The Effect of Winter Sowing, Chemical, and Nano-Fertilizer Sources on Oil Content and Fatty Acids of Dragon’s Head (Lallemantia iberica Fischer & C.A. Meyrefeer)

Dragon’s head is a multifunctional plant with diverse applications so that all its parts, including its leaves and seeds, have nutritional value. For the sake of appropriate agricultural management to enhance plant quality and quantity, the effects of sowing season and chemical—nano-fertilizer sources were explored on plant oil content and fatty acid compositions in a factorial experiment based on a randomized complete block design with 12 treatments and 3 replications. The treatments included two sowing seasons (spring and winter) and six fertilizer treatments (control, NPK soil , NPK nano , chelated-Fe nano , NPK nano + chelated-Fe nano , NPK soil + NPK nano + chelated-Fe nano ). The studied traits included grain yield, oil percentage and yield, unsaturated fatty acids (linolenic, linoleic, and oleic acids), and saturated fatty acids (stearic and palmitic acids). The results showed that the interactive effects of sowing season (winter) and NPK nano + chelated-Fe nano were significant on the grain yield. Moreover, the simple effects of winter sowing and NPK soil , NPK nano , chelated-Fe nano treatments showed the highest oil percentage and yield among which NPK soil + NPK nano + chelated-Fe nano and NPK nano + chelated-Fe nano had similar effects, so regarding these traits, it is recommended to exclude NPK soil from the fertilizer combination. However, the treatment of NPK soil + NPK nano + chelated-Fe nano performed well in enhancing unsaturated fatty acids as an advantage of this fertilizer combination. In general, the combined use of the growing season and nano-fertilizer is recommended to increase the quantity and quality of plants, which is consistent with the goals of sustainable agriculture as well.