Daijiworld Media Network - New Delhi
New Delhi, Aug 7: Groundwater samples from parts of 502 districts across 26 states and Union Territories have shown nitrate levels above the permissible limit, the government informed Parliament on Friday.
Minister of State for Chemicals and Fertilisers Anupriya Patel, in a written reply in the Lok Sabha, cited the Central Ground Water Board's (CGWB) 2025 Annual Ground Water Quality Report, stating that 20.71 per cent of analysed groundwater samples had nitrate concentrations exceeding the permissible limit of 45 mg per litre.
"Nitrate contamination above the permissible limit has been observed in parts of 502 districts across 26 states/UTs," the minister said.
She was responding to a question by Congress MP Prabha Mallikarjun from Davanagere, Karnataka.
In Davanagere district, 19 groundwater samples were tested, of which seven samples (36.8 per cent) exceeded the permissible nitrate limit. Two samples (10.53 per cent) were found to have fluoride levels above the permissible limit, while none crossed the electrical conductivity threshold.
The reply stated that Karnataka has 27 partially affected districts, including Davanagere, due to nitrate contamination.
The government, however, said the CGWB has not conducted any specific studies on pesticide residues, health impacts of agrochemical use, environmental effects of excessive fertiliser application or soil degradation caused by agricultural chemicals.
The Karnataka government has also not carried out any exclusive study on nitrate contamination or the environmental impact of excessive fertiliser use in the state.
According to the Indian Council of Agricultural Research (ICAR), long-term studies indicate that imbalanced nutrient application, particularly excessive dependence on nitrogen fertilisers, affects crop productivity and soil health.
The minister said excess nitrogen is mainly lost through nitrate leaching, leading to groundwater contamination. In some areas, nitrate concentrations have exceeded permissible levels, with contamination rising alongside increased fertiliser use.
She added that excessive and unbalanced use of nitrogen-based fertilisers, especially urea, can contribute to soil acidity or alkalinity, deficiencies of secondary and micronutrients such as zinc and boron, and nitrate leaching into shallow aquifers.
The government said pesticide residue monitoring is being carried out through ICAR and the Directorate of Plant Protection, Quarantine & Storage under the Monitoring of Pesticide Residues at National Level (MPRNL) scheme.
Under the programme, samples of fruits, vegetables, grains, fish, marine products, herbs and water are tested for pesticide residues. Farmers in areas where residue levels exceed Maximum Residue Limits (MRLs) or where unauthorised pesticide use is detected are sensitised about the risks of excessive chemical application.
The minister said ICAR's National Bureau of Soil Survey and Land Use Planning has conducted high-resolution Land Resource Inventory (LRI) mapping in several Karnataka districts, including Davanagere.
The LRI maps soil characteristics, land capability, erosion patterns and drainage conditions, helping in soil restoration, watershed development, crop diversification and site-specific nutrient management.
Karnataka's agriculture department is also distributing organic inputs, including green manure seeds, bio-fertilisers, micronutrients and soil amendments, to farmers at subsidised rates through Raitha Samparka Kendras during 2026-27 under various state and central schemes.
To reduce soil erosion and improve groundwater recharge, the state is promoting conservation measures such as check dams, trench-cum-bunds, nala bunds and contour bunding under the Pradhan Mantri Krishi Sinchayee Yojana and the Rashtriya Krishi Vikas Yojana.
The Centre said it is promoting sustainable fertiliser use through balanced application of chemical fertilisers, alternative and organic farming inputs, and resource conservation technologies, adding that achieving balanced fertilisation requires coordinated efforts involving policy measures, technology and farmer participation.