Twenty five years of nitrogen use efficiency research across soil and soilless cultivation systems

Nitrogen use efficiency (NUE) represents a central challenge in sustainable crop production, particularly as global agriculture transitions from soil-based to soilless cultivation systems. From 2000 to 2025, research on nitrogen uptake and assimilation has evolved from descriptive nutrient optimization to integrated, data-driven modeling linking molecular regulation, environmental control, and system performance. Bibliometric and comparative analyses reveal a steep increase in publication output, interdisciplinary collaboration, and alignment with sustainability over the past two decades. Early studies (2000–2010) established the mechanistic foundations of nitrogen transport by identifying nitrate and ammonium transporter families, followed by advances in isotopic tracing, kinetic modeling, and transporter regulation (2010–2018). The most recent phase (2018–2025) reflects a technological transformation, integrating genomics, transcriptomics, metabolomics, and computational pathway mapping through KEGG and STRING to model nitrogen flux across the carbon–nitrogen interface. Comparative performance assessment revealed that hydroponic and aeroponic systems achieved higher efficiencies, with nitrogen recovery rates of 85–93%, 60–70% lower nitrogen losses, and 80% greater water-use efficiency compared to soil-based cultivation. Aeroponics and hydroponics, augmented by AI-based nutrient regulation, are within the scope of this review. Persistent challenges include energy intensity, omics-to-field translation, and the standardization of NUE metrics. The convergence of molecular biology, digital sensing, and environmental engineering now defines the next frontier for climate-resilient and circular nitrogen management in controlled-environment agriculture.