Physical Sciences and Mathematics Commons^™

Stubble Retention For Control Of Wind Erosion, Dan Carter, Paul Findlater, Steve Porritt

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

The surest way to control wind erosion in continuous cropping systems is to retain stubble. Over the past ten years, Western Australian research has focused on the amounts of stubble needed to prevent that erosion.

How Arsenic Residues Get In Wool, Tony Martin, Robin Jacob, Marion Davies, Peter Rutherford

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

Wool can become contaminated with arsenic in various ways, and several different sources may each contribute to any individual arsenic residue problem.

• dipping sheep in an arsenical dip ( now illegal),

• dipping sheep in a non-arsenical dip in a contaminated dipping facility

• penning sheep on soil with high levels of arsenic before shearing.

Other possible sources include running sheep on land contaminated by gold mine tailings or exploration sites, and allowing sheep access to sites on the farm where arsenical compounds have been dumped, for example, rubbish dumps or sites where dip/sump sludge has been dumped.

Farmers …

The Role Of Earthworms In Western Australian Agriculture, Tom Mccredie, Lex Parker

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

Earthworms have a reputation as soil builders and renovators, particularly among 'organic' farmers and gardeners. They improve soil fertility through increased aeration, aggregation, water infiltration and release of nutrients from organic matter. However, the benefits of earthworms in the wheatbelt have been doubted for many years because of their poor survival in cultivated soils.

Since cropping began in the Western Auslmlian whealbelt over 1OO years ago, the physical condition of many soils has deteriorated. The primary causes of soil degradation were the European cultivation practices used by farmers and the trampling effect of introduced animals. in particular, sheep.

The Pros & Cons Of Retaining Stubble, Department Of Agriculture And Food, Western Australia

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

Few farmers in Western Australia today would question the desirability of retaining crop stubble. The problem usually is how to manage stubble so that it does not interfere with other parts of the farming system

Results Of Stubble Research In Western Australia, Michael Perry, Ron Jarvis, Mel Mason, David Tennant

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

Few farmers would question the desirability of retaining stubbles, both for control of erosion by wind and water, and to return organic matter to the soil. While the present debate is focused on the short term management of stubbles, longer term effects also need to be considered.

The Department of Agriculture has several long-running trials intended to measure long term effects.

Managing Brome Grass In The Wheat:Lupin Rotation, Aik Hock Cheam, Gurget Gil, Christine Zaicou

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

Some farmers and scientists are questioning the sustainability of the cereal:lupin rotation in the Western Australian wheatbelt.

Being a 'tight' rotation, its continuation is constantly under threat by disease, especially lupin root rots caused by Pleiochaeta (the brown spot organism) and Rhizoctonia fungi. To control disease, some farmers have lengthened the rotation to three years, such as wheat:wheat:lupins or wheat:barley:lupins. The longer cereal phase also helps to stabilise soil against wind erosion. However, such rotations can lead to a rapid buildup of brome grass during the two consecutive years of cereals. The implications of these rotations on the severity of …

Stubble : Friend And Foe, Department Of Agriculture And Food, Western Australia

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

Several articles in this issue of the Journal of Agriculture discuss some of the important issues of stubble management. The articles are condensed from some of the papers presented at a stubble workshop at Geraldton in 1991.

Red Kangaroos Can Set Back Range Regeneration, Andrew Mclaughlin

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

After years of severe drought, stocking rates in Western Australia s arid rangelands have been kept low since the 1970s to allow native pastures to regenerate. As well, extensive re-seeding programs have started and sheep and cattle grazing on these areas has been restricted or eliminated. However, pasture regeneration in the rangelands can only succeed when grazing by all animals - sheep, cattle, kangaroos, goo.ts, camels, brumbies and donkeys - is controlled Many more red kangaroos roam throughout Western Australia's pastoral areas today than 20 years ago. The installation of windmills and troughs to water domestic livestock has allowed kangaroo …

Taking The Emu To Market, Paul Frapple, Ruth Hagan

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

Licensed, commercial emu farming in Western Australia is now five years old.

This year, 13,500 birds will be processed for their meat, skin and oil. Production has exceeded demand at prices which the industry considers fair because the industry is still developing marketd for these producys.

Without secure, long term markets, over-production will worsen as the turn-off in this State increases and emus become available from other Australian states and overseas.

The Department of Agriculture is assisting the industry to develop a viable industry.

New Yellow Serradella Varieties For Low Rainfall Pastures, Clinton Revell

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

Large areas of acidic, sandy soils in Western Australia's low and medium rainfall, wheatsheep areas are suited to the pasture legume, yellow serradella.

In the past, a lack of varieties with suitable maturity has limited the use of this species.

New varieties developed in Western Australia and significantly earlier in maturity than traditional types can now extend the use of yellow serradella into these regions.

Wider Spaced Rows For Lupins, Ron Jarvis

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

In this farm scale trial at Wongan Hills, a lined combine was used to seed lupins into rows spaced 380 mm apart in wheat stubble.

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.

Wildlife Corridors In The Wheatbelt, Richard Hobbs, Denis Saunders

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

Native vegetation in the Western Australian wheatbelt now persists mostly in small areas that remained uncleared for various reasons. (See 'Remnant vegetation on farms is a valuable resource' on page 43.) On their own, most of these remnant areas are difficult to manage, and too small to retain viable populations of many of the birds and other animals found in the wheatbelt. These patches of vegetation can be linked by wildlife corridors, which may increase the ability of the wildlife to move about and persist in the area

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.

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.

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 …

The Greening Of Australia, Martine Scheltema

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

Many urban Australians have little understanding of the problems of land degradation because it's an extremely slow process that doesn 't directly influence their day-to-day lives. Understandably, they would have trouble relating to sub-soil compaction, waterlogging, increased soil acidity and salinity. They also have trouble comprehending why fencing according to soil type is an important management tool for farmers, or what role contour banks, drainage systems, the addition of gypsum and planting trees have in reversing land degradation. But given that tree loss "has been at the core of almost every aspect of land degradation in Australia ", and that …

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.

Deep Tillage : Keep An Eye On Costs As Well As Yields, Amir Abadi, Andrew Bathgate

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

Deep tillage overcomes compaction of sandy soils caused by movement of heavy machinery. Many experiments since 1981 have shown cereal yields improve as a result of deep tillage. However, the increased yield does not necessarily mean more profit when costs are taken into account. To determine the profitability of deep tillage farmers must consider its impact on other farm operations. A whole-farm analysis is needed to accurately determine the increase in profit resulting from deep tillage

Narrow-Winged Seeder Points Reduce Water Erosion And Maintain Crop Yields, Kevin Bligh

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

Sowing crops without loosening the topsoil by tillage reduces water erosion. It can increase infiltration of rainfall into loamy soils, thereby reducing runoff and increasing potential crop yields. Crop yields were maintained after I1 seasons of seeding an Avon Valley loam near Beverley with minimum and no-tillage seeding operations. Infiltration increased significantly from 80 per cent of the 1983 growing-season rainfall under the traditional three tillage operations, to 87per cent under a single tillage operation using a combine seed drill. Infiltration increased further to 96 per cent under a no-tillage system using a triple^lisc drill. At Gnowangerup, 80 per cent …

Survey Of The Damage Caused To Trees By Goats, Steve Gherardi, Dick Mills, Tim Johnson

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

The damage that goats can cause to trees is one of the major problems associated with their farming in the agricultural areas of Australia. It is also considered one of the main hindrances to the development of the goat industry. The Department of Agriculture s Goat Industry Development Unit surveyed mohair and cashmere producers to determine the prevalence of tree damage and its extent and severity; why producers believed goats damaged trees; and how producers minimised or prevented this damage.

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).

Trees And Livestock : A Productive Co-Existence, Richard Moore

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

Trees, as part of farming can help to combat land degradation problems and produce a good economic return from timber at the same time. For example, there is now clear evidence that planting trees can help combat salinity by lowering water-table levels. Trees can also substantially improve overall farm productivity by providing shelter for pastures and livestock. The challenge is to find practical and economical methods of integrating trees and farming. A combination of widely-spaced trees and livestock is one promising method. This article describes the benefits of this type of agroforestry to farmers, suitable locations and how to practice …

Variable Quality Of Saltbush Seed Influences Establishment, Stephen Vlahos, Donald Nicholas, Clive Malcolm

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

Farmers are using niche seeders to direct-seed saltbushes (Atriplex spp.) cheaply on large areas of salt affected land. While many factors influence successful establishment of these shrubs, fanners can control the quality of the seed they use. Too often, the lack of knowledge of saltbush seed quality has resulted in extremely poor establishment. The importance of seed quality is well recognized in the establishment of grain crops and pastures, but it is often overlooked when farmers buy or select seed of saltbush. If farmers know the quality of the seed they buy, they can make appropriate adjustments to the sowing …

Remnant Vegetation On Farms Is A Valuable Resource, Richard Hobbs, Ken Wallace

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

Retention of native vegetation on farms is important both from an ecological and an economic point of view. Productivity in the paddocks ultimately will depend on the retention and replacement of trees and shrubs in the landscape. Remnants of native vegetation can play their part by helping to ensure the long-term viability of the agricultural system, as well as greatly enhancing the quality of life for those living on the land.

Windbreaks Prove Their Worth, Tim Negus

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

Strong winds in the south-west of Western Australia in April 1991 carted tonnes of top soil from stubbles, over-grazed pastures, and recently prepared cropping land. However, where there were windbreaks, downwind protection into the paddock was up to 10 to 20 times the height of the windbreaks. On May 1, 1991, the author inspected farm land for damage from Narrogin to the Dongolocking area, to Harrismith, up the rabbit-proof fence to West Corrigin and back to Narrogin via Kweda. He found the extent of soil erosion varied, and that some tree species planted in windbreaks gave better protection than others

Can Kangaroos Survive In The Wheatbelt?, Graham Arnold

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

One of the costs of agricultural development in Western Australia over the past 100 years has been the loss of most of the native vegetation and, consequently, massive reductions in the numbers of most of our native fauna. Thirteen mammal species are extinct and many bird and mammal species are extinct in some areas. These losses will increase as remnant native vegetation degrades under the impact of nutrients washed and blown from farmland, from the invasion by weeds and from grazing sheep.

Even kangaroos are affected. Unless the community manages remnant vegetation to minimise degradation and enhance the regeneration of …

Phosphorus Retention Of Sandy Horticultural Soils On The Swan Coastal Plain, Ian Mcpharlin, Neil Delroy, Bob Jeffery, Greg Dellar, Maurice Eales

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

Soils can be ranked according to their phosphorus retention capacity by the phosphorus retention index (PRI). This is the ratio of phosphorus adsorbed by soil to that remaining in solution under a set of standard conditions. Although it is a laboratory measurement, the PRI seems to be a good indication of what happens in practice.

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.

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).