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ARTICLES >> Environment Articles

South Australian Murray Darling Basin Soil Reclamation Project

Posted by Bestprac on Sep 05 2012

Andrew Graham, Productive Nutrition.

Wind and water erosion are major factors that contribute to the loss of soil in the South Australia Murray Darling Basin (SA MDB) rangelands, particularly where ground cover has been eroded from drought or overgrazing. It is said that soil loss, through the degraded areas of the SA MDB rangelands, is between 330,000-440,000 tonnes per annum (Lewis 2009). The total value of this soil loss is estimated to be in excess of $600,000 per annum.

Erosion of clay plans on the current siteA recent photograph taken at a Soil Reclamation Project site (Figure 1 left) shows the erosion of clay plans, a problem that is common and of concern to many.

Productive Nutrition Pty Ltd recently met with project collaborators, Ian Warnes of Woolgangi Station, Richard Riggs of Murkaby Station and John Wood, Natural Resources, SA Murray Darling Basin (Burra office), who are participating in a project to investigate and assess the efficiency and cost benefit of different land management practices which may reduce soil erosion. Ian and Richard have kindly offered their land, time and extensive knowledge to assist with trial sites on each of their properties. This project is supported through funding from the Australian Government's Caring for our Country.

At the trial sites furrows will be ripped at 3 metre spacings and 5 metre spacings to determine the more optimal spacing and also at two different seeding rates (1.5 kg/ha and 3kg/ha), to determine which rate is more cost efficient. Figure 2, below, shows three different furrowing techniques that have been used in the past. For this project, a mouldboard plough will be used to cut deep rip lines (30 centimetres), giving the plants every chance of germination before furrows seal. Ian and Richard both agree that the deeper the rip line, the greater the reduction in wind erosion, which increases the length of time before furrows are filled in by erosion and which then provides for the best chance of revegetation.

The site on Ian’s property will not be grazed, whereas the site on Richard’s property will be grazed, providing the opportunity to monitor the impact of grazing on a range of species, some more palatable than others.

Well known natural resource specialist, Merri Tothill, worked with Andrew Graham of Productive Nutrition to assess the sites before the revegetation trial furrows to be revegetated were ripped. The soil surface is thin and loamy, over red crumbly clayey subsoil, calcareous with depth and including variable gypsum accumulations. 25 plant species were identified in the trial site area, of which many were collected to analyse for their nutritive value and mineral status.

Moulboard plough (ungrazed)Triple plough (grazed)Deep rip (ungrazed)

Figures above: Triple plough (grazed), deep rip (ungrazed), mouldboard plough (ungrazed)

A list of the plant species selected to use for revegetation is listed in table 1, below. Species were selected based on their endemism, type, palatability and availability.

Scientific Name Common Name
Acacia nyssophylla  
Acacia oswaldii Umbrella Wattle
Atriplex Vesicaria Bladder saltbush
Enclyeana Tomentosa Ruby saltbush
Maireana pyramidata Black bluebush, sago bush, shrubby bluebush
Rhagodia spinescens Thorny saltbush, spiny saltbush, hedge saltbush, creeping saltbush, berry saltbush
Atriplex nummularia Old man saltbush
Austrostipa nitida Spear grass
Casuarina cristata Black Oak, Inland Sheoak
Danthonia caespitosa Ringed wallaby grass
Lavatera plebeia Native holly hock
Tetragonia dipeta  
Tetragonia eremaea  

 

 

 

 

 

 

 

 

 

 

 

 


Throughout the trial Productive Nutrition will be collecting data, including grazing preference and the nutritional value of plant species.  An onsite workshop is planned for November 2012 which will look at the germination of the various plant species and discuss their value to livestock. How to identify plants is critical when considering this process and this important and interesting topic will be covered by Merri Tothill, with hands on exercises to assist participants develop and practice their skills.

Please contact Andrew Graham, Productive Nutrition, for further information or to register for November’s workshop. All welcome.
Phone: 08 8842 3192
Email: andrew@productivenutrition.com.au

 

Last changed: Sep 06 2012

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