Australian Soil Salinity

Most of the croplands in Australia are currently affected to some degree by saline or sodic soils. As salinity increases, crop yields and resistance to disease decreases. To counter this we use fertilizers to help the crops, but in doing so we are unwittingly adding to our salt problems.  As can be seen from the salt index table, all fertilizers add salt.

When fertilizing we not only need to take into account what the crop needs to grow, and the cost, but also the amount of salt that we are adding to the soil.

How does soil become Saline?

Salt is present naturally in our soils, surface water and ground systems.  Changes to the landscape in many areas have resulted in the redistribution and accumulation of salt at or close to the soil surface.  High levels of salt in the soil have the same effect as drought by making water less available for uptake by plant roots. This effect (the Osmotic Gradient) is caused by the difference in salt concentrations between the plant and the soil and prevents water from being absorbed by the roots and, if great enough, will cause water to be drawn out of the plant. Depending on the degree of salinity, this effect reduces the soil's ability to produce crops and lowers annual crop yields

How does salt affect plant growth?

• it can cause growth to be stunted, plants grow more slowly than those not affected

• it can degrade soil structure

• it can prevent plants from taking water from the soil

• it can be toxic to plants resulting with symptoms varying from:

  • leaves that appear to be smaller thicker and sometimes darker green in appearance

  • to a burning effect whereby the leaf margins turn yellow then brown or black as they die

  • affecting the oldest leaves first.

All fertilisers contain varying amounts of salt. Knowing the pH level and treating your soil will facilitate maximum crop production.

Adding the correct amount of Dolomite to your field will stablise your ph level and unlock the nutrients available in your soil. This will reduce your dependence on heavy use of fertilisers to grow your crops with the added bonus of adding less salt to the soil.

Flinders Trading Dolomite when compared with other fertilizers is of a high quality and relatively low cost as well as having the lowest available salt index number.