Assessment Of Greenhouse Gas Emissions From Regional Planting And Breeding Cycles

A large number of greenhouse gas emissions have led to numerous climate problems.China has set the goal of reaching the peak of carbon by 2030 and achieving carbon neutrality by 2060.Agriculture,as one of China’s important industries,generates a large amount of greenhouse gases every year,such as methane and nitrous oxide.In order to achieve the goal of carbon neutrality,research on the reduction of agricultural greenhouse gas emissions cann’t be delayed any more.With the continuous development of China’s livestock and poultry breeding industry,a large amount of livestock and poultry manure waste are generated every year,which causes serious environmental pollution.In the process of livestock manure management,a large amount of greenhouse gases will also be generated.The development of a breeding cycle type agriculture,and to realize the resource utilization of livestock and poultry manure,are an important measure related to the improvement of the production and living environment of rural residents and the promotion of green development of agriculture.Taking an organic fertilizer factory and surrounding corn farm in Tianjin as an example,this paper used life cycle and greenhouse gas emission accounting methods to study and evaluate the greenhouse gas emissions of the regional planting and breeding cycle model.The main purpose of this research is to quantitatively evaluate the greenhouse gas emission reduction effect of the planting and breeding cycle model on the base of practical investigation and life cycle analysis,and to identify important emission sources in the process,in order to provide a scientific basis for the promotion of the planting and breeding cycle model.The main conclusions of this research are shown as follows:(1)Based on the empirical research results of organic fertilizer plants and the greenhouse gas emission accounting method of the IPCC guidelines,and based on the life cycle assessment platform,the greenhouse gas emission of 1 ton of organic fertilizer is calculated to be 1.33 t CO2-eq,of which the main emission source is the direct contribution brought by the production process,and it accounts for 98.74%.This result provides a reference for the future production and emission reduction of organic fertilizer plants.(2)Based on the scenario simulation method,the greenhouse gas emissions under the scenario of replacing chemical fertilizers with organic fertilizers under the regional planting and breeding cycle mode were explored on the basis of equal nitrogen content.Planting 1hectares of maize,without considering the effect of soil carbon sequestration,the greenhouse gas emissions of the organic fertilizer substitution model will increase with the increase of the substitution ratio,but the application of organic fertilizer can significantly increase the carbon sequestration effect of the soil and make the agricultural soil free from carbon.The source becomes a carbon sink.The total amount of greenhouse gases produced by replacing chemical fertilizers with organic fertilizers at the ratios of 25%,50%,75% and 100% is-6.39 t CO2-eq、-4.42 t CO2-eq、-2.1 t CO2-eq、0.04 t CO2-eq,while the greenhouse gas emissions of 1 hectares corn planted with chemical fertilizers are 1.47 t CO2-eq.Through the comparison of the results,it can be seen that the substitution of organic fertilizers for chemical fertilizers can significantly reduce greenhouse gas emissions.(3)A regional planting and breeding cycle greenhouse gas emission accounting method is established.Taking Tianjin Organic Fertilizer Plant as an example,a baseline scenario of‘static manure stacking + full fertilizer planting’ and a project activity scenario of ‘regional planting and breeding cycle’ were constructed.The greenhouse gas emissions were calculated separately,and the results show that the regional planting and breeding cycle model has obvious greenhouse gas emission reduction effects,and the annual greenhouse gas emission reduction can reach 196.44 t CO2-eq.