BRIMPTON LAKE This Eyre Peninsula site was selected as a typical duplex sandy soil found in the district. The site is flat to gently undulating and is used for cropping (cereal, canola, lupins) in rotation with annual grass/legume based pastures. New Horizons is a South Australian Government funded program to capture an additional $800 million in agricultural production per annum in South Australia, support development of a new high value manufacturing industry in agricultural machinery, increase long-term storage of soil carbon and significantly reduce soil erosion risk. Why are we doing this? Analysis conducted for New Horizons suggests that up to 40% (4.1 million hectares) of the broadacre farming area of South Australia has soil constraints that could be overcome through the application of new advances in soil science management. On the Eyre Peninsula there are around 780,00 ha that could be modified. The Eyre Peninsula trial is designed to better understand which modifications can improve productivity on local soils most effectively. What are the key treatments at Brimpton Lake? The treatments being compared at this site are designed to address the major constraints thought to affect these soils. This includes non-wetting being addressed through the addition of clay and compaction with a spader. The control is a well managed crop using standard agronomic practices for the area. Results The best treatments tripled dry matter production and doubled yield on all three of the State’s New Horizons trial sites. Spading gave a yield response at all Nutrient and water holding capacity are sites. Adding organic matter further being addressed by mixing clay and boosted yields. organic matter. The organic matter will Some treatments at Brimpton Lake also stimulate microbial activity. were hit hard by waterlogging in Additional nutrients aims to overcome winter. limitations to production due to poor Despite some excellent responses fertility in the subsoil. some variability exists between This will ensure that there is improved treatments and sites across the state. nutrition for crop root development at Recognising that the farmer survey all depths within the modified soil indicated a clear desire for reliability profile. and surety in advice, further evaluation is required before advice on optimal techniques can be confidently provided to farmers. Above: early results from the Brimpton Lake trial site www.pir.sa.gov.au/newhorizons 1300 364 322