I-DRo: A new indicator to assess spatiotemporal diversity and ecosystem services of crop rotations

Abstract

Agroecological farming systems depend on ecosystem services (ES) to replace external anthropogenic inputs. Crop diversification is increasingly being put forward as a way to support ES service provision. Actors involved in promoting, designing and implementing diversified cropping systems presumably need to assess the degree of diversity and performance of diversified cropping systems at one stage or another. This article focuses on crop rotation diversity since it is a core component of annual cropping systems. In this study, we designed a new global indicator (I-DRo) based on a set of other indicators used to assess the temporal diversity of crop rotation (which includes functional diversity through ES provision,) as well as taxonomic diversity and spatial diversity. I-DRo covers various crop diversification strategies in the rotation: introduction of new crops or cover crops, multiple cropping, intercropping, relay cropping and strip cropping. The proposed indicators may be used separately or aggregated in a hierarchical way according to a fuzzy decision tree. Using I-DRo requires only data on field width and the main crop and cover crop species. Initial tests showed the indicator could potentially be used to support various actors in their decision-making, although results on the predictive quality were mixed given the degree of simplification. Contextualizing the calculation method for ES assessment would be one avenue of investigation. Lastly, use at EU level could support the implementation of new cross-compliance measures on crop diversification, but would require efforts to harmonize data on main crops and cover crops.