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Focus Catchments : A New Approach To Salinity Research : National Dryland Salinity Program, Steve Porritt

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

Dry/and salinity is a major threat to the resource base of many rural industries around Australia. More than 1.8 million hectares of once productive land are affected by salinity, with a further 1.6 million hectares at risk in the next 15 to 25 years in Western Australia alone. Much of the past Commonwealth and State expenditure on salinity programs and activities has been poorly targeted and coordinated. In view of this, a national dry/and salinity program that supports specific State salinity management programs has been established jointly between the Commonwealth and State government agencies.

The Upper Kent River Catchment is …

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.

Using Saltland In Pakistan : An Australian Connection, Ed Barrett-Lennard, Riaz Qureshi

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

Pakistan and Australia have a common enemy in salt. In each country millions of hectares of previously productive land have been affected by salt (or have the potential to become saline) because of inappropriate agricultural development. Since 1989 the Western Australian Department of Agriculture has participated in a research project in Pakistan which involves revegetation of salt land using Australian shrubs. Early results are very promising.

Managing Bushland On The Farm, Penny Hussey

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

Since the time of European settlement in Western Australia, the replacement of native vegetation with crops and pastures has led to problems for both agricultural production and nature conservation. The most obvious of these are hydrological changes leading to salinisation and waterlogging, and the extinction of some native plants and animals.

Protection of remaining remnants of native bushland, together with revegetation, is increasingly seen as important ways of achieving sustainable agriculture and maintaining our unique wildlife.

Reclaiming Sandplain Seeps Planting Trees, Richard George

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

Sandplain seeps affect large areas of agricultural land in Western Australia's eastern and northern wheatbelt and in the Great Southern. These seeps are estimated to account for about 10 per cent of dryland salinity in the agricultural area. Research and field observations show that seeps may be cheaply and quickly reclaimed using various types of drains or small blocks of trees (George 1990). This article discusses results of reclamation methods associated with tree planting on sandplain seeps in the eastern wheatbelt.

Planting Trees To Control Salinity, Nick Schofield, Phil Scott

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

Dense tree plantings covering at least 30 per cent of cleared land can lower groundwater levels by two metres or more in 10 years from the time of planting. This sizeable drop can be expected at sites receiving 700 to 800 mm of rain a year. Research by the Water Authority of Western Australia shows the most promising strategy when using trees is to put dense plantings on the discharge zone and on lower to midslopes. This strategy is successful where groundwaters contain less than 30,000 milligrams per litre total soluble salts (TSS).

This article discusses research in the 450 …

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.

Whole-Farm Planning : Success At Wilgi Creek, Kevin Shanhun

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

Ian and Bev Lynch own Wilgi Creek, a 376 ha mixed farming property at West Mount Barker in the 700 mm rainfall zone. In 1983, they started a whole-farm plan to overcome the problems of declining production caused by waterlogging (their biggest problem), salinity and deterioration of the remnant native vegetation. Today, their property is an example of a successful, wholefarm land conservation plan based on agroforestry, timber production, water harvesting and improved pastures.

Unique Co-Operative Landcare Venture In The Avon Catchment, Darrel Brewin, John Collett

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

The Avon catchment is bustling with landcare activity generated by a unique co-operative venture between farmers, the Department of Agriculture, the National Soil Conservation Program and Alcoa of Australia Ltd. The Avon Catchment Landcare Program was initiated by the Department of Agriculture and Alcoa, in support of the national Decade ofLandcare. The program provides financial, human and technical resources to undertake catchment and farm planning and demonstrations of rehabilitation techniques that tackle soil and water degradation problems. We know that without specially planned landcare programs and substantial changes in land management, land degradation will continue and further losses of agricultural …

Using Trees To Reclaim Land Lost To Saline Seeps, Department Of Agriculture And Food, Western Australia, Arthur Wright

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

The National Soil Conservation Program (NSCP) has tapped the vigorous community support for landcare initiatives through its demonstration sites for reclaiming sandplain seeps in the Western Australian wheatbelt. The demonstrations, which use tree plantations to reclaim seeps, began in 1989. The sites are being keenly monitored by participating farmers and members of land conservation districts (LCDs).

Regenerating The Rangelands, Adrian Williams, Ron Shepherd

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

Parts of Western Australia's rangelands have been degraded by inappropriately high stocking rates, often associated with large numbers of native or feral animals, poor seasonal plant growth, or the ravages of cyclones, floods or fire. Today, most pastoralists are keen to rehabilitate the degradation of the past, as indicated by the proliferation of Land Conservation Districts (LCDs) throughout the pastoral zones.

There is no 'quick fix' to regenerating the rangelands. It may take many years to achieve the desired result.

Tree Crops For Profit And Land Improvement, John Bartle

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

Western Australian agriculture is deficient in good perennial species. The traditional segregation of agriculture and forestry has diverted attention from commercial wood producing trees as a potential perennial crop. Recently, scientists have made rapid progress in developing tree cropping systems suitable for extensive use in the wetter (more than 600 mm average annual rainfall) areas of the lower south-west. There is potential for a major industry based on fast-growing eucalypts for pulpwood. The foundations for this industry developed from work on agroforestry, forestry sharefarming and salinity control.

Plant Growth And Survival In Saline, Waterlogged Soils, Ed Barrett-Lennard, Neil Davidson, Richard Galloway

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

Waterlogged soils in Western Australia are often salt-affected. Recent research has shown that the interaction between waterlogging and salinity has a far greater adverse effect on plant groivth and survival than either of these two factors individually. The consequences of the combined effects of salt and waterlogging for most plant species are increased salt uptake, reduced growth, chlorosis (yellowing of leaves), defoliation, and death. Salt sensitive agricultural species (nonhalophytes) are more severely affected by this interaction than salt tolerant species (halophytes).

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

Waterlogging Limits Growth On Duplex Soils, Bob Belford, Miles Dracup, David Tennant

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

Duplex soils - soils with a sandy topsoil overlying a clayey subsoil -are ividespread in Western Australia's agricultural areas (see map). These soils are potentially highly productive, but crop growth is variable and the soils can become waterlogged. Work on a duplex soil site near Beverley has shoivn that the soil ivaterlogs where the permeability of the clay is low, and that this permeability varies ividely over the site. Waterlogging accounts for an average of half of the variation in wheat yields on this site; surprisingly, lupins have so far appeared less sensitive to waterlogging- The Department of Agriculture and …

Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford

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

Lack of oxygen is the major cause of limited plant growth in waterlogged soils. When soils become waterlogged less gas diffuses to and from the roots through the soil pores; there are changes in concentrations of mineral elements in soil solutions; and toxic products of roots and soil microorganisms begin to accumulate. These changes adversely affect germination, growth and development of plants.

The Extent And Cost Of Waterlogging, Don Mcfarlane, Buddy Wheaton

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

Waterlogging is an underrated and not widely recognized problem in our cropping areas. Before we can tackle the problem through drainage and alternative cropping systems, we need to know its extent and how much crop yield is lost. The effect of waterlogging on pasture growth is also poorly known.

Waterlogging : One Reason Why Our Crops And Pastures Are Not Achieving Maximum Yields, Department Of Agriculture And Food, Western Australia

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

Water, either its lack"or excess, is the main factor affecting the yield of crops and pastures in Western Australia.

Mapping The Extent Of Waterlogged Crop Using Satellite Imagery, Jeremy Wallace, Buddy Wheaton

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

No abstract provided.

Causes Of Waterlogging, Jim Cox, Don Mcfarlane

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

Waterlogging is highly variable, both between years and within paddocks. This residts in uncertainty as to whether a paddock should be cropped in a particular year, and whether different management should be used on waterlogged areas within a paddock

A study has determined what are the most important causes of waterlogged soils.

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.

Economics Of Interceptor Drains : A Case Study, Andrew Bathgate, Ian Evans

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

This case study determines the most likely rate of return to capital invested in constructing seepage interceptor drains to reduce the effect of waterlogging on crop and pasture yields. The analysis of a farm in the Denbarker region, west of Albany, determined what increases were needed in pasture growth to justify the cost of constructing drains across four adjacent paddocks. The benefits of changing rotations to include lupins were also determined, as growing lupins was unprofitable before the construction of drains.

Planning For Horticultural Expansion On The Swan Coastal Plain, P Coghlan, Geoff Moore, Jim Dixon

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

Horticulture is an intensive, high value form of agriculture highly dependant on the availability of good water supplies for the year-round production of fresh produce. Production increase in Western Australia and the encouragement and development of export markets has caused rapid expansion if the industry in recent years.

Expansion is expected to continue, placing severe pressure on available water supplies and suitable land close to markets. At present' 90 per cent of the Stase's horticultural land is on the Swan Coastal Plain and minor selected hills areas around Perth.

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.

Wheat Growth On Saline Waterlogged Soils, E G. Barrett-Lennard

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

Studies of the growth of plants on salt-affected soils have focused maily on the effects of salt. However, many salt-affected soils are also subject to waterlogging. Glasshouse experiments conducted by the Department of Agriculture have shown that although wheat growth is not greatly reduced by low levels of salt under well drained conditions, under waterlogged conditions such levels of salt can have a severe effect.

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 …

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.