bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Flooding and Organic Matter Applications on DDT Residues in Soil
Authors: Farmer W. J. , Spencer W. F. , Shepherd R. A. , Cliath M. M.
Published: July 2010

A field in Coachella Valley, California which had received repeated applications of technical DDT to sweet corn (Zea mays L.) for ear worm [Heliothis yea (Boddie)] control was flooded 48 days, with and without organic matter amendments, to determine whether DDT soil concentrations could be effectively reduced. Applications of 180 and 45 metric tons/ha of feedlot manure and 18 and 5.6 metric tons/ha of alfalfa (Medicago sativa L.) meal were disked to a depth of 15 cm. Redox potentials in all flooded plots rapidly dropped below −150 mV at both the 7.5‐ and 15‐cm soil depths. All flooded plots including control plots showed a rapid decrease in soil levels of DDT isomers accompanied by a rapid accumulation of the respective DDD isomers in the top 15 cm. Flooding had little effect on the DDE isomers. By the end of the flood period p,p′‐DDT had decreased from 8.1 µg/g to 0.5 to 1.6 µg in flooded plots receiving organic amendments while the p,p′‐DDD level increased from zero to 4.2 to 5.6 µg/g. The rates of disappearance of DDT and the formation of DDD were significantly lower in the flooded plots receiving no organic amendments. After 18 days flooding the rates of p,p′‐DDT losses and DDD gains were in the order of 180 metric tons/ha manure ≃ 18 metric tons/ha alfalfa > 5.8 metric tons/ha alfalfa ≃ 45 metric tons/ha manure > control. The transformation of DDT isomers to DDD isomers occurred to a lessor extent at 15–30, 30–45, and 45–50 cm soil depths. The data indicate that flooding organic matter‐amended soil effectively reduced DDT concentrations to very low levels. The fate of DDD in flooded soils is unknown. However, through the formation of DDD, the conversion of DDT to the potentially hazardous DDE is prevented.
Factors Affecting the Decomposition of an Anaerobically Digested Sewage Sludge in Soil
Authors: Miller R. H.
Published: July 2010

Carbon dioxide evolution was used as a measure of the rate at which anaerobically digested sewage sludge is decomposed in soils. Variables included soil texture, moisture content (1/3 bar and saturated), loading rate (90 and 224/metric ton of dry sludge per ha), incubation time (1, 3, and 6 months), and temperature. Incubation temperatures were programmed to provide both diurnal and seasonal temperature variations. Sewage sludge was rather resistant to further decomposition with a maximum of 20% of the added carbon evolved as CO2 during a 6 months incubation. At the high rates employed, the rate of decomposition of sewage sludge was largely independent of differences in soil texture or chemical properties. Soil moisture content did not affect sludge decomposition in a sandy soil, but saturated conditions reduced it moderately in a silt loam soil and almost completely stopped decomposition in a clay soil. Soil temperature was the major factor influencing the rate of sewage sludge decomposition. A plot of the percentage sludge carbon evolved as CO2 vs monthly degree days was used to predict the amount of sewage sludge which would be decomposed per unit time at different soil temperatures.
Nitrogen‐15 Variations in Fertilizer Nitrogen
Authors: Freyer H. D. , Aly A. I. M.
Published: July 2010

Nitrogen‐15 concentrations of some commonly used nitrogen fertilizers are measured. Ammonium‐nitrogen has lower and nitrate‐nitrogen has higher 15N concentrations than atmospheric nitrogen. The mean difference between both is about 4 δ 15N.
Microbial Decomposition of Species of Freshwater Planktonic Algae
Authors: Mills A. L. , Alexander M.
Published: July 2010

Suspensions of axenically grown algae underwent aerobic decomposition in a solution free of nitrogen, phosphorus, and organic carbon. The rate and extent of mineralization of algal cell carbon and nitrogen and the solubilization of algal cell phosphorus varied appreciably among the test organisms. Chlamydomonas oblonga underwent rapid decomposition; Chlorella sp. lost carbon, nitrogen, and phosphorus slowly; and Ankistrodesmus falcatus and Astemcoccus superbus lost their carbon, nitrogen, and phosphorus at intermediate rates. Microorganisms from sewage markedly influenced the rate of liberation of some of the elements contained in A. falcatus and A. superbus but had little or no effect on the mineralization of carbon and nitrogen or on the release of phosphorus from cells of C. oblonga and Chlorella sp. Cells from 14‐day cultures of C. oblonga and A. falcatus were more quickly decomposed than cells from 28‐day cultures.
The Needs for Water Quality Models on Agricultural Watersheds
Authors: Nicholson H. P.
Published: July 2010

Man's agricultural activities contribute pollutants to surface and ground water. Preservation of water quality requires greater effort to control these pollutants including eroded soil, agricultural chemicals, oxygen‐demanding organic wastes, and sometimes heavy metals and pathogens.

Management of nonpoint source agricultural pollutants will require the management of runoff or vertical movement from the source, the efficient selection and use of appropriate pesticides and fertilizers, and the retention of animal wastes and plant residues on the land. Management programs should be planned for complete drainage basins making use of existing conservation programs. Mathematical models now under development will augment current management practices and will enable the application of computer technology to prediction of the consequences of agronomic practices.
A Mathematical Model for Phosphorus Movement in Soils
Authors: Shah Dhananjai B. , Coulman George A. , Novak Lawrence T. , Ellis Boyd G.
Published: July 2010

Land application of municipal and industrial wastes is increasingly being looked upon as an alternative for treatment of the effluent. Since phosphorus compounds constitute a major potential source of ground water contamination, it is important to study the movement of these compounds in the soil. In this paper, a model for the movement of P has been developed. Material balance equations for water in the soil pore spaces, P in the liquid phase, and adsorbed P on the soil have been formulated. These equations are solved numerically to simulate the P concentration profiles in the soil solution and in the soil as functions of depth for an operating waste disposal system. The results of the simulation show a good agreement with the field data. The model can be used to determine the response of the system for a given input of phosphates and thus is a useful tool in the design and management of such systems.
Phosphorus Movement in Soils: Theoretical Aspects
Authors: Novak L. T. , Adriano D. C. , Coulman G. A. , Shah D. B.
Published: July 2010

The renovation of waste water by land application shows promise because of the potential to use certain waste water nutrients to fertilize agricultural crops and to recycle these nutrients as agricultural products. In order to locate, design, and manage land treatment processes, quantitative descriptions of critical processes are required.

The adsorption of P by soils is a critical process which needs to be considered. This paper compares a new model for P movement in soils with existing adsorption‐desorption models developed for chromatography and ion exchange processes. The effect of the model parameters on P movement in soils is also examined.

From the new model considered here, it was found that under P adsorption, a P profile of fixed shape (shock layer) developed and moved through the soil at a speed which could be calculated from the P Langmuir adsorption isotherm, density of the soil, and the P rate of application to the soil.

Model parameters have an effect on the shape of the P profile, but over the range of condition studied here, the S‐shape P front (shock layer) was less than 4 cm in thickness. The range of conditions were chosen to cover a range of soils and operating conditions which might be considered during the selection and design of a waste water land treatment process. It should not be construed from this study, that a small shock layer exists for all adsorption cases, or for the case of desorption of P from soils during leaching.
Nitrogen Conservation under Corn Planted in Quackgrass Sod
Authors: Bennett O. L. , Stanford G. , Mathias E. L. , Lundberg P. E.
Published: July 2010

The mechanics of growing corn (Zea mays L.) in a grass sod using the no‐tillage concept have recently been developed. However, little is known abouthe fate of fertilizers, especially nitrogen, or the potential uses of such plant species as quackgrass (Agropyron repens L.) in this management system. Silage yields of corn were determined from field studies in which corn sod‐planted in quackgrass, treated with six rates of atrazine, was compared to conventionally planted corn. The effects of no tillage and conventional tillage, using two rates of atrazine on total soil N, and N mineralization potential were compared. Yields of corn silage produced in herbicide‐treated quackgrass were significantly higher than yields from conventional tillage. In the first year, silage yields increased with rates of atrazine. Quackgrass persisted for a 2‐year period at the three lowest rates of atrazine but not at higher rates. After the first season, mineral N (largely NO3‐N) was significantly greater under untilled quackgrass than under plowed plots, However, by the following spring differences associated with tillage method had disappeared. Soil N mineralization potential, NO, and total N in the 0‐ to 15‐cm layer were considerably higher for untilled than for plowed soils. However, in untilled plots, these values were unaffected by rate of atrazine.
Fungicide Treatment of Wheat Seed: Is it Necessary?1,2
Authors: Mathre D. E. , Stewart V. R. , Johnston R. H. , Baldridge D. E.
Published: July 2010

The value of using nonmercury fungicide seed treatments to increase stand and yield of winter and spring wheat (Triticum aestivum L.), and to control common stinking smut (Tilletia caries [DC.] Tul.) was investigated. In a greenhouse test using soil from 38 locations in Montana, emergence from seed treated with mercury averaged 91.2% compared to 88.4% from untreated seed. Field tests using both winter and spring wheat which had been treated with various mercury or nonmercury based fungicides, failed to produce any significant increase in stand or yield.

Control of common stinking smut in winter wheat with nonmercury seed treatments was accomplished, in some cases at rates lower than the label recommendation.

The toxicity of the various nonmercury materials that will control common stinking smut indicates that these compounds should have less deleterious effects upon the environment than the mercury‐based seed treatments.
Trace Element Concentrations of Sewage Treatment Plant Effluents and Sludges; Their Interactions with Soils and Uptake by Plants
Authors: Bradford G. R. , Page A. L. , Lund L. J. , Olmstead W.
Published: July 2010

Metropolitan sewage sludges and effluents were characterized in relation to their total and water extractable trace elements, their reactions with soils, and their effects on plants. The total concentrations of trace elements in sludges and effluents were highly variable depending on the source and were often much higher than concentrations found in soils. Concentrations of Cu, Zn, Ni, Co, and Cd were consistently greater in the saturation extracts obtained from sludges than those obtained from a large sampling of California soils. The effects of irrigating bean, barley, and tomato plants in a greenhouse sand culture experiment with diluted saturation extracts of sludges from different sources were all adverse but variable depending on the sludge source. Leaf samples from treated plants frequently contained toxic levels of B and excessive levels of one or more of the following elements: Cu, Mo, Ni, Co, Pb, and Cd.
Biological Denitrification and Its' Application in Treatment of High‐Nitrate Waste Water
Authors: Francis C. W. , Callahan M. W.
Published: July 2010

One method of removing nitrate nitrogen from waste water effluents appears to be biological denitrification. Considerable research regarding denitrification of municipal and agricultural waste water containing relatively low concentrations of nitrate (<50 ppm NO3‐N) has been conducted. However, very little research has been carried out on the feasibility of applying the process to waste water effluents which contain in excess of 1,000 ppm NO3‐N. Waste water effluents containing this magnitude of nitrates are generated in fertilizer and explosive manufacturing operations. Large quantities of nitrates are also expected to be produced at future nuclear fuel processing and uranium oxide fuel fabrication plants. This review comprehensively evaluates the various requirements for biological denitrification in respect to NO3‐N concentrations as well as quantity and type of carbon substrate and complementary cations. It also assesses which engineering design, e.g., modified activated sludge units, packed‐bed reactors, or anaerobic columns, may be most applicable in biological denitrification of waste streams containing concentrations > 1,000 ppm NO3‐N.
Influence of Treated Municipal Waste Water on Growth, Fiber, Acid‐soluble Nucleotides, Protein, and Amino Acid Content in Wheat Grain
Authors: Day A. D. , Taher F. A. , Katterman F. R. H.
Published: July 2010

Experiments were conducted at Tucson, Arizona to study effects of treated municipal waste water on growth, fiber, acid‐soluble nucleotides, protein, and amino acid content in grain from wheat (Triticum aestivum L.). Wheat grain was grown in two soil types, (i) Comoro sandy loam, and (ii) Grabe silt loam. Three irrigation and fertilizer treatments were used: (i) well water plus suggested amounts of nitrogen, phosphorus, and potassium (112, 35, and 1 kg/ha of N, P, and K, respectively); (ii) well water plus N, P, and K from commercial sources in amounts equal to those found in waste water (224, 73, and 140 kg/ha of N, P, and K, respectively); and (iii) waste water from an activated sludge sewage plant (224, 73, and 140 kg/ha of N, P, and K, respectively).

Average number of heads per unit area and grain yield were higher in wheat plots that received waste water than they were in plots that were grown with well water and suggested N, P, and K. Average days from planting to maturity, plant height, seeds per head, and seed weight were similar for the three irrigation and fertilizer treatments. Wheat grain grown with the three irrigation and fertilizer treatments contained similar amounts of total fiber and acid‐soluble nucleotides. Grain grown with waste water contained more total protein than did grain produced with well water plus suggested amounts of N, P, and K. Wheat grain that received only waste water contained more alanine, histidine, isoleucine, and proline than did grain produced with well water plus suggested N, P, and K or well water plus N, P, and K equal to waste water. Grain grown with the three treatments contained similar amounts of cystine, methionine, and threonine in all instances. High yields of high quality grain were obtained from wheat irrigated with treated municipal waste water in the southwestern United States.
Response of Corn to Zinc and Chromium in Municipal Wastes Applied to Soil
Authors: Mortvedt J. J. , Giordano P. M.
Published: July 2010

Two coarsely ground air‐dried municipal sewage sludges and a garbage compost were mixed with Hartsells fsl (limed to pH 5.5) at rates of 15, 75, or 300 g/3 kg of soil in two greenhouse pot experiments. Fine ZnSO4 and Na2Cr2O7 were each mixed with soil limed to pH 5.5 to 7.0 at rates up to 1,400 ppm of Zn and 320 ppm of Cr, equivalent to rates applied in the organic wastes. Three successive crops of corn (Zea mays L.) were planted 0, 7, and 18 months after waste application.

Corn forage yields were increased only in Crops 1 and 3 by compost applications but were not affected by sludge applications. Concentrations of Zn in the corn forage increased with application rate and Zn content of the three waste products. In contrast, Cr concentrations in the corn were not affected by the 0.05% to 1.36% Cr in the wastes. Concentrations of both Zn and Cr in the corn forage were much higher from ZnSO4 and Na2Cr2O7 from each waste at similar Zn and Cr rates and soil pH. Levels of 0.5N HCl‐extractable Zn and Cr in the soil after each harvest increased with application rate of Zn and Cr in each organic waste and inorganic salt, but were not proportional to plant concentrations.

Trivalent Cr as Cr2(SO4)3 was less toxic to corn than hexavalent Cr as Na2Cr2O7 at a rate of 80 ppm of Cr, while both sources were very toxic at 320 ppm. Toxicity resulted from ZnSO4 in pH 5.5 soil at 240 ppm Zn and at 960 ppm in soil above pH 6.5. Results of these experiments suggest that Zn and Cr contained in municipal wastes applied at high rates are not toxic to corn even after relatively long periods in the soil. Reduced plant uptake of these heavy metals in organic waste was not due entirely to their liming effect on the soil.
Comparison of Two Predictive Nonequilibrium One‐Dimensional Models for Phosphorus Sorption and Movement through Homogeneous Soils
Authors: Enfield Carl G. , Shew D. C.
Published: July 2010

Two models were tested for their ability to predict phosphorus breakthrough curves. The basic difference between the two models is the method of describing the kinetics of sorption. It was found, when comparing theoretically predicted breakthrough curves with experimental breakthrough curves, that the model using the kinetic equation ∂S/∂t = a Cb Sd produced a better fit to the experimental data than a first order rate equation.
The Responses of Soils and Soil Microorganisms to Silver Iodide Weather Modification Agents
Authors: Sokol R. A. , Klein D. A.
Published: July 2010

To determine the consequences of AgI weather modification agent accumulation to the soil microbial environment, the effects of added silver compounds on microbial growth, anaerobic cellulose degradation, and the soil environment adjacent to a cloud seeding generator were investigated. Silver ion from AgNO3 inhibited microbial growth in cultures at concentrations as low as 6 × 10−9 g ml−1 and cultures saturated with AgI displayed an inhibition of growth initiation approximately equivalent to 35 × 10−9 g ml−1 silver ion. Muds containing AgI exhibited significantly decreased anaerobic cellulose degradation rates in long term experiments, when concentrations of 100 µg AgI/g were present. An analysis of the soil surrounding a seeding generator site in Steamboat Springs, Colorado indicated that deposited silver tends to remain near the soil surface (0–2 cm). Alterations in the soil environment due to high silver concentrations were indicated by consistently higher organic matter levels, water contents, microbial populations, and rates of soil respiration. These results suggest that high concentrations of seeding agent potentially can alter the soil microbial environment by inhibiting organic matter decomposition, but that the silver levels which accumulate in seeded target areas should have no overt effects on the soil environment.
The Impact of Molybdenum‐Enriched Irrigation Water on Agricultural Soils Near Brighton, Colorado
Authors: Jackson D. R. , Lindsay W. L. , Heil R. D.
Published: July 2010

The Mo concentration in water, soils, and alfalfa (Medicago sativa L.) was monitored for one growing season to determine the impact of using Mo‐enriched irrigation water near Brighton, Colorado. The concentration of Mo in irrigation water in this area ranged from 27 to 213 ppb. A significant increase of Mo concentration in alfalfa and available soil Mo was observed at one site irrigated with water containing 213 ppb Mo. The Mo concentration in the alfalfa at this site increased during the growing season from 4.3 to 7.2 ppm. This level is below the 10 ppm level considered toxic to livestock.

Plant Mo was highly correlated (r = 0.94) with resin‐extractable Mo in a greenhouse experiment using soils from three of the field sites. Field results were less satisfactory (r = 0.51), partially due to limited indigenous levels of Mo in the soils.

A simulation model was used to assess the potential hazards of irrigating with water containing from 0 to 600 ppb Mo. The results of the simulation indicate that a level of 400 ppb Mo in irrigation water applied to soil with 40% retention of Mo in an available form would result in toxic levels of Mo in plants within 3 years.

The impact of Mo on the Brighton area during one growing season was minimal in relation to uptake of Mo by plants. Further studies are necessary to assess the long term effects of Mo accumulation in soils and irrigated with Mo‐enriched waters.
Influence of Soils on Bacterial Contamination of a Watershed from Septic Sources
Authors: Reneau R. B. , Elder J. H. , Pettry D. E. , Weston C. W.
Published: July 2010

Surface and perched ground waters collected from an 80‐ha watershed were evaluated for bacteriological quality by enumeration of total and fecal coliform densities. This watershed is located at the western edge of the Coastal Plain Physiographic Province and the eastern edge of the Piedmont Plateau. Soils present have developed from both Piedmont and Coastal Plain materials. Analyses of surface waters from areas influenced by failing septic systems demonstrated a large range in total and fecal coliform densities. Sites not subjected to runoff from areas that contained failing septic systems had no detectable fecal coliform count in four of nine observations, whereas, in other sites where septic effluent was coming directly to the surface without passing through any soil material, the total and fecal coliform densities were in excess of 2.4 × 107/100 ml at some dates. Most of the surface waters in this watershed would not meet minimum recommendations for surface waters to be used for primary contact sports or public water supplies. Total and fecal coliform counts for subsurface samples generally decreased as a function of distance from the source of pollution.
Phosphorus Movement in Soils: Soil‐Orthophosphate Reaction Kinetics
Authors: Novak L. T. , Adriano D. C.
Published: July 2010

This paper presents four models to describe the kinetics of P adsorption‐desorption reactions in soils. The mass transfer model, Langmuir kinetics model, and Langmuir‐Hinshelwood models were developed and compared with phosphate adsorption data on a soil obtained by batch‐shaken flask experiments.

For P adsorption times up to 3 hours, the mass transfer and Langmuir kinetics models described the experimental data very well. The Langmuir kinetics model gave a slightly better fit of the experimental data. These kinetic data probably represent an upper bound for unsaturated flow in soils.
Determination of Total Mercury in Soils and Sediments
Authors: Floyd M. , Sommers L. E.
Published: July 2010

A simple one‐step digestion procedure was evaluated for extracting total mercury from soils and sediments. The procedure evaluated involves digesting soil or sediment samples with concentrated HNO3 and 4N K2Cr2O7 (2:1, vol/vol) for 4 hours at 55C and analyzing mercury in the extract by flameless atomic absorption. Recovery of total mercury from diverse samples was comparable to or exceeded that obtained by four alternative total mercury procedures. Essentially quantitative recovery of mercury was obtained when samples were amended with mercuric chloride, methylmercuric chloride, phenylmercuric acetate, and mercuric sulfide. The procedure developed was precise with coefficients of variation ranging from 1 to 3%. Parameters affecting the quantitative extraction of total mercury were studied.
Phosphate Sorption Characteristics of Soils Treated with Domestic Waste Water
Authors: Sawhney B. L. , Hill D. E.
Published: July 2010

Phosphate sorption capacities of several Connecticut soils having widely different physical and chemical characteristics were determined in the laboratory using dilute P solutions. Sorption capacity was defined as the amount of P sorbed by a soil at equilibrium with a 2 × 10−4M P solution which is approximately the concentration of soluble orthophosphate in domestic waste water. Although sorption capacities of the soils varied over a 4‐fold range, calculations based on these determinations revealed that soils surrounding drainfields of septic tank systems can effectively remove P from waste water for a number of years. Treatment of undisturbed soil cores with simulated waste water for 2 years and determination of P sorption by soils from exhumed septic tank drainfields used up to 15 years substantiate these findings and further show that P moved very slowly in the soil from the source of supply. In addition, soils surrounding the oldest drainfields were not completely saturated with P and retained a portion of their P sorption capacity. These observations led to the hypothesis that P sorption sites in soils are regenerated with time. Regeneration was confirmed in further laboratory experiments. Soils that had been successively treated with P solution, showed reduced P sorption capacity but regained the capacity to sorb P after drying and wetting cycles. Thus, phosphate sorption capacities of soils are greater than simple laboratory determinations indicate.
Fixation of Arsenical Herbicides, Phosphate, and Arsenate in Alluvial Soils
Authors: Wauchope R. D.
Published: July 2010

The sorption of arsenic (as arsenate), phosphate, DSMA (disodium methanearsonate) and the sodium salt of cacodylic acid (hydroxydimethylarsine oxide) by 16 Mississippi River alluvial flood plain soils was measured in a slurry experiment in which initial pH and solute molar solution concentrations for all four solutes were identical. Sorption of the two organoarsenical herbicides was strongly correlated with arsenate and phosphate sorption, and sorption of all four species was strongly correlated with clay and iron oxide contents of the soils. In 10−3 to 10−4M solution, the arsenicals are more strongly sorbed than phosphate with sorption increasing in the order P < cacodylate < arsenate ≃ methylarsonate.
A Mound System for Onsite Disposal of Septic Tank Effluent in Slowly Permeable Soils with Seasonally Perched Water Tables
Authors: Bouma J. , Converse J. C. , Otis R. J. , Walker W. G. , Ziebell W. A.
Published: July 2010

Slowly permeable soils with seasonal high water tables cannot be used for conventional subsurface disposal of septic tank effluent. An alternative mound system is described which consists of soil‐covered seepage trenches on top of 60 cm of sand fill deposited on the original soil surface. The bottom area of the mound is sufficiently large to allow soil absorption of effluent considering the low conductivity of the subsoil, which was measured in situ with the crust test procedure. Monitoring data for four experimental mound systems and design and construction criteria are discussed.
Land Application of Sewage Sludge: III. Nitrate Accumulation and Wheat Growth Resulting from Addition of Sewage Sludge and Wood Wastes to Soils
Authors: Sabey B. R. , Agbim N. N. , Markstrom D. C.
Published: July 2010

Anaerobically digested sewage sludge, and wood and bark residues were added to a Nunn clay loam at several mixtures and rates up to 224 dry metric tons/ha in laboratory and greenhouse studies to determine the effect on wheat (Triticum aestivum L. em. Thell) growth and on nitrate accumulation in the soil.

With increasing proportions of sludge and decreasing wood‐bark residues, there was an increase in wheat growth at all application rates except 224 metric tons/ha, wherein the yield dropped with the 100% sludge treatment. Results were similar with the wood‐sludge and bark‐sludge mixtures with only slight variations.

Nitrate accumulation was low whenever the wood residue‐sludge mixtures had more than 50% wood residue. Relative NO3−‐N accumulation indices were determined for each application rate and each wood‐bark‐sludge combination, showing the N immobilization tendency of the wood‐bark‐sludge mixtures.

The relationship between wheat growth in the greenhouse and nitrate accumulation in the laboratory soils has a correlation coefficient of 0.82 (significant at 0.99 probability level). Therefore, the wheat growth may have been limited by lack of nitrate resulting from immobilization of N when high proportions of wood residues were added in the organic waste. Maximum wheat growth occurred with the same treatments in the greenhouse that caused the soil in the laboratory to accumulate about 300 ppm of NO3−‐N in a 2 month period. For this study, near maximum wheat growth resulted from several different mixtures and rates of wood (W), bark (B), and sludge (S), including 224 metric tons/ha of WB‐25%S‐75%, 224 metric tons/ha of B‐25%S‐75%, 224 metric tons/ha of W‐50%S‐50%, and 112 metric tons/ha of W‐25%S‐75%.
Effect of Ozone on the Yield and Plant Biomass of a Commercial Variety of Tomato
Authors: Oshima R. J. , Taylor O. C. , Braegelmann P. K. , Baldwin D. W.
Published: July 2010

A commercial variety of pole tomato (Lycopersicon esculentum Mill. H‐11) was exposed to 20 and 35 parts per hundred million (pphm) ozone for 2.5 hours, 3 days each week over a period of weeks. Extensive foliar injury, defoliation, and highly significant reductions in plant biomass occurred at both exposure levels. However, fruit yield was significantly reduced only at the higher 35 pphm ozone concentration. This reduction was due to a decrease in the number of fruit and not to a decrease in fruit weight. Fruit yield in the 20 pphm treatment was equal to that of the control despite a 27% reduction in total dry weight of plants. These results indicate the presence of a threshold for the effect of ozone on yield.
Determination of Total Nitrogen in Natural Waters
Authors: Nelson D. W. , Sommers L. E.
Published: July 2010

A simple, precise, and rapid method for estimating total N (to include nitrate and nitrite) in natural water is given. The proposed method involves evaporation of the water sample, pretreatment of the evaporated sample with reduced iron and H2SO4 to reduce nitrate to ammonium, and subsequent Kjeldahl digestion of the sample to recover organic N. Evaporation, pretreatment, and digestion of samples are accomplished in Folin‐Wu nonprotein tubes. Ammonium in the digest is estimated by steam distillation and subsequent titration. Evaluation of the proposed method revealed that the recovery of nitrate N and organic N in samples was affected by the amount of reduced iron added (200 mg was satisfactory), by the brand of reduced iron used (several preparations were satisfactory), and by gently boiling the sample with reduced iron and H2SO4 prior to digestion. The proposed method was effective in recovering nitrate N and organic N from water solution over a wide range in concentration and the method was successful in recovering nitrate N and organic N added to filtered and unfiltered river and pond water samples. The precision of the proposed method was satisfactory for total N analysis of water samples, and the method appears adequate for estimation of total N in most water and waste water samples.
Cadmium and Zinc Contents of Corn Leaf and Grain Produced by Sludge‐amended Soil
Authors: Jones Robert L. , Hinesly T. D. , Ziegler E. L. , Tyler J. J.
Published: July 2010

Liquid digested sludge (heated anaerobic digestion) was incorporated at different rates in Blount silt loam over 3 and 4 years. Cadmium and Zn were determined in corn ear leaf at tassel and in grain (Zea mays L.) in 1971 and 1972. Cadmium and Zn extractable from soil with 0.1/V HCI were also estimated. The elements increased in soil and tissue with sludge application. Cadmium in leaf was not affected significantly by soil pH but Cd in grain was significantly reduced above and below pH 6. Below pH 6.3, Zn content in the leaf was substantially increased by increasing availability of Zn. However, above pH 7 when large amounts of Zn were available, increases in leaf content were not observed. Zinc concentrations in grain, except at high levels in soil (about 200 ppm by 0.1/V HCI) and low pH (about 4.8), follow the distribution of Cd. Highest Cd content in grain was about 1.0 ppm when about 15 ppm of available Cd was present; this Cd level was associated with about 40 ppm Zn.
Distribution of Plutonium in Soil Particle Size Fractions of Liquid Effluent‐Receiving Areas at Los Alamos
Authors: Nyhan J. W. , Miera F. R. , Peters R. J.
Published: July 2010

The alluvial soils of three liquid effluent‐receiving areas at Los Alamos, New Mexico were sampled to determine the distribution of 238Pu and 239,240Pu in soil size fractions as a function of soil depth, distance from the waste outfall, and soil physical‐chemical properties. Although the plutonium concentrations in the <53 µm soil size fraction were 10 times higher than plutonium levels in the 2–23 mm fraction, the largest portion of the plutonium inventory in the average soil sample was found in size fractions > 105 µm. Plutonium concentrations decreased curvilinearly with distance from the waste outfall and with soil depth in the soils of discharge areas currently receiving treated liquid wastes. The < 53 µm size fractions contained 7‐fold larger surface areas and 3‐fold larger cation exchange capacities than the 2–23 mm size fractions; plutonium concentrations in the size fractions were correlated with surface area in all three discharge areas.

Significant differences in the distribution of 238Pu and 239,240Pu were found in the soil size fractions from Mortandad canyon. Most soil separates from this canyon exhibited an approximate doubling of the 239,240Pu/238Pu ratio with increased soil depth and within 40 m from the waste outfall. The <53 µm soil size fraction had a 2‐fold higher average 239,240Pu/238Pu ratio for each sampling station than the 2–23 mm size fraction.

The distribution of plutonium in the soil size fractions is discussed as a function of changing isotopic composition of the liquid wastes added to the canyons, movement of soil and plutonium in these intermittent streams, and potential isotopic differences in the behavior of 238Pu and 239,240Pu.
Geologic Nitrogen in Pleistocene Loess of Nebraska
Authors: Boyce J. S. , Muir John , Edwards A. P. , Seim E. C. , Olson R. A.
Published: July 2010

Research into the relationship between fertilizer use and water quality in Nebraska has resulted in the discovery of large quantities of geologic nitrate within the deep loess mantle of southwestern and central Nebraska. The NO3− is first encountered at a depth of about 7 m and continues to an unknown depth in excess of 30 m. Nitrate‐N values of 25 to 45 ppm characterize the N zone, but values to 87 ppm have been recorded. The NO3− exists only under the leveler uplands of the region; however, it is on this plain that rapid development of irrigation is taking place and it has been shown that the NO3− has been leached from beneath older irrigation sites on the plain.
Maximizing Denitrification during Soil Filtration of Sewage Water
Authors: Lance J. C. , Whisler F. D. , Rice R. C.
Published: July 2010

Two methods were developed to remove 80% of the nitrogen from secondary sewage effluent during soil filtration by using soil columns. No external energy source was needed to achieve denitrification with either method, and the volumes of water applied far exceeded irrigation rates for cropland. For the first method nitrogen removal was increased exponentially by decreasing the infiltration rate from 35 to 15 cm/day, which allowed nitrates formed during dry periods to mix with sewage effluent infiltrated during the succeeding flooding periods and provided a C to NO3‐N ratio favorable for denitrification. In a second method, nitrogen was removed by collecting high‐nitrate water after soil filtration, mixing it with sewage effluent, and recycling the mixture through the soil.
Ammonia Volatilization from Dairy Manure Spread on the Soil Surface
Authors: Lauer D. A. , Bouldin D. R. , Klausner S. D.
Published: July 2010

Volatilization of ammonia from manure spread in the field was measured in five experiments carried out over a period of 2 years in spring, summer, and winter. The rates of manure application were 34 and 200 metric tons/ha (15 and 90 tons/acre). Ammonia volatilization was determined after spreading by periodically measuring the total ammoniacal N (TAN) content of manure samples collected from the soil surface. Corrections were made for increase in ammoniacal N in the soil. Time spans of the experiments ranged from 5 to 25 days with total losses of NH3 ranging from 61 to 99% of the TAN content. Quantities of N volatilized as NH3 ranged from 17 to 316 kg N/ha depending on the application rate and TAN content of the manure. In the winter trial, NH3 volatilization was precluded by subfreezing temperatures, snow cover, and a rapid thaw which leached the ammoniacal N into the soil. In the other experiments, for a period of 5 to 7 days after spreading, rates of NH3 loss are represented by mean half‐lives of 1.86 to 3.36 days, respectively, for the low and high rates of manure application. After the initial period of loss, the rate of NH3 volatilization slowed in most cases. The 34 metric tons/ha manure application dried more rapidly because of its thinner ground cover, which increased the rate of NH3 loss from the manure. Volatilization of NH3 was optimum under sustained drying conditions. Effects of drying on the manure in relation to the chemistry of NH3 in aqueous solution in the manure aided in understanding the process of NH3 volatilization from the manure.
Dissipation of Residues of 2,4‐D in Static Water
Authors: Averitt W. K. , Gangstad E. O.
Published: July 2010

The rate of dissipation of residues of 2,4‐D (2,4‐dichlorophenoxy acetic acid) at the point of application, applied for control of aquatic vegetation, was found to be affected by the rate of treatment, depth of water, mean temperature, and time after treatment. For the standard rate of treatment, i.e., 4.48 kilograms acid equivalent per hectare (kg ae/ha) there was a decrease of 58 parts per billion (ppb) in residue for each 0.61 m increase in depth of water treated, a decrease of 115 ppb in residue for each 7C increase in mean temperature, and a decrease of 53 ppb in residue for each 7‐day interval of time after treatment.
Nitrogen Cycling in Lake Wingra
Authors: Isirimah N. O. , Keeney D. R. , Dettmann E. H.
Published: July 2010

Monitoring of the forms of N in water and sediment, and investigations of N cycling in Lake Wingra, a small, eutrophic, hardwater lake in southern Wisconsin, were conducted. Nitrification in the waters appeared to be by heterotrophs, while autotrophic nitrification dominated in the sediments. Rapid turnover of 15N‐NH4+ occurred in the waters, but not in the sediments, while 15N‐NO3− turnover was slow in the waters. In the sediments, denitrification and immobilization of 15N‐NO3− was rapid. About 80% of the added 15N‐NO3− was denitrified, the remainder being immobilized. Detrital‐15N was slowly mineralized in the sediments. Sediment‐water interchange occurred at a significant rate. About 40 µg NH4+‐N/liter sediment/day was formed from organic‐N, and subsequently released to the overlying water. Estimates of the overall average N content in various compartments indicated that about 50% of the “available” N was in the water, 20% in the macrophytes, and 30% in the sediments, while over 97% of the total N in the lake (to 30 cm sediment depth) was as sediment organic N. Consideration of seasonal changes in the NH4+‐N content of the sediments gave an average release rate of NH4+‐N of 7 to 29 mg m−2 day−1. This would supply from 3 to 14 metric tons of N to the lake water yearly. This is about the same order of magnitude as all external N inputs. Thus, even if the controllable point sources of N were eliminated, the biomass N in the lake water would not be significantly decreased.
The Role of Systems Analysis in the Use of Agricultural Wastes
Authors: Schulte D. D. , Kroeker E. J.
Published: July 2010

Agricultural waste management is a multidisciplinary field which has grown in an attempt to solve problems of agricultural byproduct utilization and disposal. Development of meaningful solutions to agricultural waste management problems will be much simpler if practitioners and researchers educate one another and together work to solve the different problems of the producer. Many disciplines have already become involved in the problem‐solving process; yet, there is a need for a generalist in agricultural waste management who can bridge disciplinary gaps and promote effective cooperation between specialists in various fields of study. Systems analysis can serve a useful purpose in agricultural waste management by providing a focal point for cooperation between disciplines working on various aspects of the problem. Systems analysis has been used to: (i) provide a common structure for comparison of agricultural waste management strategies; (ii) identify processes or links within waste‐utilization systems which are costly or sensitive to operating conditions; (iii) predict effects of external constraints such as government policy, fertilizer taxes, and prices on the effectiveness of waste utilization strategies; (iv) yield information to predict where research funds would be spent most effectively; and (v) assist in technology transfer from researchers to practitioners through the aid of computer‐based educational models.
Soil and Microclimate Effects on Trifluralin Volatilization
Authors: Harper L. A. , White A. W. , Bruce R. R. , Thomas A. W. , Leonard R. A.
Published: July 2010

A large fraction of many applied pesticides are lost to the air and dissipated. Microclimatological methods were used to determine the diurnal loss rates by volatilization of trifluralin applied and incorporated into the soil of a 1.26‐ha upper Piedmont plateau watershed. Trifluralin flux decreased to very low levels during daytime when surface soil water content was low even though turbulence, soil temperature, and evaporative demand were high. During nighttime, when evaporative demand subsided and the surface soil water content increased, the trifluralin flux increased as the surface soil water content increased. Trifluralin and lindane flux on a limited plot‐size study were compared and both pesticides reacted similarly to environmental conditions, except lindane volatilized more rapidly.

When the soil surface was not wet, trifluralin and lindane fluxes appeared to be controlled by surface soil water content and the water content's effect on pesticide adsorption to the soil particle. Apparently, adsorption to the soil particle upon soil drying is a reversible process since efflux of the pesticides was rapid when soil was rewetted by dew or rainfall to above the equivalent of three molecular layers of adsorbed soil water. Under controlled soil‐water conditions, where the soil surface remained wetter than three molecular layers of adsorbed water, the pesticide fluxes responded to increased soil temperature and turbulence, and atmospheric stability conditions.
The Effects of Temperature and Soil Water on Conversion of DDT to DDE in Soil
Authors: Guenzi W. D. , Beard W. E.
Published: July 2010

A laboratory study was conducted to determine the rates of DDT (1,1,1‐trichloro‐2,2‐bis [p‐chlorophenyl] ethane) degradation and DDE (1,1‐dichloro‐2,2‐bis [p‐chlorophenyl] ethylene) formation in soil. Degradation rates increased with higher temperatures and in the presence of water. Of the DDT mixed with Raber silty clay loam, 82.1, 74.5, 53.2, and 38.3% was recovered as DDT and 6.7, 12.5, 21.6, and 34.8% as DDE after 140 days incubation at 30, 40, 50, and 60C, respectively. A comparison of DDE formation in sterile and nonsterile soil showed that 84% of the conversion was due to a chemical process at 30C and 91% at 60C. In sterile systems at 30C, rates of DDE formation were similar in submerged soil and soil at 1/3 bar suction, and both were much higher than in air‐dried soil.
Nitrate‐nitrogen Movement through Soil as Affected by Soil Profile Characteristics
Authors: Devitt Dale , Letey J. , Lund L. J. , Blair J. W.
Published: July 2010

The contribution of agricultural practices to pollution of ground and surface waters by nitrogen is not completely known. Six tile systems installed on commercial farms with differing soil profile characteristics were selected for investigation. Soil solution samples were extracted from 61‐, 91‐, 122‐, and 183‐cm depths and analyzed for nitrate‐nitrogen, manganese and chloride concentrations, and electrical conductivity. Redox potential measurements were made at 91‐ and 183‐cm depths. Tensiometers were installed at 61‐, 91‐, and 122‐cm depths to measure hydraulic gradients. Tile effluent samples were also collected and analyzed. Data on redox potential, manganese concentrations, and nitrate‐nitrogen concentrations indicated that there was very low denitrificetion potential in coarse‐textured profiles and that the nitrate‐nitrogen concentration and movement were dependent on water movement and amounts of nitrate available for leaching. Irrigation management to provide low leaching fraction resulted in relatively higher nitrate‐nitrogen concentration in the tile effluent but smaller amounts of total nitrate lost as compared to irrigation management for high leaching fractions. Redox potentials and the chloride to nitrate‐nitrogen ratios indicated that subsurface layers of high clay content promote denitrificetion. With one exception, a smaller fraction of the applied nitrogen was lost in the tile effluent from profiles containing layers of high clay content as compared to the coarse‐textured profiles. The one exception was a profile having high clay content throughout which was recently brought under cultivation. Extremely high residual nitrate‐nitrogen was found in this profile which would account for the high concentrations in the tile effluent.
Nitrogen Transformations in Aerated Swine Manure Slurries
Authors: Loynachan T. E. , Bartholomew W. V. , Wollum A. G.
Published: July 2010

A laboratory study was conducted to evaluate the effect of aeration rate, temperature, and manure loading rate on nitrogen transformations in swine manure slurries. Periodic samples were collected and analyzed for residual organic N, NH4‐N, NO2‐N, and NO3‐N, as well as NH3 volatilized from the aerated slurries. It was found that organic N decreased rapidly leaving a rather constant fraction after the first several weeks. At the end of the 83‐day study at 25C, one‐fourth of the N remained in solution in organic forms. This represents N that was not mineralized and consequently would not be lost during the denitrification process. From 16 to 26% of the added N was volatilized as NH3‐N and from 48 to 87% of the added C was evolved as CO2‐C during the study. Increasing temperature, increasing loading rate, and increasing aeration tended to increase volatilization of NH3 and CO2. An N balance at the conclusion of the study showed that 22 to 48% of the N was unaccounted for. While the mechanism responsible for the N losses was not determined, NH3 volatilization apparently predominated. The quantities of lost N increased with an increase in temperature. There appeared to be no relationship between the losses of N and changes in concentration of oxidized forms of N in solution. While nitrification occurred in extensively aerated swine‐manure slurries, about 1/4 of the original total N was not mineralized. As this represents a rather stable form and because only 3% of added N occurred in a mineral form at any given time, the extent of denitrification would be limited. Consequently, nitrification‐denitrification schemes probably have limited application to N removal from waste substances.