Pulse Brain · Growing Health Evidence Index
Tier 3 — Observational / field trialPeer-reviewed

Balancing legume-cereal proportions in cover crop mixtures to minimize N2O emissions

Guillermo Guardia, Diego Ábalos, Emanuele Ribatti, Federico Ardenti, Federico Capra, Giacomo Mortella, Vincenzo Tabaglio, Miguel Ibáñez, Ji Chen, Andrea Fiorini

Geoderma · 2025

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Summary

This controlled greenhouse mesocosm study evaluated six cover crop treatments to identify optimal legume-cereal proportions for reducing N₂O emissions whilst maintaining agronomic benefits. The majority of emissions occurred post-incorporation, with roots contributing substantially more (57%) than shoots (31%) to total fluxes. A 33% vetch–66% rye mixture emerged as the optimal balance, maintaining N₂O emissions at levels comparable to rye monoculture whilst improving total biomass and nitrogen yield.

UK applicability

UK growers adopting cover crop mixtures for autumn/winter soil protection and spring fertility could apply these findings to reduce greenhouse gas emissions from arable systems. However, the study was conducted in controlled greenhouse conditions; field validation under UK soil and climate conditions would strengthen the transferability of the 33:66 vetch-to-rye ratio recommendation.

Key measures

N₂O emissions (post-incorporation and during growth), soil mineral N content, total dry biomass, nitrogen yield, fine and very fine root proportion, root length density, root C:N ratio, contribution of roots and shoots to total N₂O flux

Outcomes reported

The study measured N₂O fluxes, soil mineral nitrogen content, and biomass accumulation across six cover crop treatments during both the growing and post-incorporation phases. It quantified the relative contribution of roots versus shoots to total N₂O emissions and assessed the relationship between root traits and greenhouse gas production.

Theme
Climate & resilience
Subject
Climate & greenhouse gas mitigation
Study type
Research
Study design
Controlled greenhouse mesocosm experiment
Source type
Peer-reviewed study
Status
Published
Geography
International
System type
Arable cereals
DOI
10.1016/j.geoderma.2025.117195
Catalogue ID
SNmov0fia4-oqtmns

Topic tags

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