Question

Give reasons for the following.

Black soil is called ‘Self ploughing soil’.

Answer 1

1. It is highly clayey and fine‑grained; the clay swells when wet and shrinks when dry, causing the soil to break and move a mechanical action similar to ploughing.
2. During the dry season it develops deep, wide cracks; the topsoil falls into these cracks, effectively turning and loosening the surface layer.
3. The repeated swelling (on wetting) and shrinking (on drying) cycles cause natural mixing and loosening of soil particles, so the soil “ploughs” itself without human intervention.
4. Those cracks improve aeration and allow oxygen to penetrate to deeper layers, helping natural soil renewal, another reason it is described as self‑ploughing.
5. Its moisture‑retentive nature amplifies the wet‑dry volume changes (swelling/shrinking), making the self‑ploughing effect pronounced and beneficial for dry farming.