Science & HealthThe Soil Cannabis Is Grown In Affects THC, CBD And Terpene Levels, Federally Funded Study Shows

OG Article By Aaron Houston

October 10 2025

Study Overview

A federally funded study shows soil composition affects cannabis compounds.Funded by USDA, Penn State, and PA Options for Wellness.Published in the Journal of Medicinally Active Plants.

Key Findings

Soil health shapes cannabinoid and terpene levels.Poor soil increases THC production.Better soil boosts CBG, a precursor cannabinoid.Farmers can adjust soil to control cannabinoid profiles.

Experiment Design

Compared two cannabis cultivars: Tangerine and CBD Stem Cell.Grown in cover crop (CC) and conventional tillage (CF) fields.Fields were adjacent, with identical growing conditions.

Results

• Tangerine: CBD 1.5x higher in CF soil.

• CBD Stem Cell: CBD doubled in CC soil.

• CBG: 3.7x higher in CC-grown plants.

• THC: Up to 6x higher in CF-grown Tangerine.

• Cannabidiolic acid: Over 6x higher in CF fields.

Soil Health

Soil is an ecosystem of microbes, fungi, and minerals.Cover cropping and no-till farming enhance biological activity.These practices improve nutrient cycling and carbon retention.Soil biology influences plant defense and communication compounds.

Implications

Cover crops may reduce terpene differences across cultivars.Soil management impacts cannabinoid production beyond genetics.More research needed on enzymes converting CBG to CBD, THC, and CBC.

Broader Context

First study on soil’s effect on outdoor cannabis extracts.Builds on research into cannabis drying, terpenes, and trichomes.Supports efforts to optimize cannabis cultivation practices.