Effect of Different Fertilizers on Growth Parameters and Essential Oil Chemical Composition of Satureja Hortensis L. and Ocimum × Citriodorum

This study investigated the effects of organic, chemical, and bio-fertilizers, on the growth and essential oil characteristics of Satureja hortensis (Summer savory) and Ocimum × citriodorum (Lemon basil). Experiments were conducted over two seasons (2020-2021 and 2021-2022) with three replicates for each species revealing diverse plant responses. Integrated Nutrient Management (INM), especially the combination of compost with biofertilizers and cyanobacteria, generally improved morphological traits such as plant height (21.3%, Satureja hortensis), while compost increased leaf area by 50.7%, for both herbs, compared to control. Similarly, compost resulted in the highest significant increase in fresh (13 and 18.3%) and dry weights (10.4 and 17.7%), and herb yield (80.6 and 417 %) for Ocimum × citriodorum and Satureja hortensis, respectively. While chemical fertilizers provided immediate growth benefits, the use of organic amendments like compost consistently enhanced soil health characteristics and supported sustainable biomass production. The type of fertilization used showed a significant impact on essential oil content and chemical profiles. Notably, compost and biofertilizers increased key essential oil compounds by 41.2% and 110%, respectively, compared to control, including citral, carveol, and caryophyllene oxide, which are valuable for plants’ therapeutic properties. These findings highlight INM's potential through T7 which combines compost, biofertilizers and cyanobacteria to optimize medicinal plant production, promote sustainable agricultural practices, and enhance the value of essential oils.