Scientists at IIT-Delhi, in collaboration with scientists from the University of Illinois and the Indian Agricultural Research Institute, have developed a new model to study the growth processes of spring wheat, a staple food for millions in India and around the world. The model was used to study how environmental factors and land management practices have influenced spring wheat production in India over the past four decades.
The study, published in the European journal Earth System Dynamics, found that since the 1980s, increased levels of CO2 in the atmosphere, irrigation and nitrogen fertilizers have increased wheat production by 22 megatons (MT), an increase of 30%. At the same time, rising temperatures have reduced production by 13 tons (18%). These effects vary across the country and thus affect production at the regional level.
“Atmospheric CO2 and temperature have different effects on production. More CO2 in the atmosphere led to an increase in wheat production. This effect is known as CO2 fertilization. However, more CO2 in the atmosphere also caused global warming and the rising temperatures had a negative impact on wheat production, ”said Somnath Baidya Roy from the IIT-Delhi Center for Atmospheric Sciences.
He explained, “In nature, two or three things happen at the same time, and the end result is the net result of several things. The strength of our new model is that we can simulate all factors of wheat growth. ”
He explained that the positive effect of increased CO2 emissions has so far been stronger than the negative effect of warming. However, some idealized experimental studies on crops in the US have shown that the CO2 fertilization effect is temporary and global warming will lead to a decline in production in the long run.
“If you keep adding CO2 to the atmosphere, the CO2 fertilization will eventually stop. We will see a net negative effect by the end of this century, ”added the IIT-D scientist.
Roy stated that “the paper’s findings have revealed interesting new aspects of regional variability in wheat production that can be useful in developing strategies to mitigate climate change in the context of food security.”