Research On Dynamic Changes Of Farmland Carbon Sources/Sinks And Development Of Low Carbon Agriculture In Jiangsu Province

Agriculture is the important guarantee for the development of the national economy and social stability.In recent years,the problem of climate change has become more and more significant,with influencing the hydrothermal conditions differently in different areas.However,the greenhouse gas emissions represented by carbon dioxide from agricultural production activities are also an important driver factor of climate change.How to reduce the emissions of agricultural greenhouse gases and how to increase the carbon sink capacity of farmland ecosystems have become an urgent issue to be solved during the of process of agricultural development.In this research,the farmland ecosystem in Jiangsu Province was the main research object.The relevant data in the agricultural production process was collected and compiled.Based on the model formula of IPCC,the dynamic characteristics and trends of carbon sequestration,carbon emissions and carbon footprint of farmland ecosystems in Jiangsu Province during 2001-2016 were calculated and analyzed.With using the method of grey correlation analysis,the impact of various carbon sources on the carbon emissions of farmland ecosystems was analyzed,and the status quo of low-carbon agriculture was evaluated.Finally,according to the actual situation of farmland ecosystems of Jiangsu Province,we put forward corresponding management measures.The main results are as the following:(1)Characteristic and trend of dynamic changes of carbon emissions,carbon uptake,and carbon footprint of farmland ecosystems in Jiangsu ProvinceIn the past 16 years,the carbon emissions of farmland in Jiangsu Province have generally shown an increasing trend.In 2001,the carbon emissions of Jiangsu Province were 4,444,300 tons,and 4,599,100 tons in 2016,an increase of 3.4%.The carbon emission intensity was first increased and then the trend of decline,but the overall fluctuation is not large,the level of carbon emission intensity is generally lower than 1 t/ha.Among several important sources of agricultural carbon emissions,chemical fertilizers contribute the most to total carbon emissions,and the contribution rate is about 64.77%.The rest were agricultural diesel,agricultural film,pesticides,irrigation and machine farming,and the contribution rates were 11.65%,10.26%,9.46%,3.52%and 0.34%,respectively.From 2001 to 2016,total quantity of carbon sinks and net quantity of carbon sinks continued to increase,increasing by 35,401,700 tons and 35,257,000 tons,respectively.The overall quantity of carbon absorption intensity gradually increased;among the major carbon-absorbing crops,the horticultural crops showed significant carbon uptake and the quantity of horticultural crops is higher than food crops and cash crops.The carbon footprint showed fluctuations and showed a decreasing trend overall.In 1999,the number of farmland ecosystems was reduced by 99,483.82 ha.The carbon footprint of farmland ecosystems was less than the area of cultivated land during the same period and showed a carbon ecological surplus.(2)The influencing factors of low-carbon agriculture and evaluation of status quo of low-carbon agricultureChemical fertilizers are the primary factor influencing the development of low-carbon agriculture.It has the greatest correlation with carbon emissions from agricultural ecosystems,with a correlation coefficient of 0.87,followed by diesel,agricultural film,pesticides,irrigation and mechanical farming,and we do the analysis of each factor.From 2001 to 2016,the development level of low-carbon agriculture in Jiangsu Province has been continuously improving.(3)Strategy of low carbon agricultural developmentAdjust the agricultural structure;Optimize agricultural production methods;Optimize the structure of agricultural energy consumption;Implement low-carbon agricultural development policies;Publicize and promote low-carbon agricultural development models.