Co-composted biochar (Combi) production and its effects on ocimum basilicum plants growth

In agriculture, in recent years, more and more attention has been given to the COMBI. COMBI is a soil improver obtained from a composting process of organic material with biochar, added at the beginning of the process itself. Biochar has been used for several years and many studies have shown the benefits it brings when applied to soils, while COMBI is still little studied. This article aims to demonstrate both the effects of COMBI on the growth of Ocimum basilicum specie plants and to quantify the best quantity to be applied within the substrate. The experimental trials were performed in a greenhouse with controlled temperature and humidity, according to the following growth tests theses: Control: Soil for gardens composed mainly of peat (CTRL); thesis 1: Soil mixed with COMBI at 10% v/v (COMBI10); thesis 2: Soil mixed with COMBI at 20% v/v (COMBI20); thesis 3: Soil mixed with COMBI at 40% v/v (COMBI40); thesis 4: Soil mixed with COMBI at 80% v/v (COMBI80); thesis 5: 100% COMBI (COMBI100). The results showed good growth of basil plants in the COMBI10 and COMBI20 cases, compared to the control. COMBI80 and COMBI100 theses, on the other hand, did not lead to positive results; in particular COMBI100 did not allow either seeds germination in most cases. To compare the quality of the basil plants, the total amount of essential oil for CTRL, COMBI10, COMBI20 and COMBI 40 theses was extracted and quantified.