The entire country has been delineated into 126 agro-climatic zones by the Indian Council of Agricultural Research (ICAR). Similarly, Rajasthan has been divided into 10 agro-climatic zones. The Agro-climatic zones of Rajasthan are as follows:
- Arid North Western Sandy Plain
- Irrigated North Western Plain
- Hyper Arid Partial Irrigated Zone
- Transitional Plain of Inland Drainage
- Alluvial Plain of Luni Basin
- Semi Arid Eastern Plain
- Flood Prone Eastern Plain
- Sub Humid Southern Plain and Aravallis
- Humid Southern Plain
- Humid South Eastern Plain
These zones have been classified on the basis of agro-climatic parameters like rainfall, temperature regime, topography, soil characteristics, cropping pattern and irrigation availability.
1. Arid North Western Sandy Plain
- Rainfall: The mean annual rainfall in this zone is 100 to 400mm. The zone has erratic and uncertain rainfall witnessing frequent droughts.
- Area: The plain is characterized by vast sandy plain with sand dunes, sandy plain pediments and palayas present in the region. The vast area covered with sand dunes has coarse textured soil with CaCO3 and gypsum. This physiographic zone is located in the north western part of the state covering Jaisalmer, Barmer, Bikaner and Jodhpur districts.
- Groundwater is deep and saline but at few places tube-well water is used for irrigation.
- Rain-fed agriculture is practiced in some pockets and livelihood is primarily livestock based.
2. Irrigated North Western Plain
- Area: This plain extends in the northern part of the state in Ganganagar, Hanumangarh and north western part of Bikaner district.
- As the zone is irrigated by network of Indira Gandhi Canal, Bhakra and Gang canal, it is intensively cultivated.
- The plain is dominantly covered by the medium and fine textured deep to very deep soils. The bed of River Ghagghar stretching from Suratgarh to Anupgarh is fine textured and intensively cultivated. I
- n addition, in the southern and eastern part the region there is vast Aeolian plain covered with dunes with small area of deep buried pediments.
3. Hyper Arid Partial Irrigated Zone
- Rainfall: The normal rainfall in the zone is 185 to 390 mm.
- Area: This zone is spread in the arid region of Bikaner, Jaisalmer and parts of Churu, where the farmers have partial dependence on the sources of irrigation.
- The region has desert soil characterized by sand dunes and aeolian soil. The soil is loamy coarse in texture and with calcareous characteristics.
4. Transitional Plain of Inland Drainage
- Rainfall: The zone has average rainfall of 300-400mm.
- Area: This plain is spread in the central part of the state covering western, eastern and northern part of Nagaur and entire Sikar, Churu and Jhunjhunu districts.
- There is no drainage out of this area.
- The zone is covered with sandy plain, sand dunes and occasional hills. The area distinguishes from western sandy plain in having better Livelihood of villagers depends mainly on livestock rearing along with some rain-fed farming.
5. Alluvial Plain of Luni Basin
- Rainfall ranges between 400 and 500mm.
- Area: The physiographic zone is located in the central part of the state where a number of ephemeral streams and River Luni and its tributaries flow through this area covering Pali, Jalore, part of Nagaur, Jodhpur and Barmer districts.
- Water is saline in this zone.
- Cultivation of cash crops is Rainfed or done with the help of tube-wells. Dominant soils are medium to fine textured.
6. Semi Arid Eastern Plain
- Rainfall: Average Rainfall in the zone about 500- 700mm.
- Area: This plain is drained by the river Banas and its tributaries.
- The zone is spread in the eastern part of the state covering Jaipur, Ajmer, Dausa and Tonk districts. The plain is sandy plain.
- Occasional sand dunes and buried pediments and scattered hills with substantial area under alluvium are features of this zone.
7. Flood Prone Eastern Plain
- Rainfall: The rainfall in the zone is 600-700mm.
- Area: This zone extends in Alwar, Bharatpur and Dholpur districts. Soils are yellowish-brown to dark yellowish brown, sandy loam to clay loam and non-calcareous.
- This zone developed on the alluvium deposited by the river Yamuna and its tributaries and is spread over the eastern part of the state and forms western fringe of the Indo-Gangetic plain.
- A large area of this zone is under kharif and rabi crops.
8. Sub Humid Southern Plain and Aravallis
- The zone receives 700-900mm rainfall.
- High hills are scattered through the zone and there is a contiguous appearance of the Aravalli hills, running south to north.
- The zone extends in the southern part of the state in Bhilwara, Rajsamand, Sirohi, Udaipur and Chittorgarh districts.
- Hills and pediments are under hills for rest which support natural vegetation cover including trees, shrubs and grasses.
- Cultivated land occurs in between the hills.
- Medium to fine textured deep soils are dominant in this region.
9. Humid Southern Plain
- This zone receives 900-1000mm rainfall.
- This plain characterized by hills and valley fills is spread in the southern part of the state in Dungarpur, Banswara and Pratapgarh districts.
- In Banswara and Pratapgarh districts the soils formed from lava flow of basalt are also found.
- In between, scattered areas of deep buried pediments are also encountered.
- The hills are covered with thick density of trees, shrubs and grasses.
10. Humid South Eastern Plain
- This zone receives the highest rainfall in the state of around 700-1000mm.
- Area: South-eastern part of the state covering Sawai Madhopur, Karauli, Jhalawar, Baran, Kota and Bundi districts.
- The landscape is characterized by hills pediments and vast alluvial plain formed by the rivers Chambal, Parbati, Parwan, Kalisindh and their tributaries. Because of these rivers deep gullies and ravines have been formed. Because of the presence of fine textured alluvium deposited by the rivers in this zone the land is very productive