The capacity of crops for enhanced carbon allocation to soil in a changing climate - synergies and trade-offs

Plants are net removers of atmospheric CO2, and roots are the main source of soil organic C (SOC).

Plants are thus a viable option for climate change mitigation, but little is known about how increased root C inputs trigger other processes with potentially positive (synergies) and negative (trade-offs) effects.

Our aim is to unravel the potential of cultivar selection, mixed cultivar systems and cover crops to promote synergies between C sequestration, crop production and N retention under different hydro-climatic conditions mimicking climate change.

We will combine lysimeter studies with data from long-term field experiments (LTE) and modelling of crop growth and soil C sequestration in current and future climates.

The lysimeter studies include detailed analysis of plant growth, root traits, microbial functions, C allocation and N losses.

At the LTEs we will synthesize existing data on crop yields and N leaching, and make new measurements of SOC stocks, soil physical properties and microbial functions.

We will use a new, integrated soil-crop model constructed from existing modules accounting for interactions between SOC, soil hydraulic properties and crop growth.

Improved understanding of the potential to enhance root C inputs, whilst minimizing trade-offs with respect to yield and N losses is essential for designing novel cropping systems that promote soil C sequestration for climate change mitigation and adaptation.