RED AND YELLOW SOILS

Formation:

 These are derived from granites, gneisses and other metamorphic rocks. These are formed under well-drained conditions.

AREAS:

 Along the piedmont zone of the Western Ghat, a long stretch of area is occupied by red loamy soil. Yellow and red soils are also found in parts of Orissa and Chhattisgarh and in the southern parts of the middle Ganga plain.

Soil Colour: 

The soil develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks. It looks yellow when it occurs in a hydrated form. Often, their upper layer is red and the lower layer is yellow.

SOIL TEXTURE:

 Varies from sand to clay and loam.

Other Characteristic Features:

• The fine-grained red and yellow soils are normally fertile, whereas coarse-grained soils found in dry upland areas are poor in fertility.
• Have a porous and friable structure.
• They are generally poor in nitrogen, phosphorous and humus.
• These soils are airy and need irrigation for cultivation.
• Intense leaching is a menace in these soil areas.

Suitable Crops: In places where irrigation facilities are available, the crops cultivated are Wheat, Cotton, Pulses, Tobacco, Millets, Oilseeds, Potato, Maize, Groundnut and Orchards.

LATERITE SOIL

The word Laterite has been derived from the Latin word ‘Later’ which means brick. These soils when wet are as soft as butter but become hard and cloddy on drying. Therefore, these are widely cut as bricks for use in house construction.

FORMATION:

 The lateritic soils are particularly found on high flat erosion surfaces in areas of high(>200cm) and seasonal rainfall. The alternating wet and dry seasons lead to the leaching away of the siliceous matter of the rocks leaving behind the compounds of Iron and Aluminium. 

AREAS:

These soils have mainly developed in the higher areas of the Peninsular plateau. The laterite soils are commonly found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh and the hilly areas of Orissa and Assam.

Soil Colour:

Reddish brown in colour due to the presence of iron oxide.

Other characteristic features:

• With rain, lime and silica are leached away, and soils rich in iron oxide and aluminium compound are left behind (thus the reddish brown colour). Also, humus content of the soil is removed fast by bacteria that thrive well in high temperature.
• These soils represent the end product of decomposition and are generally low in fertility.
• The pebbly crust is the important feature of laterites which is formed due to alteration of wet and dry periods.
• These soils are acidic in character due to leaching. Application of manures and fertilisers is required for making these soils fertile for cultivation.
• These soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are in excess.

Suitable crops: red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala are more suitable for tree crops like Cashewnut. These soils are also suitable for tea plantations.

ARID SOILS

Formation: These are derived from the disintegration of adjacent rocks and are largely blown from coastal regions and Indus valley.

Areas: Arid soils are characteristically developed in Western Rajasthan, which exhibit characteristic arid topography.

Soil Colour: Arid soils range from Red to Brown in colour.

Soil Texture: They are generally sandy to gravelly in texture and have a high percentage of soluble salts.

Other characteristic features:

• These are saline in nature. In some areas, the salt content is so high that common salt is obtained by evaporating the saline water.
• Due to the dry climate, high temperature and accelerated evaporation, they lack moisture and humus.
• These soils are deficient in nitrogen and humus. The phosphate and iron content is normal. These soils are rich in minerals, but the main limitation is the lack of water.
• The soils exhibit poorly developed horizons.
• Plants are widely spaced.
• Chemical weathering is limited.
• Lower horizons of the soil are occupied by ‘kankar’ layers because of the increasing calcium content downwards. The ‘Kankar’ layer formation in the bottom horizons restricts the infiltration of water, and as such when irrigation is made available, the soil moisture is readily available for a sustainable plant growth.

SUITABLE CROPS: 

If irrigated these soils give high agricultural returns. The availability of water from the Indira Gandhi canal has transformed the agricultural landscape of desert soils of western Rajasthan. These soils are mainly devoted To Bajra, Pulses, Guar, Fodder and less water requiring crops.