Calcareous soil

A calcareous soil contains a larger amount of calcium carbonate in the soil , in calcareous soil the lime content is over 40 percent.

The lime content of the soil is very important for plant growth, as most plants need a balanced soil pH in the range 5 to 7.5 in order to be able to absorb sufficient nutrients. The lime can buffer the soil against soil acidification by humic acids or acid rain . In horticulture , therefore, attempts are being made to add more lime to acidic soils in order to raise the pH value. On the other hand, the calcium supply is less important , as there is usually sufficient calcium in acidic soils.

On calcareous soils, deficiency symptoms ( e.g. chlorosis , specks ) can occur due to a lack of iron, magnesium, manganese, boron, copper and zinc. Limestone soils are usually poor in nutrients and dry, as the water with the nutrients can easily drain away.

Calcareous soils include:

Black earth and pararendzina in loess areas

Rendzina on limestone

Soils on marl or calcareous loam , boulder clay

Aridisol

Pointer plants for calcareous soil are calcareous plants such as buttercups , lashed alpine roses , hollow lark spurs and real daphne .

The lime is often removed from the top layers of the soil so that the soil gradually becomes more acidic. The lime shifts into deeper soil layers, where it can precipitate again in lime concretions such as the loess shingles .

Fresh manure should not be fertilized on limestone soils, as a large amount of carbon dioxide can form bicarbonate , which can prevent the absorption of iron.

The lime content can be roughly estimated by adding dilute hydrochloric acid to a small sample, as the lime then dissolves with the release of carbon dioxide (effervescence). There is no effervescence with less than 1% lime content, with 1–3% weak effervescence. Short, vigorous effervescence indicates a lime content of up to 5%, with higher contents the effervescence lasts longer.