Crop residue
THE World Air Quality Report, IQAir 2023, named Pakistan as the second most polluted country. Unsustainable agricu-ltural activities, deforestation, vehicle emissions and industrial effluents are the main causes of air pollution during winters, and a major problem for human and environmental health. In 2018, the Food and Agriculture Organisation reported that 20 per cent of air pollution in Pakistan was due to crop residue burning.
Increased urbanisation and economic development demand high-yield agricu-ltural produce for which about a quarter of Pakistan’s total land is currently used for cultivation multiple times. It is usually attained by burning the leftover stalk after harvesting.
In South Asia, it is the easiest and most cost-effective way to get rid of the crop residue, but it adds pollutants to the atmosphere in the form of smog and black carbon.
Smog has been a major issue in areas around Punjab, and serves as a barrier in efforts related to climate change mitig-ation and a threat to regional climate and the planetary health. Environmental pollutants in smog are a risk factor for everyone, linked with brain health in children and adults, affecting their cognitive behaviour. This is in addition to multiple diseases related to lungs, skin, eye and heart.
Carbon is the main constituent of organic matter, and when the residue is burned, carbon is released into the atmosphere. Some other organic matter important for the soil structure and growth of crops also evaporates, depriving the soil of essential nutrients.
The crop waste is biodegradable and nutrient-rich if retained and incorporated in the fields as compost. It can reduce the use of inorganic or synthetic fertilisers.
It also serves as a barrier against soil erosion, since burning washes away the nutrient-dense topsoil, affecting the efficiency of the next crop.
The agricultural wastes are rich in bioactive compounds and can be used as a raw material for making bioenergy or biofuel. Fermentation of biowaste, and biodigesters can also generate ethanol or biodiesel.
Introducing modern dispersal techn-ologies and awareness campaigns about the benefits of sustainable agriculture management before the start of harves- ting period, and timely policy actions for controlling residue burning will minimise the smog crisis and improve the environmental and health challenges.
Tabinda Ashraf Shahid
Islamabad
Published in Dawn, October 7th, 2024