Self-ploughing of black soil
Topic: Soils of India: Types, Degradation and Conservation · NCERT: Class 10, Ch 1 "Resources and Development"
Meaning
Self-ploughing is a natural loosening of black (regur) soil. This soil is made of very fine clay. When wet, the clay swells and turns sticky. In the hot, dry season it shrinks and opens deep cracks. Air gets into the soil through these cracks, so the soil partly "ploughs itself". Wet black soil is very hard to work, so farmers till it right after the first shower or before the monsoon.
Example
On the Deccan Trap (basalt) plateau of Maharashtra and the Malwa plateau of Madhya Pradesh, black cotton fields show wide cracks in May. Farmers prepare the land with the first rains to sow cotton and soybean.
Don't confuse with
- Waterlogging: self-ploughing comes from the clay swelling and shrinking with the seasons. Waterlogging means the water table rises into the root zone, which can happen in canal-irrigated black soil areas.