Summary
This laboratory study investigated whether two plant-derived fatty acids (linoleic and linolenic acids) could suppress nitrification in soil as effectively as the synthetic inhibitor dicyandiamide. Whilst linoleic and linolenic acids significantly reduced nitrate concentrations, they appeared to work indirectly by promoting microbial immobilisation of available nitrogen rather than directly inhibiting nitrifiers, and they increased greenhouse gas emissions at high application rates. The findings suggest that biological and synthetic nitrification inhibitors operate through distinct mechanisms, highlighting the need for greater mechanistic clarity in future inhibitor research.
UK applicability
These findings are relevant to UK agricultural practice, where nitrification inhibitors are increasingly considered for mitigating nitrogen losses in high-rainfall contexts. The results suggest that biological inhibitors derived from root exudates may function differently than currently assumed, with implications for breeding programmes aimed at selecting for natural nitrification-inhibiting crop varieties in UK farming systems.
Key measures
Soil NH₄⁺ and NO₃⁻ concentrations; cumulative N₂O and CO₂ emissions; ¹⁴C-labelled mineralization rates of linoleic acid, linolenic acid, and dicyandiamide over 38 days
Outcomes reported
The study compared the efficacy of two biological nitrification inhibitors (linoleic and linolenic acids) against a synthetic inhibitor (dicyandiamide) on soil nitrate concentrations, ammonium dynamics, and nitrous oxide and carbon dioxide emissions in a highly nitrifying soil. It also tracked the mineralization rates of these compounds over a 38-day incubation period.
Topic tags
Dig deeper with Pulse AI.
Pulse AI has read the whole catalogue. Ask about this record, its theme, or how the findings apply to UK farming and policy — every answer cites the underlying studies.