in the Field
Authors: Manning W. J. , Feder W. A. , Vardaro P. M. 
Published: July 2010

AbstractBean (Phaseolus vulgaris L.) cultivars ‘Tempo’ and ‘Pinto III’, which are sensitive to oxidant injury, and cultivar ‘Tenderwhite’, which is resistant to oxidant injury, were grown in field plots. Some plants were sprayed once a week with the fungicide benomyl at 2.4 g/liter to suppress oxidant injury and allow for yield comparisons. Benomyl suppressed 75–80% of the oxidant injury on Pinto and Tempo, but did not suppress slight injury on Tenderwhite. Nonsprayed plants of Pinto and Tempo, with extensive oxidant injury, matured faster and set fruit earlier than did sprayed plants with slight visible injury. Initial fruit set was somewhat greater on nonsprayed plants of resistant Tenderwhite. Significant differences between sprayed and nonsprayed plants for total yields and fresh and dry weights of plant remains at harvest were observed only with Tempo, which was the most sensitive to oxidant injury.
Malathion Degradation by an Arthrobacter Species
Authors: Walker W. W. , Stojanovic B. J. 
Published: July 2010

AbstractThe dissipation of malathion from agricultural soils has been shown to involve both chemical and biological mechanisms, with biodegradation being of substantial magnitude. This investigation was conducted to (i) isolate from soil by enrichment techniques bacterium or several bacteria capable of readily metabolizing malathion, and (ii) isolate and identify the malathion metabolites resulting from this microbial degradation. Of 18 soil bacteria examined, 5 were capable of utilizing the malathion molecule with degradation of added insecticide ranging from 47 to 95%. The most efficient malathion utilizer, an Arthrobacter species, degraded malathion to malathion half‐ester, malathion dicarboxylic acid, potassium dimethyl phosphorothioate, potassium dimethyl phosphorodithioate, and one other unidentified metabolite. O‐desmethyl malathion, potassium salt, was also produced, but the mechanism involved was nonbiological in nature. Malathion dissipation was monitored by electron‐capture gas‐liquid chromatography, and metabolites were identified by thin‐layer chromatography and infrared spectroscopy.
Effect of Cattle Feedlot Volatiles, Aliphatic Amines, on Chlorella ellipsoidea Growth
Authors: Mosier A. R. 
Published: July 2010

AbstractAn appreciable portion of the tons of basic N‐compounds, volatilized from cattle feedyards each year, are aliphatic amines. The effect of these nonammoniacal organic bases upon organisms in surface waters located near cattle feedlots is unknown. This study was designed to determine the effect of the aliphatic amines identified as feedlot volatiles, upon a common fresh water alga, Chlorella ellipsoidea, in laboratory pure culture studies. Individual aliphatic amines caused a 50% reduction in population growth of C. ellipsoidea at concentrations ranging from 1.2 to 143 ppm amine‐N. Primary amines were more inhibitory than iso‐, sec‐, and dialkylamines. The algae did not utilize amine‐N for growth with or withour an added N source.
Relative Sensitivity of Soybean Genotypes to Ozone and Sulfur Dioxide
Authors: Miller V. L. , Howell R. K. , Caldwell B. E. 
Published: July 2010

AbstractTwenty‐one soybean genotypes [Glycine max (L.) Merr.] were evaluated for resistance to ozone and 19 genotypes for sulfur dioxide in the greenhouse and growth chamber. ‘PI 157474’ was most resistant to ozone, but ranked 14 in resistance to sulfur dioxide. ‘York’ was most resistant to sulfur dioxide and ranked fourth when subjected to ozone. ‘Peking’ was least resistant to both phytotoxicants. Experimental conditions necessary to investigate inheritance of resistance to ozone were determined by fumigating soybean plants equally spaced in a growth chamber. Relative sensitivity of each of the parents at several stages of foliar development must be established before classifying the progeny.
Surface Runoff Losses of Soluble Nitrogen and Phosphorus Under Two Systems of Soil Management
Authors: Klausner S. D. , Zwerman P. J. , Ellis D. F. 
Published: July 2010

AbstractEvaluation of surface runoff losses of soluble nitrogen (NO3‐N, NH4‐N) and phosphorus (inorganic P) was initiated due to recent concerns about the discharge of plant nutrients from the agricultural sector. The annual loss of these two elements from field plots, as derived from natural rainfall, was determined. The influence of a crop rotation, soil management practice and fertilizer rates of the previous 15 years was studied. Corn (Zea mays L.), beans (Phaseolus vulgaris L.), and wheat (Triticum aestivum L.) were combined factorially with two rates of fertilization (high and moderate) and two soil management practices (good vs. poor). Well‐managed soils produced the least surface runoff losses of N and P. Ammoniacial N losses were not significantly associated with crop, fertility level, or management practice. Values ranged from 0.14 to 1.30 kg/ha per year. Surface losses of nitrate N and inorganic P were directly influenced by crop, fertility level, and soil management. These losses ranged from 0.39–29.23 and 0.04–0.49 kg/ha per year, respectively. Heavy fall fertilization of N on wheat prior to intense rains on poorly managed soils produced the largest loss of nitrate N. Except for heavy fall fertilization of N on poorly managed soils, the total yearly accumulative N discharge in surface runoff did not exceed the amount delivered in rainfall as measured during a 10‐month period. Phosphorus losses exceeded that amount contained in rainfall.
Land Disposal of Waste Gases: II. Gas Flow from Buried Pipes
Authors: Warrick A. W. , Miyamoto S. 
Published: July 2010

AbstractSteady‐state compressible gas flow in homogeneous soils from buried porous pipes is analyzed for the purpose of developing land disposal systems for waste gases. Two different cases are considered (i) the ground surface is partially covered by an impermeable barrier, and (ii) the surface is corrugated with alternating ridges and valleys with the pipe buried under the ridges. The partial surface barrier provides a more uniform gas flow in soils than without it, but leads to an increase in the power required to inject gas at a given rate, especially when the pipe spacings are wide. Compared to an open level surface, the corrugated geometry results in a better gas distribution with little increase in power required and is probably the better system for injecting waste gas in nonstratified soils.
Occurrence of 2,4,5‐T and Picloram in Surface Runoff Water in the Blacklands of Texas
Authors: Bovey R. W. , Burnett Earl , Richardson Clarence , Merkle M. G. , Baur J. R. , Knisel W. G. 
Published: July 2010

AbstractThis investigation was conducted to determine the concentration of 2,4,5‐T [(2,4,5‐trichlorophenoxy)acetic acid)] and picloram (4‐amino‐3,5,6‐trichloropicolinic acid) in surface runoff water that may move from herbicide sprayed pastures and rangeland to untreated areas as a result of each major rainfall following treatment.A 1:1 mixture of the triethylamine salts of 2,4,5‐T + picloram was sprayed 5 times at 1.12 kg/ha every 6 months on a native‐grass pasture watershed. Soil, grasses and runoff water were analyzed periodically following herbicide treatment. Herbicide content in the Houston Black clay from May 1970 to May 1972 remained low (0 to 238 ppb). Herbicide content on grass was high (50 to 70 ppm) immediately after treatment, but degraded rapidly thereafter. Plant “washoff” was the main source of herbicide detected in runoff water. Concentration of herbicide was moderately high (400 to 800 ppb) if heavy rainfall occurred immediately after treatment, but low (<5 ppb) if major storms occurred 1 month or longer after treatment. No damage occurred to cotton (Gossypium hirsutum L.) or sorghum (Sorghum bicolor (L.) Moench) from either spray drift or subsequent runoff water in fields adjacent and below several herbicide‐treated watersheds.
Nitrate Concentrations in Deep Soil Cores as Related to Soil Profile Characteristics
Authors: Lund L. J. , Adriano D. C. , Pratt P. F. 
Published: July 2010

AbstractFifteen sites within a 30‐ha study area were studied to determine the effect of soil profile characteristics on nitrate concentrations (NO3−‐N) below the root zone. The N input, crop removal of N, and water management were similar for all sites during the previous 6 years.The soils of the study area were primarily Alfisols and Entisols of fine‐loamy, coarse‐loamy, sandy and sandy over loamy families. Nitrate concentrations varied between sites and with depth. The average nitrate concentrations below the root zone ranged from 4.9 to 15.3 µg/g when expressed on an oven‐dry soil basis.Profile characteristics were significantly correlated with the average nitrate concentrations below the root zone. A regression equation relating average nitrate concentration in the 1.8–8 m depth to control section characteristics explained 86% of the variability of the NO3−‐N concentration and was highly significant. Hence, to minimize ground‐water pollution, soil profile characteristics should be considered in selecting land for high N input whether by fertilization or waste disposal.
Losses of Inorganic Nitrogen from Aquatic Systems
Authors: Bouldin David R. , Johnson Robert L. , Burda Charles , Kao Chun‐Wei 
Published: July 2010

AbstractAdditions of NH4NO3 were made to 6 ponds near Ithaca, New York, and the loss of NH4+ and NO3− from solution was followed over a 2‐month period with the objective of investigating the mechanisms and magnitude of losses of inorganic nitrogen. In the ponds which were used, biological immobilization of nitrogen was small in relation to the total amount added.Losses of NH4+ ranged from 2 to 38% per day in different ponds. An NH3 volatilization model based on concentration of ammonium N and water pH was consistent with the experimental data, and the results were in agreement with the hypothesis that the major avenue of NH4+ loss was by NH3 volatilization across the air‐water interface.Nitrate losses ranged from 7 to 15% per day in the different ponds. The results were consistent with the hypothesis that nitrate loss was primarily by denitrification in the bottom sediments.Models for loss of both ions were derived which have general application to other bodies of water. Although the experimental data were obtained in ponds which are not necessarily typical of other bodies of water, the models are based on general chemical and physical parameters which are not peculiar to the ponds studied (that is, depth of water, water pH, and a reduced zone of sediments underlying a thin oxidized layer of sediment). The results suggest that NH3 volatilization and denitrification are mechanisms which may account for appreciable losses of N from many bodies of water.
Volatility of Atrazine from Plant, Soil, and Glass Surfaces
Authors: Burt Gordon W. 
Published: July 2010

AbstractVolatility of atrazine (2‐chloro‐4‐(ethylamino)‐6‐isopropylamino‐s‐triazine) from glass, plant, and soil surfaces was determined by passing air above the experimental material through Florisil3 columns. Atrazine volatility was determined by counting the 14C‐atrazine present in the column eluate and that remaining on the treated surfaces.Volatility from 125‐ml glass erlenmeyer flasks was influenced most by the amount of atrazine present. At 40C with an air velocity of 2 liters/min 70% of the applied atrazine was recovered from the florisil columns in 2 days when 1 µg of atrazine was applied; whereas, 10% was recovered when 1,000 µg was applied. Temperature, air velocity, and atrazine purity also affected atrazine volatility. Volatility was 25% greater at 40 than at 20C at an air velocity of 2 liters/min. An increase in air velocity increased atrazine volatility more at 20C than at 40C. Approximately 10% more atrazine was lost from a commercially formulated material than from a technically pure material. Dried plant material lost 18–27% of the applied atrazine in 2 days at 40C. Atrazine (37mM) was also applied in 2 µliter droplets to intact Cirsium arvense (Canada thistle) leaves. Two days after treatment 50% of the activity was located in the Florisil column. Volatility of atrazine from the soil was less than 10% in 2 days at 40C. It was concluded that atrazine volatility is a major factor for atrazine dissipation when applied to foliage but not when applied to the soil.
Volatility of DDT Residues in Soil as Affected by Flooding and Organic Matter Applications
Authors: Spencer W. F. , Cliath M. M. , Farmer W. J. , Shepherd R. A. 
Published: July 2010

AbstractIn a field experiment, flooding with and without organic matter additions was evaluated as a means of preferentially degrading residual DDT and thereby changing the ratio of the various isomers and metabolites volatilizing from the soil surface. Flooding for a 7‐week period, either with or without manure or alfalfa (Medicago sativa L.) meal applications, effectively degraded DDT isomers, primarily to the respective DDD isomers, but had little effect on DDE isomers. Both flooding and organic matter decreased the volatility even when soil concentrations were not affected, apparently because of increased adsorption of the compounds by added organic matter or by organic matter in the soil altered by flooding. The data indicate that minor changes in vapor concentration ratios were accomplished by flooding and organic matter additions, but regardless of treatment, the major constituent evaporating from the surface was p,p′‐DDE. To accomplish significant changes in volatilization patterns, it will be necessary to use such management practices before a major part of the DDT has been degraded to DDE. However, flooding and organic matter treatments will ultimately decrease the total quantity of DDE volatilizing from residual DDT in soils over long‐time periods because of their effectiveness in degrading DDT to DDD instead of DDE.
The Phosphorus Status of Eutrophic Lake Sediments as Related to Changes in Limnological Conditions—Total, Inorganic, and Organic Phosphorus
Authors: Wildung R. E. , Schmidt R. L. , Gahler A. R. 
Published: July 2010

AbstractTo aid in the assessment of the role of sediments as a source of P to lake waters and to provide insight into the factors which may influence sediment P release, changes with time in the P status of noncalcareous sediments of a eutrophic lake were related to changes in sediment C and N, surface water composition, pH, temperature, and phytoplankton growth.The nature and extent of changes in sediment P status and the relationship of these changes to limnological conditions differed with location in the lake. Changes in sediment composition were greatest in a bay which received agricultural runoff in the early spring. This additional supply of nutrients apparently provided the initial impetus for increased surface water biological activity in the spring relative to other locations as reflected in increased surface water organic C and N, turbidity, and phytoplankton growth. At this location, total sediment P, C, and N decreased during the late spring and early summer. These changes corresponded to the period of exponential growth of the lake phytoplankton population. During the late summer and early fall when plankton growth entered the stationary and declination phases, sediment organic C, total N and P increased, evidently as a result of the deposition of detritus containing these elements.Changes in inorganic P accounted for most of the changes in total sediment P. Combining data from all sampling locations in the lake, sediment inorganic P was not correlated with changes in surface water temperature or pH, but was inversely correlated with surface water organic C. The results thus indicate that sediment inorganic P was directly related to the biological productivity of the surface waters, and in at least one location, sediments served as a significant source of P to these waters supporting increased biological growth.
Corn Silage Yield and Soil Chemical Properties as Affected by Cattle Feedlot Manure
Authors: Mathers A. C. , Stewart B. A. 
Published: July 2010

AbstractCattle feedlot manure was applied at rates of 0‐, 22‐, 45‐, 112‐, and 224‐metric tons/ha for 3 successive years to irrigated corn (Zea mays L.). Additional plots received 448‐ and 896‐tons/ha for 2 years. Nitrate‐nitrogen in the top 180 cm of soil was maintained at about 100 kg/ha by 22 tons/ha manure applied annually. However, manure rates of 45 tons/ha caused a small increase in soil nitrate‐nitrogen and 112‐ and 224‐tons/ha rates increased the nitrate‐nitrogen remaining in the soil after three seasons to over 1,000 kg/ha. The highest concentration of the nitrate was between 30 and 60 cm, but nitrate accumulated to a depth of 360 cm. Organic matter, phosphorus, extractable potassium and sodium, and conductivity of a saturated paste extract increased in the top 30 cm of soil as the manure rate was increased. Applications of 224 tons/ha or more manure reduced corn silage (dry matter) yields. The optimum rate of manure application of corn silage production was 22 tons which supplied an average 300 kg/ha of nitrogen. Higher rates caused nitrate and salt accumulation in the soil and increased nitrate in the forage.
Relative Movement of Bromide and Nitrate Through Soils
Authors: Smith S. J. , Davis R. J. 
Published: July 2010

AbstractMiscible displacement experiments were conducted with eight different surface soils (0–15 cm depth) and their associated subsoils (61–76 cm depth). Results indicate that the movement of bromide relative to that of nitrate (0.005N salts) is identical in subsoils but variable in surface soils. Differences in relative movement of the two anions may be attributed to microbial activity involving nitrate. With the exception of 5% anion sorption in a Greenville subsoil, anion exclusion values ranged from 5 to 39%, indicating the anions were moving 1.05 to 1.64 times as fast as they would if they had been uniformly associated with all the soil water. The results support the view that bromide has utility for following the potential path of nitrate movement through soils.
Plant Uptake of Cadmium as Influenced by Cation Exchange Capacity, Organic Matter, Zinc, and Soil Temperature
Authors: Haghiri F. 
Published: July 2010

AbstractThe effects of several soil factors on cadmium (Cd) accumulation by plants were determined. Cadmium concentration in oat shoots (Avena sativa L.) was decresaed by increasing the cation exchange capacity (CEC) of the soil. Except for its CEC effect, organic matter did not influence the concentration of Cd in oat shoots. The results indicate that the retaining power of organic matter for Cd is predominately through its CEC property rather than chelating ability. Cadmium concentration of soybean shoots (Glycine max L.) increased with increased soil temperature. In the presence of 10 ppm of soil‐applied Cd, the addition of Zn from the 5 to 50 ppm range, apart from raising the Zn concentration, significantly increased the Cd concentration of soybean shoots. The increased Cd concentration was primarily due to decreased plant growth. A depression in Cd concentration of soybean shoots, relative to control, began to occur at the 100 ppm Zn level.