Soil acidity

Soil acidity is a major constraint to farming in Western Australia. Extensive surveys of soil pH profiles across the south-west show that more than 70% of surface soils and almost half of subsurface soils are below appropriate pH levels. The majority of growers now place soil acidity in their top three management priorities. Managing soil acidity is both achievable and profitable.

The department supports landholders in reducing the impact of soil acidity by providing technical information on diagnosis and management options and is currently researching innovative approaches to managing subsoil acidity in collaboration with the University of Western Australia and the Grains Research and Development Corporation.

Articles

  • Acid soils cause significant losses in production and biomass, which restricts the ability to sequester carbon.

  • If you are deep-ripping, ploughing or spading to remove subsurface compaction or another constraint, it is a good idea to incorporate lime in the same operation.

  • Liming to recover an acidic soil to an appropriate pH can result in significant production benefits, however a response to liming indicates that previous production has been lost due to an acidic t

  • The rate of soil acidification due to agriculture can be reduced but not eliminated. Liming will always be needed to prevent the soil from becoming too acidic.

  • Soil acidification occurs naturally very slowly as soil is weathered, but this process is accelerated by productive agriculture.

  • A small decrease in soil pH represents a large increase in soil acidity.

  • Agricultural lime is any product that is used to increase the pH of soil. In Western Australia, the three main sources are limesand, limestone and dolomitic lime.

  • Aluminium toxicity in the subsurface is the major problem associated with soil acidity in Western Australia.

  • Carbonate from calcium carbonate (or magnesium carbonate) neutralises acid in the soil.

  • In this section you will find detailed information on various case studies highlighting the long-term benefits of liming and different options used by farmers for incorporating lime.