While the Phyto-mediating properties of hemp are well known, a recent study shows that in addition to decontaminating soils, hemp grown on toxic soil produces more CBD without increasing its THC levels.
Toxic soil produces clean hemp flowers
The study draws several interesting conclusions for hemp growers.
On the one hand, cannabinoid production can be “remarkably influenced by the soil conditions of mining land”, representing a new and potentially lucrative opportunity for hemp farmers looking for available land, for example in northern France. Hemp removes some of the toxic heavy metals present in the soil while producing more CBD than hemp is grown in clean soil.
On the other hand, the heavy metals absorbed by hemp plants were found in the leaves of the plants, but not in the flowers, as confirmed by one of the researchers.
“We saw metal uptake in the leaves and removal from the soil, but not in the flowers,” said Sairam Rudrabhatla, a professor of biology at Pennsylvania State University-Harrisburg and one of the study’s lead authors.
The details of the flower analysis were not published in the study. But when the buds were tested for heavy metals, “none were present,” as confirmed by Hannah George, director of the Penn State Central Pennsylvania Research.
In this study, 6 different varieties of industrial hemp (Fedora 17, Felina 32, Ferimon, Futura 75, Santhica 27 and USO 31) were grown on two different types of contaminated soils and two commercial soils (Miracle-Gro Potting Mix and PRO-MIX HP Mycorrhizae High Porosity Grower Mix).
The plants were exposed to two different environmental conditions, outdoor and greenhouse. On average, the height of the plants grown in the greenhouse exceeded that of the plants grown outdoors.
Besides, an analysis of heavy metals (arsenic, lead, nickel, mercury, and cadmium) was conducted. The concentration of nickel was 2.54 times higher in hemp leaves grown in the soil of outdoor mines compared to those grown in greenhouses.
Analysis of hemp flowers grown in the mining soil showed a significant increase in total cannabidiol content (2.16%, 2.58%) compared to the Miracle-Gro control soil (1.08%, 1.6%) in outdoor and greenhouse soil, respectively. Molecular analysis indicated an 18-fold increase in the expression of the cannabidiolic acid synthase gene in plants grown on the mine soil.
“This is very remarkable,” said Rudrabhatla. “Few plants can maintain this level of nickel, arsenic and so many toxins. It’s a remarkable plant with many properties. »