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Full-Text Articles in Physical Sciences and Mathematics

Geographe Bay Catchment Natural Resource Atlas, Sarah Weaving Sep 1998

Geographe Bay Catchment Natural Resource Atlas, Sarah Weaving

All other publications

The Geographe Bay Catchment Atlas is one of a series of Natural Resource Atlases covering the agricultural region of Western Australia. The purpose of the Atlas is to provide data for people in local communities who manage or have an interest in natural resources. It is now realised that the various components of the land interact with each other and therefore need to be managed together. This Atlas is intended to present natural resource and land information in an accessible way to people of the area. It may act as a focus for catchment planning and provide a starting point …


Agricultural Water Management In The Missippi Delta Region Of Arkansas, H. Don Scott, James A. Ferguson, Linda Hanson, Todd Fugitt, Earl Smith Aug 1998

Agricultural Water Management In The Missippi Delta Region Of Arkansas, H. Don Scott, James A. Ferguson, Linda Hanson, Todd Fugitt, Earl Smith

Research Reports and Research Bulletins

Agriculture is the largest use of soil and water resources in eastern Arkansas. This bulletin summarized the recent historical use of soil and water by agriculture and the impact of irrigation on yields of rice, soybeans and cotton. The experiments conducted in the field to quantitatively schedule irrigations of crops are summarized. The results show the close relationship between the irrigation of crops and the extraction of water from the Alluvial Aquifer. The implications of this relationaship for the future are discussed.


Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr. Jul 1998

Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Land application of horse stall bedding and municipal sludge can increase runoff concentrations of nutrients, organic matter, and bacteria as well as steroidal hormones such as estrogen. Concentrations of materials in runoff from sites treated with animal manure can be reduced by aluminum sulfate, or alum [Al2(SO4)3•14H2O] treatment. The objectives of this study were to assess plots treated with horse stall bedding or municipal sludge for: (a) runoff quality [concentrations of nitrate nitrogen (NO3-N), ammonia nitrogen (NH3-N), orthophosphate-phosphorus (PO4-P), fecal coliform (FC), chemical oxygen demand (COD) …


Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997. 2. Souths' Catchment (Darkan), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr Jul 1998

Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997. 2. Souths' Catchment (Darkan), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr

Resource management technical reports

High water use vegetation systems for salinity control were trialed on a 90 ha catchment located 12 km north north-west of Darkan, Western Australia. The catchment receives about 560 mm annual rainfall and 1895 mm annual evaporation. The catchment is characterised by a number of actively expanding seeps which are developing under the strong geological control of quartz and dolerite dykes. Development of salinity is also influenced by high recharge rates in the free draining gravel soils of the upper slope.


The Role Of Soil Test Information In Reducing Groundwater Pollution, Ronald A. Fleming, Richard M. Adams, David E. Ervin Jul 1998

The Role Of Soil Test Information In Reducing Groundwater Pollution, Ronald A. Fleming, Richard M. Adams, David E. Ervin

Economics Faculty Publications and Presentations

Testing soils for nutrients is expected to improve groundwater quality. However, it is unknown whether soil testing will improve groundwater quality sufficiently to decrease the demand for direct regulation of agricultural practices. Focusing on an irrigated agricultural region in eastern Oregon, the economic and environmental aspects of soil testing are assessed using a spatially distributed, dynamic simulation model which links economic behavior with the physical processes that determine groundwater quality. Results indicate that soil testing of all fields increases farm profits and reduces groundwater nitrate concentration. However, the benefits are small in terms of potential improvements in groundwater quality.


Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 1. Wooldridge/Wright's Catchment (Kojonup), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr Jul 1998

Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 1. Wooldridge/Wright's Catchment (Kojonup), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr

Resource management technical reports

High water use vegetation systems for salinity control were trialed on a 170 ha catchment located 13 km north of Kojonup, Western Australia. The catchment receives about 470 mm annual rainfall and 1825 mm annual evaporation.


Tb169: Chemical And Physical Properties Of The Mapleton, Monson, Saddelback, And Sisk Soil Map Units, Robert V. Rourke Jun 1998

Tb169: Chemical And Physical Properties Of The Mapleton, Monson, Saddelback, And Sisk Soil Map Units, Robert V. Rourke

Technical Bulletins

Mapleton, Monson, Saddleback, and Sisk soil map units were each sampled at five locations. Soil descriptions and locations were documented in the field. Soil samples were removed from each horizon in a 30-cm square to a 100-cm depth or to bedrock whichever came first. Laboratory analyses of each soil horizon sampled included texture, volume of stones, organic content, bulk density, soil water retention, soil reaction, exchangeable cations, extractable acidity, and exchange acidity. Soil descriptions and tables of soil properties were constructed for each sample site. Soil data for each soil map unit was summarized by horizon using weighted means.


Characterization Of Dielectric Properties Of Earth Materials At Low Frequencies, Tarrah Dawn Henrie May 1998

Characterization Of Dielectric Properties Of Earth Materials At Low Frequencies, Tarrah Dawn Henrie

Undergraduate Honors Capstone Projects

Sharma and de Lima (1992) have proposed a model based on Fixman's theoretical development of charged macromolecules in external fields (1980). There are three types of charges considered: the fixed surface charges that are covalently bonded, the layer of bound counterions, and the diffuse layer (Fixman, 1980, Lyklema, 1983 ). Figure (1) shows these different layers. Other common theories, such as Schurr's only consider the bound counterions and the diffuse layer. Schurr assumes that the diffuse layer ions can exchange with the electrolyte. A consequence of this assumption is the lack of polarization of the diffuse layer. This leads to …


Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke May 1998

Utilization Of Spatially Distributed Soil Resources By Several Species Common To The Great Basin, Sarah Duke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heterogeneous spatial and temporal distributions of soil resources important to plant growth have been documented in the sagebrush steppe ecosystem. There can exist as much variability in soil resources within the root zone of individual plants as exists across an entire field. The objective of this dissertation research was to evaluate how plants respond to, utilize and influence the spatial heterogeneity of soil resources. The three specific sets of questions addressed are outlined in the three main chapters of this dissertation.

My first study addressed how the number and concentration of phosphorus (P) patches in the root zone of an …


An Atlas Of The Sand Hills, Ann S. Bleed, Charles A. Flowerday May 1998

An Atlas Of The Sand Hills, Ann S. Bleed, Charles A. Flowerday

Conservation and Survey Division

The Sand Hills region, approximately 19,300 square miles of sand dunes stretching 265 miles across Nebraska and into South Dakota, is the largest sand-dune area in the Western Hemisphere and is one of the largest grass-stabilized dune regions in the world.


Arkansas Soil Fertility Studies 1997, Wayne E. Sabbe Apr 1998

Arkansas Soil Fertility Studies 1997, Wayne E. Sabbe

Arkansas Agricultural Experiment Station Research Series

No abstract provided.


Groundwater Trends In The Agricultural Area Of Western Australia, R A. Nulsen Mar 1998

Groundwater Trends In The Agricultural Area Of Western Australia, R A. Nulsen

Resource management technical reports

In 1994 it was estimated that salinity affected more than 1.8 million ha of agricultural land in Western Australia (Ferdowsian et al. 1996). This area was predicted to expand to over three million ha by about 2020 and, if nothing is done to stem the expansion, to eventually affect some six million ha, or 30% of the agricultural land in the state. Damaging levels of salt accumulation in the root zone of both native and introduced plants can generally only occur when the groundwater levels are relatively cl te the variability of responses. Several depict episodic recharge (recharge as a …


Success With Serradella In The Wheatbelt, Clinton Revell, Bradley Nutt, Michael Ewing Jan 1998

Success With Serradella In The Wheatbelt, Clinton Revell, Bradley Nutt, Michael Ewing

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

Clinton Revell, Bradley Nutt, and Michael Ewing review the latest developments with new varieties of French serradella and yellow seradella that should provide the basis for productive legume pastures on acidic, sandy soils throughout the wheatbelt of Western Australia


No Tillage Use For Crop Production In Kentucky Counties In 1997, G. R. Haszler Jan 1998

No Tillage Use For Crop Production In Kentucky Counties In 1997, G. R. Haszler

Soil Science News and Views

Three years ago (1994) and again last year (1996), we reported the status of no-tillage adoption in Kentucky counties. Now, CTIC has published the results for 1997. As before, Kentucky leads the nation in percent of all crops produced under no tillage, but the percentage has slightly decreased from 1996. In 1994, 44% of all crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51% . It dropped to 48% in 1997. The results for 1994, 1996 and 1997 are shown in Table 1. The percentage of major grain crops (corn, soybeans and small …


Precision Agriculture: A Field Study Of Soil Test Variability And Its Effect On Accuracy Of Fertilizer Recommendations, Kenneth L. Wells, James E. Dollarhide Jan 1998

Precision Agriculture: A Field Study Of Soil Test Variability And Its Effect On Accuracy Of Fertilizer Recommendations, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of precision agriculture techniques in Kentucky during the past several years has generated interest in how to soil sample a field for use in programming computer-driven, on-the-go, variable rate fertilizer spreaders (VRS). The advantage achieved by VRS is related directly to variability of soil test (ST) values within a specific field and the accuracy of how they represent the field. Since variability of ST values commonly exists on a small scale, a very intensive sampling procedure (grids of one acre or less in size) would be required to accurately describe the nature and extent of such variability within a …


Precision Agriculture: The Effect Of Variable Rate Fertilizer Application On Soil Test Values, Kenneth L. Wells, James E. Dollarhide Jan 1998

Precision Agriculture: The Effect Of Variable Rate Fertilizer Application On Soil Test Values, Kenneth L. Wells, James E. Dollarhide

Soil Science News and Views

Use of variable rate fertilizer spreaders (VRS) is available to farmers in many areas of Kentucky. For use of VRS, a soil fertility map must be prepared for the field to be spread which requires subdividing the field into subunits. Each subunit is then soil sampled separately. A common procedure in commercial use is to grid a field into 2.5 acre blocks and to take a composite sample of 6-8 cores along the perimeter of a circular radius of 60-80 ft from the center of each block. Each block receives a separate fertilizer recommendation based on results from the soil …


Late Season Supplemental Nitrogen On Double-Cropped Soybeans, Curt Judy, Lloyd W. Murdock Jan 1998

Late Season Supplemental Nitrogen On Double-Cropped Soybeans, Curt Judy, Lloyd W. Murdock

Soil Science News and Views

Soybeans produce their own nitrogen for crop growth with the aid of nitrogen fixing bacteria in the soil that infect the soybean root and form nodules which contain the bacteria. This is a symbiotic relationship that benefits both the plant and the bacteria. The bacteria are able to take atmospheric nitrogen and convert it into a form of nitrogen that the plant can use. Much of the nitrogen requirement for soybean production begins at seed development. Soybean physiology studies suggest that the amount of nitrogen supplied for the soybean plant from fixation in the nodules is less than the potential …


A Two Year Evaluation Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Intensively Row Cropped Agricultural Watershed In Western Kentucky, Larry Reber, John Potts Jan 1998

A Two Year Evaluation Of Nitrate-N And Triazine Herbicides In Groundwater And Surface Water Of An Intensively Row Cropped Agricultural Watershed In Western Kentucky, Larry Reber, John Potts

Soil Science News and Views

The quality of water in Kentucky's agricultural watersheds has received considerable attention in recent years. The main concerns in corn production areas usually center on water content of nitrate-N from commercial fertilizer and triazines from herbicide applications. Although N can be found naturally in Kentucky soils, it cannot supply all the N that corn needs to produce optimum yields. Therefore, fertilizer N is added to ensure ample nutrition. Triazines, on the other hand, do not occur naturally in the soil but are applied to the soil to effectively control weeds. Most commonly, these herbicides are applied at the time of …


Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson Jan 1998

Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) reduce losses of nutrients, solids, and other materials from land area treated with fertilizers and manures. A number of models are available that simulate nutrient and sediment transport in VFS. While VFS effectiveness is considered to depend on lengths of pollutant source area and VFS areas, few published studies have tried to validate these models using variable pollutant source area and VFS area. The objective of this study was to validate an event-based nutrient transport model (Chaubey et al., 1995) that simulates soluble nutrient transport in VFS. This model links three sub-models: modified Green-Ampt infiltration, non-linear …


Use Of Animal Wastes On Cropland, Monroe Rasnake, M. Scott Smith Jan 1998

Use Of Animal Wastes On Cropland, Monroe Rasnake, M. Scott Smith

Soil Science News and Views

In recent months, environmental issues relating to land application of animal and industrial wastes have been widely debated in Kentucky. On several occasions, members of the University of Kentucky Agronomy Department have been asked to provide scientific information and technical interpretation related to these complex and controversial issues. To be certain that the public and policy makers are provided with consistent and scientifically sound information, the Agronomy Department has decided to release consensus statements on some of the major agronomic issues involved. These statements reflect our best scientifically based interpretations of these important subjects. Several of our faculty with long …


Western Australia Soil Acidity Research And Development Update 1998 : Time To Lime, Department Of Agriculture And Food, Western Australia Jan 1998

Western Australia Soil Acidity Research And Development Update 1998 : Time To Lime, Department Of Agriculture And Food, Western Australia

Bulletins 4000 -

Recent yield responses by canola where lime has been applied to acidic soils are very encouraging. Two sites have shown that the yield increase in canola after lime was applied in the previous year would have easily paid for the total cost of purchase, transport and application of the lime.

This work was carried out to demonstrate the increased options that are likely to be available once producers are treating or managing soil acidity. Canola is becoming increasingly important as a cash value crop and a break crop allowing wider rotations.

Growers are pushing the limits of canola’s tolerance to …


Environmental And Botanical Controls On Peatification - A Comparative Study Of Two New Zealand Restiad Bogs Using Py-Gc/Ms, Petrography And Fungal Analysis, Tomasz K. Kuder, Michael A. Kruge, J C. Shearer, S L. Miller Jan 1998

Environmental And Botanical Controls On Peatification - A Comparative Study Of Two New Zealand Restiad Bogs Using Py-Gc/Ms, Petrography And Fungal Analysis, Tomasz K. Kuder, Michael A. Kruge, J C. Shearer, S L. Miller

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study shows that chemical properties of two restiad species, Empodisma minus and Sporadanthus traversii, may contribute to their success as peat-formers in a climate of the North Island of New Zealand which is not conducive to raised mire development. Unlike Sphagnum, the equivalent northern hemisphere peat-former, restiads possess lignin in their tissues. In addition, the presence of non-lignin polyphenols (including tannins and phenolic acids) in restiads may be an important factor in peat formation due to the allelopathic decay retardation. Patterns of degradation of plant biopolymers have been examined and the pathway of degradation of monocotyledons (loss …


Resource Use In The Trinational Sangha River Region Of Equatorial Africa: Histories, Knowledge Forms, And Institutions, Heather E. Eves, Rebecca Hardin, Stephanie Rupp Jan 1998

Resource Use In The Trinational Sangha River Region Of Equatorial Africa: Histories, Knowledge Forms, And Institutions, Heather E. Eves, Rebecca Hardin, Stephanie Rupp

Yale School of the Environment Bulletin Series

This volume is based on an international conference, “Natural Resource Use Relations in the Trinational Sangha River Region of the Northwest Congo Basin,” held at Yale University in September 1997. In recognition of the bilingual context in which conservation occurs in the three countries of the Sangha region — Cameroon, Central African Republic, and Congo — all sessions of the conference were conducted simultaneously in French and English. This publication, which is a complete rendering of the conference papers and discussion sessions, is available in its entirety in both French and English.


Quartzite Fabric Transition In A Cordilleran Metamorphic Core Complex, Allen J. Mcgrew, Martin Casey Jan 1998

Quartzite Fabric Transition In A Cordilleran Metamorphic Core Complex, Allen J. Mcgrew, Martin Casey

Geology Faculty Publications

Photomicrographs 143A-143F record fabric variations in quartzite with increasing structural depth in a > 1 km thick, amphibolite-facies, normal-sense shear zone in the East Humboldt metamorphic core complex, Nevada (Figure 143.1). This shear zone and the overlying detachment system unroofed an infrastructure of high-grade, migmatitic gneiss during Oligocene to early Miocene extension (Dallmeyer and others, 1986; Wright and Snoke, 1993; McGrew and Snee, 1994). Thermobarometric constraints from near the base of the mylonitic zone record deformation conditions of 550°- 620°C and 300-400 MPa (Hurlow and others, 1991). Sample WBC6 (l43A and 143B) characterizes the mylonitic zone, whereas sample 8706-1 (143C and …


Solute And Bacterial Transport Through Partially-Saturated Intact Soil Blocks, Edmund Perfect, Mark S. Coyne, Michael C. Sukop, Gerald R. Haszler, Virgil L. Quisenberry, Ligia Bejat Jan 1998

Solute And Bacterial Transport Through Partially-Saturated Intact Soil Blocks, Edmund Perfect, Mark S. Coyne, Michael C. Sukop, Gerald R. Haszler, Virgil L. Quisenberry, Ligia Bejat

KWRRI Research Reports

Steady-state transport of water, chloride and bacteria was measured through intact blocks of Maury and Cecil soils, under partially saturated conditions. Major objectives were to determine if transport occurs uniformly or via preferential flow paths, and if soil physical properties could be used to predict breakthrough. The blocks were instrumented with TDR probes and mounted on a vacuum chamber containing 100 cells that collected eflluent. After each experiment the blocks were sampled for soil physical properties. The fluxes showed no spatial autocorrelation and the eflluent variance was not statistically different between soils. Less than 3% of the influent bacteria appeared …


Description Of The Sections And Subsections Of The Interior Highlands Of Arkansas And Oklahoma, Thomas L. Foti, George A. Bukenhofer Jan 1998

Description Of The Sections And Subsections Of The Interior Highlands Of Arkansas And Oklahoma, Thomas L. Foti, George A. Bukenhofer

Journal of the Arkansas Academy of Science

Sections and subsections of the Interior Highlands of Arkansas and Oklahoma are redefined, mapped and briefly summarized. The map was produced to support the Ozark- Ouachita Highlands Assessment (OOHA), being conducted by the USDA Forest Service. It revises the USDA Forest Service map "Ecological units of the eastern United States, first approximation" by Keys et al. (1995) and the earlier maps of the natural divisions of Arkansas (Foti, 1974; Foti, 1976; Pell, 1983) to reflect new knowledge and to achieve consistency with units recognized in Missouri. Four sections (natural divisions) are defined as opposed to the three of the previous …


Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 5 White/Beattys' Catchment (Dinninup), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr Jan 1998

Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 5 White/Beattys' Catchment (Dinninup), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr

Resource management technical reports

High water use vegetation systems for salinity control were trialed on a 250 ha catchment located three km north-west of Dinninup, Western Australia. The catchment receives about 620 mm annual rainfall and 1500 mm annual evaporation. The catchment is characterised by slopes with gradients in excess of 5%, deep weathering (15-25 m to bedrock), active seepage in the valley (piezometric heads 204 m above ground surface) and high recharge (water table fluctuations of 1-4 m).


The Use Of Red Mud/Gypsum To Reduce Water Pollution From Sandy Soils Used For Vegetable Production, Ian Mcpharlin, W. J. Robertson, R. C. Jeffery Jan 1998

The Use Of Red Mud/Gypsum To Reduce Water Pollution From Sandy Soils Used For Vegetable Production, Ian Mcpharlin, W. J. Robertson, R. C. Jeffery

Research Reports

An important domestic and export vegetable industry is located on the sands of the Swan Coastal Plain (SCP) in Western Australia. The total value of the vegetable industry on the SCP was estimated at $90M in 1996/7 or about 50% of the total value of the industry. This vegetable production has been located on good quality sands such as the Spearwood and yellow Karrakatta sands, close to the coast, since the 1950s. However in recent years competition for this land for urban and industrial use has forced vegetable production onto soils with poorer water and phosphorus retention capacity such as …


Planning To Grow Vegetables Commercially, John Burt, Peter Gartrell Jan 1998

Planning To Grow Vegetables Commercially, John Burt, Peter Gartrell

Bulletins 4000 -

This Bulletin was developed by Department of Agriculture in recognition of the increasing complexity and competitiveness in establishing a commercial vegetable enterprise. The information in this Bulletin will provide you with a useful guide to assess your likelihood of succeeding in vegetable production.

Vegetable production is not an easy lifestyle. It is a highly competitive environment with the industry consisting of growers with big investments and years of experience and knowledge. Horticultural farms require a large amount of capital and time and are increasingly expanding and becoming more specialised.

If you are serious about growing vegetables, work through this Bulletin …


Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 4. Tkk Engineering's Catchment (Williams), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr Jan 1998

Results Of Investigations Into The Groundwater Response And Productivity Of High Water Use Agricultural Systems 1990-1997 4. Tkk Engineering's Catchment (Williams), A D. Smith, Richard J. George Dr, P R. Scott, D L. Bennett, R J. Rippon, G J. Orr

Resource management technical reports

High water use vegetation systems for salinity control were trialed on a 70 ha catchment located about 15 km north of Williams, Western Australia. The catchment receives about 545 mm annual rainfall and 1870 mm annual evaporation. Development of salinity is characterised by passive discharge upslope from a dolerite dyke. Because recharge exceeds the discharge capacity of current seeps, there is potential for new seeps to develop in the mid to lower slopes.