Effects of plant nutrition on economic yield and essential oil composition of Nigella sativa L.

To investigate the effects of soil fertility methods on economic yield and essential oil compositions of Nigella sativa L., an experiment was conducted in a randomized complete block design with three replications. Experimental treatments included different levels of NPK chemical fertilizer, manure, NPK+ manure, and NPK+ manure+ inoculation of Azorizobium biofertilizer. Seed yield, aerial parts yield, and percentage, yield, and essential oil compounds were studied. The results showed that the highest seed yield (1270.43 kg.ha-1) was obtained in the 40 kg.ha-1 N+ 32 kg.ha-1 P+ 40 kg.ha-1 K+ 30 ton.ha-1 manure treatment. The highest percentage (0.25%) and essential oil yield (2.8 kg.ha-1) was obtained in the 40 kg.ha-1 N+ 32 kg.ha-1 P+ 40 kg.ha-1 K+ 30 ton.ha-1 manure+ Azurizobium treatment. The highest thymoquinone percentage (14.9%) was observed in the 30 ton.ha-1 manure treatment. Overall, the integrated and biological treatments had the most positive effects on seed yield and essential oil percentage of N. sativa. The use of suitable fertilizer sources not only increased the yield, essential oil percentage, and thymoquinone content in Nigella sativa, but also reduced the consequences of excessive use of chemical fertilizers. The use of integrated fertilization methods is an effective step to achieve the sustainable agriculture goals.