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Articles 18781 - 18810 of 19881

Full-Text Articles in Entire DC Network

Fisheries Research Report No. 92 - Spread Of The Introduced Yabbie Cherax Albidus Clark, 1936 In Western Australia, N. M. Morrissy, G. Cassells Jan 1990

Fisheries Research Report No. 92 - Spread Of The Introduced Yabbie Cherax Albidus Clark, 1936 In Western Australia, N. M. Morrissy, G. Cassells

Fisheries Research Reports

This report presents information on the probable original introduction of the eastern Australian yabbie to farm dams in the Wheat-belt Region of the southwest of Western Australia (in 1932 at Narembeen); the probable type of yabbie (the "White Yabby", Cherax albidus Clark 1936 ) and source (Miram Swamp in the Victorian Wimmera); and, in 1985, the first voicing of concern over the spread of yabbies to natural habitats, particularly in the higher rainfall region of the southwest, together with current national and international concerns and advice on introduced aquatic species.

Commercial harvesting ("extensive" aquaculture) of existing yabbie stocks in wheat-belt …


Preliminary Groundwater And Salinity Investigation In The Eastern Wheatbelt. 4. Kitto's Hillslope, Tammin - 1985-90, Richard J. George Dr Jan 1990

Preliminary Groundwater And Salinity Investigation In The Eastern Wheatbelt. 4. Kitto's Hillslope, Tammin - 1985-90, Richard J. George Dr

Resource management technical reports

The investigation revealed that a deep, brackish to saline groundwater system and dolerite dyke, contained within the saprolite were responsible for the secondary salinity; the annual discharge of water and salt at the seep from the damp groundwater system was about 2800 kL and 17 tonnes respectively; and the water-tables were not rising and that the most appropriate management of the site was to plant salt tolerant forage plants in combination with trees.


An Introduction To The Soils Of The Albany Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Albany Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With description, illustrations and notes on eight common soils.


The 1989 Saltland Survey, Richard George Jan 1990

The 1989 Saltland Survey, Richard George

Journal of the Department of Agriculture, Western Australia, Series 4

In March 1989, the Australian Bureau of Statistics (ABS) surveyed farmers in Western Australia to determine the area of previously arable land that was now too saline for conventional agriculture. Farmers reported that 443,441 ha, or 2.83 per cent, of the 15.7 million hectares of cleared farm land in south-western Australia, was saline. This was an increase of about 180,000 ha on the 1979 survey figure.

The worst affected areas were in the 350 mm to 600 mm rainfall zone and included the Shires of Tammin (9.26 per cent arable area saline), Katanning (7.96 per cent), Goomalling (7.93 per cent), …


Plant Growth And Survival In Saline, Waterlogged Soils, Ed Barrett-Lennard, Neil Davidson, Richard Galloway Jan 1990

Plant Growth And Survival In Saline, Waterlogged Soils, Ed Barrett-Lennard, Neil Davidson, Richard Galloway

Journal of the Department of Agriculture, Western Australia, Series 4

Waterlogged soils in Western Australia are often salt-affected. Recent research has shown that the interaction between waterlogging and salinity has a far greater adverse effect on plant groivth and survival than either of these two factors individually. The consequences of the combined effects of salt and waterlogging for most plant species are increased salt uptake, reduced growth, chlorosis (yellowing of leaves), defoliation, and death. Salt sensitive agricultural species (nonhalophytes) are more severely affected by this interaction than salt tolerant species (halophytes).


Shallow Drains For Reducing Waterlogging And Salinity On Clay Flats, Don Mcfarlane, Tim Negus, Arjen Ryder Jan 1990

Shallow Drains For Reducing Waterlogging And Salinity On Clay Flats, Don Mcfarlane, Tim Negus, Arjen Ryder

Journal of the Department of Agriculture, Western Australia, Series 4

Flooding, waterlogging and salinity are problems which commonly occur together on the broad valleys of the wheatbelt. Drainage lines often become poorly defined once they reach the valleys and flood waters spread out, causing inundation and waterlogging. This excess water needs to be controlled because it contributes to salinity


Waterlogging Limits Growth On Duplex Soils, Bob Belford, Miles Dracup, David Tennant Jan 1990

Waterlogging Limits Growth On Duplex Soils, Bob Belford, Miles Dracup, David Tennant

Journal of the Department of Agriculture, Western Australia, Series 4

Duplex soils - soils with a sandy topsoil overlying a clayey subsoil -are ividespread in Western Australia's agricultural areas (see map). These soils are potentially highly productive, but crop growth is variable and the soils can become waterlogged. Work on a duplex soil site near Beverley has shoivn that the soil ivaterlogs where the permeability of the clay is low, and that this permeability varies ividely over the site. Waterlogging accounts for an average of half of the variation in wheat yields on this site; surprisingly, lupins have so far appeared less sensitive to waterlogging- The Department of Agriculture and …


Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford Jan 1990

Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford

Journal of the Department of Agriculture, Western Australia, Series 4

Lack of oxygen is the major cause of limited plant growth in waterlogged soils. When soils become waterlogged less gas diffuses to and from the roots through the soil pores; there are changes in concentrations of mineral elements in soil solutions; and toxic products of roots and soil microorganisms begin to accumulate. These changes adversely affect germination, growth and development of plants.


Integrated Control Of Soil Insect Pests Of Potatoes, Stewart Learmonth, John Matthiesson Jan 1990

Integrated Control Of Soil Insect Pests Of Potatoes, Stewart Learmonth, John Matthiesson

Journal of the Department of Agriculture, Western Australia, Series 4

One of the more difficult aspects of growing potatoes in Western Australia is controlling soil insect pests. These pests have become more troublesome because the highly effective and persistent organochlorine insecticides previously used to control the main soil pests, African black beetle and whitefringed weevil, were deregistered for agricultural use in 1987. Entomologists from the Department of Agriculture and CSIRO in Western Australia are collaborating to develop new management strategies for these pests that rely less on the use of chemical insecticides


Mining In Maine : Past, Present, And Future, Carolyn A. Lepage Jan 1990

Mining In Maine : Past, Present, And Future, Carolyn A. Lepage

Maine Collection

Mining in Maine : Past, Present, and Future

by Carolyn A. Lepage, Michael E. Foley, and Woodrow B. Thompson

Maine Geological Survey, Department of Conservation, Augusta, Me., 1990.

Contents: Introduction / The Early Years: Pre-Civil War / The Civil War to World War II / The War Years of the 1940's / The Postwar Years: 1940's to 1960 / The 1960's / The 1970's / Maine Mineral Resources Association / The 1980's / Current Mining and Exploration / Future Potential / Acknowledgments / References


Statistical Prediction Of Satellite Magnetic Anomalies, H. K. Goyal, R. R. B. Von Frese, W. J. Hinze, D. N. Ravat Jan 1990

Statistical Prediction Of Satellite Magnetic Anomalies, H. K. Goyal, R. R. B. Von Frese, W. J. Hinze, D. N. Ravat

Earth and Environmental Sciences Faculty Publications

The geological utility of satellite magnetic observations is limited by orbital altitude variations which may be as large as a few hundred kilometres. This study investigates the use of fast and elegant statistical procedures for altitude normalization and gridding of magnetic anomaly data as an alternative to more commonly used equivalent source inversion procedures involving computationally extensive and complex least‐squares matrix methods. A standard statistical approach for gridding satellite magnetic anomalies is to recompute numerically averaged values from three‐dimensionally distributed observations which are within two standard deviations of an initially determined averaged anomaly estimate. the errors of this procedure for …


An Introduction To The Soils Of The Jerramungup Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Jerramungup Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on eight common soils.


Waterlogging : One Reason Why Our Crops And Pastures Are Not Achieving Maximum Yields, Department Of Agriculture And Food, Western Australia Jan 1990

Waterlogging : One Reason Why Our Crops And Pastures Are Not Achieving Maximum Yields, Department Of Agriculture And Food, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Water, either its lack"or excess, is the main factor affecting the yield of crops and pastures in Western Australia.


Comparison Of Pressurized And Gravity Distribution Systems For Wastewater Treatment, Mark A. Gross, Stan Neal, Belinda Ederington, Robert Muldoon Jan 1990

Comparison Of Pressurized And Gravity Distribution Systems For Wastewater Treatment, Mark A. Gross, Stan Neal, Belinda Ederington, Robert Muldoon

Journal of the Arkansas Academy of Science

Pressurized distribution of domestic wastewater over a sand filter surface achieves better treatment than gravity distribution. The pressurized distribution system caused the filter to better remove organics (BOD₅) and suspended solids. Pressurized distribution also caused the sand filter to achieve more complete nitrification than the filter having gravity distribution. Two slow sand filters 15.2 cm wide, 3.1 m long and 15.2 cm deep were built and loaded with domestic septic tank effluent for 250 days at a rate of 5.1 cm per day. Influent and effluent samples were collected and analyzed for five-day Biochemical Oxygen Demand (BOD₅), suspended solids, ammonia- …


Effects Of Ambient Lake Mohave Temperatures On Development, Oxygen Consumption, And Hatching Success Of The Razorback Sucker, Michael A. Bozek, Larry J. Paulson, Gene R. Wilde Jan 1990

Effects Of Ambient Lake Mohave Temperatures On Development, Oxygen Consumption, And Hatching Success Of The Razorback Sucker, Michael A. Bozek, Larry J. Paulson, Gene R. Wilde

Publications (WR)

Spawning of razorback suckers, Xyrauchen texanus, in Lake Mohave occurred from 10-22° C and larvae were collected at water temperatures from 10-15° C in 1982 and 1983. In the laboratory, hatching success was similar from 12-20° C, but reduced hatching success was found at 10° C while none hatched at 8°C. Development rate and oxygen consumption were positively related to incubation temperature. Direct effects of ambient Lake Mohave water temperatures on hatching success of razorback sucker embryos are considered minimal. Historical spawning temperatures for the species are hypothesized based upon successful incubation temperatures and comparison to the white sucker, …


Ectoparasites Of Ring-Necked Pheasants In Nebraska, William R. Payne, David W. Oates, Glen E. Dappen Jan 1990

Ectoparasites Of Ring-Necked Pheasants In Nebraska, William R. Payne, David W. Oates, Glen E. Dappen

Nebraska Game and Parks Commission: Staff Research Publications

In 1971, 1983 and 1984, ectoparasites were identified on 61 ring-necked pheasants (Phasianus colchicus) from Nebraska. Birds were collected throughout the state from 11 of 93 counties. Four species of chewing lice (Mallophaga) were collected: Lipeurus maculosus, Goniodes colchici, Lagopoecus coichicus and Amyrsidea megalosoma. One species of analgid mite, Megninia sp. was collected. Apparently, this species is new and undescribed. The four mallophagan species have not been reported from Nebraska.


Water Current, Volume 22, January 1990 Jan 1990

Water Current, Volume 22, January 1990

Water Current Newsletter

Gold Accepts Position at Texas A&M University
Platte River Policy
Congresswoman Smith Receives Water Statesman of the Year Award
Risks Not Always Easy to Measure
One Word or Two?
First Northeast Nebraska Water Quality Day Attracts 250 Persons
Who Wil Get the Water?
Water Qualty Priority of Nebraska Water Conference Council
Water Quality Outlook for the 90s Topic for Conference
Forum Addresses State Water Issues


Preserving Minnesota's Natural Heritage, Nelson T. French Jan 1990

Preserving Minnesota's Natural Heritage, Nelson T. French

Journal of the Minnesota Academy of Science

Minnesota has a rich natural resource base that can be preserved only by maintaining and expanding private and public conservation programs that contribute toward the protection of forests, soils, waters, native plants, wildlife, natural communities, and endangered species. Although efforts to protect Minnesota's natural heritage have been a model for the Midwest, increasing pressure to plow up prairie, drain wetlands, consume old growth forest resources, and urbanize the landscape continue to erode an ever decreasing base of natural habitat. Significant alteration of our state's presettlement biological communities has occurred and, in spite of conservation laws and rules adopted over the …


Mapping The Extent Of Waterlogged Crop Using Satellite Imagery, Jeremy Wallace, Buddy Wheaton Jan 1990

Mapping The Extent Of Waterlogged Crop Using Satellite Imagery, Jeremy Wallace, Buddy Wheaton

Journal of the Department of Agriculture, Western Australia, Series 4

No abstract provided.


Causes Of Waterlogging, Jim Cox, Don Mcfarlane Jan 1990

Causes Of Waterlogging, Jim Cox, Don Mcfarlane

Journal of the Department of Agriculture, Western Australia, Series 4

Waterlogging is highly variable, both between years and within paddocks. This residts in uncertainty as to whether a paddock should be cropped in a particular year, and whether different management should be used on waterlogged areas within a paddock

A study has determined what are the most important causes of waterlogged soils.


Seepage Interceptor Drains For Reducing Waterlogging And Salinity, Don Mcfarlane, Jim Cox Jan 1990

Seepage Interceptor Drains For Reducing Waterlogging And Salinity, Don Mcfarlane, Jim Cox

Journal of the Department of Agriculture, Western Australia, Series 4

Shallow interceptor drains can reduce waterlogging on sloping sites. Such drains will more than pay for themselves from the increased crop yield. Recent work has shown that these drains also decrease salinity so that they are cost-effective in the long as well as the short term.


Level Banks Used To Decrease Waterlogging Can Increase Salinity, Don Mcfarlane, Richard Engel, Arjen Ryder, Maurice Eales Jan 1990

Level Banks Used To Decrease Waterlogging Can Increase Salinity, Don Mcfarlane, Richard Engel, Arjen Ryder, Maurice Eales

Journal of the Department of Agriculture, Western Australia, Series 4

Some farmers have used level W1SALTS banks to control surface zvaters above areas affected by ivaterlogging and salinity. Because the amount of waterlogging has been reduced, crop yields have increased downslope of some banks. However, the banks divert fresh surface water into deeper salty groundwater and, in the long term, worsen salinity. This article details an investigation of the effect of level WIS ALTS banks on saline groundwaters and discusses alternative methods of preventing the waterlogging of saline areas.


An Evaluation Of Noaa's Role In Ocean Dumping Policy Implementation, Kenneth W. Barton Jan 1990

An Evaluation Of Noaa's Role In Ocean Dumping Policy Implementation, Kenneth W. Barton

Marine Affairs Theses and Major Papers

Dumping of wastes into the ocean has gone on for years especially in the New York Bight. The National Oceanic and Atmospheric Administration (NOAA) is mandated by Title II of the Ocean Dumping Act of 1972 to investigate the effects of ocean dumping on the marine environment. However, there is a perception within Congress, the public and other agencies that NOAA is not meeting it's responsibilities with regard to ocean dumping research. The effectiveness of NOAA's ocean dumping policies and programs and the difficulties in implementation experienced by the agency are evaluated by applying George Edwards' theory of policy implementation. …


From Basin To "Hydrocommons": Integrated Water Management Without Regional Governance, Gary D. Weatherford, University Of Colorado Boulder. Natural Resources Law Center Jan 1990

From Basin To "Hydrocommons": Integrated Water Management Without Regional Governance, Gary D. Weatherford, University Of Colorado Boulder. Natural Resources Law Center

Books, Reports, and Studies

22 p. ; 28 cm


An Introduction To The Soils Of The Geraldton Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Geraldton Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on eight common soils.


An Introduction To The Soils Of The Three Springs Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Three Springs Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on seven common soils.


What Are Land Conservation Districts?, Western Australian Department Of Agriculture Jan 1990

What Are Land Conservation Districts?, Western Australian Department Of Agriculture

Natural resources published reports

Land conservation groups need your support. Land degradation is not just a farming problem. We change the land and waters in many ways, whether it be clearing of precious natural bush or through the fertilizers which leach from our gardens.

By learning about the Land Conservation Districts achievements and understanding the challenges they face we can better see our own place in the scheme of things.

We will learn the ways to organize for Landcare in other rural areas, or in the city, that will be successful.

This is what the Decade of Landcare is all about - providing an …


An Introduction To The Soils Of The Esperance Advisory District, T C. Stoneman, Tim D. Overheu, P G. Muller, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Esperance Advisory District, T C. Stoneman, Tim D. Overheu, P G. Muller, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on seven common soils.


An Introduction To The Soils Of The Lake Grace Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1990

An Introduction To The Soils Of The Lake Grace Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on eight common soils.


The Probe, Issue 98 - December 1989 Dec 1989

The Probe, Issue 98 - December 1989

The Probe: Newsletter of the National Animal Damage Control Association

THE PROBE National Animal Damage Control Association
DECEMBER 1989
Vote
NADCA Elections
NADCA Annual Meeting
Letters to Ye Ed
APHIS Activity Report
Animal Rights