Sodic Soils

 

The Problem: Sodic soils have over 6% exchangeable sodium levels, which leads to soil structure breakdown, surface sealing and crusting. Sodic soils are quite extensive in Australia leading to lost production.

The Solution: Sodic soils can be ameliorated by the use of gypsum. As with applying lime to acid soils the application of gypsum can often prove expensive and uneconomic because of transport and application costs. Applying 2.5 tons/ha of agricultural grade gypsum results in a coverage which can take several years to break down and be fully utilised. While the benefits of this type of application may last several years the economic impact of bearing all the cost in the first year leads, in some instances, to no application taking place at all.

By applying gypsum using the suspension system that Rural Air Work has to offer, the product is applied in the first year, is immediately available and provides an immediate economic return.

The product used is high grade (93%+) gypsum that is finely ground to 100% < 80 microns. This ensures a rapid integration into the soil thus providing immediate benefits to the plants.

The system provides a very even spread of the fine particles ensuring availability to all the plants in the first instance.

Application Rates: Rates of gypsum have been applied from 200kg/ha to 400kg/ha. Trials carried out on cotton country in North West New South Wales and Southern Queensland during the 2002/2003 cotton season gave an economic yield response. While gypsum alone was applied, in the future it is envisaged incorporating trace elements, such as Zinc, into the mix will yield an even greater result - far superior to results achieved with conventional means.

While there are no tried and proven application rates at present, the results achieved with 200kg/ha and 400kg/ha application rates, has meant an ongoing demand for this type of application to Sodic soils in the North West of New South Wales and Southern Queensland.

Because this system uses only high grade Gypsum (93%+) as opposed to products of lesser quality it means transport costs are significantly reduced, as product isn’t being transported that will give no economic return.

Suspension System Benefits:

• Quick application.
• High quality product used.
• Ability to incorporate trace elements.
• 100% of application area is covered with an even spread.
• No soil compaction.
• Immediate results.
• Return on investment in first year.