A model study conducted by a team of international researchers has revealed that due to climate change-induced water shortage, the growth stage of rice crop in India is shrinking while the time for total maturity from the day the crop is planted to the day it is harvested is getting shorter.
“The crops are maturing faster, and as a result, you don’t get the full potential of the yield,†said the team led by Prasanta Kalita, professor in the Department of Agricultural and Biological Engineering at University of Illinois and lead author of the study.
The researchers had collected data on rice yield and climate conditions, then used computer simulations to model future scenarios based on four global climate models.
“If farmers maintain current practices, rice yield will decrease substantially by 2050,†Kalita said, pointing out that it was a matter of concern given the United Nations’ Food and Agriculture Organization (FAO) estimates, the world population will grow by two billion people and food demand by 60 per cent by 2050.
But various management strategies can mitigate the effects of climate change, and the researchers provide a series of recommendations, said the researchers in the article, “Predicting the water requirement for rice production as affected by projected climate change in Bihar, India†published in journal Water
“Overall, the best approach to achieve a 60% increase in rice production while minimizing additional irrigation needs is a combination of conservation strategies and a 30 per cent reduction in post-harvest loss,†they suggested.
“If you look at where they traditionally grow rice, it is countries that have plenty of water, or at least they used to. They have tropical weather with heavy rainfall they depend on for rice production. Overall, about 4,000 liters of water go into production and processing per kilogram of rice,†he said.
Climate change is likely to affect future water availability, and rice farmers must implement new management practices to sustain production and increase yield, Kalita said.
Kalita and his colleagues conducted the study at the Borlaug Institute for South Asia’s research farm in Bihar, India where farmers grow rice during the monsoon season, when heavy rainfall sustains the crop.
The researchers collected data on rice yield and climate conditions, then used computer simulations to model future scenarios based on four global climate models.
The purpose of the study was to estimate rice yield and water demand by 2050, and evaluate how farmers can adapt to the effects of climate change.
Traditional rice farming involves flooding the fields with water. Rice transplants need about six inches of standing water. If fields aren’t level, it requires even more water to cover the crops, Kalita said. However, if farmers use direct-seeded rice instead of transplants, they can increase production while using significantly less water.
Another practice involves soil conservation technology. “The soil surface continuously loses water because of temperature, humidity, and wind. If you keep crop residue on the ground, it reduces the evaporation and preserves water. Furthermore, when the crop residue decomposes, it will help increase soil quality,†Kalita explained.
The researchers also suggested implementing strategies to prevent post-harvest crop losses.
FAO estimates about 30% of crops are lost or wasted after harvest, so efforts to reduce those losses can further increase crop availability and food security. Ranjeet Jha, Richard Cooke, Praveen Kumar, Paul Davidson, and Rajkumar Jat, all from the University of Illinois were the part of the team which conducted the study.
