Daniel Rasse

Head of Department/Head of Research

(+47) 922 63 608
daniel.rasse@nibio.no

Place
Ås H7

Visiting address
Høgskoleveien 7, 1433 Ås

Abstract

Biochar has emerged as a promising carbon dioxide removal (CDR) solution that combines long-term carbon storage with benefits for soil health, waste management, and industrial applications. This report provides a comprehensive assessment of the current state of biochar across feedstocks, production technologies, material properties, and end-use pathways, with a particular focus on its role in climate mitigation. Drawing on scientific literature and international case studies, the report evaluates the carbon sequestration potential, environmental performance, and technological maturity of biochar systems. It distinguishes between applications that deliver durable carbon removal and those that primarily contribute to emission reductions. The report further examines deployment barriers, including feedstock availability, regulatory frameworks, market development, and safety considerations, and reviews the status of biochar implementation across Mission Innovation countries. Based on these insights, it outlines key opportunities and recommendations to support the responsible scale-up of biochar as a climate solution.

Abstract

Cover crops enhance soil quality and organic matter stability, yet the mechanisms linking belowground inputs to persistent soil organic matter (SOM) remain unclear. This study examined the effects of diversified cover cropping in barley systems on root biomass, SOM fractions, soil structure, microbial activity, and yield in central Norway (63.9° N), three years post-implementation. Six treatments were tested: (1) Control (barley without NPK), (2) Biochar-Fertilizer (barley + NPK + 3 Mg ha⁻¹ biochar), (3) Monocrop (barley), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). Ryegrass and Clover systems produced 28.65 g m-² more root biomass at 0–13 cm (p < 0.05) and, along with Monocrop, stored 2.2 Mg ha-¹ more mineral-associated organic matter (MAOM) carbon and 0.2 Mg ha-¹ more MAOM nitrogen at 0–20 cm than other treatments. The Chicory system improved soil structure and biology, with higher aggregate stability, lower bulk density, and greater microbial abundance. Barley yields remained consistent across treatments, suggesting that cover cropping and low biochar inputs do not reduce productivity. Strong correlations (p < 0.01) between root biomass and MAOM stocks highlight root development as a key driver of SOM stabilization via organo-mineral associations. These findings underscore the role of root-enhancing cover crops in promoting MAOM formation and long-term SOM persistence, offering valuable insights for sustainable soil management.