Carbon Footprint Evaluation Of Agricultural Products Based On LCA And Research Of Carbon Tag Evaluation Method

Greenhouse gases produced by agricultural activities have become one of the main sources of global greenhouse gas emissions.This paper explores the suitable carbon footprint valuation method and evaluation method of carbon label for the cultivation of agricultural products in China.The main purpose is to provide technical and theoretical support for China’s carbon footprint value standardization,carbon label evaluation system and low carbon agricultural development.Contents and conclusions of this study are as follows:1.When using LCA method to evaluate agricultural carbon footprint,the first is to classify agricultural products,select functional units and the corresponding system boundary according to the different assessment requires,then analyze carbon sources and sinks of agricultural products from different categories.The last is to calculate the carbon footprint of agricultural products according to the calculation method of carbon source and carbon sink.Each link of the production of greenhouse gas emissions can clearly draw by the LCA carbon footprint assessment.Then find out the production of high carbon and high carbon source process of agricultural products,implement reduction measures.Compared some abroad calculation methods,this study tried to find out a calculation method and parameters that more suitable for China’s production conditions and environmental elements,so selected the parameters that mainly from China’s research achievements;2.Use LCA method to evaluate millet product carbon footprint of Jin Poluo village in Beijing.The study designed the simple millet carbon footprint calculation tool by using HTML language,JavaScript（jQuery）and Echart plug-in,figured out the greenhouse gas emissions in different parts of the production of the entire production process.The greenhouse gases emission of millet products in the production process was 513.75 kg CO₂ eq per Mu,mainly from the fertilization process,it accounted for 97.53% of total emissions.The carbon emissions from sowing,harvesting and plough were close to each other.N2 O emission is 448.57 kg CO₂ eq per Mu,and it was the largest in all kinds of greenhouse gas emissions,accounted for 87.31% in total emissions.So this village should focus on the control of N2 O emission.In the fertilization process,greenhouse gases were mainly produced by the application of organic manure,accounted for 91.62% in the fertilization process.In direct and indirect emissions,the contribution rate of direct emission was the largest,which accounted for 70.18% of direct and indirect emissions.The amount of carbon sequestration in farmland soil was 432.19 kg CO₂ eq per Mu.After taking into account the soil carbon sink,the carbon footprint of the whole system under different functional units were 81.56 kg CO₂ eq per Mu、0.82 kg CO₂ eq per kg、15.68 kg CO₂ eq per thousand yuan;3.The case showed that although agricultural production process of carbon emissions increased due to farmland organic fertilizer and take straw back to farmland,the soil carbon sequestration increased through these changes of farmland management,made the carbon footprint of whole system lower.From the perspective of agricultural production,the use of organic manure,straw returning,not only reduced the use of chemical fertilizer and the fertilizer harm to the production environment,but also made waste profitable,realized the effective utilization of manure,straw and other waste of resources,increased the soil organic carbon content,ensured the soil more fertile and productive;4.In the face of increasingly fierce international low carbon competition and the possible import and export policies of carbon label trade,the establishment of China’s carbon label evaluation system is an inevitable choice.So China needs to : establish the carbon label system policy,compose the carbon footprint calculation standards,improve the carbon footprint database,authorize qualified audit and certification institutions for agricultural product carbon labeling evaluation,start pilot and then gradually developed to the national,strengthen social propaganda,raise public awareness.