alkaline soil Soil with a pH greater than 7.0. Degrees of soil alkalinity are recognized. The USDA lists soils with a pH 7.4–7.8 as mildly alkaline; 7.9–8.4 as moderately alkaline; 8.5–9.0 as strongly alkaline; and more than 9.0 as very strongly alkaline. Soil is not regarded as highly alkaline unless the reaction is between 8.0 and 10.0. The full range of the pH scale (0–14) is not used in soils, as the reaction of most soils is between pH 3.5 and pH 10.0. Base saturation of 100 per cent indicates a pH of about 7.0 or higher. Alkaline soils are usually rich in calcium ions. Plants characteristic of such soils are called calcicole.

alkaline soil Soil with a pH greater than 7.0. Degrees of soil alkalinity are recognized. The USDA lists soils with pH 7.4–7.8 as mildly alkaline; 7.9–8.4 as moderately alkaline; 8.5–9.0 as strongly alkaline; and more than 9.0 as very strongly alkaline. Soil is not regarded as highly alkaline unless the reaction is between 8.0 and 10.0. The full range of the pH scale (0–14) is not used in soils, as the reaction of most soils is between pH 3.5 and pH 10.0. A base saturation of 100 per cent indicates a pH of about 7.0 or higher. Plants characteristic of such soils are called calcicole.

alkaline soil Soil with a pH greater than 7.0. Degrees of soil alkalinity are recognized. The USDA lists soils with pH 7.4–7.8 as mildly alkaline; 7.9–8.4 as moderately alkaline; 8.5–9.0 as strongly alkaline; and more than 9.0 as very strongly alkaline. Soil is not regarded as highly alkaline unless the reaction is between 8.0 and 10.0. The full range of the pH scale (0–14) is not used in soils, as the reaction of most soils is between pH 3.5 and pH 10.0. A base saturation of 100% indicates a pH of about 7.0 or higher.