The interest in applying clay to sandy soils is surprisingly large judging by those I spoke to who visited the PIRSA tent at the Paskeville Field Days. The main benefit looked for by visiting farmers was to either overcome the affects of water repellence where that is a problem, or to make the surface less susceptible to erosion.

The display was conducted as part of the Advisory Board of Agriculture Sandy Soil project funded by the National Landcare Project and Dept of Water, Land & Biodiversity Conservation.

The other surprise to me on talking to the large number of visitors to the claying display was how many farmers had already tried applying some clay, and of these, how all of them had found it to be beneficial and that they would like to apply clay to a larger area on their properties.

What impressed these farmers who had already applied clay was how their sandy soil not only became more manageable through reduced water repellence, greater stability and less susceptibility to erosion, but also how the productivity of the sand had increased.

For those who have suffered frost damage over the last few years, claying susceptible sandy soiled areas greatly reduced the likelihood of frost damage due to the greater ability of clayed soils to hold heat.

A number of farmers in the Mid North are currently arranging for a delver in autumn to bring clay through the profile and to the surface where the clay is not too deep. On deeper sands they will be using a clay spreader, as are others on upper Yorke Peninsula who are keen to try claying an area of sandy soil.

The cost when considering the benefits and the NRM Board subsidy, available at least in the Northern and Yorke board area, is considered reasonable, especially when modifying a sand hill at a time. A 15 hectare area might cost around $5500 to apply clay with a spreader, but only $4125 when the subsidy is taken into account. Delving shallower sandy areas is much less than this, but levelling and incorporation is likely to cost much more than for spreading. Check with your NRM board before you start claying.

It is important for claying to be carried out properly the first time, as once done, it lasts for a very long time. Where done incorrectly, often a paddock is left worse off.

The key factors governing the success is to get enough, but not too much clay on the sand, good incorporation, and the application of sufficient nutrition to supply the new productive potential. Most importantly however, sufficient exploration of the depth and quality of the clay is needed to find the best source as close to the area of sand as possible. This can take some time and effort, although made easy with the use of a backhoe, but must be done thoroughly to ensure the right rate of clay is applied, that the clay is selected with as little lime as possible, and the lowest cost is incurred.

Those with sandy soil are encouraged to consider giving a small area a go to assess the benefits and to start modifying the sand on their property. Clay spreaders or Rural Solutions SA officers including our soil consultants or myself are keen to answer any queries you might have.

AUTHOR: Tom Yeatman, Senior Sustainable Agricultural Systems Consultant, Rural Solutions SA

CONTACT: Tom Yeatman, Rural Solutions SA Clare Office, Telephone (08) 8842 6244, Mobile 0419 831 027, Email yeatman.tom@saugov.sa.gov.au