The cultivation and production of hemp are increasing in Europe, following the return of the use of this plant in the industry, but also the explosion of the cannabinoid market.
The CBD levels of the hemp sources used vary greatly, depending of course on their origin, but also on their modes and means of cultivation.
Hemp and contaminated soil
Following a study done (available by clicking here) in the United States at Penn State Harrisburg in Middletown, a new, little-known factor also appears to impact the cannabinoid rate of harvested flowers.
Industrial activities harm the environment and health when high concentrations of pollutants are released.
In fact,Phytoremediation is a natural method of using plants to remove soil contaminants. The purpose of this study was to investigate the ability of Cannabis sativa L. to sustainably cultivate and remediate coal mine soils in Pennsylvania.
6 different varieties of industrial hemp (Fedora 17, Felina 32, Ferimon, Futura 75, Santhica 27 and USO 31) were grown on 2 types of contaminated soils and 2 commercial soils (Miracle-Gro Potting Mix and PRO-MIXING of the blend for cultivator with high porosity HP Mycorrhizae).
Also,Plants growing in all soil types have been exposed to 2 environmental conditions (outdoors and in the greenhouse). Seed germination response and plant height showed no significant difference between all varieties of hemp grown in different soils.
CBD and hemp
However, on average, the height of plants grown in the greenhouse was higher than that of plants grown outdoors. Also, a heavy metals analysis of arsenic, lead, nickel, mercury, and cadmium was conducted.
Thus, the researchers demonstrated that these 6 different varieties of industrial hemp produced higher concentrations of CBD on soils contaminated with lead, nickel, mercury, and cadmium (between 2.2 and 2.6%) compared to a normal soil (between 1.1 and 1.6% CBD).
In fact, the analysis of secondary metabolites of hemp flower buds grown in mineral soils showed a significant increase in the total content of cannabidiol (2.16%, 2.58%) compared to the control soil Miracle-Gro (1.08%, 1.6%) for outdoors and in greenhouses., respectively.
Molecular analysis using qRT-PCR revealed an 18-fold increase in expression of the cannabidiolic synthase acid gene in plants grown on the mine floor.
The nickel concentration was 2.54 times higher in hemp leaves grown outdoors in mine soils than in greenhouse conditions.
The authors concluded that the data indicated a high tolerance to heavy metals, as indicated by physiological analysis and metabolites