A multi-product landscape life-cycle assessment approach for evaluating local climate mitigation potential

Increasing demand for land-based climate mitigation requires more efficient management of agricultural landscapes competing objectives. Here we develop methods assessing trade-offs and synergies between intensification carbon-sequestering conservation measures in annual crop production using the DayCent ecosystem model Greenhouse Gases, Regulated Emissions, Energy Use Technologies (GREET) life-cycle assessment (LCA) model. We compiled county-scaled yields, fertilizer application rates, tillage intensity a corn–soybean farming case study landscape US state Iowa. Using DayCent, estimated baseline soil organic carbon (SOC) accrual rate 0.29 Mg C ha?1 y?1 driven by historical increases productivity reductions intensity. then simulated effects interventions targeted toward (stover removal) SOC sequestration (tillage reduction winter cover addition) individually combination. propose new multi-product landscape–LCA approach that analyzes marginal changes corn grain, stover, soybean from terms their value biofuel (corn ethanol, soy biodiesel, cellulosic ethanol stover) associated net displacement conventional fossil-derived fuel use. This enables us to evaluate both common CO2-equivalent units. also used DayCent-simulated yields under different land scenarios estimate farm-level costs revenues. Our results show via collecting 30% stover would increase total greenhouse gas (GHG) potential this 0.93 CO2e provide $49 additional revenue biomass sales, but reduce accumulation approximately 40%. In contrast, integrated approaches include co-adoption cropping and/or result increased rates above baseline, achieving simultaneous improvements farm profits overall GHG landscape.