How to address challenges in the life cycle assessment of innovative cropping systems: Insights from a comparative study of a pesticide-free and a conventional system

CONTEXT Understanding environmental impacts of innovative cropping systems is integral to their development process. The most common method used for this purpose is life cycle assessment (LCA). However, several methodological challenges complicate the reliable application of LCA to such systems. OBJECTIVE This study critically reflects on six methodological challenges in the LCA of innovative cropping systems. These challenges are examined through the lens of a case study, comparing the LCA of a pesticide-free and a conventional cropping system. Building on these findings, the study identifies perspectives and research needs for more robust and fair comparative LCAs of innovative cropping systems. METHODS The cradle-to-farm-gate study was based on field trial data from south-west Germany. Two functional units were applied: per hectare and year (ha*a), and per cereal unit (CU). The assessment included eighteen impact categories (ReCiPe 2016), investigating eight in detail based on a materiality analysis. Additionally, greenhouse gas (GHG) emissions from indirect land use change (iLUC) were modelled. RESULTS AND CONCLUSION While the pesticide-free system performed better in twelve impact categories per ha*a, only seven impact categories showed better results per CU than the conventional system. Major impact contributors included fertilisation and machinery use. GHG emissions from iLUC accounted for an additional 11% of the results for both functional units. For method development, the study highlights the need for improved interpretation of results across multiple functional units, better environmental models for estimating field emissions, impact category development and participatory selection processes, data representativeness for innovative technologies, assessment methods and data that reflect the regional context, and more comprehensive consideration of system dynamics. SIGNIFICANCE This paper addresses key challenges in the LCA of innovative cropping systems and highlights the need for methodological diversity, interdisciplinary capacity, and a move beyond conventional-organic divides in agricultural systems research.