Root exudate-mediated plant–microbe interactions and next-generation strategies for sustainable nitrogen management in agricultural soils

Agricultural nitrogen (N) losses remain a major global concern, with substantial fractions of applied fertilizer escaping as nitrate (NO 3 − ) leachate, ammonia (NH 3 ) emissions, and nitrous oxide (N 2 O), thereby reducing nitrogen use efficiency and contributing to climate and water quality degradation. Strategies that retain ammonium and moderate biological oxidation are central for mitigating these losses. This review provides an integrative assessment of two major approaches to suppress nitrification: synthetic nitrification inhibitors and plant-derived root exudates. We evaluate their mechanisms, performance across contrasting soils, and associated trade-offs, including microbial guild shifts and the risk of increased NH 3 volatilization. We further examined emerging innovations such as exudate-responsive fertilizers, nanomaterial-enhanced delivery systems, precision sensing technologies, and the breeding or engineering of crops with elevated biological inhibition capacity. Building on these developments, we proposed a conceptual framework linking root exudation, soil physicochemical filters, microbial functional groups, and field-scale N outcomes. Key challenges include rapid exudate transformation, soil-dependent efficacy, regulatory barriers, and the need to recalibrate monitoring tools in ammonium-enriched rhizosphere. Together, these insights outline a multi-scale pathway to improve N retention, enhance crop N-use efficiency, and more resilient agroecosystems.