Please tell me about soil acidity
Answers
Soil acidity is a major environmental and economic concern. Approximately 50 % of Australian agricultural land or 50 million ha have surface pH values less than or equal to 5.5 which is below the optimal level to prevent subsoil acidification. If untreated, acidity will become a problem in the subsurface soils, which are more difficult and expensive to ameliorate. Subsurface acidity is already a major problem for large areas of Western Australia and New South Wales. It is estimated that 12 to 24 million ha is extremely to highly acidic with pH values less than or equal to 4.8 (NLWRA, 2001).
Acidic soils cause significant losses in production and where the choice of crops is restricted to acid tolerant species and varieties, profitable market opportunities may be reduced. In pastures grown on acidic soils, production will be reduced and some legume species may fail to persist.
Degradation of the soil resource is also of wider concern and off-site impacts must be considered. Off-site impacts mainly result from reduced plant growth. Deep-rooted species required to increase water usage may not thrive, increasing the risk of salinity. Increased run-off and subsequent erosion has detrimental impacts on streams and water quality. Increased nutrient leaching may pollute ground water.