Regur Soils are black in colour and are also known as `black soils`. Since they are perfect for growing cotton, they are also called cotton soils. These soils are most characteristic of the Deccan trap (Basalt) region, spread over the north-west Deccan plateau and are made up of lava flows. They cover the plateaus of Maharashtra, Saurashtra, Malwa and southern Madhya Pradesh and continue eastwards in the south, along the Godavari River and Krishna River Valleys. In their creation, climatic conditions are immensely important just like their parent rock materials. Hence they lengthen much further than the `tava` plateau itself.

Black soils are exceptionally delicate. Owing to the high proportion of clay, Regur soils are sticky when wet and consequently becomes difficult to plough. They are well-known for their ability to retain moisture. In addition, they are prosperous in soil nutrients, like calcium carbonate, magnesium carbonate, potash and lime. They are usually poor in phosphoric content. They develop thick fissures in the field during hot weather. This helps in their ventilation; hence their self ploughing eminence. This soil is viscous and unmanageable to work, unless tilled without delay, after the first or pre-monsoon showers.

Regur soils develop under semi-arid conditions specifically in the areas that are covered with basalt. In the southern region of Tamil Nadu, granites and gneisses with iron content also form black soils under the required semi-arid climatic conditions. Regur soils are formed in Surat and Broach districts and also in the Narmada Valley and Tapti Valley. In these regions, humus is almost absent in the soil and black colour of the soil is because of the presence of certain salts. In the hilly region of the country, Black soils are usually thin, poor and sandy.

Black soils or Regur soils are rich in lime and it is not unusual to find lime nodules deposition under the layer of this type of soil. Moreover, this soil is highly retentive of moisture and is highly productive particularly in the plains and along the river valleys where it is clayey and deep. It is said that the feature of retaining moisture in the soil is extremely useful. Thus, the deeper the soil, the larger is the amount of moisture held. However, nitrogen which is considered as useful for the growth of plants is not sufficiently found in the Regur soil.