Description of practice
Liming is the application of calcium- and magnesium-rich materials such as marl, chalk, limestone, or hydrated lime to soil. These alkaline materials neutralize soil acidity, often improving plant growth and increasing the activity of soil bacteria. However, over-application may result in harm to plants.
| Examples of how to use liming | Further information (see Note below) |
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Agricultural limeAgricultural lime (ground limestone or chalk) is spread on the soil surface as a cheap method of adjusting soil pH. Varying release rates help to regulate the pH over several years. |
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Granulated limeGranulated lime is ground much more finely (< 0.1mm) than agricultural lime and then formed into granules. It reacts faster than agricultural lime and allows field pH to be kept more precisely at the desired level. |
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Dolomitic limeCrushed dolomitic limestone contains a mixture of calcium and magnesium carbonates. It is specifically recommended for use in magnesium-deficient soils and, if it is cheaper, is an alternative to agricultural lime. |
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GypsumGypsum (calcium sulphate) changes soil pH very slightly. It is more soluble than lime so the calcium can move further down into the soil, inhibiting aluminium uptake at depth, promoting deeper rooting and allowing plants to take up more water and nutrients. |
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Shell gritUsed as a pH regulator, shell grit has a long-term (>3 years) and long-lived effect, so that micro-organisms in the soil are not disturbed. Being much coarser than lime, grit is not so susceptible to wind erosion. |
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Note: Most of the Further information links are to a full description of the example in the WOCAT database. However sometimes the link may be to similar practices or a research paper. Occasionally the link is to a commercial product in which case it should be understood that this does not imply any endorsement of the product by iSQAPER.