The red soils are formed due to

1. Weathering of ancient crystalline rocks
2. Disintegration of sedimentary rocks
3. Deposition by the rivers
4. Transport by the rivers

Red soils are rich in

1. Potash
2. Lime
3. Nitrogen
4. Phosphate

An area in India where Gully erosion takes place

1. Narmada valley
2. Chambal ravines
3. Ganga river
4. Damodar river

Black soils are found in

1. Haryana
2. Maharashtra
3. Meghalaya
4. Uttar Pradesh