Crop diversity in rotation and hedgerows: Two important but potentially insufficient levers to support the multifunctionality of agroecosystems

Climate change and biodiversity loss necessitate agricultural systems that support multiple ecological functions simultaneously, i.e. multifunctional agroecosystems. Many studies have shown that crop diversity in rotation and hedgerows positively affect individual functions, but few have examined their combined effect on agroecosystem multifunctionality by considering above- and below-ground functions. The aim of this study was to characterise the effects of crop diversity in rotation and hedgerows on agroecosystem multifunctionality. In 24 winter cereal fields in Brittany (France), we assessed the average multifunctionality index on the basis of eight potential functions: crop production, nutrient cycling, carbon storage, erosion control, pest regulation, weed infestation, pollination and biodiversity conservation. We used generalized linear mixed models to analyse the effects of crop diversity in rotation and that of hedgerows on the multifunctionality and functions indices. We did not find any effects of crop diversity in rotation and hedgerows on agroecosystem multifunctionality. We found no effect of crop diversity in rotation on functions and positive effects of hedgerows on crop production and pollination. The multifunctionality, pollination and biodiversity conservation indices decreased with distance from edges. However, we did not find any effects of distance from hedgerows on the multifunctionality and functions indices. Our results suggest that crop diversity in rotation and hedgerows may not be sufficient for enhancing agroecosystem multifunctionality. Other levers, such as reducing input use, may influence agroecosystem multifunctionality. These results improve our understanding of factors that shape agroecosystem multifunctionality and may be used to improve sustainable agriculture. • Multifunctionality index encompassed eight above- and below-ground functions. • Crop diversity and hedgerows did not increase multifunctionality. • Multifunctionality and functions did not vary with distance from hedgerows. • Crop diversity did not increase function indices. • Hedgerows supported crop production and pollination without raising weed infestation.