Potential for Greenhouse Gas Mitigation at a Typical Roughage Production System in the Japanese Dairy System

Increasing domestic roughage production is an important measure in designing a sustainable dairy production system in Japan. However, roughage production is one of the agricultural activities that have a significant environmental impact. The objectives of this study were to reveal potentials of greenhouse gas (GHG) emissions in typical roughage production systems using the life cycle assessment method (LCA). Comparative LCA was conducted to evaluate GHG emissions between the domestic roughage production system and imported hay utilization system. The functional unit of LCA was defined as roughage production at 10a, and GHG/TDN ratio was applied comparing roughage production and GHG emissions of domestic and imported roughages. The results showed that the domestic roughage production system produced 20 % less GHG emissions than the imported hay utilization system. GHG/TDN ratios were associated with the LCA results to compare GHG emissions with production of different roughage production systems.