Climate and Soils of Madhya Pradesh: Rainfall and Soil Types

Madhya Pradesh sits in the middle of the country, with no coast and no snow, so its climate is the plain tropical monsoon type: a hot, dry summer, a wet season of about three months and a short, pleasant winter. The Tropic of Cancer runs almost through the middle of the state, passing Ratlam, Ujjain, Bhopal, Vidisha, Sagar, Jabalpur and Shahdol, which is the first fact every state paper asks. The rain comes mainly from the Bay of Bengal branch of the south-west monsoon, reaching the state from the east, and that single fact explains the whole rainfall map: the eastern and southern districts are wet, and the rain thins out towards the north-west.

The climate and the rainfall

Rainfall in Madhya Pradesh falls away from the south-east to the north-west. The wettest country is in the east and on the Satpura, where Balaghat, Mandla, Dindori, Sidhi and the hills around Pachmarhi receive well over 1,400 millimetres; the driest is the Gwalior and Chambal region of the north-west, where Bhind, Morena, Gwalior and Shivpuri manage about 700 to 800 millimetres. The state average works out at roughly 1,000 to 1,100 millimetres, almost all of it between the middle of June and the end of September.

Summer in the north is severe, with the hot dry wind called loo blowing across Gwalior, Bhind and Morena, while the Satpura and Maikal hills stay cooler. Pachmarhi in the Satpura is the only hill station of the state and the site of Dhupgarh, its highest point, which is why it appears both in the climate chapter and in the physiography chapter. Winter brings clear, dry weather, and a passing western disturbance may drop light rain that helps the standing wheat and gram.

The soils of Madhya Pradesh

Soil in the state follows the rock beneath it. Over a very large part of Madhya Pradesh that rock is the basalt of the Deccan trap, and its weathering has produced the black soil, also called regur or cotton soil, which covers the largest area of the state. It is clayey, rich in iron, lime and magnesium but poor in nitrogen and organic matter, swells and becomes sticky when wet, cracks deeply in summer and so ploughs itself; because it holds moisture it carries the state's soybean, cotton, wheat and gram. The deepest black soil lies in the Narmada valley and the Malwa plateau, which is why that belt is the granary of the state and the heart of the country's soybean country.

What damages the soil

• Gully erosion along the Chambal in Bhind, Morena and Sheopur, where the ravines, called bihad, have eaten into good farmland for centuries.
• Sheet erosion on the slopes of the Vindhya and Satpura, where the forest has been cleared and the topsoil washes off with the first heavy rain.
• Loss of nitrogen and organic matter in black soil, which is naturally poor in both, so the crop depends on manure and rotation.
• Waterlogging and salt in parts of canal commands where irrigation water stands too long on heavy clay.

For the exam the logic is worth more than the list: basalt gives black soil and black soil gives soybean, cotton and wheat; old crystalline rock in the east gives red and yellow soil and that gives rice; heavy rain on the plateau leaches the soil into laterite; and the rivers of the north lay down alluvium and then cut it into ravines.