Because of variance in climatic and terrain in Rajasthan, the soil types vary widely in the state. There are major soil Types which are desert soil, red loamy soil, black soil, alluvial soil. Western Rajasthan consists of desert soil whereas there is alluvial soil in the eastern plain. In the southern districts there is black soil where they farm cotton. These soils vary in fertility and also determine the farming activities in the region.

Key points for RAS Mains

What are soils?

• Soil is the surface part of the earth surface that is made out of the rock breakup. 
• It is very important in the areas of agriculture, forestry and biodiversity.
• It is made of minerals, organic matter, air, and water on top of which terrestrial ecosystems revolve, supporting the development of plants.

Soil Classification

• National-Level Classification:
  • The Indian system divides its soils into 8 broad groups with 27 subtypes with the help of which suitability pertaining to agriculture and land management is identified.
• Rajasthan’s Classification:
  • Diversity in climate (arid to semi-arid) in Rajasthan leads to varied soil profile.
  • State Agriculture Department Classification: 14 unique types on the basis of region.
• USDA Scientific Classification:
  • There are 5 major soil types; this classification is based on the properties of the soil aspects such as; texture, formation etc.

Institutions:

• ICAR (1929, New Delhi): First in soil research in India.
• USDA (1862, USA): Establishes international criteria of the soil classification.

Soil Types by Rajasthan Agriculture Department

USDA Scientific Soil Classification in Rajasthan

Various types of soil found at Rajasthan

1. Sandy Soil (Dry Soil)

• Site: Jaisalmer, Bikaner, Barmer, Jodhpur
• Characteristics: rough, bad water absorption, high calcium
• Crops: Bajra, Moong, Moth, Guar, Groundnut

2. Brown Sandy Soil

• Place: Luni Basin (Jalore, Pali, Nagaur, Ajmer, Sikar)
• Features: Erosion sandstone, phosphate rich

3. Saline Soil: Reh/Kallar salty soil

• Place: Barmer, Jalore, Sri Ganganagar and Hanumangarh
• Qualities: irrigation misuse: white salt crust
• Agricultural products: pomegranate, sugarcane

4. Alluvial Soil

• Jaipur, Dholpur, Karauli, Alwar, Bharatpur
• Attributes: Potash rich, fertile soil laid down by rivers
• Farm crops: Wheat, Mustard, Barley, Bajra

5. Red Loamy Soil

• Place: Banswara, Dungarpur, Pratapgarh, South Udaipur
• Characteristics: reddish because of iron oxide, well drained
• Agricultural products: Maize, Rice, Sugarcane

6. Black Soil (Regur/Volcanic)

• Place: Hadoti (Kota, Bundi, Jhalawar)
• Aspects: Gritty, moisturizing, clay-like
• Agriculture: Cotton, Soybean, Spices

7. Red-Black Soil

• Place: Pratapgarh, Jhalawar, Bhilwara
• Agricultural produces: Maize, Cotton and Opium

8. Red-Yellow Soil

• Place: Udaipur, Ajmer, Bhilwara, Chittor
• Features: iron rich, needs erosion control

Soil Problems in Rajasthan

1. Soil Erosion

• Causes: Caused by deforestation, overgrazing and over tilling
• Categories: Layer, Sheet, Gully erosion
• Remedies: Plantation of trees, fencing, bunding

2. Salinity

• Causes:: Excessive irrigation, inadequate drainage, capillary movement
• Solutions: Leaching, utilization of gypsum
• Jalore, Bikaner, Ganganagar

3. Waterlogging

• Causes: Over-irrigation, poor drainage
• Solution: Eucalyptus plantation, drip /sprinkler systems, solutions

4. Alkalinity

• pH Level:>8
• Causes: Sodium/calcium/magnesium high salts
• Remedies: Guar-drenching, Gypsum, Rock phosphate

5. Soil Degradation

• Causes: Overuse of fertilizers, monocropping
• Solutions: Organic farming, crop rotation

Conclusion

Rajasthan is the land of tremendous soil variation, ranging between nutrient deficient deserts to highly productive regur soil. This variability is confirmed by geography, climate as well as type of rock. There is a necessity of having the best land and water management to ensure that powerful agricultural outcomes are realized but natural resources must be preserved.