Effects of vermicompost and humic acid application on the uptake of macro-elements, seed, and essential oil yield of cumin (Cuminum cyminum L.)

To study the effects of different levels of vermicompost and humic acid on the seed macro-elements uptake, seed yield, and essential oil of cumin (Cuminum cyminum L.), an experiment was conducted in a field located in Mobarakeh city as factorial based on a randomized complete block design with three replications during the growing season 2016-2017. Experimental treatments included vermicompost at three levels (0, 5 and 10 ton ha-1) and foliar application of humic acid at four levels (0, 2, 4 and 6 lit ha-1). The results showed that the application of 10 ton ha-1vermicompost increased the essential oil yield and seed phosphorus content by 86.7 and 33% as compared to control, respectively. The foliar application of 4 lit ha-1 humic acid along with 0, 5, and 10 ton ha-1vermicompost application increased the seed potassium content by 27.8, 9.6, and 9.2% as compared to control, respectively. The highest percentage of seed nitrogen was observed in the combined application of humic acid at 4 lit ha-1 and vermicompost at 10 ton ha-1, which was 11.7% more than control. The foliar spray of 4 and 6 lit ha-1 humic acid at 10 ton ha-1 vermicompost increased seed yield by 11.1 and 9.9% as compared to control, respectively. The combined use of humic acid and vermicompost could meet the nutritional needs of cumin and could be considered as an effective step towards achieving sustainable agriculture goals while increasing quantitative and qualitative performance.