Sustainable Land Use and Management of Sandy Soils
Sandy Soils Project Update
There are over 3.1 million ha of sand and loamy sand soils under agricultural production in SA. Found across all regions and in different rainfall zones, (refer Table 1) these soil types are often associated with areas of existing or of high potential risk of soil and water degradation. The Sandy Soils Project is working with farmers to the development of a solution to manage sandy soils. First results from test sites are expected by late 2005. It is planned to work with Bureau members in the following eight regions: Wattle Range, Sherwood (South East), Geranium (Mallee), Karkoo/Ungarra, Wharminda/Rudall (Eyre Peninsula), Charra (Far West) and Alford/Wokurna (Mid North-YP) and Kangaroo Island.
Project update
The project conducted a Needs Analysis with groups across the state in 2004 to determine issues farmers were facing in managing sandy soils. Activities resulting from these meetings included the development of a number of demonstration sites across the state on both clayed and unclayed sands. Soil testing and analysis was followed by application of a range of treatments such as deep ripping and various nutrition treatments.
Rural Solutions SA and SARDI staff have provided technical support to the development of these sites and presented at field days. A total of over 500 farmers have attended field days held at sites located on eastern and central Eyre Peninsula, Northern Yorke Peninsula, Coomandook, Sherwood/Keith, Wattle Range and Kangaroo Island.
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Over 500 farmers have attended field days
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Clay spreading and delving fact sheets prepared
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Lameroo Clay Spreading Analysis
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"Yeomans" plough available to groups for demonstration activities
Results from the demonstration and trial sites are summarized below. If you would like any further information on this project please call the Bureau on 8226 0351.
Wattle Range
The Wattle Range pasture demonstration was conducted on a sand over clay soil with low nutrient retention capacity. A range of treatments aiming to increase inherent fertility were trialed. These included bentonite clay, organic amendments, different fertilizers and addition of different rates of clay. The only treatment to demonstrate significant benefits in pasture growth was a "double" rate of clay (500t/ha). Soil data is currently being analysed to determined what soil chemical changes occurred following each treatment.
Sherwood/Keith
The Sherwood trial site is a sand over clay soil that was clay spread in 2004. Replicated trials were conducted on canola to assess different rates, and depth of placement on slow release fertilizers and standard fertilizer treatments.
Reponses on the slow release products was mixed however, there appeared to be some response to deep placed fertilizer compared to standard placement.
Green manuring trials were also conducted on sands to the north of the main site. Visits and workshops to sites have been conducted. Results are still being analysed.
Southern Mallee
Soil sampling and analysis of a number of clayed paddocks in the Lower Mallee has been undertaken. There is a clear correlation between 'good' and 'bad' sites and the type of clay used. This data is being compiled into a publication and distributed in the region. Activities have included a bus tour to Coomandook site and workshops at Geranium and Parilla.
Yield mapping conducted on a paddock at Coomandook has demonstrated strong relationships with soil issues identified during previous EM mapping of the paddock. Yields ranged from 0.5t/h up to 5t/ha depending on soil depth. This work has lead to the development of a precision agriculture project funded by the National Landcare Program in 2006.
Kangaroo Island
Three demonstration sites were developed in the Island comparing deep ripping and various nutrition treatments. Responses to deep ripping were significant and there were some lesser responses to the addition of potassium. Activities have included field days, on-site and meetings with farmers.
Eyre Peninsula
Ripping and deep nutrition on clayed sands. Demonstration sites on sandy soils spread with calcareous clays used various treatments to address deficiencies caused by carbonate in the clay. Yield increases up to 225% were delivered where manganese was applied as either a soil or a foliar application.
Details of the trials and the results will be available on the Bureau website shortly
Currently Rural Solutions SA staff are meeting with farmer groups to determine activities to be undertaken during 2006. Details will be provided on this site when they become available. Activities have included a Field day on site, four to five stickybeak days site/field tours and six workshop meetings in conjunction with the EP farming systems project.
Northern Yorke Peninsula
Ripping, and nutrition in dune swale systems. Sandy Soils Field Days 2005 at Sandy Soils sites Boomans and Bute and at the Ag Excellence Field day February 2006.
If you would like any further information on this project please call the Bureau on 8226 0351.
