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1984

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Articles 1 - 30 of 52

Full-Text Articles in Fresh Water Studies

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson Dec 1984

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …


A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson Nov 1984

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m3. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m3. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …


Use Of Microcomputers To Aid Wastewater Treatment Plant Operations, David G. Parker, Sandra C. Parker Sep 1984

Use Of Microcomputers To Aid Wastewater Treatment Plant Operations, David G. Parker, Sandra C. Parker

Technical Reports

This report presents the development of a microcomputer based data management system for wastewater treatment plants. The relational database model was shown to be well suited for data management applications in wastewater treatment plants. A general data management system was developed for use with a microcomputer using a commercially available relational database management system. Use of the developed system requires no special computer training. The system was tailored for use at the wastewater treatment plant at Springdale, Arkansas. The capabilities of the system were demonstrated with actual data from the Springdale plant.


Studies Of Effectiveness Of Commercial Home Treatment Systems, William W. Trigg, Raymond D. Couser Sep 1984

Studies Of Effectiveness Of Commercial Home Treatment Systems, William W. Trigg, Raymond D. Couser

Technical Reports

Eleven home water systems were tested representing six different types of filtering systems. Tests were made for Sulfates, Nitrates, Phosphate, Iron and Escherichia coli and Enterobacter aerogenes before and after passing through a home treatment system. All of the systems removed iron adequately but had little effect on the removal of nitrates, phosphates, sulfates or control of pH. Since none of the ground waters was contaminated by coli- forms, nothing was established regarding the effectiveness of bacterial removal by these systems.


Wetlands Forest Communities As Indicators Of Flooding Potential In Backwater Areas Of River Bottomlands, Edward E. Dale Jr. Sep 1984

Wetlands Forest Communities As Indicators Of Flooding Potential In Backwater Areas Of River Bottomlands, Edward E. Dale Jr.

Technical Reports

A phytosociological study was made of forest types that occur in backwater and river bottomlands of the Gulf Coastal Plain, Arkansas Valley, and Mississippi Delta Regions of Arkansas. Twenty different forest types dominated principally by a single species were identified and described. Their occurrence was then correlated with flooding conditions in their habitats and the types were arranged along decreasing moisture gradients. Those forest types tolerant of flooding or saturated soils between three months to a year or more are Taxodium distichum, Nyssa aquatica, Cephalanthus occidentalis, Salix nigra, and Planera aquatica types. Those tolerant from one to three months are …


Evaluation Of Nitrogen And Phosphorus Enrichment Using In Situ Enclosure Bags With Temporal Indigenous Phytoplankton Populations, Richard L. Meyer, W. Reed Green Sep 1984

Evaluation Of Nitrogen And Phosphorus Enrichment Using In Situ Enclosure Bags With Temporal Indigenous Phytoplankton Populations, Richard L. Meyer, W. Reed Green

Technical Reports

An in situ experimental procedure and protocol was developed to evaluate nitrate and phosphate enrichment using isolated indigenous phytoplankton assemblages during different seasons. Results of the comparison of the parameters-temperature, pH, alkalinity, conductivity, and dissolved oxygen between the open water and enclosed systems indicated that there was no significant influence of the physicochemical factors on the isolated biological processes. Growth responses were measured by turbidity, biomass and chlorophyll-a, the most sensitive being chlorophyll-a. Additions of nitrate and phosphate were added in known concentrations and in different magnitudes of concentration based upon ambient conditions and ratio. During the fall, phosphorus influenced …


Factors Affecting The Removal Of Suspended And Dissolved Solids In High Strength Wastewater From Vegetable Processing, William A. Sistrunk Sep 1984

Factors Affecting The Removal Of Suspended And Dissolved Solids In High Strength Wastewater From Vegetable Processing, William A. Sistrunk

Technical Reports

Fifty or more individual factorial experiments were designed to study the effectiveness of physical-chemical and micro-biological treatments in removal of suspended and dissolved solids in effluent from potatoes, hominy, dry beans and other vegetables. The wastewaters were obtained from local processing plants and treated with 3 to 5 inorganic salts, 13 polymers, and 3 or more pH levels during 12 months. Also, selected strains of yeast and fungi were used to assimilate the effluent. Individual inorganic salts were more effective on a certain vegetable effluent than others. Polymers (anionic and cationic) were more effective in coagulating suspended solids in combination …


Water Management Simulator Presentations, Leslie E. Mack Sep 1984

Water Management Simulator Presentations, Leslie E. Mack

Technical Reports

One of the larger stumbling blocks to comprehensive water management is the lack of public understanding of the multitude of variables that operate at the same time within the hydrologic cycle. With more public understanding, there is greater public support for various water projects. Dr. John R. Amend from Montana State University developed a water management simulator which could handle a large number of variables simultaneously of natural surface and groundwater flow plus a number of water use variables on an accelerated time sequence. By using several remote control devices, participants can "control" their water use but have no control …


Groundwater Quality And Mineral Deposits Relationships In The Ozark Mountains, Kenneth F. Steele Sep 1984

Groundwater Quality And Mineral Deposits Relationships In The Ozark Mountains, Kenneth F. Steele

Technical Reports

Ninety-nine groundwater sites were sampled in northern Arkansas in order to determine the effect of local manganese, phosphate, pyrite, lead-zinc and uranium mineralization on the groundwater chemistry. Most of this study (75 springs) was concentrated in the Batesville manganese district. Hydrogeochemical exploration for these types of manganese deposits appears possible with 44 percent of the springs within 2000 feet of mineralization having anomalous metal concentrations (especially manganese). Because only a few springs were sampled in the remaining areas, the results are not conclusive; however, only the pyrite and small lead-zinc deposit would appear worthy of additional investigation. None of the …


Precedings Of Arkansas Lakes Symposium Limnological Studies Of Lake Chicot, Arkansas, Joe F. Nix, Frank R. Schiebe Aug 1984

Precedings Of Arkansas Lakes Symposium Limnological Studies Of Lake Chicot, Arkansas, Joe F. Nix, Frank R. Schiebe

Technical Reports

Lake Chicot is an oxbow lake that was created more than 600 years ago by the meandering of the Mississippi River. It is located in Chicot county in southeastern Arkansas adjacent to the present Mississippi River. As the largest natural lake in Arkansas it earned an early reputation for its good fishing and recreational value. Development of a levee system forced the enlargement of the lakes watershed to its present 350 square miles. Initially this alteration affected only the volume flow through the lake, drastically reducing the water residence time. Because the watershed was located in one of the most …


Identification Of Critical Water Levels In Flooded Rice Fields, Carl L. Griffis Aug 1984

Identification Of Critical Water Levels In Flooded Rice Fields, Carl L. Griffis

Technical Reports

A mathematical model was developed to simulate the transient hydrology of a flooded rice field. With the model, users can determine the critical interlevee areas in which to monitor the water levels so that the irrigation well can be turned on at the critical low water level, and turned off at the critical high water level, in order to maximize water application efficiency. Sensitivity analysis performed with the model showed that it will be necessary to calibrate the model for each specific field. A calibration procedure has been developed.


Evalution Of Drainage Tile To Alleviate Salt Building In Heavy Soils Irrigated With Brackish Water And Cropped With Rice And Soybeans, T. C. Keisling, J. T. Gilmour, H. D. Scott, A. M. Sadeghi, R. E. Baser Aug 1984

Evalution Of Drainage Tile To Alleviate Salt Building In Heavy Soils Irrigated With Brackish Water And Cropped With Rice And Soybeans, T. C. Keisling, J. T. Gilmour, H. D. Scott, A. M. Sadeghi, R. E. Baser

Technical Reports

The use of tile drains for alleviating soluble salt accumulation on silt loam soil was investigated during 1984. Although the chemical analyses of the floodwater and tile drainage water were very similar suggesting that the floodwater was moving to the tile drain, the overall results so far indicate that this is not a feasible solution owing to lack of significant drainage. Application of DRAINMOD utilizing soil and weather data from Arkansas showed no significant effluent from the tile drains for our experimental site during rice production. This was attributed to the extremely slow saturated hydraulic conductivity values for this particular …


Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde May 1984

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …


Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo Apr 1984

Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo

OES Theses and Dissertations

Autotrophic biomass and productivity as well as nutrient distributions and phytoplankton cell populations in the James River estuary, Virginia, from Newport News Shipyard to the 0 o/oo isohaline, were sampled on a monthly basis from August of 1981 to December of 1982. Particular emphasis was placed on the very low salinity region (defined as the location where surface salinity measured between 0.0 and 0.75 o/oo based on conductivity) in order to determine the fate of fresh water phytoplankters upon being advected into the estuary because of their suspected role in the biogeochemical cycling that occurs there.

Both chlorophyll a and …


Laser-Photoacoustic Detection Of Water Pollutants, Gregory J. Salamo, Richard J. Anderson Mar 1984

Laser-Photoacoustic Detection Of Water Pollutants, Gregory J. Salamo, Richard J. Anderson

Technical Reports

We have investigated the potential of amplitude-modulation laser-photoacoustic scheme for the detection of trace pollutants in water. The technique has been found to be non-disturbing and easy-to-apply. In particular, the technique could be used to detect pollutants with a concentration corresponding to an absorption coefficient of 10-6cm-1. The sensitivity was found to be limited by a background signal resulting from light absorption by water. In addition to the amplitude-modulation scheme we also investigated the potential of a wavelength modulation scheme. Although this approach did reduce the background signal due to water absorption, we found the technique to be much more …


Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency Feb 1984

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982.

A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …


Sea Grant College Designation Program, Virginia Institute Of Marine Science, School Of Marine Science, College Of William And Mary Jan 1984

Sea Grant College Designation Program, Virginia Institute Of Marine Science, School Of Marine Science, College Of William And Mary

Miscellaneous

October 25, 1984. The designation of the Virginia Sea Grant Program as the nation's twentieth National Sea Grant College Program in January 1984, recognized that the Sea Grant activities in Virginia were providing state and national leadership in the marine sciences and related fields.


Oilseed Agronomy, A G. Mckay, R J. Larsen Jan 1984

Oilseed Agronomy, A G. Mckay, R J. Larsen

Experimental Summaries - Plant Research

Potential of triazine tolerant rapeseed – 84AL44, 84MA23, 84WH31.

Rates and times of triazines on triazine tolerant rapeseed – 84MA22, 84WH33.

Fitness of triazine tolerant and susceptible F1's - 85GL7.

Cleaning crops for cereals – 84MA2.

Interstate variety evaluation – 84MA24, 84MT42,84WH32.


Foliar Disease Of Wheat, A. G. P. Brown Jan 1984

Foliar Disease Of Wheat, A. G. P. Brown

Experimental Summaries - Plant Research

Wheat leaf diseases were at much reduced levels in 1984. This may have been caused by prolonged summer rain prematurely setting off dispersal of spores and also initiating microbiological breakdown of stubble residues. No survey was carried out in 1984 but a good indication of the seasonal effect can be gained by noting that in the spray-timing experiment at Badgingarra disease levels were extremely low until the end of August some 90 days after sowing. Timing of fungicide for Septoria and Yellow Spot control. 84BA32, 84GE59. Effect of Yellow-spot at Merredin (with S. Trevenen) 84ME57. Yellow-spot is common though not …


Lupin Growth And Water Use; Wheat, Barley, Pea, Rob Delane, J. Hamblin, A Bishop Ms Jan 1984

Lupin Growth And Water Use; Wheat, Barley, Pea, Rob Delane, J. Hamblin, A Bishop Ms

Experimental Summaries - Plant Research

84C16/84C17 Lupin Growth and Water Use. 84C19 Effect of Density and Nitrogen on Growth and Yield of Uniculm and Tillering Wheat. 84C20 Maturity, Nitrogen and Density Effects of Barley. 84C21 Wheat Variety Trial. 84C18/23/28/33 Pea Research in the Geraldton Region. 84C32 Effect of Terra Sorb on Wheat Yield.


Seed Ecology Of Weeds, A H. Cheam Jan 1984

Seed Ecology Of Weeds, A H. Cheam

Experimental Summaries - Plant Research

1. Emergence of weed seedlings from different soil depths 82MT49 Mt Barker Research Station 83MT4 Mt Barker Research Station 82NR12 Northam Research Station 83NR2 Northam Research Station 82C37 Chapman Research Station 83C3 Chapman Research Station

2. Longevity of buried weed seeds 82MT50 Mt Barker Research Station 83MT5 Mt Barker Research Station 82NR13 Northam Research Station 83NR3 Northam Research Station 82C38 Chapman Research Station 83C4 Chapman Research Station

3. Emergence of weed seedlings in relation to soil type and cultivation 82PE32 South Perth

4. Changes in the number of viable dock seeds in soil under different soil surface treatments 83V2 Vasse …


Effect Of Various Crop And Pasture Species On The Growth Of A Subsequent Wheat Crop, N Delroy, J W. Bowden, I Rowland, M Ralph, R Lunt, M Baker Jan 1984

Effect Of Various Crop And Pasture Species On The Growth Of A Subsequent Wheat Crop, N Delroy, J W. Bowden, I Rowland, M Ralph, R Lunt, M Baker

Experimental Summaries - Plant Research

83WH29: The effect of various crop and pasture species on the growth of a subsequent wheat crop. Aim: To characterise the effect of various crop and pasture species on the growth and yield components of a subsequent wheat crop with special emphasis on the nitrogen nutrition of that crop. To provide validation data for modelling wheat growth and nitrogen uptake. Measurements: Factors to be monitored through time were; Soil moisture profiles; Mineral nitrogen profiles; Root growth profiles; Top growth and nitrogen uptake; Development score; Incidence of disease and pests.

Seasonal notes, trial design, weed diseases and pests. Results: The results …


Low Rainfall Pasture Project, M. A. Ewing Jan 1984

Low Rainfall Pasture Project, M. A. Ewing

Experimental Summaries - Plant Research

1. Variety experiments: (a) Rows 84M39. (b) Small Plots 84M40. (c) Large Plots 84M41, 84WH40, 84N22, 84LG39, 84M56, 84M57. 2. Pasture establishment systems: 84TS38, 84M61. 3. Pasture grazing (defoliation) experiments: 84M43, 84LG34, 84LG33, 84M42. 4. Cereals following pastures: 84ME47. 5. Pasture wheat rotaton experiments: 82WH39, 82M47. 6. Medic rhizobial studies - see report of J. Howieson. 7. Lupins - see report R. French.


Soil Acidity Survey. Lime Responses In The Central Wheatbelt, P J. Dolling Jan 1984

Soil Acidity Survey. Lime Responses In The Central Wheatbelt, P J. Dolling

Experimental Summaries - Plant Research

Introduction: In 1984 a project commenced to examine the influence of soil acidity on barley production in the main barley growing areas of Western Australia. To carry out some of the projects objectives a soil survey was carried out.

Aims: 1. To select nine sites for liming trials in 1985. 2. To obtain more information about the soil acidity problem in the medium rainfall region of W.A. 3. To determine if there is a relationship between the pH and aluminium content of the soil.

Survey details: Area covered - Katanning and Narrogin District Office (DO) areas. Sampling period - Mid …


The Ecology Of Skeleton Weed .(Chondrilla Juncea L.) In Western Australia , Afghan Thistle (Solanum Hoplopetalum) Ecology, J. Dodd Jan 1984

The Ecology Of Skeleton Weed .(Chondrilla Juncea L.) In Western Australia , Afghan Thistle (Solanum Hoplopetalum) Ecology, J. Dodd

Experimental Summaries - Plant Research

1. The ecology of skeleton weed .(Chondrilla juncea L.) in Western Australia - 84PE18 Seed production and water use in the glasshouse. 1.2 Seed production and water use of field-grown skeleton weed (84BA17, 84BA18). Water use. 1.3 Germination in relation to soil water content. 2. Afghan thistle (Solanum hoplopetalum) ecology. 2.1 Water relations (84N048). 2.2 Growth in Afghan thistle (84N050). 2.3 Afghan thistle reproductive biology (84N049, 84N063, 84PE19).


Annual Medicago Spp. For Wa Rangelands - Selection And Establishment Techniques, G Gintzburger Jan 1984

Annual Medicago Spp. For Wa Rangelands - Selection And Establishment Techniques, G Gintzburger

Experimental Summaries - Plant Research

1) Exp 84KG1: Annual Medicago spp, for W.A. Rangeland. Ecotype testing with seeds sown (Woolibar Station). 2) Exp 84KG2: Pod seeding of annual Medics and response to phosphate fertilisation (I). (Woolibar Station). 3) Exp 84KG3: Serena Medics on Goldfield Rangeland - Pod seeding and pitting (Jeedamya Station). 4) Exp 84KG4: Pod seeding of annual Medics and response to phosphate fertilisation (II). (Woolibar Station). 5) Exp 84CA1: Establishment and survival of annual Medics - Pod seeding on W.A. rangelands simulating aerial seeding (Quobba Station). 6) Exp 84CA2: Annual Medicago spp. for W.A. rangeland - Ecotypes testing with seed sown (Hamelin Station). …


Nitrogen Flows From Several Species And Varieties Of Legume, John Hamblin Dr Jan 1984

Nitrogen Flows From Several Species And Varieties Of Legume, John Hamblin Dr

Experimental Summaries - Plant Research

Trial 83C24: N flows from several species and varieties of legume.

Trial 83C27: The effect of seeding rate, planting and variety on the residual value of lupins.

Trial 84C25: Small rotation trial for 1985.

Trial 84C34: Nitrogen response on large rotation plots at ECRS.

These trials were carried out in collaboration with: Mr R. Delane, and with assistance from: Mr. T. White, Ms. A. Bishop.


Water Use Of Alternative Wheatbelt Crop Species, A P. Hamblin, M W. Perry, D Tennant, Neil C. Turner Dr Jan 1984

Water Use Of Alternative Wheatbelt Crop Species, A P. Hamblin, M W. Perry, D Tennant, Neil C. Turner Dr

Experimental Summaries - Plant Research

84M5, 84M6, 84M7. Location: Merredin Research Station Merredin, Western Australia. Three experiments were conducted to measure the productivity and water use of alternative wheatbelt crop species on contrasting soil types in a dry mediterranean environment. Crop species investigated were wheat, barley, cereal rye, narrow leafed lupin and field pea. These were grown on three contrasting soil types, a red-brown earth, a sandy loam over clay and a deep loamy sand; all soils occurring within close proximity to each other. Detailed measurements were made of meteorological conditions, dry matter production, leaf area, root growth, soil water profiles, light interception and plant …


Long Term Minimum Tillage Investigations, Stubble Management, Deep Ripping, R J. Jarvis, L G. Butcher Jan 1984

Long Term Minimum Tillage Investigations, Stubble Management, Deep Ripping, R J. Jarvis, L G. Butcher

Experimental Summaries - Plant Research

Direct drilling Long term minimum tillage investigations (1) Continuous cropping – 77A16, 77A18, 77MT15, 77WH17, 77WH13, 78M25. (2) Rotational cropping – 77A43, 77E52, 77M35, 77M56, 77MT51, 77WH8. Stubble management – 79M7, 79WH6, 82M34, 84M1, 82LG4, 82LG46 (82KD1). Deep ripping - 82M35 in Minimum Tillage Rotation section also contains a deep ripping treatment. 77WH17, 80A44, 80NO46, 81M45, 81NO3, 81NO4, 82GE37, 82GE38, 82M30, 82M46, 82M60, 82ME38, 82N32, 82WH49, 84E24, (84C42, 84C43, 84C44, 84C45, 84C46) Eradu Sandplain – ECRS, 84E23, 84E24, 84JE43, 84JE44, 84LG37, 84M38, 84NO58, 84WH2, 84WH3, 84WH39. Additional deep ripping research is included in summaries by W. Bowden, D. Tennant, J. …


Crop Oil Additives To Herbicides, R Madin, A Lindsay Jan 1984

Crop Oil Additives To Herbicides, R Madin, A Lindsay

Experimental Summaries - Plant Research

Crop oil additives to herbicides - 84LG42.

Umbrella grass (Cyperus eragrostis) control in irrigated pasture - 85HA1.

Stinkwort control - 85NO5, 85PE14.

Ice plant (Mesembryanthem nodiflorum) control in crop and pasture - 83SG20, 83SG21.