INVESTIGATIONS ON WATER QUALITY IN SOUTHERN BLACK SOIL REGION OF FCV TOBACCO IN ANDHRA PRADESH

Abstract

A study on water quality of FCV tobacco growing areas of Tanguturu mandal under Southern Black Soils of Prakasam district was undertaken to explore and assess the water quality in order to develop different spatial maps of water quality to know the distribution and classify the available ground water suitable for irrigation with the help of Water quality Index (WQI) values calculated. The study area mostly black and mixed type of black and red soils. The pH of irrigation water in the study area was slightly alkaline to alkaline. The spatial thematic maps showed that ground water pH and chlorides in most of the area was in the range of 8.0-8.5 and 1.0 – 10.0 meq /l, respectively. While, bi-carbonate concentration of most of the study area ranged between 2.0 and 4.0 meq/l. Dominating ion is chloride in the system and following an order of Chlorides > Sodium> Bicarbonates > Carbonates > Potassium. Relatively high potassium (2.36 meq/l) was found in ground water in few villages which certainly help in better quality FCV tobacco. The major irrigation water quality class of the study area was moderately suitable (60 %) followed by suitable (14 %) with respect to FCV tobacco based on water quality index values developed. Conjunctive use of ground water and harvested rainwater is the effective way of utilisation of available ground water resource in the study area for FCV tobacco cultivation.