Context:
Excessive nitrates have been found in groundwater in 440 districts as of 2023, an increase from 359 such districts in 2017, a report by the Central Groundwater Board (CGWB)
Nitrogen Pollution:
- Refers to the presence of excessive amounts of nitrogen compounds into the environment, leading to various negative effects on ecosystems and human health
Sources, Benefits and Effects of different nitrogen compounds:
| Nitrogen Compound | Source | Benefits | Effects |
| Nitrous Oxide (N2O) | Combustion, Agriculture and Industrial wastes | Used in propellants of rockets Used in medical industry – Eg: Laughing gas | 300 times more potent than carbon dioxide. Causes depletion of the stratospheric ozone layer |
| Di – Nitrogen (N2) | Makes up about 78% of the air we breathe | Maintains a stable atmosphere for life on Earth | Chemically unreactive, Harmless |
| Ammonia (NH3) | Fertilizers, Burning of biomass | In fertilizers – foundation for amino acids, proteins, enzymes etc | Causes eutrophication; Affects biodiversity; Forms particulate matter in the air; Affects lung functions |
| Nitrate (NO3) | Industrial wastewater Agriculture waste Oxidation of NOx | Used in fertilisers and explosives | Forms particulate matter in the air; Causes blue baby syndrome; Leads to eutrophication in water bodies |
| Nitric Oxide and Nitrogen Dioxide | Transport combustion Industrial waste Energy sector wastes and combustion | Essential in human physiology (NO) | Major air pollutant; Contributes to heart disease; Causes respiratory illness |
Related Government Initiatives:
- Bharat Stage (BS VI) Emission Standards –To curb the release of nitrogen oxides and particulate matter, to air and water pollution
- Soil Health Cards – Issued to farmers to provide soil nutrient status and promote balanced nutrient
- Nano Urea – Increases crop productivity by reducing the unbalanced and indiscriminate use of conventional urea
- Nutrient-Based Subsidy (NBS) – Incentivizes the use of controlled-release fertilizers encouraging more efficient nutrient management
Source: TH
Previous year Question
Which of the following adds/add nitrogen to the soil?
1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation
Select the correct answer using the codes given below:
[UPSC Civil Services Exam – 2013 Prelims]
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (c)
Explanation:
Burning of coal produces Oxides of Carbon ,Sulphur ,Nitrogen and a variety of by products, including fly-ash, flue gas and scrubber sludge but it does not directly add nitrogen to the soil.