Consider the following statements about black soil.1. Most of the Deccan Plateau is covered with black soil.2. These soils are also known as ‘Raegur soil’ or ‘Black cotton soil’.3. These soils have self-cultivating properties.4. They are rich in phosphorus, nitrogen and organic matter.Which of the above statements is/are correct?

Main points
-Volcanic rocks formed in the Deccan Plateau are the source material for most of the black soil.
-Black soil covers most of the Deccan Plateau , which includes parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and Tamil Nadu . So, statement 1 is correct .
-In the upper reaches of the Godavari and Krishna and in the northwestern part of the  Deccan Plateau, the black soil is very deep.
-These soils are also known as 'Ragur soil' or 'Black cotton soil' . Therefore, statement 2 is correct.
-Black soils are generally clayey, deep and impermeable .
-They swell and become sticky when wet and shrink when dry. So, during dry season, this soil develops wide cracks. Thus, a kind of ' self plowing' takes place. Therefore, statement 3 is correct.
-Due to this characteristic of slow absorption and loss of moisture, black soil retains moisture for a long period of time, which helps crops, especially rainfed ones, to survive even during the dry season.
-Chemically, black soils are rich in lime, iron, magnesia and alumina .
-They also contain potash .
-But they lack phosphorus, nitrogen and organic matter . Therefore, statement 4 is not correct.
-The color of the soil ranges from deep black to grey .