Types of soils in Bihar
Soils in Bihar can be broadly divided into seven types, which are distributed in the state according to the map given below:-
| Distribution of Soils in Bihar |
1. Piedmont Swamp Soil
In Bihar these are found in the North-Western parts of West Champaran district (in the foothills of Himalayas) in Bihar.
Here abundance of swamps are found, which favour the cultivation of paddy in this region.
2. Terai Soil
Terai soil in Bihar is found along the 8-10 km belt of India Nepal border from West Champaran to Kishanganj.
It is also swampy in nature with slight amount of silt content. Terai soil has sufficient amount of Nitrogen and humus content but lag in phosphorus content.
In this region tall grasses and forests are found in abundance, but sufficient land surface is available for cultivation. Major crops cultivated in this region are wheat, Paddy, sugarcane, jute etc.
3. Alluvial Soil
Alluvial soils are found in about 15 lakh hectares of land in India amounting to about 40% of it's total geographical area. However in Bihar it is found in 50% of total geographical area. These are formed by deposition of alluvium brought by Indo-Gangetic-Brahmaputra river system.
In Bihar two types of Alluvial Soils are found:-
- Khadar Soil
- Bhangar Soil
3.1. Khadar Soil
These are newer Alluvium brought by rivers every year. Khadar soils are found near the banks of flood basins of rivers. Since most of the flood prone rivers are found in North Bihar. Hence, most of Khadar soil region is in North Bihar along Koshi, Ganga, Gandak, Burhi Gandak and other rivers.
Khadar soil can be found in Purnea, Saharsa, Darbhanga, Muzaffarpur, West and East Champaran, Saran, Siwan, Vaishali, Samastipur, Khagaria and Bhagalpur districts of Bihar.
It is basically fine sandy dirts and top layer of the soil are filtered. Hence it is deficient in Calcareous and Carbonaceous sands.
Since it is renewed/rejuvenated every year by frequent floods, hence it is the most fertile region of Bihar. But Kharif crops in this region are generally affected by floods every year.
Rice, wheat, sugarcane, jute, tobacco, vegetables, maize and oilseeds are the major crops cultivated in this soil in Bihar.
3.2. Bhangar Soil
This soil is also known as Karail-Keval. This soil is generally found in the upper parts of flood basins of rivers (generally 30 m above the flood basin). South Bihar has abundance of Bhangar soil because of the lack of any significant flood causing rivers (rivers in South Bihar are Seasonal in nature) and slightly elevated as well.
Bhangar soil is more clayey in nature their colour is dull. In this type of soil major crops cultivated are paddy, wheat, sugarcane, wheat etc.
4. Balsundari Soil
It is found mainly in Kishanganj, Purnea, Saharsa, Darbhanga, Muzaffarpur and Southern parts of West Champaran district.
This soil has more than 30% content of lime, which makes it alkaline in nature and hence infertile in nature. But coarse cereals can be cultivated in this soil.
In this soil maize, wheat, sugarcane, paddy, tobacco are cultivated.But this soil region is most famous for plantation cropping of Mango, Litchi and Banana.
5. Tal Soil
This soil is found in 8-10 km strip along the southern bank of the Ganga river from Badh(Patna) to Bhagalpur.
This is formed due to flooding in the Ganga river basin in rainy season. It is fine to coarse and greyish in colour. In some parts it's texture is like sandy-Kewal.
Tis soil has almost same features as Khadar soil (Newer Alluvial Soil) does have. Tal region remains flooded in rainy season. Hence, the scope of cultivation of the Kharif crops is limited or negligible. But the Rabi crops in this region are cultivated at a very large scale.
6. Balthar Soil
This type of soil is found from Kaimur to Banka in 8-15 km wide strip along Chhotanagpur Plateau and Rajmahal Hills.
This soil is Yellowish-red in colour. It has good content of iron and limestone but lack in Nitrogen and humus. This is naturally acidic and sandy in nature of soil(which reduces it's water holding capacity).
All above factors make this soil infertile for almost all crops, but pulses like Arhar, Kurthi, Masoor etc. and Coarse cereals like Jowar, Bajra etc. can be efficiently cultivated in this soil region.
7. Laterite Soil
This type of soil is found between Ghaghra-Gandak Doab. It is infertile but if irrigated it can be fertile.