Punjab, known for its sprawling agricultural fields, is equally famous for burning of paddy and wheat straw by farmers after the harvesting season. The smoke released from burning of paddy straw is extremely bad for health.
"Each year, the agriculture department spreads the same message highlighting the ill-effects of straw burning in the fields, but farmers rarely pay heed to it. Burning of straw causes severe harm to soil fertility and creates massive air pollution, inviting health problems," said Dr Lakhwinder Singh Hundal, chief agriculture officer, Gurdaspur.
It is estimated that about 40 million tonnes of cereal crop waste -- 23 million tonnes from paddy and the remaining from wheat -- is generated in Punjab every year.
While most of the wheat straw is used as dry fodder for cattle, only a small part of paddy straw is utilised in generating power at biomass thermal plants. The remaining is set on fire in the fields. Owing to high silica content, paddy straw cannot be directly fed to animals, he adds.
The department is also creating awareness among farmers on how to manage paddy straw without burning it.
It has been officially stated that the burning of paddy straw residue causes soil nutrient loss -- 3.85 million tonne of organic carbon; 59,000 tonne nitrogen, 20,000 tonne phosphorus and 34,000 tonne of potassium -- besides severely affecting the quality of ambient air.
A government report reads: "The nutrient content of the soil is adversely affected. Straw carbon, nitrogen and sulphur are completely burnt and lost to the atmosphere in the process of burning." These nutrients then have to be replenished through organic or inorganic fertilisers, which come at a cost.
A study conducted by the National Remote Sensing Agency indicated that paddy burning in Punjab contributed 261 giga gm (1 gg=1,000 tonne) of carbon mono dioxide, 19.8 gg of nitrogen oxide, and other gases to the atmosphere.
Punjab Agricultural University (PAU), Ludhiana, has estimated that total crop residue (paddy and wheat) contained 6 million tonnes of carbon, which on burning could produce 22 million tonnes of carbon dioxide. Open burning of residue in the fields kills micro flora and fauna beneficial to soil and removes a large portion of the organic material, thereby depleting the organic matter in the fields.
On the other hand, the suspended particulate matter in the air coming from the smoke aggravated chronic heart diseases and lung ailments, besides causing respiratory problems such as asthma.
Highlighting the measures suggested by the agriculture department to address the issue, Dr Amrik Singh, agriculture development officer, said that farmers should incorporate paddy straw in the soil with the help of mould bold plough or rotavator or disc harrows which improve the soil health.
He also said that direct sowing of wheat without removing the paddy straw from the fields by using a specially designed "happy seeder" and using straw to generate power is also a best option for management of paddy straw.