Introduction
Soil organic matter (SOM) is crucial in regulating global carbon (C) and nitrogen (N) cycles, affecting climate change. Mineral-associated organic matter (MAOM) is essential for long-term C sequestration as a recalcitrant SOM fraction. This study examines the impacts of different tillage/cover crop systems and fertilisation strategies (organic and mineral) on C and N concentrations in MAOM. Understanding these interactions is vital for optimising agricultural practices to boost soil fertility and reduce greenhouse gas emissions.

Approach
We analysed soil samples from field experiments using a randomised block/split-plot design, comparing conventional and no-tillage systems (with cover crops), carbon amendments (none, biochar, compost, and composted biochar), and mineral N fertilisation at 0%, 50%, and 100% of CaNO3 standard dose. C and N in MAOM were measured, and treatment interactions were evaluated using a statistical model.

Results
Preliminary findings indicate significant interactions between tillage/cover crops and organic amendments on soil C and N, favouring no-till/cover crop systems enriched with compost and composted biochar. These amendments, combined with no-till/cover crops and mineral N fertilisation, substantially increased C and N in MAOM compared to other treatments.

Conclusions
No-till/cover crop systems, with carbon amendments and mineral N fertilisation, enhance soil C and N storage in the recalcitrant MAOM fraction, supporting sustainable agriculture with lower environmental impacts and improved soil health.

Learning Objectives
Delegates will understand how no-tillage systems with targeted fertilisation improve soil C and N storage, boosting both yields and sustainability.