Physical Sciences and Mathematics Commons^™

The Thirsty Earth: Acid Rain - A Sour Drink, Margaret R. Souza

Bridgewater Review

No abstract provided.

Environmental Impact Of Being Busy In The Creation, Delmar Vander Zee

Pro Rege

No abstract provided.

Increasing Groundwater Salinity In The Northern Wheatbelt, R J. Mcgowan

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

Every farmer in western Australia's northern wheatbelt will know of a groundwater supply, be it bore, well or soak. that has become increasingly saline. The groundwater may have become more saline over a period of 15 years or more, or have been noticed only recently. Inevitably, the bore will lie within an area cleared for agriculture. This increase in groundwater salinity may be associated with soil salinisation. Although researchers have some understanding of the processes causing salinisation of groundwater in the wheatbelt and the extent of the problem, little is known about the rates of salinisation and groundwater rise. A …

Analysis Of Arkansas Fur Harvest Records - 1942-1984: I. State And Regional Accounts, Gary A. Heidt, James H. Peck, Tiny Sheldon, Joseph D. Clark

Journal of the Arkansas Academy of Science

Fur harvest records maintained by the Arkansas Game and Fish Commission from 1942-1984 summarized the number of pelts sold by region (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta) and the average price per pelt for 16 furbearers. Analysis of these records showed that in the 1979-80 trapping season (the record year for both harvest and value both in Arkansas and the nation), the value of the Arkansas fur harvest ranked 14th nationally (2.12% of total national value). Fur harvests in Arkansas were high in the 1940's, declined in the 1950's and 1960's and then experienced a rapid …

Response Of Fishes To Revetment Placement, C. H. Pennington, S. S. Knight, M. P. Farrell

Journal of the Arkansas Academy of Science

Routine fish sampling with hoop nets was conducted monthly from April through December 1978 along natural and revetted riverbanks on the lower Mississippi River near Eudora, Arkansas, to monitor changes in fish populations affected by placement of new revetment for bank protection. Eighteen species of fish were collected with four species comprising over 75% of the total catch. During the months prior to revetment placement, freshwater drum, Aplodinotus grunniens, was the most abundant (32.7% of the catch) species collected. Following in abundance were the flathead catfish, Pylodictis olivaris, (9.8%), common carp, Cyprinus carpio, (7.8%), and blue catfish, Ictalurus furcatus, (3.3%). …

Fluctuations And Relationships Of Selected Physiochemical Parameters In Dardanelle Reservoir, Arkansas, 1975-1982, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

Annual and seasonal fluctuations and relationships are described for discharge, turbidity, chloride, total hardness, conductivity and suspended solids over an eight-year period in Dardanelle Reservoir. The parameters fluctuated rather widely primarily in response to seasonal patterns of rainfall. Chloride and conductivity were related and generally fluctuated together as did turbidity and suspended solids. Hardness appeared to vary independently of the others prior to 1979 then varied more closely with chloride after March 1979. Inherent differences between the Illinois Bayou arm and the main Arkansas River sections complicated the precise identification of any overall impact of power plant operation. No significant …

Laser Levelling Land For Flood Irrigation, M D. Green, J. P. Middlemas

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

Since the introduction of laser levelling to Western Australia's South-West irrigation area five years ago, many farmers have benefited from this new and precise method of land-forming.

The use of lasser controlled earthmoving equipment to redevelop irrigated paddocks has led to improved irrigation efficiency and drainage. Less water is used for each irrigation, water is applied more evenly and less labour is needed. many older, grass-dominated paddocks have been reseeded to improve pasture species.

Eradicating Fruit Fly From Carnarvon, Kingsley Thomas Fisher

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

Late last year the Mediteranean fruit fly (Ceratitis capitata Weidemann) was eradicated from Canarvon, Western Australia by using an intergrated programme of sterile insect releases and bait spraying.

The eradication marked the end of a four-year study on the use and effectiveness of the Sterile Insect Technique, a biological control technique which uses an insect pest against itself. such a study can be used as a basis for treating other threatening insect pests, such as the serious cattle pest screw-worm fly, should they be found in Asustralia.

Being a biological control method, the Sterile Insect Technique is an exellent …

Water Quality For Irrigation, P R. George

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

Although irrigation and salinity problems are frequently inseperable, there is a range of management methods that can be used to handle marginal quality water. Freuently these methods are simple, but require careful planning.

The wide range in tolerance of crops to salinity can be exploiter to ensure that appropriate crops are selected for the water available.

Because crops vary in their sensitivity to salt uptake in the leaves or the roots, watering methods can be changed to avoid problems. For profitable production enough water should be applied to ensure adequate water is available for plant growth as well as to …

Salinity Control In Northern China, G A. Robertson

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

China has vast areas of saline land, perhaps as much as six million hectares. Some of this saline land is a result of marine influence in coastal areas and some is the resultof soil formation in areas with saline geological deposits and inadequate rainfall to leach out the salts at that time.

However, most saline soils in China are as a result of secondary salinisation processess induced by a hydrological imbalance resulting from over-clearing of the land or irrigation. This imbalance has produced rising watertables bringing the salt closer to the soil surface.

In this article, G..A. Robertson, Commissioner …

Residual Values Of Australian Rock Phosphates, Michael D A Bolland

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

For years superphosphate has been the cheapest, convenient and most effective way of supplying phosphorus to newly cleared soils in Western Australia's South-West that are acutely deficient in phosphorus. However its effectiveness as a phosphorus source falls markedly after application. Regular applications are needed to maintaine profitable pastures and crops on these soils.

After a big jump in supperphosphate prices in the mid 970s, researchers tested the use of Australian rock phosphates as potentially cheaper alternative phosphorus fertilisers to superphosphate. On the none-leaching sands, as this article shows, none of the rock phosphates was as effective for plant growth as …

Water Supplies : Dams And Roaded Catchments, W J. Burdass, T. R. Negus, A. L. Prout, I. A. F. Laing

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

Western Australia's Upper and Lower Great Southern statistical areas include most of the broad-scale agricultural land south of a line from Perth to Hyden. Much of the area is well-developed and carries 13.4 million sheep, 203 00 cattle and 95 000 pigs, almost half the State's livestock.

There are few natural rivers and lakes to water livestock in summer and much of the bore water is salty. On-farm waterr conservation, therefore, consits mainly of excavated earth tanks (dams) which are filled by surface runoff or shallow seepage. In the drier areas and in the sandplain roaded catchments have neen built …

Dam Site Selection In The North-Eastern Wheatbelt, J L. Frith

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

Western Australia's wheatbelt farm dams are dug three to eight metres deep and are generally sited in soils which either are inherently impermeable or can be made so during construction.

In the eastern and north-eastern wheatbelt, however, only a small proportion of the soils meets these criteria. Dam site selection in these areas therefore depends on a good knowledge ofwhich soils aresuitable and on our being able to locate them efficiently by using surface indications such as surface soil, natural vegetation or topographic features.

Northern Wheatbelt Water Supply Study, I A F Laing, R. M. Pridham

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

Department of Agriculture surveys have shown that many farms in Western australia's northern wheatbelt have inadequate water supplies. More than 80 per cent of all farms in that area depend soley on groundwater for watering livestock, a much higher percentage than for most other farming areas. Because groundwater salinities have increased in recent years, concern is held for the long-term future of this recource.

In contrast to more southern agricultural areas, farm dams in the northern wheatbelt are relatively uncommon. Only 30 per cent of the existing dams in the northern wheatbelt constitute effective water supplies. More than half of …

Model To Predict Arkansas Gray Fox Fur Harvests, James H. Peck, Gary A. Heidt

Journal of the Arkansas Academy of Science

Linear regression analysis of total gray fox (Urocyon cinereoargenteus) fur harvests from 1954-1983 in Arkansas showed a high correlation with mean pelt values (r = 0.956). Single variable models using linear regression analyses of current season's pelt values (CSPV) and previous season's pelt values (PSPV) were designed to predict fur harvests. These models demonstrated high correlations for predicting harvests (r = 0.933 and r = 0.893 respectively). Regional analyses revealed a high correlation between mean pelt values and harvest for the Ozark Mountain region (r = 0.923), Ouachita Mountain region (r = 0.971 ), and Gulf Coastal Plain (r = …

Lime Needs And Trends In Arkansas, Clifford S. Snyder, Stanley L. Chapman

Journal of the Arkansas Academy of Science

Consumption of agricultural lime in Arkansas declined significantly during the past seven years. During each of the past four years, lime consumption was lower than any time since 1960. The quantity of lime needed for optimum crop production on Arkansas' soils is estimated to be 2,678,700 metric tons (MT) (3,000,000 tons), based on University of Arkansas soil testing summaries. Since 1980, less than 285,728 MT(320,000 tons) of lime have been used each year. It is the natural tendency for most soils in Arkansas to become more acidic with time. Periodic addition of agricultural limestone, however, can neutralize soil acidity and …

Watershed Land Uses And Phosphorus Export Coefficient Relationships: A Planning Tool For Lake Resources Management, Carl R. Stapleton

Journal of the Arkansas Academy of Science

Relationships between nonpoint source pollutant loadings and water quality degradation in lakes have been established. However, practical methodologies necessary to identify and manage nonpoint sources in accordance with lake water quality indices have been lacking. Objectives of the current study were as follows: (1) to compare predicted model values for in-lake total phosphorus (TP) concentrations with actual values; and (2) to determine the applicability of areal phosphorus loading models for lake resources management. The research site was located 19 km west of the City of Little Rock in the Lake Maumelle basin. Areal total phosphorus (TP) loadings in g m^-2yr^-1 …

Analysis Of Arkansas Fur Harvest Records - 1942-1984: Iii. Harvest-Price Relationships, Joseph D. Clark, Gary A. Heidt, Tina Sheldon, James H. Peck

Journal of the Arkansas Academy of Science

Correlation and linear regression analyses between mean annual pelt price and total harvest of 13 Arkansas furbearer species between 1965 and 1983 were performed for state and regions (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta). Statewide, strong correlations (r > 0.80) were identified for bobcat (Felis rufus), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), mink (Mustela vison), nutria (Myocastor coypus), opossum (Didelphis virginiana), and raccoon (Procyonlotor). Moderate correlations (r = 0.55 - 0.79) were identified for eastern spotted skunk (Spilogale putorius), muskrat (Ondatra zibethicus), river otter (Lutra canadensis), and striped skunk (Mephitis mephitis). Nonsignificant correlations (r < 0.468) were shown for beaver (Castor canadensis) and long-tailed weasel (Mustela frenata). Regional differences were noted for each species.

Analysis Of Arkansas Fur Harvest Records - 1942-1984: Ii. Species Accounts, James H. Peck, Joseph D. Clark, Tiny Sheldon, Gary A. Heidt

Journal of the Arkansas Academy of Science

Fur harvest records were maintained by the Arkansas Game and Fish Commission on the following 16 furbearers: badger, beaver, bobcat, eastern spotted skunk (civet), coyote, gray fox, long-tailed weasel, mink, muskrat, nutria, opossum, raccoon, red fox, red wolf, river otter, and striped skunk. These harvest records were analyzed for each species in terms of mean pelt price and numbers of pelt sold by region (Ozark Mountains, Ouachita Mountains, Gulf Coastal Plain, and Mississippi Delta) per year. Historical or biological influences important in interpreting species accounts are presented.

Changes In Forest Soils Following Clearcutting Of Pine Forests In The Ouachita Mountains Of Arkansas, Harlan R. Stoin, Bajuri Bin Kadmin, Lyell F. Thompson

Journal of the Arkansas Academy of Science

Soil characteristics of the mineral surface soil (0-6 cm) on three small watersheds in the Ouachita Mountains of Arkansas from which the pine forests have been clearcut, crushed, and burned for site preparation were studied for the first two years following clearcutting and compared to soils from adjacent uncut pine forest watersheds. Following clearcutting and burning, soil pH was generally higher than in uncut forest soils. The greatest pH differences occurred within several months of burning and generally decreased through the end of the second year. Soil organic matter content was lower immediately following clearcutting and burning and increased to …

Improved Catchments For Farm Dams, I A F Laing

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

The amounts and frequency of runoff from unimproved farmland catchments in Western Australia's cereal and sheep districts are notoriously variable and unreliable. As a result many farmers have constructed improved catchments to ensure better reliability of farm dams for livestock and homestead water supplies.

Improved catchments which are used extensively on these farms are all of the compacted or bare-earth type. These include roaded catchments, flat batter dams and, to a lesser extent, scraped catchments. This article mainly discusses roaded catchments, the most common of the improved catchment types on farms.

Sandplain Hardpan : A Different Dam Construction Material, A F. Mccrea

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

Before 1980, the Department of Agriculture did not believe that suitable farm dam materials could be found in light land soils. However Beacon earthmoving contractor, V> J> Pavlinovich, has demonstrated that where suitable cemented subsoils or 'hardpan' existed, a succcessful dam site could be found.

This material should not be confused with compaction or traffic hardpans ehich are dense layers of soil found near the surface. Traffic hardpans result from compaction of soil materials with the passage of vehicles and farm machinery. Rather, the hardpan referred to here is a natural subsoil layer that has been cemented by silica and …

Drought Proofing The Farm : Case Studies, J L. Frith

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

For many years, Western Australia's north-eastern wheatbelthas suffered chronic shortages of water for stock and domestic use. The area's averageannual rainfall is generally low - less than 300 millimetres - and droughts in the 1970s caused futher problems. manydams in the area leak or have inadequate catchmentsand groundwater is scarce ormofmpoor quality.

In March 982, the Western Australian Government provided $100 000 for the Department of agriculture to demonstrate the potential of establishing permanent, drought-proof water supplies on farms in the north-eastern wheatbelt. The methods were to use exixting techniques to build dams and catchments. In a year of low …

Underground Water Supplies In The Wheatbelt, T T. Bestow

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

Underground water originates from rainfall. The size of the underground recource in any region is broadly related to the amount of rainfall. However, rainfall intensity and seasonal distribution are just as importent as the quality. A relatively small annual fall which consists of a series of heasvy showers or storms close together, may be a more effective source of recharge to underground water than a larger fall that is more evenly distributed over a longer period.

A large annual rainfall, however, is no guarantee that underground water supplies will be readily available. This is because soils and the underlying rocks …

Chemical Sealing Of Earth Dams, R G. Pepper

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

Leakage is not a major cause of failure of farm dams in the Western Australian wheatbelt, but it is a problem in some districts where it can limit stock carrying capacity. Leaking dams are especially common in the West midlands, the north-eastern wheatbelt and the 'jarrah-belt' which extends from Bindoon, southward to Manjimup and Mt Barker (see map and Table 1).

Some dams which leaked when first built have sealed themselves over the years. Others have been successfully sealed using sodium tripolyphosphate.