New Delhi, Dec. 6: A brown haze of pollution hanging over the Indian subcontinent may eat into the nation’s future rice harvests, a new study that investigated how changes in the atmosphere will affect rice yields has indicated.
The air pollutants from fossil fuel emissions and wood burning might have also contributed to the observed slowdown in growth of rice yields in India over the past decade, the study conducted by scientists in the US has said.
The growth rate of rice yields in India increased for two decades from the mid-1960s, and peaked in 1985 when growth touched 3 per cent. Since then, it has dropped and is now just under 1 per cent. Agricultural scientists have attributed the slowdown in growth to soil degradation, deteriorating irrigation systems and maximum yields from best-existing rice varieties.
Now, atmospheric scientist Veerabhadran Ramanathan at the Scripps Institution of Oceanography in the US and his co-workers have shown that pollution particles which form a brown haze that is suspended over much of Asia and greenhouse gases that are warming the planet may lead to a decline in rice harvests.
The study, published in the Proceedings of the National Academy of Sciences this week, shows that if air pollutants had been removed, then harvests in the period 1985-1998 would have been 10 per cent higher than they actually were. If the warming effects of greenhouse gases had also been removed, then harvests would have been 14 per cent higher.
“We are adding an explanation to existing ones, not replacing them with it,” said Jeffrey Vincent, professor of environmental economics at the University of California, San Diego, co-author of the study. “We believe our additional explanation is interesting because it suggests a new strategy for boosting rice harvests,” Vincent told The Telegraph.
Vincent said the study also justifies efforts to reduce air pollution, which have been viewed as mainly benefitting residents of cities. “Our findings indicate that reduced air pollution benefits rice farmers too,” he said.
However, senior Indian scientists have said that while air pollutants and higher night- time temperatures in a warmer planet may lower rice yields, there is no evidence yet that the observed slowdown has been caused by such changes.
“There is still potential for increasing yields in some states,” said Ebrahim Siddiq, a rice geneticist, formerly with the Indian Council of Agricultural Research in Hyderabad.
