Application of zeolite improves water and nitrogen use efficiency while increasing essential oil yield and quality of Salvia officinalis under water-deficit stress

Soil moisture and nitrogen (N) are two of the most important factors affecting the production of medicinal plants. So, the management strategy of these factors is critical and to be identified. In order to study the application of zeolite (Z) (0 and 10 ton ha⁻¹) in S. officinalis culture medium under different irrigation regimes (30 % depletion of available soil water (ASW)) and 60 % depletion of ASW) and N (0, 75 and 150 kg N ha⁻¹) a split-factorial experiment was carried out with three replicates in 2018. The highest fresh and dry weight were achieved at irrigation after 30 % depletion of ASW while using 150 kg N ha⁻¹ and 10 ton Z ha⁻¹. Maximum water use efficiency (WUE) (22.10 g.L^-1) was obtained after 60 % depletion of ASW and 150 kg N ha⁻¹ and 10 ton Z ha⁻¹. Besides, the maximum nitrogen use efficiency (NUE) was obtained after 60 % depletion of ASW and 75 kg N ha⁻¹ and 10 ton Z ha⁻¹ (14.25 kg.kg^-1N). Maximum essential oil (EO) content (1.06%) and cis-Thujone were obtained from plants subjected to 60 % depletion of ASW and, application of 75 kg N ha⁻¹ and 10 ton Z ha⁻¹. Applying Z with N, in different irrigation regimes did improve soil conditions for achieving higher, WUE and NUE, increased the EO content and yield while decreasing the negative effects from water-deficit stress and has provided a direction towards a stable system.Keyword: Essential oil, Nitrogen use efficiency, S. officinalis, Zeolite, Water use efficiency