SOILS OF INDIA
ICAR on the basis of origin divides the soils of India into the following four categories.
- Allunal soil
- Black soil
- Red soil
- Laterite soil
Alluvial Soil: It covers the Great Plains and coastal plains. It is described as the heart of Indian civilization. It is rich in Potash and poor’ in Nicobar, Phosphorus and humus. It is broadly clarified into 2 sub-categories: Bangar & Khadar. Bangar is Old Alluvium & Khadar is New Alluvium. In the high rainfall regions Paddy is the important crop and relatively low rainfall regions wheat is the most important crop.
Black Soil: It covers volcanic plateau of Kathiawar, Malwa and Deccan Trap. It is rich in Iron, Magnesium, Aluminum & Salt and it is poor in Nitrogen, phosphorus and humus. It is highly fertile and moisture extensive. As it absorbs moisture, it expands and turns sticky and in the summers (dry season) cracks develop.
Traditionally it is associated with cotton cultivation and it is therefore also called Black Cotton Soil or Regur. In usual irrigated areas of Maharashtra, sugarcane is another important crop.
Red Soil: it covers the Aravalis in the north, plateau of Andhra, Karnataka & Tamil Nadu in the south. Its formation is a consequence of decomposition and disintegration of quartzite which is the metamorphic form of sandstone. Presence of iron oxide gives it the color red. It is sandy in nature, poor in moisture retention, soil nutrition and traditionally it is associated with rain-fed crops which are drought resistant (which can survive moisture deficiency) e.g.: Jawar, Bajra in the north and Ragi in the south. This soil requires composting and manuring to increase soil fertility and moisture retention capacity. Oilseeds are also grown.
Laterite Soil: It covers the Highlands of Indian peninsular viz, Western Ghats, Eastern Ghats, Hills of Chota Nagpur Plateau. This soil is formed in Hot & Humid Tropical Monsoon climate with Seasonal Rainfall. In such a climatic condition Base & Silica are leached (removed) from the soil.
Therefore the soil is going to the acidic in nature. Soil is going to be rich in oxides of iron and Aluminum. Crops like Coffee & Tea are grown.
VEGETATION OF INDIA
Distribution of natural vegetation in India is controlled by the following factors:
- Distribution of rainfall.
Consequently, these are the vegetation types identified in India.
- Tropical Evergreen & Semi-Evergreen Forest.
- Tropical Deciduous Forest.
- Tropical Thorn
- Mangrove Forest.
- Northern Mountain Forest.
- Southern Mountain Forest.
- Tropical Evergreen and Semi-Evergreen Forest: These regions have rainfall > 200 cm throughout the year. Tropical evergreen and semi-evergreen forests are seen in the windward side of the Western Ghats and the north-east.
- Tropical Deciduous Forest: Here, there is a seasonal rainfall of 50-200cm. the vegetation profile is as under:
a (100-200) cm : MOIST DECIDOUS
b (50-100) cm : DRY DECIDUOUS
- Tropical Thorn: Here, the rainfall is less than 50 cm. Vegetation consists of Xerophytes like Cactus and trees like Babul. West side of Aravalis & the Central Plains is dominated by Tropical Thorn Forest.
- Mangrove Forest: Delta formation is necessary for the occurring of mangrove forest. This is why the East Coast of India is dominated by mangrove forests. Littoral forest means that part of coast which is between High Tide & Low Tide is known as the Intertidal Region of a coast. Mangroves are connected with tropical and sub-tropical region.
- Northern Mountain Forest: This forest cover is associated with the Himalayan mountain ranges. Vegetation type changes with altitude.
- Southern Mountain Forest
The southern forest or southern mountain forests are net temperate and endemic with great biodiversity. Endemic forests are always developed in geographically located conditions. Because of great bio-diversity these are also called Shola Forest.