Well-designed multi-species grassland mixtures enhance both soil carbon inputs and aboveground productivity

Summary

Increasing species diversity in managed grasslands may serve multiple environmental purposes, especially when legumes are included. Yet, how to design such legume-based grassland mixtures to increase soil C inputs remains unclear. This is particularly true for C inputs into deep soil layers, and via rhizodeposition. This field study investigated the effects of mixture design on root C and net-rhizodeposition to 1 m depth in managed grasslands with the aim to combine high soil C inputs with high aboveground productivity. Net-rhizodeposition was defined as accumulated C lost from roots, which remained in the soil at the end of the growing season. We used multiple-pulse isotopic labelling with 13 C-CO 2 to quantify the soil C inputs from roots and rhizodeposition in a range of species mixture