Assessing Nitrogen-Fixing Bacteria and MineralNitrogen Fertilization Regimes for BoostingGrowth, Photosynthesis, and Essential OilProduction of Clary Sage (<i>Salvia sclarea</i> L.)

Clary sage (Salvia sclarea L.) is a valuable medicinal biennial herb, and its oil is characterized by an ambergris scent and finds uses as a spice and a vital ingredient of cosmeceutical products such as perfumes, soaps, cosmetics, and aromatherapy.However, its scale of production has remained far below its potential, especially owing to inappropriate plant nutrition management.To bridge this research gap, a field experiment was conducted to comparatively assess the mineral nitrogen (N) fertilizer doses (120 and 60 kg N ha -1 ) and nitrogen-fixing bacteria (NFB, including azotobacter, chroococcum, and cyanobacteria) for boosting the growth, yield, oil content, and primary essential oil composition of clary sage plants.The results revealed that the higher dose of N applied in conjunction with azotobacter and cyanobacteria recorded the highest concentration of macro and micronutrients in clary sage plants, except for iron content.Additionally, the same treatment exhibited unmatched photosynthetic efficiency as demonstrated by significantly higher NDVI (normalized difference vegetation index), SPAD (soil plant analysis development), and chlorophyll fluorescence values, which resulted in the highest leaf