Write two characteristics of black soil.

Hint: 1. Black soils are mineral soils enriched with organic carbon at least 25 cm deep with a black surface horizon.
2. Two black soil classifications (1st and 2nd categories) are known. The categories are distinguished to recognise the higher importance of certain soils (Category 1) and hence the greater need for protection, while also including a broader variety of soils within the overall concept of Black Soil (Category 2).

Complete answer:
Major features of black soil are as follows:-

1. In nature, it is fine textured and artificial.
2. It has high concentrations of lime, iron, magnesium and low levels of phosphorus, nitrogen and organic matter in general.
3. Since it is made from weathered lava rocks, it is black in colour.
4. It has up to 50 percent clay content and is therefore extremely water-retentive. These soils expand when wet, due to the high clay content, and become difficult to plough through. These soils shrink and grow large cracks during the dry season that assist in air circulation.
5. In most of the areas where it is located, the soil is highly fertile.
6. The black soil, after a volcanic eruption, is created by the weathering of igneous rocks and the cooling of lava. The characteristics of black soils are as follows:- black soils are usually artificial, deep and impermeable. When wet, they swell and become sticky and when dry, they shrink.
7. Cotton, wheat, jowar, linseed, Virginia tobacco, castor, sunflower and millets are some of the main crops cultivated in the black soils.

Note: Red soil is a type of soil that grows under deciduous or mixed forest in a humid, temperate, moist environment, with thin organic and organic-mineral layers overlaying a leached yellowish-brown layer resting on a red illuvium layer. In general, red soils are derived from crystalline rock.