Notwithstanding its small size and population compared to other States and UTs, Puducherry tops the chart in consumption of major fertilizers from 2015-16 to 2019-20 (in kg/hectare) followed by Telangana and Punjab. Interestingly Bihar is in a neck-to-neck competition with Haryana in the use of fertilizers.

Andhra Pradesh, Tamil Nadu, Uttar Pradesh, West Bengal and Karnataka are also among the top 10 States using fertilizers.

Punjab, Haryana and Telangana also feature among the top five States using pesticides, with Maharashtra leading the chart followed by Uttar Pradesh. Tamil Nadu, Andhra Pradesh and West Bengal are other States that use pesticides excessively.

Use of chemical fertilizers

According to the Ministry of Agriculture, as per latest information available, the use of chemical fertilizers in the country during 2017-18, 2018-19, 2019-20 and 2020-21 (upto kharif 2020) was 54.38 million tonnes, 56.21 million tonnes, 59.88 million tonnes and 33.85 million tonnes of fertilizer products (Urea, Di-Ammonium Phosphate (DAP), Murate of Potash (MOP), Complexes and Single Super Phosphate), respectively.

The data presented by the States and UTs to the Central government show that Maharashtra, Madhya Pradesh and Kerala are among the States using less amounts of fertilizers.

According to the Impact Study of Soil Health Card Scheme conducted by the National Institute of Agricultural Extension Management, India consumes about 25.6 million tonnes of fertilizers, mostly nitrogen (17 million tonnes) followed by phosphorous (6 million tonnes) and potassium (2.5 million tonnes).

“India spends about ₹1 lakh crore on fertilizer subsidy. It is estimated that subsidy amount is about ₹6,500/ha of the net cropped area and about ₹7,000/farmer resulting in excessive use of fertilizers, especially nitrogen, at the cost of micro-nutrients and manure,” said a report. As a result of the excessive and imbalanced use of fertilizers, the amount of food grain produced per kg of fertilizer applied declined from 13 kg in the 1970s to just 4 kg by 2010, according to the report.

Experts fear that imbalanced use of chemical fertilizers, coupled with low addition of organic matter and neglect of micro and secondary nutrients over the years, will result in multi-nutrient deficiencies and deterioration of soil health, particularly in intensively cultivated areas.

Impact on soil health

The All India Coordinated Research Project on ‘Long Term Fertilizer Experiments’ over five decades indicates that continuous use of nitrogenous fertilizer alone had a deleterious effect on soil health and crop productivity showing deficiencies of other major and micro nutrients.

Even with recommended doses of NPK and more, deficiency of micro and secondary nutrients has become yield limiting factors over the years.

Deficient nutrient may also affect plant growth and cause plant physiological disorders. There is also the possibility of nitrate contamination in groundwater above the permissible limit of 10 mg NO3-N /L due to excessive/over-use of nitrogenous fertilizers, particularly in light-textured soils that have a consequence on human/animal health if used for drinking purpose.