(i) The three states having black soil are Madhya Pradesh, Chhattisgarh and Maharashtra. The crops, which mainly grown are cotton, tobacco and sugarcane.
(ii) Alluvial soil is found in the river deltas of the Eastern coast.
Three main features ofthis type of soil are
(a) It is very fertile.
(b) It is a transported soil.
(c) The soil contains adequate proportion of potash, phosphoric acid and lime.
(iii) Following steps should be taken to control soil erosion in hilly areas
(a) Afforestation :The best way to conserve soil is to increase the area under forests.
(b) Terracing and contour bunding: Terracing and
contour bunding across the hill slope is very effective and one of the oldest methods of soil conservation.
(c) Restricted grazing of animals: Animals should be moved over different pastures so as to avoid erosion of soil.
(d) Plugging of gullies to prevent gully erosion.
(iv) Biotic resources :All resources which are obtained from the biosphere and have life are known as biotic resources.
Thus, forests and their products, crops, animals, birds, marine life, etc are biotic resources.Abiotic resources All resources which are non-living, are called abiotic resources e.g. mineral ores, petroleum, etc.