The effects of microbial inoculation and intercropping on yield and active ingredients of savory (Satureja hortensis L.) intercropped with common bean (Phaseolus vulgaris L.)

The study was aimed to investigate the effects of bacterial fertilizer (BF) application and planting patterns on quantitative and qualitative yield of savory intercropped with common bean. An experiment was performed using a factorial based on randomized complete block design (RCBD) with three replications. The factors included microbial inoculation (mix of nitrogen-fixing + phosphate-solubilizing + potassium-solubilizing bacteria and non-inoculation), and planting patterns [one row of savory + one row of common bean (1S:1CB), two rows of common bean + two rows of savory (2S:2CB), two rows of savory + one row of common bean (2S:1CB), one row of savory + two rows of common bean (1S:2CB), as well as the pure culture of both plants]. The results showed that the seed yield of common bean and dry matter yield of savory was recorded in pure culture conditions treated with BF. The 2CB:2S intercropping pattern with BF fertilization produced the highest essential oil (EO) content of savory (1.96%). In addition, the application of BF enhanced the EO yield of savory by 35% compared to control. The major constituents of savory EO were carvacrol, gamma-terpinene, alpha-terpinene, p-cymene, and beta-myrcene. The 2CB:1S intercropping pattern with BF fertilization produced the maximum content of carvacrol and p- cymene. The maximum content of phenolic compounds including rosmarinic acid, coumaric acid, chlorogenic acid, cinnamic acid, and apigenin was recorded in the intercropping pattern of 2CB:2S treated with BF. Overall, intercropping pattern of 2CB:2S treated with BF could be recommended to farmers as eco-friendly strategies to improve EO quality and quantity as well as phenolic compounds.

Automated summary

The study investigated the effects of bacterial fertilizer application and planting patterns on the yield and quality of savory intercropped with common bean. The results showed that the application of bacterial fertilizer increased the seed yield of common bean and the dry matter yield of savory. The intercropping pattern of 2CB:2S with bacterial fertilizer produced the highest essential oil content of savory. Additionally, the application of bacterial fertilizer enhanced the essential oil yield of savory and the content of phenolic compounds.