Carbon emissions inventory of farm size pig husbandry combining Manure-DNDC model and IPCC coefficient methodology

Abstract

The increasing demand for pork products has contributed to the increase in greenhouse gas emissions (GHG). Based on survey data of pig farms in Yancheng, Jiangsu Province, China, we developed a hybrid model DICPig (DNDC and IPCC combined model for pig husbandry) by combining the Manure-DNDC (denitrification and decomposition model for manure) model with the IPCC (Intergovernmental Panel on Climate Change) agricultural greenhouse gas calculation method to calculate the total GHG emissions from the pig husbandry life cycle. This hybrid model allowed the analysis of the pig husbandry carbon emissions component structure and the identification of the factors affecting the level of emissions. The results showed that CO2 (Carbon Dioxide) emission per pig in its life cycle is about 672.27 kg CO2-eq. In the process of pig waste disposal, the N2O (Nitrous oxide) emitted is 1.17 kg, and the CH4 (Methane) emitted is 1.36 kg. Pig waste disposal and feed production processes were the two most important contributors to total pig husbandry GHG emissions, accounting for 56.92% and 28.62% of the total emissions respectively. GHG emissions from pig farms could be reduced significantly by optimizing manure management measures, constructing and utilizing biogas digesters, reducing the amount of fertilizer applied to cropping, and adopting a planting-breeding combination policy.