Which of the following features are associated with Regur (black) soils in India? 1. It develops on crystalline igneous rocks as a result of intense leaching. 2. It is rich in iron, potash and phosphoric contents. 3. It is typically found in north-west region of Deccan Plateau and is made up of lava flows. 4. It is rich in calcium carbonate, magnesium, potash and lime. How many of the statements given above are correct?