Temporal Irrigation Water Quality Monitoring and Analysis in Semiarid Tropics: Implication on Crop Production

Abstract

Irrigation water quality analysis and monitoring is tricky task in semiarid tropics (SAT characterized) experiencing water scarcity. Conjunctive use of water in SAT have emphasizes on surface and ground water quality analysis for increase in agricultural production. Surface water quality analysis is carried out for reservoir water, canal flow, return flow and streams for a Devarabelakere, Village in Harihara Taluk in Davangere District of Karnataka State, India. It is located 12 Km towards west from Davanagere and 9 Km from Harihara. Devarabelakere pickup is constructed at downstreamof the Bhadra Reservoir at a distance of 136.00 Km. The total catchment area of this sub-project is 2106.90sq. Km. of which 1338.90 sq.Km SAT. Average Water quality index in the pre and post monsoon season for surface water was found between in the range of 51 to 75 and falls in the poor water quality status and suitable for irrigation and industrial purpose. Ground water sampling is also carried out at Deverabelekere command area and water quality index in pre and post monsoon seasons was found between the  range 26 to 50 and falls in good water quality status and used for drinking, irrigation and industrial purpose. Although WQI shows many of the water samples were suitable or fit for irrigation, calculated other indices such Kelly’s Ratio (KR), Permeability Index (PI), Magnesium Absorption Ratio (MAR) with higher values covering all factors makes the water unsuitable which influences the irrigation water quality. In the study area the crops grown like Sugar cane in area of 28 ha, Plantation crop in area of 34 ha and Semi dry plant grow in 1152 ha and efficiency was found 37.03 % in post monsoon season for canal water and 44.38 % in pre monsoon due to temporal variations in season implicating the yield which is addressed by this paper.