Harnessing biological nitrification inhibition to reduce soil nitrogen losses – Systematic quantification of plant and soil factors to maximise field-scale benefits

Summary

This systematic review examines biological nitrification inhibition—the natural suppression of ammonium-to-nitrate conversion via plant root exudates—as a mechanism to reduce nitrogen losses in cropping systems. The authors synthesise evidence on key plant and soil factors governing BNI activity, particularly soil pH, ammonium concentration, and phenological stage, and propose a quantification framework to support field-scale implementation. The review identifies substantial knowledge gaps regarding BNI compound composition and efficacy in major grain crops (rice, maize) beyond the well-studied Brachiaria humidicola and sorghum.

Regional applicability

The findings are potentially relevant to UK arable systems seeking to improve nitrogen use efficiency and reduce nitrate leaching and nitrous oxide emissions. However, the review notes that most evidence derives from tropical and subtropical cropping systems; UK-specific field trials under temperate soil and climate conditions would be required to validate BNI effectiveness and optimise management for local conditions.

Key measures

Soil pH, soil ammonium concentration, plant growth stage, BNI compound release timing, mobility and longevity of BNI compounds in soil, nitrification inhibition potential

Outcomes reported

The paper systematically quantifies plant and soil factors affecting biological nitrification inhibition (BNI) activity, including how soil pH, ammonium concentration, and plant growth stage influence BNI compound release. It proposes a conceptual framework for BNI quantification and identifies research gaps in understanding BNI efficacy across major grain crops.

Topic tags