Soil Science

As Rajasthan is mostly covered by desert, it has sandy soil to the most extent. Soil that has very less capacity to hold water is sandy soil. Sandy soils have low moisture storage. High evaporation & low capacity limit the availability of rain water for plant use. 

The largest area in Rajasthan is occupied by desert soil, which covers the area west of the Aravallis up to the Pakistan border. The entire area is ill watered and unproductive and characterized with sand dunes, hillocks and rock outcrops. The soils contain about 90 to 95 per cent sand and about 5 to 7 per cent clay.

In arid and semi-arid areas, evaporation is always greater than precipitation. Under such circumstances, two main factors determine the nature and properties of soils. Firstly, there is very little vegetation and the soils lack humus content. Hence the soils are invariably of light colour. Secondly, the excess of evaporation makes soils lime accumulating. Thus they are bound to be pedocal in nature. This is the main reason behind the formation of Pedocal soil in Rajasthan.

In Rajasthan, both granite and sandstone give birth to sandy soil. Sandy soils have low moisture storage. High evaporation and low capacity limit the availability of rainwater for plant use. As Rajasthan is mostly covered by desert, it has sandy soil to the most extent.

Desert soils range from red to brown in color. They are generally saline in nature. Desert soils lack humus due to lack of vegetation in desert areas. Humus is a dark, organic material that forms in soil when plant and animal matter decays.  If there will be a lack of vegetation, then no humus will form in desert soils.

Soil formation is influenced by factors such as parent rock, climate, time, relief, and organisms. Soil texture is a property of the soil itself, not a factor that causes its formation.

This is a duplicate question of 468427 with identical content. Western Rajasthan soils are calcium-rich due to arid conditions and calcium-bearing parent materials. The high calcium content is characteristic of desert soils in this region.

The crystalline granites produce laterite type of soils in moist parts. Laterite is a rock type soil rich in iron and aluminium, and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. 

The largest area in Rajasthan is occupied by desert soil, which covers the area west of the Aravallis up to the Pakistan border. The entire area is ill watered and unproductive and characterized with sand dunes, hillocks and rock outcrops. The soils contain about 90 to 95 per cent sand and about 5 to 7 per cent clay. Among the given options both the statements are true which says that the percentage of calcium carbonate is high and has very low organic content.

Alluvial soil which occupies Alwar, Bharatpur, Jaipur and Sawai Madhopur and the central part of Ganganagar district is deficient in Lime, Phosphoric acid, Humus. It varies from clayey to sandy loam in texture. The top soil contains 'kankar’ which lie either on sands or sandy clays. A wide variety of crops including wheat, rice, cotton and tobacco are grown in this soil.

Formation of soil is called pedogenesis. Soil formation is the process of soil formation from its parental material. In addition to the soil parent material, soil formation is also dependent upon other prevailing processes like climate, relief, etc.

In natural depressions like Pachpadra, Sambhar, Ranns of Jalore of Rajasthan saline sodic salts are found. color of these soils are dark grey to pale brown. Water table is sometime close to surface. Cultivation is not possible due to the impeded drainage and high degree of salinity. The only vegetation consists of some salt tolerant grasses and shrubs

Hill soils that are present at foot hills of Aravallis are also called as lithosols. Dungarpur, Banswara & parts of Udaipur, Chittorgarh districts have such soils. These soils are reddish in colour with granular/crumb structure & well drained. These soils have rich content of iron-oxide and devoid of calcium salts because calcium salts soluble in water and are easily washed away. Soils are suitable for maize, chillies, wheat, barley and rapeseed cultivation.

The crystalline granites produce non-laterite type of soils in drier areas. These include tropical sandy like desert soils and clayey soils which are gravelly in some places 

Ferruginous red soil which occupies central and southern part of Udaipur district and the entire Dungarpur district is poor in Nitrogen, Phosphorus, Humus. Red soil had been formed from ancient crystalline and metamorphic rocks. The characteristics of this soil are light texture, porous and friable structure.