Combination of humic biostimulants with a microbial inoculum improves lettuce productivity, nutrient uptake, and primary and secondary metabolism

Abstract Background and aims Biostimulants of natural origin represent a growing ecological strategy to increase crops productivity, especially when applied in combination with microbial bioeffectors. We studied the effect biostimulants such as Potassium Humates (KH) from Leonardite Compost Tea (CT) green compost on both productivity nutritional status lettuce plants, well primary secondary metabolism treated amended either alone or commercial inoculum (M+), mainly based arbuscular mycorrhizal fungi (Micosat TabPlus). Results The biomass production uptake macro- micronutrients by plants significantly increased mixture humic materials (MIX) combined inoculum. Similarly, synergic MIX_M+ treatment affected more than their individual applications, increasing, respectively, biosynthesis essential amino acids carbohydrates, that antioxidant polyphenolic compounds, hydroxycinnamic acids, flavonols coumarins. Conclusions Our findings suggest calibrated bioactive molecules consortia represents potential tool improve crop its metabolic status.