Assessing Impacts on the Natural Resource Soil in Life Cycle Assessment: Methods for Compaction and Water Erosion

There
are currently limited life cycle impact assessment methods
existing for assessing impacts on the natural resource soil. In this
paper, we develop methods for the assessment of compaction and water
erosion impacts within one framework, which can be expanded with additional
degradation processes in the future. Our methods assess potential
long-term impacts from agricultural activities on the production capacity
of soils and are able to distinguish between different management
choices such as machinery selection and tillage practices. Characterization
factors are provided as global raster data sets at high spatial resolution
(∼1 km) and for larger geographic units including uncertainties
of spatial aggregation. Uncertainties due to variability of climate
and weather are provided where possible. The application of the methods
is demonstrated and discussed in a simplified case study. Results
show that in a highly mechanized scenario of global agriculture without
any conservation measures, long-term yearly soil productivity losses
due to compaction and water erosion can amount to up to double-digit
percentages for major crops. This confirms the relevance of compaction
and water erosion impacts for agricultural LCAs.