Impact
Soil alkalinity is a naturally occurring phenomenon that can be escalated by human activity. The natural development of alkalinity is due to the release of sodium carbonate through weathering of soil minerals. Alkalinity can be induced through the application of fertilisers and irrigation water that are high in sodium bicarbonates. Alkalinity problems are more common in clay soils than in loamy, silty or sandy soils. When soils are strongly alkaline, it can have serious implications for soil health and vegetation growth. Soil alkalinity is often associated with saline soils and sodic soils.
Suggested indicator: Soil pH
Soil pH refers to the acidity or alkalinity of a soil. It is measured on a scale of 0 to 14, with a pH of 7 denoting neutrality. Higher pH values indicate alkalinity and lower values indicate acidity.
Increased soil alkalinity may be associated with:
| Potential associated impacts | Suggested indicators |
| Declined soil structure |
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| Reduced water infiltration capacity that increases runoff |
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Reduced soil nutrient availability, leading to:
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| Reduced soil biota |
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| Increased potential for soil erosion |
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| Reduced water quality if eroded sediments are washed into waterways |
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