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Articles 52441 - 52470 of 59400

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Making Horticulture Sustainable, Bob Paulin, Neil Clifton Lantzke, Ian Mcpharlin, Murray Hegney Jan 1995

Making Horticulture Sustainable, Bob Paulin, Neil Clifton Lantzke, Ian Mcpharlin, Murray Hegney

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

Sweet crunchy carrots, luscious strawberries at very reasonable prices, crisp green vegetables - these are just a few of the horticultural products that Western Australians take for granted and eat almost every day. But is their future availability guaranteed as population grows, suburbia spreads and environmental concern increases?


Cooperative Landcare Venture Revisited, Kate Mcinnes Jan 1995

Cooperative Landcare Venture Revisited, Kate Mcinnes

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

Four years ago, the Journal of Agriculture reported on a unique partnership forged in 1989 between the Department of Agriculture Alcoa of Australia Limited and six catchment groups located in the Avon River catchment.

Kate McInnes reports on progress with the Avon Catchment Landcare Project.


Storm : [Wind Erosion In The Great Southern], Dan Carter Jan 1995

Storm : [Wind Erosion In The Great Southern], Dan Carter

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

On Thursday 11 May 1995, a low pressure system with central barometric pressure of 990 hPa formed of south-western Australia. This depression directed gale force winds over the South-West Land Division for some seven hours.

Dan Carter reports on the widespread damage to soils and property, and management practices that would have reduced the problem.


Biological Processes: Relationships Between Earthworms And Soil Temperature, Edwin C. Berry, Jerry K. Radke Jan 1995

Biological Processes: Relationships Between Earthworms And Soil Temperature, Edwin C. Berry, Jerry K. Radke

Journal of the Minnesota Academy of Science

Soil fauna play important roles in many soil processes and conditions which relate to agricultural systems. Earthworms are credited with enhancing soil fertility and soil physical properties by their feeding and burrowing activities. Most research on earthworms has focused on the warmer seasons of the year and relatively little is known about earthworm activity and survival during the portion of the year with frozen soils. Earthworms may survive winter by acclimatization, aestivation, or by burrowing to deeper depths where the soil is not frozen. More research is needed on the fate of earthworms in frozen soils. Suggested research areas include: …


Migration Of Water During Winter In West Central Minnesota Soils, Brenton S. Sharratt Jan 1995

Migration Of Water During Winter In West Central Minnesota Soils, Brenton S. Sharratt

Journal of the Minnesota Academy of Science

Soil freezing influences the amount and quality of our water resources, yet, little is known concerning the impacts of soil texture and water content before freezing on water migration in frozen soils. Columns of Hamerly clay loam and Sioux loam at 3 initial water contents were subjected to the vagaries of the field environment at Morris, Minnesota during the winter of 1993-1994 and then sectioned to determine changes in soil water content. Redistribution of water in the frozen soil layer became more apparent with an increase in initial water content. Little movement of water occurred at the lowest initial water …


Soil Freeze-Thaw Processes: Implications For Nutrient Cycling, C. Wayne Honeycutt Jan 1995

Soil Freeze-Thaw Processes: Implications For Nutrient Cycling, C. Wayne Honeycutt

Journal of the Minnesota Academy of Science

Soil freeze-thaw processes can regulate nutrient availability to plants by influencing nutrient leakage from plant tissues, nutrient release from soil organisms, mineral weathering, various inorganic nutrient transformations, and nutrient transport in both soil solution and sediment. These aspects of freeze-thaw processes are given in this review. A frequently reported observation is that soil water content controls the extent of freeze-thaw impacts on several chemical, physical, and biological processes and components important for nutrient cycling. Practices affecting soil water content, such as tillage and crop residue management, may therefore provide opportunities for managing freeze-thaw impacts on nutrient use efficiency in crop …


Overwinter Changes In Dry Aggregate Size Distribution Influencing Wind Erodibility In A Spring Wheat-Summerfallow Cropping System, Stephen D. Merrill, Alfred L. Black, Ted M. Zobeck Jan 1995

Overwinter Changes In Dry Aggregate Size Distribution Influencing Wind Erodibility In A Spring Wheat-Summerfallow Cropping System, Stephen D. Merrill, Alfred L. Black, Ted M. Zobeck

Journal of the Minnesota Academy of Science

A long-term study of the wind erodibility properties of a two-year spring wheat-summerfallow cropping systems was started in 1988 in south-central North Dakota as part of an USDA-ARS led effort to construct a process-oriented soil erosion predictive model. Observations were conducted on a conservation tillage experiment established in 1984 on soil classified in the U.S. as Typic-Pachic Haploborolls and in Canada as Brown to Dark Brown Chenozemic. The experiment included four residue-management treatments defined by targeted residue coverages: no-till, > 60% cover; minimal-till, 30% to 60% cover and undercutter dominated; conventional-till, < 30% cover and disk dominated; low-residue, < 5 % cover. Fall and spring measurements of dry aggregate size distribution (ASD) of surface soil (0 to 4 cm depth), and overwinter changes in ASD are reported here. A rotary sieve produced six size fractions ranging from < 0.42 mm to > 19.2 mm diameter. Measurements of ASD are expressed as geometric …


Relative Soil Aeration In A Cultivated Prairie Pothole, Alan Olness, J. A. Staricka, J. A. Daniel, G. R. Benoit, J. L. Rinke Jan 1995

Relative Soil Aeration In A Cultivated Prairie Pothole, Alan Olness, J. A. Staricka, J. A. Daniel, G. R. Benoit, J. L. Rinke

Journal of the Minnesota Academy of Science

Many small prairie potholes receive surface runoff from their catchments and serve as a focal point of ground water recharge. Soil aeration controls the solubility and form of many soil chemicals. Platinum electrodes are sensitive to oxygen and provide a very sensitive indicator of its presence. Electrodes were installed at the 15-, 30-, and 45-cm depth across two transects within a shallow, cultivated depression which serves as a recharge site for groundwater. Soils on the rim of the depression remained aerobic throughout two consecutive cropping years even at 45 cm. Soils within the depression became anaerobic briefly in the first …


1995, Spatial And Temporal Variability Of Late Neogene Equatorial Pacific Carbonate, T. K. Hagelberg, Nicklas G. Pisias, Larry A. Mayer, N. J. Shackleton, Alan C. Mix Jan 1995

1995, Spatial And Temporal Variability Of Late Neogene Equatorial Pacific Carbonate, T. K. Hagelberg, Nicklas G. Pisias, Larry A. Mayer, N. J. Shackleton, Alan C. Mix

Affiliate Scholarship

High-resolution, continuous records of GRAPE wet bulk density (a carbonate proxy) from Ocean Drilling Program Leg 138 provide one the opportunity for a detailed study of eastern equatorial Pacific Ocean carbonate sedimentation during the last 6 m.y. The transect of sites drilled spans both latitude and longitude in the eastern equatorial Pacific from 90° to 110°W and from 5°S to 10°N. Two modes of variability are resolved through the use of Empirical Orthogonal Function (EOF) analysis. In the presence of large tectonic and climatic boundary condition changes over the last 6 m.y., the dominant mode of spatial variability in carbonate …


Seismic Stratigraphy Of The Eastern Equatorial Pacific Ocean: Paleoceanographic Implications, Stephen F. Bloomer, Larry A. Mayer, Ted C. Moore Jr Jan 1995

Seismic Stratigraphy Of The Eastern Equatorial Pacific Ocean: Paleoceanographic Implications, Stephen F. Bloomer, Larry A. Mayer, Ted C. Moore Jr

Affiliate Scholarship

The collection of Leg 138 well-log and shipboard physical-property data, in conjunction with high-resolution seismic profiles, provides an opportunity to understand the paleoceanographic significance of seismic reflectors and to gain insight into the paleoceanographic evolution of the eastern equatorial Pacific Ocean. A series of eight reflectors or reflector packages were traced between two transects connecting five Leg 138 sites. By generating synthetic seismograms at each of these sites and comparing these to the field records, the origin of these seismic reflectors was determined in terms of physical-property variations and other core measurements. In particular, these reflectors were usually associated with …


Paleoceanography Of The Eastern Equatorial Pacific During The Neogene: Synthesis Of Leg 138 Drilling Results, Nicklas G. Pisias, Larry A. Mayer, Alan C. Mix Jan 1995

Paleoceanography Of The Eastern Equatorial Pacific During The Neogene: Synthesis Of Leg 138 Drilling Results, Nicklas G. Pisias, Larry A. Mayer, Alan C. Mix

Affiliate Scholarship

The primary objective of Leg 138 was to provide detailed information about the ocean's response to global climate change during the Neogene. Two north-south transects were drilled (95° and 110°W) within the region of equatorial divergence-driven upwelling (and thus high accumulation rates and resolution) and spanning the major equatorial ocean current boundaries (and thus recording a high-amplitude signal of the response of the sediment to climatically and/or tectonically driven changes in ocean circulation). The Neogene is marked by a number of well-known climatic and tectonic events (the closing of the Isthmus of Panama, the onset of North Atlantic Deep Water …


Flood Insurance Study, Town Of Joseph, Utah, Sevier County, Federal Emergency Management Agency Jan 1995

Flood Insurance Study, Town Of Joseph, Utah, Sevier County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study revises and updates a previous flood Insurance Rate Map for the Town of Joseph, Utah. This information will be used by the Town to update existing floodplain regulations as part of the Regular Phase of the National Flood Insurance Program (NFIP). The information will also be used by local and regional planners to further promote sound land use and floodplain development.


Flood Insurance Study, City Of Riverdale, Utah, Weber County, Federal Emergency Management Agency Jan 1995

Flood Insurance Study, City Of Riverdale, Utah, Weber County, Federal Emergency Management Agency

All U.S. Government Documents (Utah Regional Depository)

This Flood Insurance Study investigates the existence and severity of flood hazards in the City of Riverdale, Weber County, Utah, and aids in the administration of the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. This study will be used to convert Riverdale to the regular program of flood insurance by the Federal Emergency Management Agency. Local and regional planners will use this study in their efforts to promote sound flood plain management.


Holocene Archeology Near Squaw Butte, Canyonlands National Park, Utah Jan 1995

Holocene Archeology Near Squaw Butte, Canyonlands National Park, Utah

All U.S. Government Documents (Utah Regional Depository)

This document is the final technical report of cultural resources investigations in the Needles District of Canyonlands National Park, southeastern Utah. These investigations were part of the multiyear Canyonlands Archeological Project. Inventory of 878 acres in the Squaw Butte Area revealed 80 sites which were occupied by Archaic people during all phases of the Archaic period, aborigines of unknown cultural affiliation during the Early Formative period, Mesa Verde Anasazi during Pueblo III or late Pueblo II-III, and the Navajo during historic or modern times. Paleoindians may have also been in the general area, if not the actual project area. Limited …


Managing Lodgepole Pine To Yield Merchantable Thinning Products And Attain Sawtimber Rotations, United States Department Of Agriculture, Forest Service Jan 1995

Managing Lodgepole Pine To Yield Merchantable Thinning Products And Attain Sawtimber Rotations, United States Department Of Agriculture, Forest Service

Forestry

This paper suggests solutions for a longstanding problem in managing lodgepole pine forests -- that of managing individual stands to reach their planned rotation age, despite serious hazard from bark beetles and wildfire. The management regimes presented yield merchantable thinning products. The 80-year sawtimber rotation can be achieved using these management recommendations. Thinning at 30 years of age is central to achieving the recommended alternative management regimes. The authors suggest that agencies give roundwood operators a portion of the thinning stemwood as payment. Management regimes that provide attainable rotations are presented in summary tables, by three site index classes and …


Hydrocarbons And Mineral Resources Of The Uinta Basin, Utah And Colorado, United States Department Of The Interior, Indian Affairs Bureau Jan 1995

Hydrocarbons And Mineral Resources Of The Uinta Basin, Utah And Colorado, United States Department Of The Interior, Indian Affairs Bureau

Mines and Mineral Resources

The Uinta Basin holds special fascination for economic geologists because of its rich and diverse assemblage of mineral and hydrocarbon resources. Due to their presence in rocks of the basin, much effort has been put into assessing and exploiting uranium, phosphate, gold, copper, coal, and evaporite minerals. However, the basin is probably best noted for its extensive and very rich accumulations of hydrocarbons such as, oil, gas, bituminous sandstones, oil shale (shale oil), and gilsonite and other solid and semi-solid hydrocarbon species. More importantly, several of these commodities have proven to be a major source of wealth and resources for …


Bones Of Puffinus Lherminieri Lesson (Aves: Procellaridae) And Two Other Vertebrates From Cueva Del Agua, Mona Isalnd, Puerto Rico (West Indies), Angel M. Nieves-Rivera, John M. Mylroie, Donald A. Mcfarlane Jan 1995

Bones Of Puffinus Lherminieri Lesson (Aves: Procellaridae) And Two Other Vertebrates From Cueva Del Agua, Mona Isalnd, Puerto Rico (West Indies), Angel M. Nieves-Rivera, John M. Mylroie, Donald A. Mcfarlane

WM Keck Science Faculty Papers

From a dive in Cueva del Agua, Mona Island, Puerto Rico, twelve un-mineralized bones of Puffinus Lherminieri Lesson, one of Cyclura stejnegeri Stejneger, and one of Moormops blainvilii Leach were collected. The subfossil evidence confirms that P. Lherminieri was a common species on Mona Island. Cyclura stejnegeri and M. blainvilii probably became trapped and died in the pool chamber.


Relating United States Crop Land Use To Natural Resources And Climate Change, K. G. Hubbard, F. J. Flores-Mendoza Jan 1995

Relating United States Crop Land Use To Natural Resources And Climate Change, K. G. Hubbard, F. J. Flores-Mendoza

National Drought Mitigation Center: Faculty Publications

Crop production depends not only on the yield but also on the area harvested. The yield response to climate change has been widely examined, but the sensitivity of crop land use to hypothetical climate change has not been examined directly. Crop land-use regression models for estimating crop area indices (CAIs) - the percent of land used for corn, soybean, wheat, and sorghum production - are presented. Inputs to the models include available water-holding capacity of the soil, percent of land available for rain-fed agricultural production, annual precipitation, and annual temperature. The total variance of CAI explained by the models ranged …


Land Resources Of The Bencubbin Area, Gerard J. Grealish, John Wagnon Jan 1995

Land Resources Of The Bencubbin Area, Gerard J. Grealish, John Wagnon

Land resources series

This survey of the Bencubbin area is part of the Agriculture Western Australia's regional land resource mapping program, and covers approximately 1.5 million hectares in the Merredin, Trayning, Koorda, Mount Marshall, Mukinbudin, Westonia and Nungarin Shires of Western Australia. The climate is Mediterranean, with hot dry summers and cool winters. Land is used for winter cereal production and grazing, and about 60% is cropped each year. Wheat is the main crop and is grown in rotation with lupins, field peas, barley and medic pasture. This report provides primary and interpreted information on the character and capability of the land, for …


Is Coral Community Structure Linked To Damage Susceptibility? A Case Study From South Africa, Bernhard Riegl, Peter A. Cook Jan 1995

Is Coral Community Structure Linked To Damage Susceptibility? A Case Study From South Africa, Bernhard Riegl, Peter A. Cook

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Africa's southernmost coral communities are situated in northern Natal, South Africa (27°50' S), within the Maputaland and St. Lucia Marine Reserves. Growing concern about the possible impact of recreational acti vities on the health of the coral ecosystem prompted the present study on the structure and health of the reefs. Coral community studies by means of line transects identified three basic coral community types, which correlated with the geomorphology of the sandstone outcrops on which corals grew. 1) Fossil dunes were dominated by alcyonacea in depths between 8 and 24 m. 2) Flat outcrops between 18 and 24 m depth …


Remnant Vegetation Inventory On The Southern Agricultural Areas Of Western Australia., G R. Beeston, G Mlodowski, A Sanders, D True Jan 1995

Remnant Vegetation Inventory On The Southern Agricultural Areas Of Western Australia., G R. Beeston, G Mlodowski, A Sanders, D True

Resource management technical reports

Remnant vegetation mapping and its incorporation into a Geographical Information System (GIS) data base is the first stage in an overall documentation and promotion of conservation of remnant vegetation in Western Australia. The primary objective of this project being to determine the amount, distribution and regional location of native vegetation remaining on private land in the agricultural area of south-west Western Australia.


Avian Use Of Field Windbreaks, Herbaceous Fencerows And Associated Cropfields In East Central Nebraska, Natalie J. Sunderman Jan 1995

Avian Use Of Field Windbreaks, Herbaceous Fencerows And Associated Cropfields In East Central Nebraska, Natalie J. Sunderman

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Geomorphic And Geochemical Evidence For The Source Of Sand In The Algodones Dunes, Colorado Desert, Southeastern California, Daniel R. Muhs, Charles A. Bush, Scott D. Cowherd, Shannon Mahan Jan 1995

Geomorphic And Geochemical Evidence For The Source Of Sand In The Algodones Dunes, Colorado Desert, Southeastern California, Daniel R. Muhs, Charles A. Bush, Scott D. Cowherd, Shannon Mahan

United States Geological Survey: Staff Publications

The Algodones dunes of southeastern California comprise one of the largest active dune fields in the United States. The source of sand of the Algodones dunes is controversial, and the source of stabilized aeolian sand in the adjacent East Mesa area has not been investigated at all. We used mineralogical compositions and trace element concentrations to ascertain the most likely source of sand for these active and stabilized dunes. Results indicate that alluvium derived from the San Bernardino Mountains, which enters the Salton trough to the northwest of the dune fields, and alluvium derived from the Chocolate Mountains, which is …


Source Of The Northeastern Idaho Batholith: Isotopic Evidence For A Paleoproterozoic Terrane In The Northwestern U.S., Paul A. Mueller, Robert Duncan Shuster, K. A. D'Arcy, A. L. Heatherington, A. P. Nutman, I. S. Williams Jan 1995

Source Of The Northeastern Idaho Batholith: Isotopic Evidence For A Paleoproterozoic Terrane In The Northwestern U.S., Paul A. Mueller, Robert Duncan Shuster, K. A. D'Arcy, A. L. Heatherington, A. P. Nutman, I. S. Williams

Geography and Geology Faculty Publications

The northeastern portion of the Idaho batholith (NIB) intruded Proterozoic rocks of the Belt-Purcell supergroup between SO and 90 Ma. Whole-rock Sm-Nd isotopic analyses of batholithic rocks yield depleted mantle model ages (T oM) between 1. 72 and 1.93 Ga and values of eNd between -17. 7 and - 21.2, similar to associated metamorphic rocks and within the range for Belt-Purcell sedimentary rocks. Premagmatic zircons from one sample of the NIB were analyzed individually using the SHRIMP ion microprobe and yielded a single age population at 1.74 Ga. This apparently single-aged source contrasts with the range of ages reported for …


Rangeland Reference Areas : Summary Of Cooperative Project Between The Western Australian Department Of Agriculture And The Environmental Protection Authority, D A. Blood Jan 1995

Rangeland Reference Areas : Summary Of Cooperative Project Between The Western Australian Department Of Agriculture And The Environmental Protection Authority, D A. Blood

Resource management technical reports

The development of agriculture in south-western Australia has been characterised by the replacement of deep-rooted, perennial species of native vegetation with shallow-rooted, annual species. Except for the high rainfall areas, the native vegetation was able to intercept and transpire nearly all of the rainfall resulting in low stream flows and recharge to a groundwater system which was typically deep and restricted to the major valleys. The lack of surface or groundwater movement out of inland catchments used large quantities of cyclic salts to become stored in the regolith. Although annual crops and pastures can be high water users, they are …


Geologic Map Of Morrill County, Nebraska, James B. Swinehart, Robert F. Diffendal Jr. Jan 1995

Geologic Map Of Morrill County, Nebraska, James B. Swinehart, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Morrill County, Nebraska, is perhaps the most geologically interesting county in the panhandle of Nebraska. Surficial deposits of alluvium, colluvium, loess, and eolian sand of Quaternary age cover large parts of the county. Holocene and latest Pleistocene(?) eolian sand as much as 150 It thick covers much of the area north of North Platte Valley and mantles Quaternary alluvial deposits to the south. A thin veneer of loess overlies bedrock in the uplands of the southern part of the county. Alluvium underlies the valley floors and caps river and stream terraces. Two units of older Quaternary alluvium are exposed in …


Bermuda Solution Pipe Soils: A Geochemical Evaluation Of Eolian Parent Materials, Stanley R. Herwitz, Daniel R. Muhs Jan 1995

Bermuda Solution Pipe Soils: A Geochemical Evaluation Of Eolian Parent Materials, Stanley R. Herwitz, Daniel R. Muhs

United States Geological Survey: Staff Publications

Solution pipes found in the Quaternary eolian and marine carbonates of Bermuda are filled with reddish to reddish-brown soil material. The bulk of the soil is composed of clay and silt-sized quartz and aluminosilicate clay minerals. The carbonates are of high purity and, therefore, are not likely to have been the parent material. Previous workers have hypothesized that Saharan dust may have been the soil parent material. The fine-grained component of loess from the Mississippi River Valley of North America also could have contributed. Paleoclimate models indicate that both North Africa and North America could have been important source areas …


Introduction To Special Section: Mechanical Involvement Of Fluids In Faulting, Stephen Hickman, Richard Sibson, Ronald Bruhn Jan 1995

Introduction To Special Section: Mechanical Involvement Of Fluids In Faulting, Stephen Hickman, Richard Sibson, Ronald Bruhn

United States Geological Survey: Staff Publications

A growing body of evidence suggests that fluids are intimately linked to a variety of faulting processes. These include the long-term structural and compositional evolution of fault zones; fault creep; and the nucleation, propagation, arrest, and recurrence of earthquake ruptures. Besides the widely recognized physical role of fluid pressures in controlling the strength of crustal fault zones, it is also apparent that fluids can exert mechanical influence through a variety of chemical effects.

The United States Geological Survey sponsored a Conference on the Mechanical Effects of Fluids in Faulting under the auspices of the National Earthquake Hazards Reduction Program at …


Resource News-Summer 1995 Jan 1995

Resource News-Summer 1995

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Chronostratigraphic Significance Of Cathodoluminescence Zoning In Syntaxial Cement: Mississippian Lake Valley Formation, New Mexico, Tracy D. Frank, Kuger C. Lohmann, William J. Meyers Jan 1995

Chronostratigraphic Significance Of Cathodoluminescence Zoning In Syntaxial Cement: Mississippian Lake Valley Formation, New Mexico, Tracy D. Frank, Kuger C. Lohmann, William J. Meyers

Department of Earth and Atmospheric Sciences: Faculty Publications

Echinoderm-syntaxial cement crystals have been collected at several stratigraphic levels within the Lake Valley Formation, which is overlain by a major pre-Pennsylvanian subaerial exposure surface. The crystals were microsampled along growth bands, and yielded high-resolution elemental and isotopic information that record fluid evolution during their growth. Although cement crystals show little variation in cathodoluminescence character and bulk chemistry throughout the regional extent of the formation, intracrystalline patterns in minor element and stable isotope chemistry allow for the identification of several settings of cementation, including the marine phreatic, marine-meteoric mixing, and meteoric phreatic zones. When placed in a regional-stratigraphic context, crystal …