Physical Sciences and Mathematics Commons^™

Wa Soil Erosion Under Investigation, George Richard Dr

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

A survey of soil erosion at 70 sites throughout Western Australia, recently completed as a part of a National Reconnaissance Survey, has shown that erosion is occurring at an unsustainable rate. While still to be compiled into a national publication, Dr Richard George reports on the Western Australian results, and discusses options for management and further investigation.

Comparing Size In Lime, Mark Whitten

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

Extensive research into the management of soil acidity in Western Australia is increasing farmer awareness that lime use can reduce soil acidity and improve crop yields. However, as lime use increases, the question of lime performance and particle size is becoming more critical. Chris Gazey from the Department of Agriculture is heading up the soil acidity project, with the team comprising members from the department, CSIRO and the University of Western Australia. Mark Whitten reports on project outcomes relating to lime particle size.

Success With Serradella In The Wheatbelt, Clinton Revell, Bradley Nutt, Michael Ewing

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

Clinton Revell, Bradley Nutt, and Michael Ewing review the latest developments with new varieties of French serradella and yellow seradella that should provide the basis for productive legume pastures on acidic, sandy soils throughout the wheatbelt of Western Australia

No-Till Sowing : Helping To Keep Cropland Soils In Place, Kevin Bligh, Paul Findlater

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

Repeated erosion of tilled land can ;ower crop and pasture yields because of reduced available moisture and nutrient storage. Kevin Bligh and Paul Findlater look at the causes of water and wind erosion and the role of no-till sowing in minimising erosion.

Making Horticulture Sustainable, Bob Paulin, Neil Clifton Lantzke, Ian Mcpharlin, Murray Hegney

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

Sweet crunchy carrots, luscious strawberries at very reasonable prices, crisp green vegetables - these are just a few of the horticultural products that Western Australians take for granted and eat almost every day. But is their future availability guaranteed as population grows, suburbia spreads and environmental concern increases?

Cooperative Landcare Venture Revisited, Kate Mcinnes

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

Four years ago, the Journal of Agriculture reported on a unique partnership forged in 1989 between the Department of Agriculture Alcoa of Australia Limited and six catchment groups located in the Avon River catchment.

Kate McInnes reports on progress with the Avon Catchment Landcare Project.

Storm : [Wind Erosion In The Great Southern], Dan Carter

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

On Thursday 11 May 1995, a low pressure system with central barometric pressure of 990 hPa formed of south-western Australia. This depression directed gale force winds over the South-West Land Division for some seven hours.

Dan Carter reports on the widespread damage to soils and property, and management practices that would have reduced the problem.

Lupin Stubbles : Getting The Best With Weaner Sheep, Keith Croker, Colin Mcdonald, Jeremy Allen

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

Sweet lupins are now grown on about a million hectares in Western Australia each year. If half of the State's seven million weaners were grazed as recommended on half of the lupin stubbles, it could generate about $15 million from reduced supplementary feeding, greater wool production and other advantages. But correct management is important, particularly knowing when to take weaners out. Research by the Department over the last five years is now indicating how this should be done.

How Sustainable Is Grazing Sheep On Annual Pastures In The Woolbelt?, Don Mcfarlane, Richard George

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

Low wool prices have reduced the profitability of producing wool from clover-based annual pastures in the south-western woo/belt. The heavy reliance on one commodity is economically unsustainable for many farmers. But we should also consider how ecologically sustainable the practice is.

Shallow-rooted annual pastures contribute to widespread salinity in the area, annual legumes are acidifying the soils and making them water repellent, and bare, detached soils from heavy grazing cause sheet and rill erosion during autumn storms. In addition, stock are degrading remnant vegetation and destroying the soil's structure.

To counteract this degradation, the woo/belt needs more perennial pastures and …

No-Tillage Sowing Decreases Water Erosion On Loamy Soils And Increases Earthworm Activity, Kevin Bligh

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

No-tillage sowing places seed and fertiliser in the soil without loosening all of the topsoil. Soil is cultivated only in the sown rows, leaving the inter-row areas largely undisturbed.

No-tillage sowing reduces both wind and water erosion. Soil structure is generally improved, and pasture regeneration is increased because seed is not buried too deeply for re-establishment.

Two long-term trials were establis_hed on loamy soils to determine effects of tillage and cropping on runoff and soil loss.

Red Mud : Cutting Pollution And Boosting Yields, Rob Summers

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

A by-product from the refining of bauxite ore in the South-West is proving a bonus for agriculture.

When spread over the land, not only is it improving soil quality, but it is helping to prevent leaching of phosphorus and the consequent massive algal blooms in the waterways.

Bauxite residue is also showing considerable promise in human and animal effluent disposal systems, composting urban refuse, sewage treatments and as a road base.

Western Australia is now in the forefront of this research which is attracting world-wide interest.

Improving Sustainable Production From Water Repellent Sands, Paul Blackwell

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

The agricultural management of water repellent ( non-wetting) sands is difficult, and production from them is mostly low. However, there are ways to make them more productive.

Furrow sowing and the incorporation of dispersive clay are two likely methods to make these soils easier to manage, more productive and more profitable than they are now.

This article discusses several aspects of our research on water repellent sands. In addition, some of the costs and benefits of alternative management strategies are outlined.

Controlling Wind Erosion In Field Pea Stubbles, Jeff Russell

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

The area sown to field peas in Western Australia's eastern wheatbelt has increased from 4000 ha in 1985 to about 35, 000 ha in 1992.

While field peas can be grown on soil types not suited to lupins, their stubble is highly fragile and prone to wind erosion, even at low grazing pressure. This is one reason why some farmers are hesitant to grow field peas.

Haroest losses of field peas can also be high; levels of JOO to 200 kg/ha of seed on the ground are not uncommon. For this reason farmers believe the stubbles should be grazed.

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.

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.

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.

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.

How To Reduce Spending On Land Conservation, Tim Negus

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

Heavy spending on capital works for land conseroation is usually out of the question in the present financial climate, but the recession does not mean that landcare must be abandoned. There are many aspects of landcare that involve little or no extra cost. Soil conseroationist Tim Negus discusses them in this article.

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 …

The Tammin Alcoa Landcare Education Centre, Department Of Agriculture And Food, Western Australia

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

The town is home of the Tanimin Alcoa Landcare Education Centre. This is an ambitious concept by the Shire of Tammin and the Tammin Action Group to use the whole shire to demonstrate land conservation practices on farms, and to show urban and other communities what Western Australia's farmers are doing to conserve the land and practise sustainable agriculture.

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

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.

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.

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.

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

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 …

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.

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 …