Magnetized and Aerated Irrigation Promotes Nitrogen Dynamics and Metabolite Accumulation in Salvia miltiorrhiza

The cultivation of Salvia miltiorrhiza in arid regions is challenged by limited water availability and suboptimal soil aeration, which constrain nitrogen uptake and the accumulation of secondary metabolites. This study evaluated the integrated effects of magnetized and aerated irrigation on mitigating these constraints. Results indicated that the combined magnetized and aerated irrigation treatment demonstrated remarkable efficacy, achieving a 25.2% increase in soil nitrate nitrogen availability and 36.1% enhancement in root dry matter weight. Crucially, this optimized rhizosphere environment preferentially boosted the biosynthesis of salvianolic acid B and key tanshinones (T. IIA, Cryptotanshinone, T. I), with content increases exceeding 22% compared to conventional irrigation, representing substantial improvements in the herb’s therapeutic value. Water terminal magnetization proved superior to water source positioning, while aerated irrigation enhanced soil nitrification more effectively than magnetization alone. By concurrently improving rhizosphere oxygenation and creating favorable conditions for nutrient uptake, this strategy offers a sustainable approach for improving the quality and biomass of Salvia miltiorrhiza in water-limited environments.