June 4, 2022

Farmers in Punjab, Haryana, Uttar Pradesh and Bihar – the Indo-Gangetic Plains - plant and harvest two crops a year: typically rice during the monsoon season, from May to September, and wheat from November to April. These northern states are critical to the food security and livelihood of more than 400 million Indians.

Each year, after harvesting the rice, farmers burn more than 23 million tons of leftover plant debris to prepare the fields for planting wheat. Last year, for instance, between November 1 and November 13, there were 57,000 farm fires in Punjab and the neighboring state of Haryana, according to satellite images from NASA, the U.S. space agency. Punjab alone contributes more than two-thirds of the farm fire emissions in the region.

The farm fires are a key factor in Delhi, Ghaziabad, Noida and several other north Indian cities being among the most polluted cities in the World. The fires account for about a tenth to a half of the air pollutants in those cities. Other contributors to the pollution include dust, industrial and vehicular emissions, and incineration of paper, wood and garbage, especially by the poor to stay warm during the cold winter nights. Earth.org organized data to report the top 15 most-polluted cities in the world: 12 of the top 15 are in India with the remaining two in Pakistan and one in China.

Nine of ten farmers fear that the burning could damage “soil health and lower crop yield” and that it “impacts the air quality of nearby cities,” according to a study led by Tianjia (Tina) Liu. Yet, the cost and time savings of burning far outweigh their concerns. In addition, rice plant residue is unsuitable as cattle feed.

The study, conducted while Liu was a PhD student at Harvard University, combined a survey of 2,000 farmers in the Indo-Gangetic Plain in 2017 with satellite data from 2003 to 2018.  The satellite data reveal that “observations of active fires and burned area shows increases” ranging from 40% to 142% during those years. Farmers in Punjab began using fires to clear out the rice plant residues 65 years ago, in 1957.  

 The gases and aerosols released by the fires “increase risk to acute respiratory infection and other lung and cardiac diseases,” but may also damage crops due to elevated surface ozone exposure, the study noted.

“We look at concentrations of fine particulate matter, or tiny aerosols, that fires emit,” Liu told an interviewer for the Lakshmi Mittal and Family South Asia Institute at Harvard University. “Because these aerosols are smaller in diameter than that of your hair, they can get lodged deep into the lungs and can even enter the bloodstream, causing cardiovascular and respiratory diseases and worsening pre-existing conditions.” 

Liu is a graduate student associate, 2021-2022, at the Mittal Institute. Her research focuses on using satellite data and atmospheric modeling to quantify the impacts of fires on air quality and public health in India, Indonesia, and globally. 

She completed her PhD dissertation from the Department of Earth and Planetary Sciences at Harvard. In the coming academic year, she will be a NOAA Climate & Global Change postdoctoral fellow at the University of California, Irvine, primarily working on wildfires in the Western U.S. Liu received her B.A. in Environmental Science at Columbia University.

The Indian government has imposed fines, sought court orders and filed a few criminal cases against farmers setting fires. But, given the political clout of the mostly wealthy farmers who use fires to clear their fields, the fines and implementations of court orders are rare. Also, last November, following a year-long protest by farmers for minimum support prices and other agricultural issues, the government decriminalized the farm fires.   

The farmers say that they are willing to pursue environmentally friendly alternatives provided the cost is borne by the government. One alternative is the Happy Seeder, a machine which removes the rice plant debris while simultaneously sowing wheat for the next planting. Though the government offered subsidies of 50% to 80% for the machine’s purchase, there are very few such machines in use. Farmers say the $15,000 cost of the machine and a tractor, to which it needs to be attached, is too high. The Happy Seeder was developed by Punjab Agricultural University in Ludhiana in collaboration with Australian Center for International Agricultural Research.

There is also a bio-decomposer, developed by the Indian Agricultural Research Institute, which turns the rice plant debris into manure in about two to three weeks. But farmers are unwilling to wait that long between crops.

In 2019, the Indian Supreme Court ruled that several northern states ought to give Rs. 2,400 ($32) per acre to every farmer who did not burn the plant debris. The state governments, which face budget problems, have ignored the court orders. Charandeep Grewal, a farmer in Punjab told BBC, "I don't know any farmer who has been paid."

For access to stories each week, follow on: LINKEDIN or TWITTER or FACEBOOK