bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic Health Record Decision Support and Quality of Care for Children With ADHD
Authors: Co John Patrick T. , Johnson Sarah A. , Poon Eric G. , Fiskio Julie , Rao Sowmya R. , Cleave Jeanne Van , Perrin James M. , Ferris Timothy G.
Published: July 2010

OBJECTIVES:

The objective of this study was to assess the effect of electronic health record (EHR) decision support on physician management and documentation of care for children with attention-deficit/hyperactivity disorder (ADHD).

METHODS:

This study involved 79 general pediatricians in 12 pediatric primary care practices that use the same EHR who were caring for 412 children who were aged 5 to 18 years and had a previous diagnosis of ADHD. We conducted a cluster randomized trial of EHR-based decision support that included (1) clinician reminders to assess ADHD symptoms every 3 to 6 months and (2) an ADHD note template with structured fields for symptoms, treatment effectiveness, and adverse effects. The main outcome measures were (1) proportion of children with visits during the 6-month study period in which ADHD was assessed and (2) quality of documentation of ADHD assessment. Generalized estimating equations were used to control for the clustering by providers.

RESULTS:

Children at intervention sites were more likely to have had a visit during the study period in which their ADHD was assessed. The ADHD template was used at 32% of visits at which patients were scheduled specifically for ADHD assessment, and its use was associated with improved documentation of symptoms, treatment effectiveness, and treatment adverse effects.

CONCLUSIONS:

EHR-based decision support improved the likelihood that children with ADHD had visits for as well as care related to managing this condition. Better understanding of how to optimize provider use of the decision support and templates could promote additional improvements in care.
Agricultural Chemicals in Relation to Environmental Quality: Insecticides Today and Tomorrow
Authors: Metcalf Robert L.
Published: July 2010

Insecticides are used in agriculture as purposeful environmental contaminants to increase cost/benefit ratio in favor of the farmer and the citizen as consumer of food and fiber. However, their use has become a focal point in public concern for the preservation of environmental quality. Insecticides are widely estimated to have returned an average of about $5 to the farmer for every $1 expended. They have become an essential part of farm technology and their use is the inevitable consequences of the monoculture approach to modern high production agriculture. As ever increasing quantities of a widening variety of organic chemicals are used for pest control, the problems of environmental micropollution became intensified. There is an urgent need to learn much more about the environmental distribution and fate of not only the newer insecticides but also of the older materials still widely used.

Pesticides of all kinds will be widely used for the forseeable future. However, newer selective and biodegradable compounds must replace the older highly toxic and persistent chemicals. Pest management programs directed by pest control specialists will make pest control an integral part of crop production and will reduce the extent of environmental pollution by pesticides. Prescription sale and supervision of pesticides use will provide the best way to prevent the misuse and abuse of pesticides.
Interrelationships Between Agricultural Chemicals and Environmental Quality in Perspective
Authors: McNew George L.
Published: July 2010

A general discussion is provided on the role of agricultural chemicals in assuring a reasonable supply of food and fiber to the American people. These chemicals were inevitable when intensive agriculture was developed under conditions that favored depletion of the soil and an increase in crop and livestock pests. Every pest‐averting device such as the use of resistant crops, modification of the environment, promotion of antagonism and parasitism by other forms of life, and rotation of crops must be employed as skillfully as possible. The use of chemicals becomes a form of crop insurance that must be applied when changes in the environment upset these biological control devices. Since such chemicals will have to be used in the foreseeable future it becomes necessary to design more specific, safer materials that present little hazard to the environment and nontarget subjects. Some changes in the objectives of chemical research should be less dependence upon the lipid solubility, that leads to magnification to toxicity in a food chain, more specificity of action to reduce adverse side effects, greater susceptibility to degradation by soil microorganisms and oxidation, and use of nontoxic compounds that readily convert to toxicants in the presence of the pest or host metabolic processes so as to avoid heavy deposits of potentially toxic chemicals.
Chemical and Thermal Aspects of Pesticide Disposal
Authors: Kennedy M. V. , Stojanovic B. J. , Shuman F. L.
Published: July 2010

Pesticides, when treated with sodium biphenyl reagent, were decomposed to the extent of 80 to 99%. However, when these compounds were treated with a mixture of metallic sodium and liquid ammonia, 15 of the 19 compounds were completely degraded. When metallic lithium was substituted for metallic sodium, the mixture was less effective but still completely degraded 8 of 19 compounds. The decomposition products resulting from these reactions were not tested for toxicity.

The pesticide formulations were incinerated, either singly or mixed, at 900C. Analyses of the volatile products revealed that at least four hazardous gases (chlorine, hydrogen chloride, hydrogen sulfide, and nitric acid) were produced.
Engineering Aspects of the Disposal of Unused Pesticides, Pesticide Wastes, and Pesticide Containers
Authors: Shuman Fred L. , Stojanovic B. J. , Kennedy M. V.
Published: July 2010

From preliminary research on various methods of disposal of pesticides and containers it appears that incineration offers the greatest potential for rapid reduction of these materials. Work has been done in the laboratory, on model incinerators, and on the design of a pilot plant and a full‐scale plant for incineration and disposal of pesticides and containers. The primary over‐all objective of this work is to provide a safe method for disposal of hazardous materials generated in the future (without pollution of the air, soil, and water), and to provide a means for removing existing potentially hazardous materials from the environment.
Waste Management in the Food Processing Industry
Authors: Soderquist Michael R.
Published: July 2010

Public awareness of the current environmental crisis has prompted the food processing industry to initiate action on several fronts. This activity has been aimed at reducing the impact of waste products on the environment. Although the quantities of food processing wastes generated annually are massive, and production takes place mainly during the summer months when assimilative capacities of receiving waters are minimal, significant progress in the areas of waste reduction, wastewater recycling, by‐product development, and waste treatment has been made. Examples of such successful efforts include production of animal feed from vegetable wastes, development of fish hatchery rations from seafood scrap, design of a less wasteful potato peeling method, development of cheese whey concentration techniques, culturing of single‐cell protein on solid wastes, treatment of maraschino cherry brine for reuse, and others. Further advances will be made by the food processing industry in the 1970's through the utilization of the unified systems approach, which considers individual operations, from harvest through waste disposal, as integrated sub‐units of the total process. Through the utilization of this concept, maximum benefit can be derived from given inputs of time and effort, yielding a complete system which has been optimized to produce a practicable minimum of waste materials.
An Argument for the Open Ocean Siting of Coastal Thermal Electric Plants
Authors: Tarzwell Clarence M.
Published: July 2010

A great deal of research is yet to be done before we will definitely know all the effects of thermal electric generating plants. It is evident, however, that the chlorination of the intake water is definitely lethal to a high percentage of planktonic and other organisms; that thermal shock is detrimental to some of the more sensitive forms; that the continued exposure to high temperatures after thermal shock is lethal to many forms, especially the zooplankton; that the screening and turbulence in such plants is lethal to larval fishes and several invertebrates, and that immense amounts of waters are put through the plant and such transfer can be detrimental.

In view of these findings, I believe that in most instances bays and estuaries are not suitable for the location of a number of thermal electric plants. Discharges to the open ocean should be encouraged or required because acre for acre our bays and estuarine waters are more important and valuable for the production of marine life than is the open ocean. It is certain that we must have electricity; that the demand for electricity will increase, and that these plants must be built. It is recommended, however, that each situation be examined as to all possible adverse effects, and that these plants be so located or corrective measures built in so that they cause the least amount of damage to the aquatic environment and the various water uses. If damage cannot be prevented, it is best to damage the least valuable area.
DDT and Toxaphene Movement in Surface Water from Cotton Plots
Authors: Bradley J. R. , Sheets T. J. , Jackson M. D.
Published: July 2010

When 13.4 kg/ha of DDT were applied to cotton (Gossypium hirsutum L.) during the 1969 growing season, 2.83% was found in natural runoff between July 11, 1969 and January 5,1970. About 96% of the DDT in runoff was associated with suspended sediment. Of 26.8 kg/ha of toxaphene applied, 0.36% was detected in runoff, and 75% of the toxaphene in runoff was in the sediment fraction. When DDT and toxaphene were applied to the same plot (13.4 and 26.8 kg/ha, respectively, over the season) only 1.03% of the DDT was found in runoff, and the percentage for toxaphene was 0.61. A much greater percentage of DDT and toxaphene remained as soil residues than was found in runoff, but a high percentage of the pesticides applied was not recovered. Residues of DDT in water from a small pond within one experimental watershed ranged from <0.35 ppb before spraying to 13.4 ppb during the spraying season. Toxaphene residues in pond water varied from <1 ppb before spraying to 65 ppb about midseason.
Tolerance and Susceptibility of Kentucky Bluegrass (Poa pratensis L.) Cultivars to Air Pollution: In the Field and in an Ozone Chamber
Authors: Wilton A. C. , Murray J. J. , Heggestad H. E. , Juska F. V.
Published: July 2010

During late summer and autumn of 1970, differential injury, believed to be due to air pollution, was observed on five Kentucky bluegrass (Poa pratensis L.) cultivars: ‘Merion’, ‘Kenblue’, ‘Windsor’, ‘117‐27‐6’, and ‘Belturf’. Belturf was injured most, 117‐27‐6 least, and the other three cultivars were intermediate as to injury. Damage was less severe on parts of plots fertilized with N at 293 kg/ha than on parts of plots fertilized with 146.5 kg/ha of N.

Subsequent tests of three of these cultivars in an ozone chamber (30 pphm 2 and 4 hours) showed cultivar injury ratings corresponding to field injury ratings. Belturf was most severely injured, Windsor next, and 117‐27‐6 least. Differences among cultivars were highly significant at both levels of ozonation. Injury was significantly greater when ozone was applied at 30 pphm for 4 hours, than at the same level for 2 hours. The 117‐27‐6 was unique in that it tolerated ozone considerably better than did previously investigated Kentucky bluegrass cultivars. The chance selection of this extremely tolerant cultivar was possibly related to its having been selected from M3 progeny of irradiated Merion seed.

This ozone experiment also indicated that bluegrass may build up some tolerance to repeated ozone treatments.
Agriculture, Man, and His Environment
Authors: Bentley Orville G.
Published: July 2010

The relationship between the scientific and social aspects of environmental problems imposes responsibilities and constraints on both scientist‐educators and laymen. Scientists now have much of the technological knowledge needed to help clean up the American environment, but pollution control can be successful only if Americans are made aware of and accept the tremendous social and dollar costs involved. In some way, every American will be affected in the process of implementing solutions to pollutional problems. The problem for the businessman is whether the public will buy his product if he spends millions on his plant to reduce pollution, and then passes this “social” cost on to the consumer in the form of higher prices for products. Caution is needed, for some small businessmen may be forced out of business if strict enforcement of pollution controls call for production changes that the small businessman cannot afford. In the area of the quality of life, public universities must make education available to all who are qualified for it, and should help produce social leaders who can reside in and help resolve the problems of violence‐torn communities. A list is presented of seven environmental problem areas in which colleges of agriculture are conducting or should conduct research.
Agriculture's Contribution to Open Space and Natural Beauty
Authors: Skinner Henry T.
Published: July 2010

In addition to the economic, recreational, or conservation values of open spaces of our rural and urban landscapes, we can no longer afford to ignore the factors of esthetics. As an item of increasing public concern, esthetics pegs open spaces at values which call for new methods of prediction and calculation. A major element of open space, of natural beauty, and of esthetics, is plant life: the trees, shrubs, and groundcovers of the hillside, the home lot, and the city street.

A review of plant cultural problems, especially problems of the artificial urban environment, points up need for discovering superior plants or for breeding improved ones. Improvements involve upgraded quality for esthetic effect, adaptability to man‐made environments, but especially the increase of resistance to pests of diverse kinds and to pollutants of the air and soil. A recently “remade” London plane (Platanus acerifolia) or sycamore (Platanus) tree, likely to be both pest‐ and pollution‐resistant, provides an example of manufactured plants of this sort.

An urgent need of the 1970's is for the development of workable programs designed to preserve and protect the total values of the countryside—agricultural, conservation, scenic, and recreational—on a countywide, statewide, and nationwide basis. Within these objectives, the environmentalist is concerned for the threatened species of animals and plants. But our concern should go further. Within the species, it is the variant individual which can become immensely valuable as genetic studies progress, and which, when identifiable, should not be lost.
Role of Plants in Improving the Environment
Authors: Waggoner Paul E.
Published: July 2010

Foliage, especially foliage that is well watered and rapidly taking in carbon dioxide, improves our environment in tangible ways as well as aesthetically. Properly arranged, foliage can shade us without stilling the breeze and thus balance our energy budgets comfortably. When the productivity of crops per acre is increased, this frees land for parks and wilderness. Plants can also heal scarred land and scavenge pollutants from waste. Finally, we have recently learned that foliage can take in air pollutants, and the estimated cleansing of the air is considerable.
An Interpretation of Reservoir Sedimentation: I. Effect of Watershed Characteristics
Authors: Paulet Manuel , Kohnke Helmut , Lund L. J.
Published: July 2010

The value of a water storage reservoir can decrease rapidly if its capacity is reduced by settling of eroded and suspended soil. Many factors determine the rate of this “siltation.” The purpose of this paper is twofold: to analyze to what extent the influence of the characteristics of the soils of the contributing watershed upon rate and type of sedimentation of reservoirs can be assessed quantitatively and to determine how these effects are correlated with other geomorphological factors.

This study was made on 14 reservoir‐watershed combinations in Indiana and Illinois. The majority of the soils were silt loams. Under the conditions of this study, as the mean particle size decreases and the more uniform their particle size, the greater were the sedimentation rates. Sediment volume weight was found to be a function of particle size and organic matter content. The larger the mean particle size and the smaller the organic matter content of the sediment, the greater was the bulk density. The variation of sediment particle size and sedimentation rates could be evaluated quantitatively as functions of geomorphological and pedologic watershed characteristics.
Nitrification in Sediments of Selected Wisconsin Lakes
Authors: Chen R. L. , Keeney D. R. , Konrad J. G.
Published: July 2010

Nitrification rates in lake sediment‐water systems were investigated in the laboratory. Samples from Wisconsin eutrophic and oligotrophic hard‐ and soft‐water lakes were incubated at 10C or 25C in the dark using nonstirred (i.e. quiescent) and stirred (magnetic stirrer) systems open to the atmosphere. Nitrate was not formed in the acid sediments from soft‐water lakes. However, in calcareous sediments from hard‐water lakes, nitrification proceeded readily when the systems were stirred to increase oxygen diffusion. Nitrate did not accumulate when the samples were not stirred. Experiments with N‐Serve indicated that autotrophic organisms were mainly responsible for nitrification in the Lake Mendota samples.

Considering the high oxygen diffusion rate required for nitrification in sediments, it is likely that this process occurs only at the sediment‐water interface in oxygenated waters.
Denitrification and Nitrate Reduction in Wisconsin Lake Sediments
Authors: Chen R. L. , Keeney D. R. , Graetz D. A. , Holding A. J.
Published: July 2010

The fate of 15N‐labelled NO3‐N in Wisconsin lake sediment‐water systems was investigated in laboratory and field experiments. In the laboratory, approximately 90% of the added NO3‐N disappeared from a calcareous sediment (Lake Mendota) compared to about 40% from a noncalcareous sediment (Trout Lake) after 48 hours when incubated under He. About 10% (Mendota) and 5% (Trout) of the added NO3‐N was recovered as organic‐N and NH4‐N. The presence of significant amounts of 15NH4‐N, particularly in Lake Mendota sediment, indicated that immobilized N was subject to rapid mineralization. Nitrate‐15N not accounted for was assumed lost through denitrification. Under aerobic conditions 10% (Mendota) and 2% (Trout) of the 15N was recovered as organic N but little 15N appeared in the NH4‐N fraction.

In a field investigation, 15NO3‐N, added to Lake Mendota sediment samples and returned to the lake bottom in wide‐mouth plastic bottles, disappeared within 4 days. After 4 days about 37% of the added NO3‐N was in the organic and NH4‐N fractions, while the remaining 63% was likely lost through denitrification. These data illustrate that denitrification and NO3‐N reduction in sediments receiving NO3‐N in ground waters must be evaluated in calculating nitrogen budgets of seepage lakes.
Lead Uptake by Lettuce and Oats as Affected by Lime, Nitrogen, and Sources of Lead
Authors: John Matt K. , Van Laerhoven C.
Published: July 2010

Uptake of lead by lettuce (Lactuca sativa L.) and oats (Avena sativa L.) as a result of application of lime, nitrogen, and various sources of lead to the soil was studied in a growth chamber experiment. Soil application of lead increased the uptake of lead by lettuce to a greater degree than by oats. Application of lime repressed the uptake of added lead by both plants, while application of low levels of nitrogen reduced the uptake of lead by lettuce and oat roots only. Application of lead chloride lowered the amount of sulfur and phosphorus in plants, but levels of other elements studied were not affected by any lead treatment.
Nitrogen Balance in Soil Columns Intermittently Flooded with Secondary Sewage Effluent
Authors: Lance J. C. , Whisler F. D.
Published: July 2010

Short, frequent cycles of flooding soil columns (2 days flooded and 5 days dry) with secondary sewage effluent caused no net removal of N but transformed almost all of the N to nitrate. The net N removal during longer cycles (9–23 days flooded and 5 days dry) was 30%, and half of the N remaining in the water was concentrated into a wave of high‐nitrate water, which represented 10% of the total volume of reclaimed water and was collected immediately after the dry period. Water collected from the columns after the wave of high‐nitrate water passed contained 67% less N than the incoming sewage water.

Alternate flooding and drying periods were necessary for consistent N removal. The net N removal was probably due to a combination of several reactions dominated by denitrification. Cation exchange was important in holding NH4+ in the soil until it could be nitrified, thereby concentrating N into smaller volumes of high‐nitrate water. Denitrification is the logical reaction to investigate for higher net N removal because the soil microorganisms nitrified most of the NH4+ and N can be removed from the system as an inert gas by denitrification.
Molybdenum Availability as Influenced by Application of Fly Ash to Soil
Authors: Doran J. W. , Martens D. C.
Published: July 2010

Relationships between fly ash application to soil and Mo availability were evaluated by greenhouse and laboratory procedures. Seventeen samples of fly ash under study ranged from 5.6 to 39.3 ppm in total Mo content. Thirteen of the fly ash samples were alkaline in reaction, and these samples neutralized from 0.01 to 3.74 meq H3O+/g. Incorporation of two samples of fly ash, which contained the extremes in the range of total Mo content, increased alfalfa (Medicago sativa L.) yield on an acidic Groseclose silt loam. The increase in yield was attributed to alleviation of toxicities associated with low levels of soil pH. Molybdenum uptake data indicated approximately equal availability of Mo in fly ash and in Na2MoO4·2H2O.
Copper Toxicity in Snapbeans (Phaseolus vulgaris L.)
Authors: Walsh L. M. , Erhardt W. H. , Seibel H. D.
Published: July 2010

A 2‐year field experiment was conducted to determine whether Cu applied for pathogen control could accumulate to a level that would be toxic to snapbeans (Phaseolus vulgaris L.). Copper sulfate and Cu(OH)2 were applied at rates varying from 0 to 486 kg/ha Cu on a Plainfield loamy sand to approximate 1, 3, 9, and 27 years of fungicidal treatment. Correlation and regression analyses were used to compare the amount of Cu extracted from the soil by 3 extraction procedures (0.1N HCI, EDTA, and DTPA) with crop yield and the concentration of Cu in snapbean tissue.

Rates of up to 54 kg/ha Cu had no deleterious effect on the yield of snapbeans in either year. Slight yield decreases were noted when the rate of Cu exceeded 130 kg/ha, and a marked reduction in yield occurred when 405 kg/ha of Cu as Cu(OH)2 or 486 kg/ha of Cu as CuSO4 was applied. Yield decreases were similar the 1st and 2nd years after Cu application, indicating that Cu toxicity was not being ameliorated over a 2‐year period of time. Soil Cu and yield were highly correlated for each of the extraction methods. Based on the regression equations, a significant yield depression was obtained when HCI or DTPA‐extractable Cu exceeded 20 ppm, and when EDTA‐extractable Cu exceeded 15 ppm. Soil Cu extracted by each extraction procedure was highly correlated with Cu in the leaf tissue, especially for the immature first trifoliate leaf. Yield reductions were noted when the Cu concentration in the seedling trifoliate increased from 20 to 30 ppm, and severe toxicity was observed at tissue concentrations in excess of 40 ppm Cu.
Genetics of Disaster
Authors: Harlan Jack R.
Published: July 2010

Erosion of some of the most vital resources for human survival goes on with no notice from the public and very little attention from the scientific community, which should be better informed. The germ plasm base required for improvement of the basic food crops that feed the world is being rapidly destroyed. This destruction of genetic resources is caused primarily by the very success of modern plant breeding programs.
Fungicidal Management of Pathogen Populations,
Authors: Rowell J. B.
Published: July 2010

Fungicides are the only means of controlling disease epidemics in a susceptible crop when conditions favor a virulent fungal pathogen that produces air‐borne spores rapidly and abundantly. Most available fungicides are surface protectants that act externally on the host to prevent infection by the pathogen. A high percentage of the plant tissue must be protected because large amounts of inoculum are produced by small numbers of infections. Maintenance of a protective chemical deposit effective throughout the vulnerable period of crop development requires frequent fungicidal spray applications of relatively high dosages. In contrast, systemic fungicides now under development act within the host and control disease with one or two applications at low dosages. Many of these materials are highly selective; they are effective against specific groups of pathogens. Some systemic fungicides suppress epidemics of rust and mildew diseases when applied as seed or soil treatments at planting. Such fungicides have great potential for preventing severe disease epidemics in field crops threatened by virulent, aggressive fungal pathogens.
Stabilizing Racial Populations of Plant Pathogens by Use of Resistance Genes
Authors: Nelson R. R.
Published: July 2010

Vertical resistance (VR) genes in plants function by restricting the infection site and the infection process of parasites. Such genes are effective against certain races and ineffective against others. Horizontal resistance (HR) genes in plants function by reducing the amount of disease by reducing disease increase. Horizontal resistance is effective to some extent against all races. The use of resistance genes to curb population shifts is examined herein. It is probable that HR curbs population shifts by virtue of its polygenic inheritance which requires that the parasite obtain and accumulate a number of new virulence genes. The use of VR genes in multilines holds some promise, deployment of VR genes probably does not, and pyramiding of VR genes seems most worthy. The concept of stabilizing selection is presented, discussed, evaluated, and deemed of doubtful validity as a means of curbing racial shifts.
New Concepts in Chemical Seed Treatment of Agronomic Crops
Authors: Futrell Maurice C.
Published: July 2010

The presence of Helminthosporium maydis Nisik. & Miyaka race T in corn (Zea mays L.) seed reduced germination and vigor of the seedlings. Ten percent of the seedlings damped‐off in soil in a growth room. Treating seed with Vitavax (5, 6‐dihydro‐2‐methyl‐1, 4‐oxathiin‐3‐carboxanilide) and Vitavax‐Thiram (Tetramethylthiurum disulfide) reduced the activity of H. maydis in the seed. Benomyl [Methyl 1(butylcarbamoyl)‐2‐benzimidazolecarbamate] and thiobendazole [2(4‐thiazolyl)‐benzimidazole] arrested Fusarium moniliforme Sheldon infection in corn seed. Mixtures of Vitavaxthiram and benomyl were effective in controlling both species of fungi in seed.
Southern Leaf Blight of Corn—Present Status and Future Prospects
Authors: Hooker A. L.
Published: July 2010

Two races, T and O, of Helminthosporium maydis Nisikado & Miyake cause southern blight of corn (Zea mays L.). The new race T spread widely in the USA in 1970 and to a lesser extent in 1971. It produces a pathotoxin specific to cms‐T cytoplasm of corn plants and infects the leaf, leaf sheath, husk, and ear parts. Race O, normally confined to the warmer parts of the USA, does not produce a specific pathotoxin and infects leaves primarily. Other races may exist or appear in the future.

Resistance to race O is based on nuclear genes, and in most sources is quantitative in expression and polygenic in inheritance; one source with recessive gene inheritance expresses chlorotic lesions with reduced fungus sporulation. Resistance to race T is both cytoplasmic and nuclear. Normal cytoplasms and many cytoplasms for male‐sterility such as the cms‐C and cms‐S types are highly resistant in the field. Resistance in cms‐T cytoplasm is partial and probably due to the same nuclear genes that give resistance to race O.

A diversity of cytoplasms within hybrids and the selection of high levels of nuclear‐gene resistance in a stalk rot resistant background are suggested as breeding and seed production objectives.
Soil Nitrogen Balance in selected Row‐Crop Sites in Southern California
Authors: Adriano D. C. , Takatori F. H. , Pratt P. F. , Lorenz O. A.
Published: July 2010

Nine row‐crop sites, where data for nitrogen fertilizer use, crop yields, and amounts of irrigation water used were available for a number of years, were studied to estimate the N balance as related to NO3− in water in the unsaturated zone from below the zone of root influence to the water table or to the 15‐m depth.

The system of predicting NO3− concentrations in drainage waters based on the difference between N inputs and N removal in harvested crop sand the drainage volume in which the excess N, converted to NO3−, is dissolved, was valid in open‐porous soils containing no layers that restrict water movement within the soil profile (0‐ to 2‐m depth). A combination of losses plus net immobilization of up to 56% had to be assumed in some soils to account for all the N loss. In two soils that had been used for disposal of feedlot manure, net mineralization of N from the organic N pool had to be assumed to explain the data obtained.

The current fertilization and irrigation practices used for some row crops in southern California leave varying amounts of NO3− in the drainage water. The amounts depend on the total N added, crop removal, drainage volume, net mineralization, and losses.
Cadmium Absorption and Growth of Various Plant Species as Influenced by Solution Cadmium Concentration
Authors: Page A. L. , Bingham F. T. , Nelson C.
Published: July 2010

Solution culture techniques were used to study the response of corn, turnips, beets, beans, tomatoes, cabbage, lettuce, green peppers, and barley to Cd levels in solution in the range of 0.1 to 10 µg/ml. Tolerance of the plants to Cd varied. Growth of beets, beans, and turnips was reduced by 50% at Cd solution concentrations of 0.2 µg/ml. Similar growth reductions for corn and lettuce occurred where the solution concentration level was about 1 µg Cd/ml. Tomatoes and barley were somewhat more tolerant with levels of about 5 µg Cd/ml required to produce 50% growth reduction. Cabbage, the most tolerant plant species tested, showed 50% growth reduction at Cd solution concentrations of 9 µg/ml.

Cadmium concentrations of plant leaves increased as the amount of Cd added to the substrate solution increased. Amounts accumulated when the solution concentration was 0.1 µg/ml varied between 9 µg/g (bean leaves) and 90 µg/g (corn leaves). At solution concentrations of 1.0 µg Cd/ml the range was 35 µg/g (bean leaves) to 469 µg/g (turnip leaves). Similarly at 10 µg Cd/ml the range was 175 µg/g (barley) to 112 µg/g (tomato leaves). The results presented show that plants vary in their tolerance to Cd solution levels and their leaves are capable of accumulating excessive Cd amounts when the solution concentration is of the order of a few tenths of a µg/ml.
Lead Availability Related to Soil Properties and Extractable Lead
Authors: John Matt K.
Published: July 2010

Lead content of lettuce (Lactuca sativa L.) and oats (Avena saliva L.) was related to lead extracted from 29 contaminated soils by several different extraction procedures. Correlation studies showed that 1N nitric acid extractable lead was significantly related to lead in lettuce; however, milder extraction with 0.01N nitric acid and 1N ammonium acetate provided a better correlation with lead content of oat shoots and roots. Soil properties, particularly soil pH, were also important when attempting to predict plant lead. Lead availability was related to soil pH, extractable aluminum, and total nickel. No relationship with organic matter was observed.
Organic Matter Reactions Involving Herbicides in Soil
Authors: Stevenson F. J.
Published: July 2010

Documentary evidence is presented in support of the view that organic matter plays a major role in the adsorption of herbicides in soil, and that organic matter content is usually the soil factor most directly related to herbicidal behavior. Major attention is given to the nature and origin of humic and fulvic acids, with special emphasis being given to the types of reactive sites responsible for the binding of pesticide chemicals. The various aspects of humus chemistry are discussed as they relate to investigations on herbicide‐soil organic matter relationships, including the inadequacies of methylation procedures for blocking specific functional groups in connection with bonding mechanism studies. Adsorption mechanisms are suggested and possible chemical transformations brought about by organic substances are outlined.
Weeds: Coexistence or Control
Authors: Nalewaja John D.
Published: July 2010

This presentation is a review of literature with the purpose of exposing the direct role weeds have in affecting the well being of man and animal. Mankind working to feed its masses cannot afford weeds which captivate crop fields, nor can it afford not to use chemical energy to control these weeds.

Weeds are vigorous competitors with crops causing severe yield losses as well as many indirect losses such as increased production and transportation costs. For example, the yield reduction from infestations of less than one plant/30 cm of row was 40,300 kg/ha or 51% from kochia (Kochia scoparia L. Schrad.) in sugarbeets (Beta vulgaris L.), 600 kg/ha or 27% from smooth pigweed (Amaranthus hybridus L.) and 21% from wild mustard (Brassica kaber D. C.) in soybeans (Glycine max L. Merr.), and from 100 wild mustard plants/0.9 m2, 36% in wheat (Triticum aestivum L.), 29% in barley (Hordeum vulgare L.), 32% in oats (Avena sativa L.), and 88% in flax (Linum usitatissimum L.). The degree of competition from a weed is dependent upon the crop, climatic, and edaphic factors. Protein of wheat, cotton lint grade, flax oil and iodine value, and potato grade have been reduced by weed competition. Weed seed contamination of grain may impart objectional flavors to the marketed product, render grain unfit for seed, and cause storage problems.

Common ragweed (Ambrosia artemisiifolia L.) and giant ragweed (A. trifida L.), which both adversely affect 4% of the population, account for 40% of the late summer pollen polluting the air. Many weeds are toxic to man and animals causing discomfort, congenital defects, and death. Three to five percent of the cattle, sheep, and horses on Western ranges in the United States are killed by consuming poisonous weeds each year.
Effects of Sediment on Water Quality
Authors: Stall John B.
Published: July 2010

Flowing water in a stream carries sediment which is considered a pollutant because it interferes with many uses of water. Other pollutants in the water may be attached to or greatly affected by the sediment. The ultimate source of most sediment is soil loss from sheet erosion which can be computed by the universal soil loss equation. It may be as high as 100 metric tons/ha per year on a steep, loose, cropped soil, or on any soil left bare during construction activity. Nearly level land in Illinois may lose 10 tons/ha per year regularly.

Sediment yield, or that delivered to a downstream point, can be estimated from the many measurements available. Yields are 15 tons/ha per year in Mississippi, the highest in the United States; yields are 10 in western Illinois and western Iowa, and less than 2 for the forest‐covered east and the arid west. Sediment problems are usually proportionate to sediment yields. In the Upper Mississippi River Basin 27% of the land has sediment yield double the level described as being tolerable. In this basin total sediment damage of $25 million/year is about comparable in amount to the upstream damage done by all floods.

Rivers carry a load of suspended sediment as a crucial part of their total energy balance. This natural sediment load is reflected in the median turbidity of 33 Jackson turbidity units found to be representative of all river waters in Illinois. If the suspended sediment load of a river is reduced, the stream will erode its bed or banks to pick up sediment to re‐establish its energy balance.

Traditional soil conservation measures will reduce soil loss from the farmer's field; this will also reduce sediment yield to a downstream reservoir. Reductions are often 70% to 90%. The river turbidity will be reduced, but it will never be eliminated. Stream turbidity affects many common uses of water. It is necessary to reduce this turbidity artificially in order to use the water.
The Oxygen Status of Lake Sediments
Authors: Howeler R. H.
Published: July 2010

The presence of oxygen in the surface layer of sediments greatly affects the abundance and availability of Fe, Mn, nitrates, phosphates, and sulfates. The concentration of O2 in the oxidized layer depends on the balance between the rate of O2 diffusion into the sediment and the rate of consumption by the sediment. Several mathematical diffusion models were developed to describe this relationship between diffusion and consumption. With these models the flux of O2 across the water‐mud interface and the thickness of the oxidized zone can be calculated. Experimental testing of the models showed that the steady state O2 consumption rates were proportional to the square root of the O2 concentration at the mud surface. The relative contribution of biological and chemical O2 consumption depended mainly on the organic matter content of the sediment, the biological consumption being highest in high‐organic matter soils. Determination of the Fe distribution near the sediment surface showed that Fe diffused upward from the reduced soil and accumulated in the oxidized zone. This freshly precipitated Fe could function as a phosphate sink, absorbing phosphates from the water and storing it in the sediment.
The Economics of Environmental Quality
Authors: Headley J. Charles
Published: July 2010

The economics of environmental quality is characterized in two dimensions. These are resource allocation and income distribution. The optimum allocation of resources leads to economic efficiency. Environmental problems that involve externalities may involve resource use at less than optimal economic efficiency and suggest a need for reallocation. Externalities result from jointness of production of “goods” and “bads” and from the end products of consumption and persist due to market failure. As resources are reallocated to improve environment quality, the relative prices of resources are shifted which can result in changing incomes for resource owners. This redistribution of income is related to property rights and will be opposed by those whose rights are restricted. People are more concerned about income distribution than optimal resource allocation. Externalities can be internalized and economists should outline the consequences of various alternatives for efficiency and income distribution.
Endrin Transformations in Soil
Authors: Nash R. G. , Beall M. L. , Harris W. G.
Published: July 2010

A Lakeland sandy loam was treated at three depths with 14Cendrin insecticide in which one crop of soybeans (Glycine max L., Merr.) was grown. After harvesting the soybeans, the soil was sectioned and assayed for endrin residues. At least three and possibly five transformation products of endrin occurred. Two products were identified as 1,8,9,9,10,11‐hexachloropentacyclo [6.3.0.12,5 .03,7.06,10] dodecan‐12‐one (endrin delta ketone) and 1,8,9,9,10, 11‐hexachlorohexacyclo [6.3.0.12,5.03,7.06,10.011,12] dodecan‐12‐ol (endrin alcohol). A third product may have been 1,8,9,9,10,11‐hexachloropentacyclo [6.3.0.02,11.03,7.06,10] undecan‐12‐carboxaldehyde (endrin aldehyde). Endrin transformation appeared to increase with soil depth. In an extremely acid soil (pH 4.2) endrin transformed to some endrin ketone and probably endrin aldehyde during treatment of the dry soil, but not of moist soil. Acid or base treatment of endrin and several endrin isomers indicated that endrin was stable under basic conditions and that endrin alcohol and endrin aldehyde (presumably) were stable in all treatments tested, except the base treatment at 100C for endrin aldehyde.
Fate of Nitrate from Manure and Inorganic Nitrogen in a Clay Soil Cropped to Continuous Corn
Authors: Kimble J. M. , Bartlett R. J. , McIntosh J. L. , Varney K. E.
Published: July 2010

Effects of dairy manure and N fertilizer were studied on plots that had received in a factorial arrangement two levels of manure (0 and 66 metric tons/ha) and two levels of N (0 and 224 kg/ha) applied every spring for 6 years. Laboratory incubation studies using soil profile samples showed potential denitrification to be greater in soil from the manure treated plots than in plots receiving either inorganic N or no N. The amount decreased with depth to 96 cm, below which energy for anaerobic microbial activity appeared to be limiting.

Laboratory analyses of profile samples indicated decreasing nitrate‐N/chloride ratios at all depths from fall to spring, suggesting that denitrification rather than leaching was responsible for a significant portion of the nitrate loss during this period. Abrupt decreases in the nitrate‐N/chloride ratios from the surface to the 45‐ to 71‐cm depth indicated that denitrification had taken place and that a nitrate bulge at 96‐ to 122‐cm probably was caused by denitrification above that depth.

The results indicate that more nitrate was lost by leaching when N was applied as NH4NO3 than when applied as dairy manure, both because there was more nitrate in the profile and because it was less susceptible to denitrification.
Nitrate in Unsaturated Zone of an Alluvial Soil in Relation to Fertilizer Nitrogen Rate and Irrigation Level
Authors: Adriano D. C. , Pratt P. F. , Takatori F. H.
Published: July 2010

Soil samples to the 15‐m depth beneath asparagus (Asparagus officinalis L.) and celery (Apium graveolens L.) were taken to determine the NO3− concentration in the solution of the unsaturated zone and to estimate the soil N balance. Transit time for water to move to the 15‐m depth was calculated from drainage volumes and volumetric water contents. Nitrogen balance was calculated from data for N input, N removal in harvested crops, and water records for the calculated transit time.

The NO3− concentration in the unsaturated zone increased with increase in N rate but was inversely related to the leaching volume. Denitrification was assumed to be the cause of high N losses with high irrigation levels. However, the rather high loss of 67.7% in the celery experiment, which received large amounts of chicken manure, was assumed to be a result of both net immobilization and denitrification. A combination of high losses of N, which ranged from 18.3 to 67.7%, and large amounts of excess N, in the NO3− form in the soil could have been one cause of the low efficiency of recycling N by these crops. The data suggest that high rates of N combined with high levels of water use are conducive to denitrification in relatively permeable soils.
Potential of an Eroding Urban Soil for the Phosphorus Enrichment of Streams: II. Application of Adopted Method
Authors: Ryden J. C. , Syers J. K. , Harris R. F.
Published: July 2010

The method developed in Part I was used with mixtures of A1 and B1 or A1 and 3C1 horizons of varying ratios to predict the potential of horizons from an eroding urban soil for the phosphorus enrichment of streams. A 1:9 mixture of A1 and 3C1 horizons sorbed greater or similar amounts of added inorganic P (0 to 200 µg P/liter) than a 1:9 mixture of A1 and B1 horizons at a solution/ soil ratio of 400:1. Nomograms were constructed to illustrate the relationship between initial inorganic P concentration (0 to 150 µg P/liter), equilibrium inorganic P concentration, and varying mixtures of these soil horizons using a 400:1 solution/soil ratio. Predictive ability is maximized because the data can readily be extrapolated to a wider solution/soil ratio (1000:1) which is more realistic in terms of a stream environment. Mixtures containing the A1 and 3C1 horizons maintained lower equilibrium P concentrations than those containing the A1 and B1 horizons. Calcium ions released from the calcareous 3C1 horizon apparently reduced the dissolution of P from the moderately soluble calcic P fertilizer‐soil reaction product present in the A1 horizon. The validity of the adopted method is discussed with reference to conditions existing in stream environments.
Meteorological Aspects of Atmospheric Ozone as a Potential Threat to the Forest Industry of North Florida
Authors: Davis D. R. , Dean C. E.
Published: July 2010

Observations over the past 8 years showed diurnal, daily, seasonal, and yearly variations in ozone levels. Ozone concentrations were highest in the late winter, spring, and early summer, and lowest in late summer. Day‐to‐day variations were associated with changes in weather patterns. Minor increases accompanied some but not all thunderstorms and cold frontal passage. Major increases were observed with squall lines, ozone‐rich air masses, and with stagnating air masses containing air pollutants.

This report compares highest observed ozone concentrations with reported damaging threshold concentrations for pine and other commercially important trees.

Ozone is apparently a minimal threat to the forestry industry of North Florida at the present time. However, as air pollution increases, photochemically produced ozone in stagnating air masses may become a problem to the industry as it has in other parts of the country.
Phosphate Chemistry in Lake Sediments
Authors: Syers J. K. , Harris R. F. , Armstrong D. E.
Published: July 2010

The amounts and forms of inorganic and organic phosphate (P) in lake sediments are discussed in relation to sediment composition and properties. The ability of noncalcareous and calcareous sediments to sorb and desorb added P in the laboratory and in the lake environment is interpreted in terms of the amounts and reactivities of sediment components involved in the sorption of P; emphasis is placed on the role of an Fe‐rich gel complex. Factors controlling the chemical mobility and biological availability of sediment inorganic and organic P are considered. Whether sediments act as a P source or sink is determined by sediment composition and limnological conditions. The factors involved in the interchange of P between the sediment interstitial water and the overlying water column are reviewed. The role of P in lake eutrophication is discussed briefly.