CEMF January 11, 2018

 

Time: January 11-11, 2018

 

Venue: The Third Conference Room of Graduate School of Chinese Academy of Agricultural Sciences

 

On January 11, 2018, the China Energy Modeling Forum Agriculture and Land Use Seminar was held in Beijing. The seminar brought together model teams from Tsinghua University, Peking University, Chinese Academy of Sciences, Chinese Academy of Agricultural Sciences, Renmin University of China, China University of Mining and Technology, etc. The scholars present focused on agriculture and land use under China's low-emission development strategy, conducted in-depth exchanges on their respective research fields and subdivision directions, and put forward prospects for the optimization and expansion of future models.

 

The morning meeting was presided over by Researcher Lin Erda, former director of the Institute of Agricultural Environment and Sustainable Development, Chinese Academy of Agricultural Sciences. He first briefly introduced the background of CEMF Topic Research 2 and the topic of the forum. On behalf of the secretariat, Qin Hu from the Beijing Representative Office of EPA introduced CEMF and the research theme of this issue to the participants. The main purpose of the establishment of the China Energy Modeling Forum is to build a communication platform between model teams and to promote a dialogue platform between model teams and policy decision makers. He also pointed out that not only the field of energy models can solve policy problems, but also can provide comprehensive support for decision-making through exchanges and cooperation between different fields and different models. This is also the reason for organizing research on agriculture and land use under the China Energy Modeling Forum. Zhang Yanqing, director of the Institute of Environmental Development, Academy of Agricultural Sciences, introduced the history and main research directions of the Institute to the guests, as well as the application of the model in the green development of agriculture.

 

Huang Yao, a researcher from the Institute of Botany, Chinese Academy of Sciences, gave a special report entitled Contribution of China's Farmland Soil Carbon Sequestration to Greenhouse Gas Emission Reduction. Researcher Huang first introduced the calculation of agricultural soil organic carbon changes and carbon sinks through literature review methods and model analysis methods. His research team combined literature data integration analysis and model analysis to obtain carbon density changes that were basically at the same time. A range, to achieve the basic judgment of the changes in China's farmland soil organic carbon. Secondly, researcher Huang introduced how to calculate the emission of methane, the main greenhouse gas in rice fields, through model methods. Among them, the emission of methane is positively correlated with the growing season of rice. Then researcher Huang introduced the method of calculating farmland nitrous oxide combined with hydrological conditions, and pointed out that the input and application of chemical fertilizer nitrogen is the main reason for the direct emission of farmland nitrous oxide. Researcher Huang's research found that the contribution of soil organic carbon in paddy fields to emission reduction is lower than that in dryland farmland, while the soil organic carbon in farmland shows an overall increasing trend, which has an obvious carbon sink effect.

 

Researcher Guo Liping introduced the research background and main methods of agriculture and land use to the guests. Mr. Guo decomposed the changing trend of greenhouse gas emission sources such as planting and breeding in agriculture, and the calculation method of greenhouse gas emission inventory. Among them, the use of model methods to calculate the emission inventory can take into account the complex influencing factors in agricultural production. Mr. Guo said that future work includes using the IPCC method to distinguish parameter empirical models, and the GAINS model combined with socio-economic scenarios.

 

Associate researcher Kuang Wenhui from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences introduced the spatiotemporal characteristics and driving factors of land use cover change in the past 30 years. Land use cover change is an important factor affecting climate change. The Institute of Geography of the Chinese Academy of Sciences has carried out land use dynamic monitoring work since the 1990s. By comparing the remote sensing data of the three time dimensions of 1990-2000, 2000-2010, and 2010-2015 with the data of actual field surveys, It can be found that after 2000-2010, with the obvious increase of urbanization rate and working land, it led to a very obvious phenomenon of ecological conversion of farmland. At the same time, Mr. Kuang said that after 2010, the intensity of the rate of land change had significantly weekend

 

Researcher Wang Shaoqiang, also from the Institute of Geography of the Chinese Academy of Sciences, introduced the latest research of his team, keeping the straw that was originally burned in the open air in the field to reduce air pollutant emissions and soil carbon sequestration. Teacher Wang divided China's farmland into seven regions according to statistical data, and then used the EPIC model to simulate the total amount of soil carbon sequestration if the proportion of straw burned in the open air in each province and city was returned to the field, and the actual return rate was added. The simulation results of the model are verified with the actual data, and the conclusion is that there is relatively no straw returning to the field, and a considerable amount of carbon storage can be increased if the burned straw is returned to the field. At the same time, Teacher Wang made suggestions on the carbon trading system. China's carbon market and future international carbon trading should take into account the carbon sequestration of farmland soil.

 

Professor Liu Xuejun from China Agricultural University introduced the relationship between ammonia emissions and air pollution. Agricultural ammonia emissions are related to temperature and have obvious seasonality; and the ammonia concentration in the atmosphere is directly related to the time of fertilization. In the atmosphere, The secondary transformation of ammonia salt is an important factor for the rapid formation of smog. There is a good linear relationship between ammonia emissions in cities and motor vehicles, but there is still a lack of research on ammonia emissions from non-agricultural sources. Professor Liu said, There is a lot of room for reducing ammonia emissions, and the technology is relatively mature. However, when it comes to food security and other issues, we should maintain a cautious attitude as a whole.

 

The afternoon meeting was chaired by Professor Guo Liping. Cheng Kun from the team of Professor Pan Genxing from the School of Resources and Environment, Nanjing Agricultural University first introduced his team's research on paddy soil carbon sinks and low greenhouse gas emissions. The research shows that the amount of nitrous oxide in paddy fields Emissions will vary according to regional differences and fertilizer types. Methane emissions are mainly simulated using the modified DAYCENT model. At the same time, his team used model method analysis to find that reducing nitrogen fertilizer use combined with intermittent flooding, or conservation tillage combined with intermittent flooding Under these conditions, the potential for reducing greenhouse gas emissions during rice production is relatively high.

 

Researcher Zhu Zhiping from the Institute of Environmental Development of the Academy of Agricultural Sciences introduced methane emissions and waste disposal in the breeding process. His team assessed the impact of dairy cows' intestinal fermentation and feed type, and found that the potential of clearing straw to reduce emissions can be It can reach about 30%. The addition of mineral licking bricks improves the feed conversion efficiency and can also reduce methane emissions by about 20%. At the same time, the direction of animal husbandry waste treatment is to use biogas and organic fertilizer as the main direction, through solid-liquid separation and composting. This combination mode can reduce ammonia emissions by 60-80%. He said that the most critical emission reduction technology is the grain-to-feed project, and silage technology may be the best way to reduce emissions.

 

Researcher Zhu Jianhua from the Chinese Academy of Forestry gave an introduction to land use change and forestry greenhouse gas inventory. Mr. Zhu said that the compilation of greenhouse gas inventory has a quantification of the greenhouse gas sinks or emission sources in the entire field, and can be quantified to specific forest types and each carbon pool. This helps formulate emission reduction policies and implement some measures in this field. Strong guiding significance. In the future, the accuracy of inventory compilation can be improved by combining remote sensing data and geographic information system data. Secondly, further subdivide land types to improve the accuracy of relevant emission factors and parameter selection. Again, our current relevant parameters are divided according to biomass, and our biomass parameters are based on specific vegetation types, including tree species, forest types, and even subdivided into age stages.

 

During the discussion session, Gao Ji from the Beijing Representative Office of the US Environmental Defense Fund further explained the setting goals and work plan of CEMF's low-emission strategy research. He said that the final demand of the Energy Modeling Forum is to propose a roadmap for agricultural and land use emission reduction at key time points such as 2020, 2035, and 2050 around the goal of 2050, and at the same time nest some optimization technologies at each node , emission reduction technologies, and evaluate their economic viability.

 

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