Soils in Rajasthan (Old System)

Introduction

Soil is one of the most important natural resources as mankind is dependent on soil for food. Soil, the top-most layer of earth crust, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. The soils of Rajasthan have developed under the arid and humid climate over the bed rocks of complex nature predominately through the process of Laterization.

The tints, chemical composition, texture, structure, reaction, and plant food contents bear large scale as well as local variations, according to environments. By considering all these factors, the soil of Rajasthan is classified into two system –

  1. Old System of Soil Classification
  2. New System of Soil Classification
Old System of Classification
  • This system of classification was developed by scientists (Thorpe & Smith) of U.S department of Agriculture in 1949.
  • This system of classification is based upon differences in climate and mineralogy. As per this system, soils of Rajasthan can classified into 8 types:
    1. Desert Soils
    2. Dunes and Associated Soils
    3. Brown Soils
    4. Sierozems
    5. Red Loams
    6. Alluvial Soils/and Black Soils
    7. Hill Soils (Lithosols)
    8. Saline Sodic Soils (Solonchaks)
Soils in Rajasthan (Old Classification)
Soils in Rajasthan (Old Classification). Source : Contemporary Geography by L R Bhalla
Desert Soils in Rajasthan
  • These types of soils cover most parts of Nagaur, Jodhpur, Jalore, Barmer, Hanumangarh, Sriganganagar, Churu, Jhunjhunu and Sikar districts, where rainfall is less then 400cm.
  • This soil contains a high percentage of soluble salt & has high Ph value.
  • It has varying percentage of calcium carbonate & generally poor in organic matter.
  • These soils are pale brown, single grained, deep and well drained.
  • Texture of this soil is Sandy to Sandy loam
  • The Calcium carbonates sometime occur in form of Kankar nodules which increases with depth.
  • In most of the desert soils nitrogen is low with a range of 0.02% to 0.07%. This deficiency is balanced to some extent by the presence of high available nitrogen in forms of nitrates. Thus, the phosphates together with nitrates have made these desert soils fertile for agriculture crops and plants where water supply is regular.
Dunes and Associated Soils in Rajasthan
  • These types of soils cover most parts of Barmer, Bikaner, Jaisalmer, Jodhpur, Churu and Sikar districts.
  • These have been grouped separately from desert soils as they are only deposited sand and little profile development has taken place.
  • Dunes are of varying heights from low shifting dunes to high and very high stabilized dunes.
  • Texture of this soil is loamy fine sand to coarse sand and may or may not be calcareous.
  • These soils are light yellowish brown in colour sandy to sandy loam, deep and well drained
  • Calcium carbonate, sometime occur in the form of Kankar nodules which increases with depth.
  • The Cultivation is practiced in rainy season on the slopes of low to medium high dunes and usually rainfed Bajra or Kharif pulse are grown.
Brown Soils in Rajasthan
  • These types of soils cover most parts of Tonk, Bundi, Sawai Madhopur, Bhilwara, Udaipur and Chittorgarh districts.
  • Major area of these soils is in the catchment area of Banas River.
  • Texture of this soil is Sandy loam to clay loam.
  • The Colour of this soil Ranges from grayish brown to yellow brown.
  • They are rich in calcium salts but have poor organic matter. So, Use of fertilizers becomes essential to get good harvest.
  • As the ground waters are saline, soils irrigate with these waters have accumulated salts. Tank irrigated soils have also developed problem of high water table.
  • The annual rainfall in this area is 50 cm to 75 cm, which is sufficient for Kharif crops. However, Rabi crops are grown under irrigation.
Sierozems Soils in Rajasthan
  • These types of soils cover most parts of Pali, Nagaur, Ajmer, Jaipur and Dausa districts and lies on both the side of Aravalli Hills.
  • Texture of this soil is Sandy loam to Sandy clay with weak structure and is permeable.
  • The Color of this soil is mostly yellowish brown.
  • The rainfall in the area in higher than the desert of the extreme west.
  • The annual rainfall in this region 50 cm to 70 cm.
  • Natural vegetation is also seen at some places.
  • The soils are suitable for cultivation but for low rainfall and high evaporation.
  • The Kharif crops are rainfed and Rabi crops are grown through well irrigation.
  • In the Kharif crops Bajra, Jowar, pulses are grown and in Rabi crops wheat, mustard & vegetables are grown.
Red loms in Rajasthan
  • These types of soils cover most parts of Dungarpur, Banswara & parts of Udaipur and Chittorgarh districts.
  • The annual railfall in this region is 70 cm to 100 cm.
  • Texture of this soil is Sandy loam to sandy.
  • The Parent material of these soils is the red sandstone or yellow sandstone which is found in Vindyan rocks.
  • These soils are reddish in colour with granular or 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, chilies, wheat, barley and rapeseed cultivation
Alluvial Soils in Rajasthan
  • These types of soils cover a vast area in north-western, eastern and south-eastern plains of the state.
  • These soils are brought by the different rivers, therefor, different ara have soils of different characteristics.
  • The soils deposited by the river Ghaggar in Shir Gangapur and Hanumangarh districts. Are yellowish brown in color, loam to silty loam with massive or blocky structure and are calcareous in nature. Stratification is common in these soils.
  • Some alluvial soils are deposited in earlier times and now there are no recurring deposits. So these are called older alluvium soil. This soil covers major parts of Bhilwara, Tonk and Ajmer districts and some minor parts of Udaipur, Chittorgarh and Jaipur districts. The color of this soil ranges from greyish brown to yellowish brown. They are sandy loam to clay loam in texture.
  • The soils of recent alluvium cover almost whole of the Bharapur district and parts of Alwar, Dausa, and Jaipur district. These soils are yellowish brown to brown, loamy sand to sandy loam and weakly structured, calcareous and free lime is sometimes present in small amounts.
  • The black soils of Kota, Baran, Bundi and Jalawar districts are also alluvial soils, mostly brought by River Chambal and its tributaries. The fine textured alluvium is of igneous origin (Deccan traps) and the sedimentaries of Vindhyans. These soils are clay loam to clay in texture. Generally, these soils are good in the productivity.
Hill Soils (Lithosols) in Rajasthan
  • These types of soils are fond on and at the foot hills of Aravalli in Sirohi, Pali, Nagaur, Udaipur, Rajsamand, Chittorgarh, Bhilwara and Ajmer districts.
  • The color of this soil is Reddish to yellowish red to yellowish brown.
  • Texture of this soil is Sandy loam to clay and well drained.
  • The Cultivation of crops in these soils is very much restricting due to shallow nature of these soils and presence of stones on the surface.
  • Soil erosion due to water is another problem of these soils
Saline Sodic Soils (Solonchaks) in Rajasthan
  • These Saline Sodic soils are seen in the far flood plains of river Ghaggar and in Luni Basin. These soils are also found in the natural depressions of saline lakes.
  • The colour of this soil is Dark grey to pale brown.
  • Water table is sometime close to surface.
  • The 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.
Reference Articles / Books

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