ABSTRACT Conservation agriculture (CA), which includes reduced tillage and residue retention, has the potential to improve soil structure and support beneficial microbial communities such as arbuscular mycorrhizal fungi (AMF). At the same time, CA practices may also influence nitrous oxide (N 2 O) emissions, a potent greenhouse gas contributing to global warming through their effects on the soil environment. This study examines the effects of CA practices on AMF biomass fluctuations and on N 2 O emissions over a year. It was hypothesized that CA would promote AMF and reduce N 2 O emissions. In a field experiment under temperate climate on sandy loam soil in Denmark, AMF biomarkers and mineral N were assessed 8 times throughout the year while N 2 O fluxes were measured on 35 occasions during 2022‐2023. Signature fatty acids associated with AMF storage lipids (neutral lipid fatty acids) showed greater seasonal variation than those linked to the AMF hyphal network (phospholipid fatty acids), both of which were negatively affected by ploughing. Residue retention had no significant effect on AMF biomarkers but was associated with approximately 44% lower N 2 O emissions during late spring. No clear patterns emerged between seasonal variations in AMF biomarkers and N 2 O fluxes during a year, indicating there was no link between them. These findings highlight the importance of evaluating microbial and gaseous indicators in parallel to assess the broader impacts of CA on soil health and environmental sustainability.
Thomopoulos et al. (2026) studied this question.