- Old System of soil Classification
- New comprehensive System of soil classification
Old System of soil Classification:-
This system of soil classification is based on the soil as a natural body concept and has a strong genetic bias. According to this classification soils of Rajasthan are classified into eight soil groups.
- Desert Soils
- Dunes and Associated Soils
- Brown Soils
- Sierozems
- Red Loams
- Hill Soils (Lithosols)
- Saline Sodic Soils (Solonchaks)
- Alluvial Soils/and Black Soils
Desert Soils:
Districts – Nagaur, Jodhpur, Jalore, Barmer, Hanumangarh, Sriganganagar, Churu, Jhunjhunu and Sikar.
Rainfal l- Less than 400 mm
Texture – Sandy to Sandy loam
It 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.
Calcium carbonates sometime occur in form of Kankar nodules which increases with depth.
In most of the desert soils nitrogen is low.
Range – 0.02% to 0.07%
It is not fertile but it can be made fertile for agricultural crops and plants where water supply is regular by putting phosphates with nitrates Under normal rainfall Kharif crops (summer) are grown but failure of crops due to low rainfall is common.
Dunes and Associated Soils:
Districts – Barmer, Bikaner, Jaisalmer, Jaipur, Jodhpur, Churu
Texture – loamy fine sand to coarse sand and may or may not be calcareous.
These soils are yellowish brown in colour sandy to sany loam, deep and well drained
Calcium carbonate, sometime occur in the form of Kankar nodules which increases with depth.
Cultivation is practiced in rainy season on the slopes of low to medium high dunes and usually rainfed Bajra or Kharif pulse are grown.
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.
Brown Soils:
Districts – Tonk, Bundi, Sawai Madhopur, Bhilwara, Udaipur and Chittorgarh
Annual Rainfall – 50 cm to 75 cm is sufficient for Kharif crops.
Texture – Sandy loam to clay loam
The colour of soils ranges from grayish brown to yellow brown.
Major area of these soils is in the catchment area of Banas River.
They are rich in calcium salts but have poor organic matter
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.
Rabi crops are grown under irrigation.
Sierozems:
Districts – Pali, Nagaur, Ajmer, Jaipur, Dausa (lies on both the side of Aravalli Hills)
Annual Rainfall – 50 cm to 70 cm
Texture – Sandy loam to Sandy clay
They are mostly yellowish brown
The rainfall in the area in higher than the desert of the extreme west
Natural vegetation is also seen at some places.
The soils are suitable for cultivation but for low rainfall and high evaporation.
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 Loams:
Districts – Dungarpur, Banswara & parts of Udaipur, Chittorgarh
Rainfall – 70 cm to 100 cm
Texture – Sandy loam to sandy
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, chilies, wheat, barley and rapeseed cultivation
Parent material of these soils is the red sandstone or yellow sandstone which is found in Vindyan rocks.
Hill Soils (Lithosols):
Districts – At the foot hills of Aravalli in Sirohi, Pali, Nagaur, Udaipur, Rajsamand, Chittorgarh, Bhilwara and Ajmer
Colour – Reddish to yellowish red to yellowish brown
Texture – Sandy loam to clay and well drained.
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):
Districts – In the natural depressions like the Pachpadra, Sambhar, Deedwana, Ranns of Jalore and Barmer
Saline Sodic soils are seen in the far flood plains of river Ghaggar and in Luni Basin.
Colour – 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 shuribs
Alluvial Soils/and Black Soils:
Districts – Sriganganagar in soil deposited by Ghaggar, Kota, Bundi, Baran, Jaipur