India's grain crops are vulnerable to climate changes and yields from rice, experience larger declines during extreme weather conditions, found Kyle Davis Environmental data scientist at Columbia University.
The research published in the 'Environmental Research Letters' studied the effects of climate on five major crops: finger millet, maize, pearl millet, sorghum, and rice. These crops make up the vast majority of grain production during the June-to-September monsoon season - India's main growing period - with rice contributing three-quarters of the grain supply for the season. Taken together, the five grains are essential for meeting India's nutritional needs.
"By relying more and more on a single crop - rice - India's food supply is potentially vulnerable to the effects of varying climate," said Davis, the lead author on the paper.
"Expanding the area planted with these four alternative grains can reduce variations in Indian grain production caused by extreme climate, especially in the many places where their yields are comparable to rice. Doing so will mean that the food supply for the country's massive and growing population is less in jeopardy during times of drought or extreme weather," added Davis.
Temperatures and rainfall amounts in India vary from year to year and influence the number of crops that farmers can produce. And with episodes of extreme climate such as droughts and storms becoming more frequent, it's essential to find ways to protect India's crop production from these shocks, according to Davis.
The authors combined historical data on crop yields, temperature, and rainfall. Data on the yields of each crop came from state agricultural ministries across India and covered 46 years (1966-2011) and 593 of India's 707 districts.
The authors also used modelled data on temperature (from the University of East Anglia's Climate Research Unit) and precipitation (derived from a network of rain gauges maintained by the Indian Meteorological Department). Using these climate variables as predictors of yield, they then employed a linear mixed effect modelling approach - similar to a multiple regression to estimate whether there was a significant relationship between year-to-year variations in climate and crop yields.
"This study shows that diversifying the crops that a country grows can be an effective way to adapt its food-production systems to the growing influence of climate change. And it adds to the evidence that increasing the production of alternative grains in India can offer benefits for improving nutrition, for saving water, and for reducing energy demand and greenhouse gas emissions from agriculture," said Davis.
