Prevalence of groundwater nitrate in Kolar district influenced by total rain fall and agricultural activity

Abstract

The geographical area of Kolar district is about 4012 square kilometers, falls under eastern dry agro climatic zone of Karnataka, while population is over 20 lakhs. The primary occupation of 20 lakhs people of Kolar district is agro-chemically (fertilizers and pesticides) based agriculture. However, in fewer cases inadequate amount of compost manure is also adding to the soil for agriculture activity because compost manure producing biomass (livestock) of number drastically decreased due to water crisis and absence of natural vegetation as fodder. The water crisis is caused by inadequate rainfall and by overexploitation of groundwater or by combination of both. Since groundwater currently provides over 94% of all drinking water, it is crucial to control its quality. Groundwater is contaminated by the common anion nitrate (NO3). This essay examines the analysis of chemical elements like nitrate in groundwater obtained from bore wells in various Kolar district communities. For the purpose of gathering and analyzing water samples, 50 different sampling sources were chosen. Nitrate concentration variations in water samples were noted. Selected water sample parameters that were analyzed were compared to IS 10500:2012 standards. The findings indicated that certain samples from sources had nitrate levels that were higher than the upper limit of the norm. The minimum standard level was also lower in some samples from various sources. Due to below-average rainfall, severely reduced cow breeding (livestock), and decreased agricultural operations, it may be because agro-chemicals (fertilizers and pesticides) and compost manure are used less frequently.