From capturing CO2 to regenerating soils and enhancing biodiversity, hemp farming offers multiple environmental benefits that help mitigating the effects of climate change and restoring healthy ecosystems.
Hemp captures carbon
If used as an alternative to carbon-based raw materials, hemp would allow us to capture and store a substantial amount of CO2. Through photosynthesis, hemp plants have the ability to store considerable amounts of carbon in both the stems and the roots. Hemp grows rapidly (4 to 5 months), is tall (up to 5 meters) and deep rooted into the ground (up to 3 meters), making it the perfect crop for storing carbon.
But how much carbon can be stored?
One tonne of harvested hemp stem contains 0.7 tonnes of cellulose (45% carbon), 0.22 tonnes of hemicellulose (48% carbon) and 0.06 tonnes of lignin (40% carbon). Consequently, every tonne of industrial hemp stems contains 0.445 tonnes carbon absorbed from the atmosphere (44.46% of stem dry weight). Converting carbon to CO2 (12 t of C equals 44 t of CO2), this represents 1.6 tonnes of CO2 absorption per tonne of hemp. On a land use basis, using a yield average of 5.5 to 8 t/ha, this represents 9 to 13 tonnes of CO2 absorption per hectare harvested.
Hemp regenerates and improves the quality of our soils
Being a fast-growing crop and having a high leaf turnover rate, hemp can, if grown in ideal conditions, fully cover the ground three weeks post-germination. The dense leaves rapidly form a natural soil cover material that reduces water loss and soil erosion. In addition, fallen leaves provide vital nutrition for the soil. Moreover, because of its height and shading capacity hemp efficiently eliminates weeds, leaving the soil in optimum condition.
Hemp can also be used with great efficiency in land reclamation. In fact, it is considered as an optimal pioneer crop, notably because of its phytoremediation capacity, meaning the ability to remove heavy metals from the ground.
To sum up, hemp has very positive effects on soil health because it stabilises erosion, adds nutrients to the soil, naturally removes heavy metals and increases the yield of subsequent crops.
Hemp enhances biodiversity
Hemp produces pollen for bees and other pollinators in a period of floral scarcity and nutritious seeds for wild birds.
The flowering cycle usually occurs between July and September, coinciding with a lack of pollen production from other farm crops. Being a wind pollinated, dioecious and staminate plant, cannabis produces large amounts of pollen, a vital nutritional source for bees during periods of floral scarcity.
Hemp promotes sustainable farming
Hemp farming requires very low or no inputs. Due to a lack of natural predator insects, insecticides can be avoided as hemp is susceptible to few serious pests and is usually cultivated without, or with very little need for chemical treatments, such as herbicides.
Moreover, its processing generates zero waste: all parts of hemp, from the roots to the flowers, can be used or further transformed! That is why, the real added value of industrial hemp is its ability to produce different products with one crop: food, feed, cosmetics, biomaterials, energy while achieving positive environmental externalities with one rotational crop.
Hemp saves water
Studies have shown that hemp is more ecologically neutral than other fibres, particularly in water usage. As an example, cotton requires 9,758 kg of water per kg while hemp needs between 2,401 and 3,401 kg of water per kg. This represents a 75% water saving.
Hemp helps reducing deforestation
Hemp is a good and sustainable source of cellulose for paper making that could help reducing deforestation.
Today, approximately 80% of hemp paper produced is used for cigarette papers and other specific applications, but it has the potential to be used more widely as heavy-duty cardboard, food packaging, sanitary papers and also for filtration and absorption purposes.
Mature hemp stalks are rich in cellulose: they contain around 65-70% cellulose (wood contains around 40%, flax 65-75% and cotton up to 90%), and they only take 5 months to mature. This high cellulose content coupled with the fast growth of hemp stalks – only few months, compared to years for forest wood – in an industrial setting typically yields a pulp production up to 4 times that of a mature tree plantation, on a hectare basis.
Furthermore, hemp paper can be recycled 7-8 times, compared with only 3-5 times for wood pulp paper!