bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic Matter Reactions Involving Herbicides in Soil
Authors: Stevenson F. J. 
Published: July 2010

AbstractDocumentary 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

AbstractThis 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

AbstractFlowing 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractEffects 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

AbstractSoil 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

AbstractThe 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

AbstractObservations 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

AbstractThe 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.
The Florida Citrus Industry's Commitment to A Better Environment
Authors: Tucker D. P. H. , Wardowski W. F. 
Published: July 2010

AbstractThis paper discusses the citrus industry's potential role in environmental pollution and steps it is taking to combat any undesirable effects. Where pertinent, grove cultural practices and the fresh fruit packing and processing segments of the industry are analyzed.The Florida citrus processing industry has made considerable strides in pollution abatement procedures. It is a leader in the utilization of food wastes and has been active in this field since the early 1900's. A striking example of potential pollutants converted to industrial profits is the large number of by‐products now in commercial production and in various stages of research and development.This recycling plus some use of beneficial insects to control pests, revised fertilization, water usage, heating and processing procedures make the citrus industry of Florida one of the few industries with such a high potential for complete raw product utilization while holding its pollution contribution to acceptable levels.
Municipal Waste Compost: Effects on Crop Yields and Nutrient Content in Greenhouse Pot Experiments
Authors: Terman G. L. , Soileau J. M. , Allen S. E. 
Published: July 2010

AbstractFive greenhouse pot experiments were conducted to study the utilization or disposal of urban waste compost on agricultural soils. Highly carbonaceous compost applied without additional N induced N deficiency in corn (Zea mays L.) grown on very N‐deficient Mountview sil. This was corrected by applying soluble N. Apparent N deficiency of corn was not induced by compost on soils higher in crop‐available N. Compost supplied considerable N, P, K, Ca, and Zn for corn and tall fescue (Fescue arundinacea Schreb.); P and K in the compost were relatively more available than its content of N. Placing P with compost did not increase availability of the P for corn.Heavy applications of compost (made from garbage and sewage sludge solids) to soil had a considerable liming effect and increased Zn concentrations and uptake by corn and tall fescue. The liming effect apparently prevented toxicity to corn and snap beans (Phaseolus vulgaris L.) from Zn accumulations from compost on an acid Sango sil.
Municipal Compost: Effects on Crop Yields and Soil Properties
Authors: Mays D. A. , Terman G. L. , Duggan J. C. 
Published: July 2010

AbstractThese field experiments were conducted in connection with the recent upsurge of interest in composting as a disposal method for municipal refuse. Heavy applications of compost made from municipal refuse and sewage sludge were evaluated for production of forage sorghum (Sorghum bicolor L. Moench × Sorghum sudanense P. Stapf.) and common bermudagrass (Cynodon dactylon L.) at Muscle Shoals, Ala., and for corn (Zea mays L.) at Johnson City, Tenn.Positive yield responses were observed t o annual compost application at rates up to 80 metric tons/ha on bermudagrass, 143 metric tons/ha on sorghum, and 112 metric tons/ha on corn. However, the highest yields of bermudagrass or sorghum attained from compost application were equaled or surpassed by application of fertilizer nitrogen (N) at the rate of 180 kg/ha together with adequate phosphorus (P) and potassium (K). Compost‐induced K deficiency was not observed in any crop.Incorporation of compost over a 2‐year period significantly increased moisture‐holding capacity and decreased bulk density and compression strength of the soil. The pH, organic matter, K, calcium (Ca), magnesium (Mg), and zinc (Zn) levels were also increased. Soil and plant tissue analyses indicated that potentially toxic amounts of Zn could accumulate in the soil if compost were applied at rates totaling several hundred tons/ha over a few years.
Cadmium Uptake by Plants
Authors: Haghiri F. 
Published: July 2010

AbstractAbsorption of 115mCd by soybean (Glycine max L.) plants via foliar and root systems and translocation into the seed was determined. The uptake of 115mcd by soybeans via the root system was more efficient than that of the foliar placement.Growth and Cd concentrations of soybean and wheat (Triticum aestivum L.) tops were influenced by soil‐applied Cd. In both crops, the Cd concentration of plant tops increased while yield decreased with increasing levels of applied Cd. Cadmium toxicity began to occur in both crops at the lowest level of soil applied Cd (2.5 ppm). With soybean plants, Cd toxicity symptoms resembled Fe chlorosis. For wheat plants there were no visual symptoms other than the stunted growth.The relative concentration of Cd found in several vegetable crops varied depending on the plant species. The relative Cd concentration in descending order for various vegetables was lettuce (Lactuca sativa L.) > radish top (Raphanus sativus L.) > celery stalk (Apium graveolens L.) > celery leaves ⩾ green pepper (Capsicum frutescens L.) > radish roots.
Recycling and Recovery of Nitrogen, Phosphorus, and Potassium by Coastal Bermudagrass: II. Under Grazing Conditions with Two Stocking Rates
Authors: Rouquette F. M. , Matocha J. E. , Duble R. L. 
Published: July 2010

AbstractThe effect of two stocking rates on the recycling of N, P, and K was studied for 2 years on a Coastal bermudagrass [Cynodon dactylon (L.) Pers.] sward. Samples for chemical analysis were taken at 14‐day intervals. Available forage, forage yield, and forage consumption were estimated from samples taken at 2‐ to 4‐week intervals. Soil samples were taken prior to, during, and at termination of the grazing trial. Plant nutrient recycling on the high stocked pastures was approximately twice as great during the dry, 1969 season and about 10% higher during the 1970 season compared to that on the low stocked pastures. Recoveries of applied plant nutrients averaged over stocking rates were 84, 50, and 155% for N, P, and K, respectively, during 1969, and 180, 73, and 172% for N, P, and K, respectively, during 1970. There was a substantial soil accumulation of plant nutrients under both stocking rates with a considerable advantage in favor of the high stocked pastures. On the high stocked pastures, total soil N accumulation was slightly less than twofold, available soil P increased threefold, and available soil K increased more than twofold over the 2‐year period.
Enrichment of the Atmosphere with Nitrogen Compounds Volatilized from a Large Dairy Area
Authors: Luebs R. E. , Davis K. R. , Laag A. E. 
Published: July 2010

AbstractA dairy cow population of 143,000 in an area of 150 km2 enriched the atmosphere with distillable N (mostly NH3) over an area in excess of 560 km2. Over an area of 35 km2, where cow population density was approximately 1,600 cows/km2, the concentration of distillable N in the atmosphere was between 20 to 30 times greater than at a control site outside the dairy area. Highest concentrations of N were associated with wet corral surfaces and favorable evaporative conditions. Approximately 20% of the total N absorbed by acid‐surface traps in the dairy area was nondistillable N while filtered air samples contained 5% or less. Rainfall delivered three times as much N to the land surface inside than outside the dairy area.
Fate of a Mercuric‐Mercurous Chloride Fungicide Added to Turfgrass
Authors: Gilmour J. T. , Miller M. S. 
Published: July 2010

AbstractThe behavior of a mercurous‐mercuric chloride fungicide (Caloclor) added to turfgrass and bare soil was investigated. From 44 to 56% of the total Hg added to a turfgrass surface was lost in 57 days. Plant uptake and removal upon cutting did not account for these losses which were attributed to volatilization of metallic Hg formed in the turfgrass‐soil system. Where additions were made in the turfgrass root zone, loss was reduced and redistribution of Hg in the soil followed a pattern in qualitative agreement with metallic Hg formation and redistribution. Verification of volatilization from bare soil surfaces was made.