Indian crops' adaptation to climate change assessed using 60 years' data

Using data over 60 years, scientists have examined how deviations in weather from long-term averages affected the yields of three major cereal crops of India—rice, maize and wheat.

The researchers from the University of Illinois, US, found that farmers were able to adapt to changes in temperature for rice and maize but not wheat. However, increased precipitation enhanced rice yield, but adversely affected wheat and maize yields.

"We also found that farmers are customising their strategies across different regions and crops. For example, heat-prone districts fared better to higher temperatures compared to districts in colder regions," said Madhu Khanna, a professor of agriculture and consumer economics and corresponding author on this study.

The study has been published in the journal Agricultural Economics.

The researchers also found that farmers who worked in areas that were less productive, and therefore at the lower tail of the distribution, differed in their response to those who worked in areas where the yields were higher—the former took more adaptation measures due to higher impacts.

"Higher productive regions have better irrigation facilities and are less dependent on the monsoon, and so the difference between long-term and short-term impacts is negligible," said Surender Kumar, a professor of economics at the University of Delhi, India.

The researchers used quantile regression statistical models to determine if farmers were adapting to the long-term changes in climate. To do so, they used 60-year data sets on temperature, precipitation, the length of the growing season, and crop yield to create different models for short-term and long-term responses of crops.

According to their analysis, if differences in temperature, for example, have no impact in either model, there have been no adaptations. On the other hand, if the short-term impact is worse, it means that the farmers have been able to adapt and smooth out the effects.

Changes in weather are short-term, like a hot day with a sudden thunderstorm.

However, such variations may be distinct from long-term differences, which are the hallmark of climate change.

"We were looking to see if the effect of short-term deviations in extreme temperature and precipitation are significant when compared to their long-term averages and if their effects are absent in the long term as farmers adapt to climate change," said Khanna.

The researchers suggested two ways by which the crops could adapt—the farmers could change their management practices or the varieties themselves be sturdier. While making it clear that they could not distinguish between the two possibilities, they suggested action could be taken to improve seed varieties and educate farmers on how they can adapt to changing climate.

"This study is a part of our overall effort to build understanding across different countries. In the past we did a similar study in the US and now we're doing it for India. It's interesting that the results of this study are telling us that in both countries, although there is a negative impact of climate, the crops are adapting. However, these effects differ across crops and across the type of effects they are adapting to," said Khanna.