Carbon neutral food production solutions
China is working with researchers from the US and Germany to develop a production system that reduces carbon emissions in agriculture.
According to an assessment from the Nanjing Institute of Soil Science of the Chinese Academy of Sciences (CAS), the total carbon emissions from the production of China's main food crops, including rice, wheat and corn, amounting to 666.5 million tons in 2018.
After completing a comprehensive life cycle assessment of food crops, the team found that an integrated biomass pyrolysis and power generation system, along with commonly used methane and nitrogen mitigation measures, is currently in place. can help neutralize greenhouse gas emissions in agriculture.
Rice straw was burned into biochar in the field test. Photo: Zhao Xu
Specifically, traditional emission reduction and sequestration measures such as increasing the rate of straw returning to the field, optimizing nitrogen fertilizer management and intermittent irrigation in rice fields can reduce total carbon emissions. in food crop production from 666.5 million tons to 560 million tons. As further carbonization of rice straw into biochar is continued and returned to the field, total carbon emissions will further decrease from 560 million tons to 230 million tons, achieving a reduction rate of about 66%.
On that basis, the research team designed an innovative energy harvesting system to refine bio-oil and biogas during biochar production to generate electricity as an alternative to energy and reduce emissions. . Through the operation of this system, carbon emissions from major food crop production in China (230 million tons) can be converted into a carbon sink (-40 million tons), reaching a neutral level. carbon.
Experimental rice fields using biochar. Photo: Zhao Xu
"This new solution can help China reach carbon neutrality in food production without reducing food production. It also prevents atmospheric pollution, increases the utilization rate of fertilizer resources and increases by more than 30 years. % economic and environmental benefits," said Yan Xiaoyuan, a leading scientist at the Nanjing Institute of Soil Science.
The CAS-led study, in collaboration with Agricultural University of China, Tsinghua University and Cornell University, was published online in the journal Nature Food in February 2023.