Physical Sciences and Mathematics Commons^™

Communication Networks And The Adoption Of Three Farn Practices, P. W. Fry, F. K. Goss

All other publications

The report commences with a discussion of the diffusion and adoption model, and illustrates some of the research observations and practical outcomes that have emerged in recent years, An overview of social network research is presented as a means of understanding communication exchanges and providing data relevant to the diffusion debate. The communication and adoption studies are then reported in three separate sections in the order they were conducted. (A map of the location of the survey areas is shown in Figure I ) . The objectives, survey method, results and a summary are presented for each study.

A background …

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 …

Draining Irrigation Areas, K S. Cole, J P. Middlemas

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

Many irrigation schemes throughout the world have turned into unproductive saline flats and swamps. This dramatic change can occur within a few years of irrigation starting and has been part of irrigation schemes from earliest times up to the present day.

The main cause of this salinisation is normally excess irrigation water use combined with poor drainage. Any form of waterlogging will have an adverse effect on plant growth.

Sub-Surface Drainage Methods For Salinity Control, P R. George

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

Sub-surface drainage can control waterlogging and salinity of arable land by removing excess groundwater.

There are two broad types of sub-surface drainage: interception drainage and relief drainage.

The cost of drainage will depend on the specific design for the site. For relief drains the prime determinate of cost will be the required spacing. In general, clay soils of low permeability or seepage areas will need narrower spacings and will be harder and more expensive to reclaim than sands or areas only needing drainage of local water.

Drainage To Control Waterlogging, D J. Mcfarlane, T R. Negus, J W. Cox

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

Drains can be classified in several ways. Drains on flat land have similar drainage effects on either side of the drain and are called relief drains. Drains on sloping land intercept seepage water moving down hillsides and therefore have most effect on the downslope side. They are called interceptor drains.

Drains can also be classified as being open drains (that is, open at the ground surface) or buried drains (for example, tube drains).

Saltland Drainage : Case Studies, P R. George, R A. Nulsen

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

Over the past five years farmers have become increasingly interested in the use of drainage to overcome saltland problems.

Experimental work by the Department of Agriculture on sub-surface drainage includes tube drainage and drainage by pumping. The Department is also monitoring the performance of open drains installed by farmers. Major sites are at Esperance, Dalwallinu, Namban and Watheroo.

Some of these projects have been reported in an earlier issue of the Journal of Agriculture. In this article P. R. George, Research Officer and R. A. Nulsen, Principal Research Officer with the Salinity and Hydrology Research Branch, discuss recent results from …

Serradella Trial Programme., L. Cransberg

Experimental Summaries - Plant Research

Serradella Line Evaluation - Stage 2 85A155, Serradella Line Evaluation - Stage 3 85A156, Serradella Establishment - Time of Seeding x Seeding Rate 85A157, Serradella Establishment - Pod Undersowing (Variety x Rate) 85A158, Serradella Establishment - Pod Undersowing (Inoculation) 85A159.

Summary Of Rhizobium Experiments., J G. Howieson

Experimental Summaries - Plant Research

The screening of 33 isolates of R. meliloti collected in Sardinia in 1984, and isolated on a low pH medium, 84ME33. Assessment of the possibility of establishing an 'Index of Symbiotic Competence' for species of Medicago, 85M57. Assessment of the effectiveness of several strains of R. meliloti on M.littoralis, and their saprophytic competence in an acid soil, 84ME35. The screening of the pre-1984 collection of R.meliloti held at the W.A. Department of Agriculture for acid tolerance, 84M34. Assessment of the survival of the Serena WSM419 symbiosis on a range of soil types, 84ME32, 84WH24, 84N18. Assessment of the acid tolerance …

Experimental Summaries Various Trials 1985, R Madin, F Schoonens, A Lindsay

Experimental Summaries - Plant Research

85WH55, 85M55. The effect of timing of Roundup and spray.

85NO87, Evaluation of herbicides for control of lupins in cereals.

85NO89, Control of self sown lupins in cereal crops.

85NA59, Grass controI in barley with Isoproturon, Cinch and Metribuzin.

85NO88, Control of wild oats with hoegrass and oil.

85NO86, Tolerance of wheat to hoegrass and oil.

85NO84, Tolerance of lupins to Fusilade plus oil.

85NA63, Ryegrass control in crop with hoegrass plus crop oil.

85A15, Rates of Fusilade for seed set control in grasses.

85A17, Pasture topping herbicides and oils (Silvergrass).

85WH64, Crop oil additives to seed set control herbicides. …

Weed Seed Ecology, A H. Cheam

Experimental Summaries - Plant Research

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. 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. Emergence of weed seedlings in relation to soil type and cultivation. 82PE32, South Perth. Emergence and fate of weed seeds in different depths of cultivated and undisturbed compacted soil. 84C49, Chapman Research Station. 84MT62, Mt …

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 …

Assessment Of Waterlogged Sites, D J. Mcfarlane

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

Soil is said to be waterlogged if any part of the plant root zone is saturated with water. In severe cases soil is saturated to the surface and waterlogging is obvious. Waterlogging is distinguished from flooding in which surface runoff brings down water from higher up in a catchment. However, flooding may result in waterlogged sites.

Interceptor Drains And Waterlogging Control, J W. Cox, T R. Negus

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

Department of Agriculture trials of seepage interceptor drains from 1972 to 1983 primarily assessed the effects of such drains on salt encroachment. Although these trials showed that the drains had little influence on salt storage within the topsoil, they did reduce waterlogging downslope.

To investigate this drainage effect further, the Department's Narrogin office surveyed 35 drains on 14 properties in the winter of 1981, followed by detailed crop measurements in December that year. Provided the drains were properly designed, surveyed and constructed, and well maintained, they could be expected to increase crop yields during a waterlogging year by about 1 …

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 …

Drainage Prospects For Saline Wheatbelt Soils, P R. George

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

Sub-surface or groundwater drainage by buried tube drains or open ditches can reclaim saltland in the Western Australian wheatbelt. However, this method is expensive and not all sites can be drained cost-effectively. Each drainage site is unique, so careful investigation of each site is essential before recommendations on drainage method and design can be made.

Hillside Seepages, R A. Nulsen

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

'Hillside seepage' is a local, descriptive term applied to almost any wet patch occurring out of the valley bottom. Depending on their surface appearances, 'hillside seepages' are described as 'springs', 'soaks', 'wet patches', or seeps.

Whatever they are called, seeps can cause problems. The land in the seep is wet, unworkable and non-productive. If the seep is saline and the water flows downhill, further land is lost from production, bared and subject to erosion. Even small seeps, while not affecting much land, break up a paddock and complicate the working pattern for tillage and harvest.

Draining A Saline Seep, W J. Burdass

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

Sub-surface drains have dried out a salty seep on farm land in the Katanning district. Capeweed and clovers are now growing on more than three-quarters of the land that was previously bare or carried only patchy sea barley grass.

The drains are still running water after five years. The salt content of the surface soil has been reduced markedly and the salt content of the effluent water is decreasing.

However, to complete the reclamation, further drains will be necessary. Both existing and any new drains will have to be flushed periodically because blockages of pipes cause problems.

Impact Of Petroleum Exploration Activity On Range Resources And Pastoral Pursuits In The West Kimberley, N Klepacki, S J. Black, M H. Marchant

Resource management technical reports

No abstract provided.

A Land Resource Survey Of The Fall Point Coastline, Broome, W.A., P A. Hesp, P J. Curry

Resource management technical reports

The purpose of this study was to find a suitable location for a bird observatory and provide adequate coastal land resource data for the area. The main selection criteria and conditions were: the location was closely adjacent to major wader roosting and feeding sites; all-seasons access was required; the location provided a site of around 2 1/2 hectares to provide space for one or more buildings, camp ground and associated facilities ; anticipated access tracks, site developments and levels of use.

The Taarblin Experience : A Planned Approach To Soil Conservation, Greg Astbury, Owner/Manager Of Taarblin, Tim Negus

Bulletins 4000 -

Many farms in Western Australia were cleared and developed before there was a full and clear understanding of the effects of bush clearing - that is salinization of soil and water supplies, wind and water erosion, waterlogging and soil structure decline. The productive capacity and inherent problems of the different soil types was also largely unknown.

Modern-day Conservation Farm Planning aims to provide a blue-print for the redevelopment of properties to ensure long term soil fertility, to prevent soil erosion and degradation by waterlogging and salinity. It also provides for a spread of reliable stock watering points and more efficient …

Shire Of Rockingham : A Study Of Land Resources And Planning Considerations, Veronica P M Oma, N L B Richards, M R. Wells

Resource management technical reports

No abstract provided.

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 …

Drainage And The Law, G A. Robertson

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

Drainage is being increasingly used in Western Australia as an attempted cure for land salinisation and waterlogging. This is nor surprising as drainage is a technical approach that has, in some cases, improved saline land and reduced the effects of waterlogging. However, drainage is not always successful or cost-effective. A detailed site assessment is required before any large or costly drainage system is attempted. Articles in this issue of the Journal of Agriculture discuss that aspect in detail.

Pasture Species Investigations., D. A. Nicolas

Experimental Summaries - Plant Research

Screening of alternatives to cv. Woogenellup clover. N. Bannister, 81NA37. Byford, 81PE6.

Screening 83MA7, Wilgarup, 83AL49, Hazelvale, 83BU22, Bramley 84V7 - Vasse Research Station.

Screening of early to midseason maturing lines of subterranean clover. 85N056, Beverley, 85M043, W. Calingari.

Screening of early maturing lines of subclover. Tarwonga, 84NA27. Wongan Hills Research Station, 84WH35. Dangin, 85N055. Wongan Hills Research Station, 85WH33.