Physical Sciences and Mathematics Commons^™

Salinity Action Plan, Department Of Agriculture And Food, Western Australia

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

In November, the Premier of Western Australia, Richard Court, released his governments strategy to tackle one of the State's most serious environmental problems - salinity. This article provides a summary of the action plan, full details are available in a two volum set 'Salinity - a situation statement for Western Australia' and 'Western australian salinity action plan'.

Copies of the reports are available from Publication Section, Agriculture Western Australia, 3 Baron-Hay Court, South Perth 6151. Phone (09) 368 3729

Degradation Of Remnant Vegetation, Richard George, Don Mcfarlane, Russell Speed

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

Remnant vegetation, wetlands and riverine systems on both private and public land throughout south-western Australia are being rapidly degraded by dryland salinity, inundation, silting, nutrient enrichment and weed invasion. Richard George, Don McFarlane and Russel Speed outline some of the reasons why this is happening and provide some case studies that highlight actions to protect these remnants.

Revegetating Salt-Affected Land With Shrubs, Ed Barrett-Lennard, Fionnuala Frost, Steve Vlahos, Norm Richards

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

The establishment of salt-tolerant shrubs such as saltbush and bluebush on salt-affected land reduces the risk of soil erosion, and can also fit into farm programmes as a profitable enterprise. Salt-tolerant shrubs can be used as forage for sheep in summer and autumn, when the availability of annual pastures is low or annual pastures are just beginning to emerge. This article describes three methods for establishing shrubs on salt-affected land and what affects shrub establishment.

Drainage Of Sandplain Seeps For Salinity Control And Stock Water Supplies, Richard George, Peter Frantom

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

Sandplain seeps are derived from a shallow groundwater system which flows from the deep sandplain soils upslope. Seeps result in small areas of salinity and waterlogging, which can be the focus of soil erosion. Sandplain seeps may represent as much as 10 per cent of Western Australia's salt problem in the drier agricultural area. Several drainage experiments conducted between 1986 and 1989 determined the best methods of reclaiming sandplain seeps.

This article discusses the results of these drainage experiments. It comments on the most suitable method for reclaiming sandplain seeps and developing them for stock water supplies.

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

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

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.

Seepage Interceptor Drains And Topsoil Salinity, T R. Negus

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

The Department of Agriculture established 121 trials in its Narrogin advisory district starting in 1972 to measure the effect of bulldozer and grader built seepage interceptor banks and drains on the topsoil salinity of the land downslope of them.

After 14 years of moniterin, there was no evidence that seepage interceptor drains and banks reduced the top soil salinity on 10 of the 11 sites in the Pingelly, Brookton and Wickepin Shires.

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.

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 …

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.

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 …

A Central Midlands Catchment Study : The Prospects For Land Drainage, B J. Hillman, B. J

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

Flooding, waterlogging and salinity problems in Western Australia are complex. Usually broad areas of land are affected, thus it is hard for one farmer alone to combat the effects because the problem so often starts and finishes off his farm.

The Causes Of Saltland : A Case Study At Esperance, P R. George, S. C. Bull

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

A series of bores on the Esperance Downs Research Station has demonstrated that the groundwater levels change after clearing, and the relatiojnnship between groundwater levels and soil salinity has been emphasised. This pattern of hydrological change leading to soil salinity problems applies widely in the wheatbelt.

The Dryland Salinity Problem In North America, P R. George

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

North america also has a dryland salinity problem although the source is different.

Western Australian Soils Store Large Quantities Of Salt, C V. Malcolm, R. A. Nulsen, C. Henschke

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

Enormous quantities of salt are stored in the soil in the agricultural areas of Western Australia. Small movements in this salt can produce large effects on farms.

Soil Salinity In Western Australia : A Summary, T C. Stoneman

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

Soil salinity problems have long been recognised in Western Australia. The earliest published explanation in 1924 suggested that removing native vegetation increased stream salinity, and this basic cause has been confirmed by many studies since.

Effects Of Surface Drainage On Dryland Salinity, P R. George, T. R. Negus

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

Areas which are salt-affected are often also flooded. Although flooding is not the basic cause of salinity, surface drainage may improve conditions for plant growth, and this article describes suitable methods

Landform, Natural Drainage And Salinity, Eric Bettenay

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

An understanding of salt movement in streams and groundwater may lead to better methods of control and prevention of salinity.