Survey, Characterization and Categorization of Underground Water for Irrigation of Ajmer District of Rajasthan, India
Rajveer *
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
S. C. Meena
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Ranjeet Singh
Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India.
R. B. Dubey
Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India.
R. H. Meena
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Jagdish Choudhary
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Vinod Saharan
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
K. K. Yadav
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
B. S. Shekhawat
Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India.
Satyendra Kumar
ICAR-Central Soil Salinity Research Institute, Karnal, India.
B. L. Meena
ICAR-Central Soil Salinity Research Institute, Karnal, India.
B. S. Kherawat
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
Jasveer Singh
Swami Keshwanand Rajasthan Agricultural University, Bikaner, Rajasthan, India.
Dinesh
Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan, India.
*Author to whom correspondence should be addressed.
Abstract
Ground water is considered to be safer and less vulnerable to contamination than surface water resources. However, uncontrolled discharge of industrial effluents, agricultural runoff containing fertilisers and pesticides, improper disposal of domestic sewage, irrational land use practices, certain adverse geological formations, low rainfall and poor natural recharge conditions have significantly deteriorated ground water quality in many parts of the country. The survey of 216 underground water samples from seven tehsils of Ajmer district showed substantial variation in ionic composition and irrigation-water quality. Sodium was the dominant cation, followed by magnesium, calcium and potassium, whereas chloride was the dominant anion, followed by bicarbonate, sulphate and carbonate. Across the study area, pH ranged from 7.04 to 8.59 and electrical conductivity from 0.42 to 8.54 dS m⁻¹, indicating a broad range of salinity conditions. The mean SAR and RSC values were 7.38 and 1.07 me L⁻¹, respectively, while the mean adjusted SAR was 17.53 and the mean soluble sodium percentage was 67.88. Classification based on EC and SAR placed 11.57% of samples in C₂S₁, 40.28% in C₃S₁, 30.10% in C₄S₁ and 18.05% in C₄S₂. The results therefore show that irrigation-water quality is not uniform across Ajmer district and that the identified salinity, sodicity and alkalinity classes should be considered when planning water and soil management for irrigation.
Keywords: Cations, anions, water, SAR, RSC, potential salinity, pHc