Recently researchers at Stanford University, U.S. studying the impact of emissions from coal-fired power plants on rice and wheat yield in India found that coal power plant emissions reduce crop yield by up to 10% in some states.The research focused on the effects of nitrogen oxides, particularly nitrogen dioxide (NO₂), on crop growth.While the negative effects of pollutants like NO₂ on crops were already known, this study is the first to systematically link coal power plant emissions with crop yield losses in India.The study analysed India’s 3 major rice-producing states, Uttar Pradesh, West Bengal, and Punjab, and its 3 major wheat-producing states, Madhya Pradesh, Punjab, and Uttar Pradesh.
Key Findings of the Study
Major Emissions from Coal-Fired Power Plants
- Emit pollutants such as carbon dioxide (CO₂), nitrogen oxides (NOₓ), sulfur oxides (SOₓ), particulate matter, soot, and trace gases.
- These pollutants contribute to smog, acid rain, and reduced air quality, impacting crops and human health.
Effects of Nitrogen Oxides (NOₓ) on Crops
- Phytotoxic properties: NOₓ stresses plants, hinders cellular function, and interferes with crucial enzymatic activities.
- Ozone formation : NOₓ contributes to ozone production, which worsens crop damage.
- Particulate matter accumulation : Blocks sunlight, reducing photosynthesis efficiency.
Crop Yield Losses Due to NO₂ Exposure
- Rice yield losses: 0.0006 metric tons per hectare for every 1 ppb (parts per billion) increase in NO₂.
- Wheat yield losses: More affected than rice due to winter fog and reduced sunlight availability.
Regional Differences in Coal Pollution Impact
- Chhattisgarh: Highest share of NO₂ pollution from coal plants (19% in monsoon, 12.5% in winter).
- Uttar Pradesh: High overall NO₂ levels, but only a small portion comes from coal power.
- Tamil Nadu: Relatively low NO₂ pollution, but majority originates from coal plants.
Economic Impact of Crop Losses
- Rice and wheat yield losses from coal power emissions cost India up to $820 million (₹7,000 crore) annually.
- Targeting highly polluting power stations could significantly reduce losses and improve agricultural productivity.
Sources of Nitrogen Oxides (NOₓ) Emissions
| Category of sources | Description |
| Natural Sources | Lightning Strikes: High-temperature reactions in the atmosphere produce NOₓ. Soil Microbial Activity: Nitrification and denitrification by microbes release NOₓ. Volcanic Eruptions: Combustion of nitrogen-containing compounds emits NOₓ. Wildfires and Biomass Burning: Burning forests and grasslands releases NOₓ. |
| Fossil Fuel Combustion | Power Plants: Coal, oil, and gas-fired stations emit NOₓ. Industrial Boilers & Factories: Cement, steel, and chemical industries contribute significantly. Vehicles: Cars, trucks, trains, and airplanes burn fuel, producing NOₓ. Residential Heating and Cooking: Use of coal, wood, and biomass stoves adds emissions. |
| Agricultural Sources | Synthetic Fertilizers and Manure: Fertilizer breakdown and microbial activity release NOₓ. Crop Residue Burning (Stubble Burning): Seasonal burning of crop waste emits NOₓ. Livestock Farming: Animal waste decomposition generates NOₓ. |
| Waste Processing and Combustion | Landfills and Sewage Treatment Plants: Decomposition of organic waste releases NOₓ. Incineration of Waste and Biomass: Municipal and industrial waste burning emits NOₓ. Petroleum Refining & Chemical Industries: Industrial refining processes contribute to NOₓ emissions. |