To investigate the effect of biochar application on some characteristics of Satureja hortensis L under deficit irrigation and partial root-zone drying conditions, a factorial experiment based on a completely randomized design with 3 replications was conducted in 2024 at the research greenhouse of Torbat Jam Higher Education Complex. In this experiment, treatments included three levels of irrigation (100% of water requirement, 50% deficit irrigation, and 50% partial root-zone drying) and three levels of biochar application (0, 2.5, and 5% by weight of soil per pot). The results showed that applying 50% deficit irrigation (DI) and partial root-zone drying (PRD) increased water use efficiency by 52.13% and 65.91%, respectively. The results also indicated that applying biochar at 2.5% and 5% by weight per pot increased water use efficiency compared to no biochar application. Based on the above results, it can be concluded that the savory plant was sensitive to drought stress, and deficit irrigation would lead to a reduction in yield in this plant. Furthermore, based on the results of this research, the partial root-zone drying (PRD) method was identified as a more suitable method than deficit irrigation (DI) in terms of increasing water use efficiency, elemental concentration, and essential oil percentage in Satureja hortensis L.