Potential greenhouse gas emission reductions in soybean farming: a combined use of Life Cycle Assessment and Data Envelopment Analysis

• The DEA results show that 46% of the studied farms operated efficient.
• Fertilizing agents generated the highest GHG emissions among the farm operations.
• Irrigation is the main contribution to the total GWP reduction.
• Limiting of crop residue burning has a significant impact on improving GHGs performance.
• The potential GWP reduction for the whole sample was found around 11%.

Joint implementation of Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) has recently showed to be a suitable tool for measuring efficiency in agri-food systems. In the present study, LCA + DEA methodologies were applied for a total of 94 soybean farms in Iran to benchmark the level of operational input efficiency of each farmer. Likewise, potential reductions in the consumption levels of the physical inputs were determined, while estimating the environmental improvements linked to these reduction targets. Our results indicate that 46% of the farms studied operated efficient. The estimated Global Warming Potential (GWP) reduction for the whole sample was obtained∼11% according to DEA model results. Among the field operations, the contribution of irrigation to the total GWP reduction was the highest (63%) followed by fertilization (34%). The results also revealed that farms which burnt crop residue in the field generate significantly more greenhouse gas emissions than other farms. The raising of operational input efficiency and limiting of crop residue burning in the field are recommended options to ensure more environmental friendly soybean farming systems in the region.