On 26 January the S&T platform in collaboration with the Department for International Cooperation and the Institute for Environment and Sustainable Development in Agriculture (IEDA) of the Chinese Academy of Agricultural Sciences (CAAS) organized a panel on “Animal manure management practices in China and Germany” at the International online conference “Progress in Manure & Digestate. Science meets Practice” by the IBBK-Biogas competence network.
The participation in the conference also marked the kick-off for this year’s virtual study tour on “Animal Manure Utilization” in Germany, which has been designed by DCZ in close cooperation with Prof. Walter Stinner from the German Biomass Research Center (DBFZ) and Prof. Dong Hongmin from IEDA. DCZ sponsored the conference participation fee for 15 participants from China, including researchers from IEDA, the Biomass Research Institute of the Chinese Ministry of Agriculture and Rural Affairs (MARA), the China Agricultural University, the Nanjing Institute of Agricultural Mechanization, the Jilin Academy of Agricultural Sciences, the Liaoning Institute of Energy Research as well as researchers from Chinese companies. Despite the time difference between Europe and Asia, which meant that most events of the conference were scheduled in late evening Beijing time, there was a strong participation from China in the conference, showing the great interest in the topic of manure treatment and biogas. 61 participants attended the China/Germany panel. In her introduction DCZ Science Advisor Dr. Eva Sternfeld introduced the DCZ and the collaboration with CAAS and outlined the context of the panel within the framework of the upcoming virtual study tour on animal manure utilization with upcoming workshops in April and early summer.
Dr. Sternfeld’s introduction was followed by a presentation by Dr. Liu Yi from the Biomass Research Institute of MARA. In his presentation Dr. Liu Yi outlined the development of biogas in China. He showed that although the majority of biogas plants are small and medium sized facilities there is a trend in recent years to large, centralized facilities. After a steep increase of small facilities in the first decade of this century, in the past years the number of smaller facilities has been decreasing while the share of energy produced by large facilities considerably increased. According to Dr. Liu, China’s Biogas industry developed in three stages: the first stage starting from 1970s was focusing on small household digesters and intended to supply farmers in remote rural areas with energy for cooking; in the second phase biogas development has been promoted for environmental protection reasons, by feeding biogas plants with agricultural waste; in the third phase the mitigation of Greenhouse gases became an important driver for the development. As Dr. Liu noted, in China economic benefits have not been the driver for biogas development, but environmental and climate protection benefits. In the final part of this presentation Dr. Liu also elaborated on the Chinese regulations related to digestate and animal manure utilization including the Guideline for using Animal Waste on Agricultural Land by MARA and standards for irrigation water quality and for discharge of pollutants from livestock and animal breeding.
In her presentation Prof. Dong Hongmin, deputy director of the CAAS Institute for Environment and Sustainable Development in Agriculture and DCZ partner for facilitating the virtual study, provided an overview over the “Animal Utilization Practices in China”. Dong explained that at the present stage direct land application is the dominant practice for manure and slurry management from pig and dairy farms. About 10 percent of solid manure is further processed and applied as commercial organic fertilizer and only 6.5 percent of solid and 20 percent liquid parts is used for biogas production. As challenges for manure management Prof. Dong mentioned the contrast between small-scale crop farmers (as the majority of Chinese farmers have only about or even less than one ha of farmland) and the increasing number of large-scale livestock farms. Therefore, in China it is considered to involve third parties for organizing the transportation and supply of manure, but how to organize this system is still under discussion. Another challenge is how to ensure the safty and aviod potential environmental pollution from heavy metal and antibiotics in animal manure.
The third Chinese speaker was Sun Hui from China Agricultural University who presented the results of his PhD research on “Ensiling excessively wilted maize stover with biogas slurry”.
The last two speakers brought in the German perspective. In his presentation Walter Stinner, who is also DCZ’s lead expert for the design of the virtual study tour, elaborated on the “Emission Reduction in the Manure Chain” as digestate treatment and utilization is one of the most relevant part of the biogas technology in terms of emissions. He discussed the German target for GHG emission reduction and the potential for emission reduction at the different stages of the process of manure and digestate treatment. The last speaker in this panel was Dr. Britt Schumacher, who is project manager for biogas technology at the DBFZ. She presented the results of a recent survey of German biogas plant operators. Results showed that since 2012 there is no significant increase in the German biogas sector and that new construction was limited to manure based small-scale plants. However, results of the survey also showed that construction costs (EURO/kWel) tend to be higher with a higher share of animal manure.
The participation in the IBBK conference marked the successful start of the virtual study tour, which will be continued in early April 2021 with a two-day seminar on “Environmental and administrative aspects of animal manure utilization”.