Integrating spatial-explict life cycle assessment into multidimensional trade-offs analysis for soil organic amendment strategies

As global demand for food, energy, and climate change mitigation continues to increase, decision-makers in these sectors must find suitable agricultural production strategies to meet Sustainable Development Goals. While several models have been created to aid in decision-making in these systems, there is a lack of robust integrated models that enable an understanding of the multidimensional trade-offs of these systems. Additionally, long-term field measurements for model calibration and optimization is always challenged. We therefore integrated with climate and crop growth model (DSSAT), fed into Life-Cycle Assessment tools (LCA) and economic analysis model using GIS-based integrated platform, and combining a ten-year field measurements of greenhouse gas emissions and soil organic carbon sequestration in a maize-wheat rotation system. The impact of soil organic amendment strategies (e.g. straw return, manure input) on crop yield, soil organic carbon (SOC) dynamics, carbon footprint and cost-benefit indicators were synthesized, and the synergies and trade-offs analysis were conducted at field and regional level to identify gaps and areas where policies should be tailored and targeted. Results showed that model can accurately evaluate grain yield and carbon balances of maize-wheat system and its response to synthesized fertilizer substitution practice. Soil organic amendment strategies (i.e.manure application, crop straw incorporation) increased the yield-scaled carbon footprint by 5.9% and 126.9% respectively, while simultaneously enhancing crop productivity and SOC compared conventional practices. The net benefit was $6.57/ha in maize-wheat cropping system (ten-year average) and the results showed that under low and medium prices for maize and wheat cultivation might difficult to meet the break-even point. Our study indicated that the global warming potential will be increased by long-term fertilization legacy effect, caution shall be made when providing guidance in organic amendments strategies. This discovery underscores the significance of long-term field measurements in emission assessment, providing theoretical support for the formulation of precise greenhouse gas emission inventories and regional sustainable agricultural policies.