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Articles 31 - 60 of 125

Full-Text Articles in Physical Sciences and Mathematics

Waterlogging Limits Growth On Duplex Soils, Bob Belford, Miles Dracup, David Tennant Jan 1990

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 …


Seepage Interceptor Drains For Reducing Waterlogging And Salinity, Don Mcfarlane, Jim Cox Jan 1990

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.


The 1989 Saltland Survey, Richard George Jan 1990

The 1989 Saltland Survey, Richard George

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

In March 1989, the Australian Bureau of Statistics (ABS) surveyed farmers in Western Australia to determine the area of previously arable land that was now too saline for conventional agriculture. Farmers reported that 443,441 ha, or 2.83 per cent, of the 15.7 million hectares of cleared farm land in south-western Australia, was saline. This was an increase of about 180,000 ha on the 1979 survey figure.

The worst affected areas were in the 350 mm to 600 mm rainfall zone and included the Shires of Tammin (9.26 per cent arable area saline), Katanning (7.96 per cent), Goomalling (7.93 per cent), …


Waterlogging : One Reason Why Our Crops And Pastures Are Not Achieving Maximum Yields, Department Of Agriculture And Food, Western Australia Jan 1990

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.


Level Banks Used To Decrease Waterlogging Can Increase Salinity, Don Mcfarlane, Richard Engel, Arjen Ryder, Maurice Eales Jan 1990

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.


Rock Phosphates Are Poor Fertilizers For Non-Leaching Soils In South-Western Australia, Michael D A Bolland, Bob Gilkes Jan 1989

Rock Phosphates Are Poor Fertilizers For Non-Leaching Soils In South-Western Australia, Michael D A Bolland, Bob Gilkes

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

Field experiments conducted on our non leachng soils from 1975 to 1988 have consistently shown that rock phosphates, compared with freshly applied superphosphate each year, are a relatively ineffective fertilizer in the year of application and in the years after application.


The Effect On Farm Profit Of Conserving Stubble To Prevent Wind Erosion, A D. Bathgate Jan 1989

The Effect On Farm Profit Of Conserving Stubble To Prevent Wind Erosion, A D. Bathgate

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

Over-grazing of stubbles is a major cause of winf erosion on WesternAustralian farms. Stubble contributes to the 'roughness' of the paddock; as the roughness is reduced, the risk of winf erosion is increased.

The risk of lupinosis in sheep has previously reduced the likelihood of lupin stubble being over grazed, but the development of Gungurru, a phomopsis-resistent variety of lupin, has increased the potential for over-grazing and hence the probability of wind erosion.

This article describes the economic benefit (or cost) of conserving stubble at the conservation standards.


Water Erosion Of Farmland In 1988, K J. Bligh Jan 1989

Water Erosion Of Farmland In 1988, K J. Bligh

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

Widespread heavy rains in WesternAustralian agricultural areas in 1988 caused severe water erosion, much of which could have been avoided by minimum cultivation and lower stocking rates.


Seepage Interceptor Drains And Topsoil Salinity, T R. Negus Jan 1987

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.


Mogumber Drainage Works Succeed, L K. Lenane Jan 1987

Mogumber Drainage Works Succeed, L K. Lenane

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

The loss of arable farmland from soil erosion, waterlogging and salinity is a severe problem on some Western Australian farms.

When the arable land comprises only 40 per cent of the total area within the Mogumber Soil Conservation District, this loss is a real cause for concern. So too is the resulting damage to roads, siltation of railway culverts, and deaths of roadside trees from rising saline watertables.

However, drainage, contour and other works undertaken by the Mogumber Soil Conservation District have halted this degredation. Badly eroded areas that were fenced off now have a satisfactory ground cover. A wheat …


Field Peas In The Wheatbelt, R J. French Jan 1987

Field Peas In The Wheatbelt, R J. French

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

Plantings of lupins in the Western Australian wheatbelt increased rapidly in the late 1970s and early 980s as improved varieties became available and farmers realised the benefits to be gained from growing grain legumes. Grain legumes are useful not simply as alternative cash crops. They provide 'fixed' atmospheric nitrogewn to following cereal crops and act as a cleaning crop to break cereal disease cycles. They are also valuable sheep feed.

In 1975, throughout the wheatbelt, the Department of Agriculture began a comparison of several alternative legumes. The crops included field peas, faba beans, chickpeas, lentills and various vetches. Field peas …


Serradella Prospects At Esperance, Michael D A Bolland Jan 1986

Serradella Prospects At Esperance, Michael D A Bolland

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

Yellow serradells is a promising introduced annual legume suitable for some of Western Australia's well drained sandy acid soils where other pasture legumes failto persist.

In the Esperance area serradella grows siccessfully on some sandy soils more than 0.5 metres deep. I develops deep roots rapidly - up to three times deeper than subterranean clover - and this is probably the main reason for its persistance.

At present only two late maturing, registered serradella cultivars are available to farmers in southern Australia. This article describes research at Esperance to delect earlier flowering cultivars for persistence in areas with less than …


Draining Irrigation Areas, K S. Cole, J P. Middlemas Jan 1985

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 Jan 1985

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 Jan 1985

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 Jan 1985

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 …


Assessment Of Waterlogged Sites, D J. Mcfarlane Jan 1985

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.


Drainage Prospects For Saline Wheatbelt Soils, P R. George Jan 1985

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 Jan 1985

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 Jan 1985

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.


Modifying Fertiliser Practices, J S. Yeates, D. M. Deeley, M. F. Clarke, D. Allen Jan 1984

Modifying Fertiliser Practices, J S. Yeates, D. M. Deeley, M. F. Clarke, D. Allen

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

If modified fertiliser practices are adopted phosphorus losses from the Peel-Harvey catchment can be reduced. Farmers can save money on fertiliser applications and the need for more expensive catchment management measures to reduce algal pollution of the estuary will be avoided.

Research data available so far indicate that, with farmer co-operation and the use of the new slow release fertiliser New Coastal Superphosphate, long-term phosphorus application rates can be reduced by 30-40 per cent - and possibly even halved - without lowering agricultural production. This will also reduce phosphorus loss to drainage water.

Although much of the research since 1982 …


Sources Of Lime In The South-West, I M V Brown Jan 1984

Sources Of Lime In The South-West, I M V Brown

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

Many Western Australian farmers topdress or incorporate lime into their acid soils to neutralise them and to improve crop or pasture yields. Most use pulverised limestone or limesand which is cheap and relatively easy tospread.

Agricultural lime isdefined as "any fertiliser used principally for the purpose of reducing soil acidity and having calcium carbonate or magnesium carbonate, or both, as its main ingredients".

Less extensive sources of liming material are found in scattered inland areas where deposits of calcrete have been formed by the weathering of calcium-rich rock and also in association with internal drainage systems.

Magnesite, generally formed by …


Soil Acidity In The Eastern Wheatbelt, W M. Porter, I. R. Wilson Jan 1984

Soil Acidity In The Eastern Wheatbelt, W M. Porter, I. R. Wilson

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

In Western Australia parts of the sandplain of the eastern wheatbelt are very acid and produce poor crops, It was not until the late 1970s that the effect of soil acidity on the productivity of the sandplain soils was examined in any detail.

Since then researchers have learnt a great deal about the nature of soil acidity in the eastern wheatbelt sandplain soils and can suggest management options for farmers.

This article discisses the problem of the very acid soils. It does not deal with the moderately acid, medium textured soils of the eastern wheatbelt. Although the acidity of these …


Soil Acidity And Liming In The Lower Great Southern, R N. Glencross, M. G. Clarke Jan 1984

Soil Acidity And Liming In The Lower Great Southern, R N. Glencross, M. G. Clarke

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

In the 375 to 750 millimetre rainfall area of the Lower Great Southern, reports of loss of subterranean clover from established pastures, reduced carrying capacity for sheep and increasing soil acidity lead to the establishment in 1981 of a research programme into the effects of soil acidity on pasture productivity in that region.


Soil Types And Drainage, Eric Bettenay, N. J. Schofield Jan 1984

Soil Types And Drainage, Eric Bettenay, N. J. Schofield

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

At least 90 per cent of the phosphorus entering the Peel-Harvey estuarine system comes from land cleared for agriculture, most of it from the coastal plain. These soils are naturally deficient on phosphorus and sulfur and this is supplied in superphosphate, which contains about 10 per cent phosphorus and 1 percent sulphur.

However, rain leaches some of this applied phosphorus from the land into drains and rivers which flow into the estuary. In 1981, farmers in the Harvey River-Mayfields Drain catchment lost the equivalent of 1,300 tonnes of superphosphate into the estuary. Between them they have in effect spent $120,000 …


Treating Saltland, Department Of Agriculture, Western Australia Jan 1981

Treating Saltland, Department Of Agriculture, Western Australia

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

No abstract provided.


Western Australian Soils Store Large Quantities Of Salt, C V. Malcolm, R. A. Nulsen, C. Henschke Jan 1978

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 Jan 1978

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.


Farm Dams In The Wheatbelt, I A F Laing Jan 1977

Farm Dams In The Wheatbelt, I A F Laing

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

Of the estimated 76 000 farm dams in the wheatbelt, about 8 per cent either leak or are salt affected. The remaining 70 000 dams are capable of holding water for livestock use and can be regarded as sercicable dams.

A great many of the serviceable dams are unreliable water supplies due to the combined effects of lack of runoff from catchments, shallow depth of storage and small size of storage in relation to expected demand from livestock and evaporation loss.


Nitrogenous Fertilisers For Cereal Production, M G. Mason Jan 1975

Nitrogenous Fertilisers For Cereal Production, M G. Mason

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

Among the many factors influencing crop response to nitrogen applications, the most important are the season, soil type, paddock history, time of application and source of nitrogen. Before deciding whether to use nitrogen on a cereal crop, which source to use and at what rate, the farmer needs some understanding of how these factors work.