Increasing global rice production is not a simple prospect. According to Shen Yuan, a postdoctoral research associate at Huazhong Agricultural University in China who spent two years as a visiting scholar at the University of Nebraska-Lincoln in the USA, global rice production is challenged now because of its negative environmental impact, water scarcity, labour shortage and slowing yield increases in many parts of the world.
The challenge is to produce more rice on existing cropland, and to do so while minimising the environmental impact. New research led by Shaobing Peng, a professor of agronomy at Huazhong Agricultural University, and Patricio Grassini, associate professor of agronomy at Nebraska and co-leader of the Global Yield Gap Atlas, provides an analysis of roadmaps toward sustainable intensification for a larger global rice bowl. The research was published in Nature Communications on the 9th December 2021.
“Comparing rice cropping systems around the world in terms of productivity and efficiency in the use of applied inputs can help identify opportunities for improvement,” Grassini said.
The global assessment was led by Huazhong Agricultural University and the University of Nebraska-Lincoln, in collaboration with the University of California, Davis, and Texas A&M’s AgriLife Research Center in the United States, the International Rice Research Institute, the Africa Rice Center, the Indonesian Center for Rice Research and the Assessment Institute of Agricultural Technology in Indonesia, the Federal University of Santa Maria and EMBRAPA Arroz e Feijão in Brazil, the National Institute of Agricultural Research in Uruguay, the Indian Institute of Farming Systems Research and the Indian Institute of Water Management. The study assessed rice yields and efficiency in the use of water, fertiliser, pesticides and labour across 32 rice cropping systems that accounted for half of global rice harvested area.
“This study is the most comprehensive global evaluation of production systems for a major staple crop that I am aware of, and it will set the standard for future global comparison of such systems,” said Kenneth G. Cassman, professor emeritus at Nebraska and a co-author of the paper.
The good news, according to the study, is that there is still substantial room to increase rice production and reduce the negative environmental impact.
“Around two-thirds of the total rice area included in our study have yields that are below the yield that can be attained with good agronomic practices,” Yuan said. “Closing the existing yield gap requires better nutrient, pest, soil and water management, reduction of production risk and breeding programmes that release rice cultivars with improved tolerance to evolving pests and diseases.”
Another important finding from the study is that food production and environmental goals do not conflict. “We found that achieving high yields with small environmental impact per unit of production is possible,” Peng said. “Indeed, there is room for many rice systems to reduce the negative impact substantially while maintaining or even increasing rice yields.”
Grassini pointed out that producing more and minimising the environmental footprint was an enormous challenge. “Improved agronomic practices, complemented with proper institutions and policy, can help make rice cultivation more environmentally friendly,” Grassini said. “Our study marks a first step in identifying systems with the largest opportunities for increasing crop yields and resource-use efficiency, providing a blueprint to orient agricultural research and development programmes at national to global scales.”
Shen Yuan, Patricio Grassini: Sustainable intensification for a larger global rice bowl; Nature Communications, December 2021
More information: Global Yield Gap Atlas