The alternative uses of hemp continue to amaze us day after day: the CBD extracted from its fibers has a muscle relaxant , anxiolytic and anticonvulsant effect and can be used to fight acne and many other sensitive skin problems; its fiber is a precious and resistant raw material ; Seeds and hemp flour-based food products contain omega-3 , vitamins and many other substances that are fundamental for the body.
But it didn't end here. Scientists continue to test the infinite potential of this plant and, recently, another very important use of hemp has been identified. According to scientific studies, hemp has the power to purify the land on which it is planted . Phytoremediation , i.e. the absorption or degradation of the contaminant through the action of plants, is a remediation technique suitable in case of contamination by heavy metals and dioxins .
There are many plants capable of phytopurifying the soil, but Cannabis seems to be - once again - the best choice. Hemp, as widely documented in the scientific literature, is capable of absorbing heavy metals effectively and - unlike hyper-accumulating plants, which have a very modest vegetative development - can be used in various compatible fields, mainly for some industrial uses and for energy production.
What makes hemp the perfect plant for photopurification?
Hemp is a bioaccumulator , that is, it is a plant capable of storing heavy metals present in the soil within it without compromising its growth.
One of the characterizing biological aspects of hemp is the presence of a very developed and deep root system , associated with a broad absorption capacity. It is precisely the roots of the hemp plant that make it optimal for reclaiming polluted land, precisely because it absorbs many more substances than other plant species. Different international studies show that the plant is capable of accumulating nickel, lead and cadmium in the leaves and not in the fibre .
Hemp shows a high potential in the accumulation of copper, which is efficiently transferred from the roots to the shoot, while it is not absorbed by the fibre, which is thus marketable.
A study conducted in Hawaii ( Kolosov CA Evaluating the public interest: regulation of industrial hemp under the controlled substances act. UCLA Law Review) revealed that hemp is able to lower the concentration of organic pollutants, especially hydrocarbons present in many industrial sites .
Industrial hemp is therefore an ideal candidate if you want to combine a profit crop with the remediation of land contaminated by heavy metals because it accumulates high concentrations of such metals especially in the leaves while showing relatively low levels of the same in the fibre; the fiber derived from plants used for phytopurification can be used for the production of composite materials or the entire plant can be used for the production of energy in thermal power plants.
In summary, hemp is perfect for reclaiming land because:
- grows in a wide range of climatic conditions ;
- tolerates high concentrations of heavy metals ;
- it has deep roots , about one metre, and is sown with high densities, so it can reclaim a considerable volume of land in one season;
- in some cases the contaminants remain mainly in the root, so the oil can be used to produce biodiesel while the fibers can be used to produce paper ;
- it has proven effective for absorbing cesium radioisotopes (Cs 137), which remains incorporated into the roots and does not affect the quality of the fibers or oil;
- benzo [α]pyrene (carcinogenic and mutagenic for animals in general) and chrysene (irritant in contact with the skin, carcinogenic in case of prolonged exposure), appear to be growth stimulators for hemp , which seems to be capable of metabolizing them in some way;
- hemp cultivation is among those with the lowest greenhouse gas emissions per unit of biomass produced.
How do I grow industrial hemp?
Until the 1970s, Italy was the second largest producer of industrial hemp in the world, after the Soviet Union, and was the largest supplier to the English navy. Until that moment, cannabis was tolerated in Italy , also because there was no law prohibiting it. It was even smoked as a replacement for tobacco, which was more expensive than weed at the time, but when – in the 1960s and 1960s – it became the symbol of rebellious youth, the government felt the need for a crackdown. Thus it was included in the list of psychotropic substances and was eliminated whenever it was used.
Something changed in 2016. The cultivation of hemp has become legal again thanks to law 242/2016 , on its cultivation and supply chain. To better understand the topic, the initial passage to article 1 of the law is decisive, which speaks of hemp as a "crop capable of contributing to the reduction of the environmental impact in agriculture, the reduction of land consumption and desertification and the loss of biodiversity, as well as as a crop to be used as a possible replacement for surplus crops and as a rotation crop" . Law 242/2016 allows the cultivation and sale of hemp-based products, inflorescences with THC levels lower than 0.2%, and plants to produce industrial fibre.
Thanks to law 242/2016, no authorization is no longer necessary for the sowing of certified hemp varieties with a THC content of up to 0.2%. Notifying the police is no longer necessary. The only obligations for the grower are to keep the tags of the seed purchased for a period of no less than twelve months and to keep the purchase invoices of the seed for the period required by current legislation.
The seeds must be certified varieties that have a maximum of 0.2% THC. Currently, Carmagnola, Fibranova and Eletta Campana would be available as Italian varieties , but it is also possible to import seeds from France, Germany or Eastern Europe . The percentage of THC in the plants analyzed can vary from 0.2% to 0.6% without causing any problems for the farmer. Any checks will be carried out by a single person and always in the presence of the grower, and the inspectors are required to release a sample taken for any counter-checks.
In the event that the percentage of THC exceeds the threshold of 0.6%, the judicial authority can order the seizure or destruction of the cultivation, but even in this case "the farmer's responsibility is excluded".
A direct experience
Unfortunately, Italy is full of polluted land awaiting reclamation . The procedures are often long and complex and, sometimes, those who live from agriculture and livestock risk losing everything. This is what happened in 2008 to Vincenzo Fornaro , a farmer from Taranto, forced to cull his two thousand sheep due to dioxin contamination. Vincenzo had his business in an area not far from the ILVA industrial center and, almost certainly, it was the dioxin released by the steel plant that contaminated his land.
The entire business, carried on by his family for over a century, had gone up in smoke in an instant. But Vincenzo didn't give up and decided to try another way: he planted hemp in three hectares of his land, taking advantage of the phytodegradation process .
The same path was taken by other farmers in the province of Brindisi, whose lands are located near the Punta della Contessa natural park, close to the Enel power plant in Cerano and the petrochemical hub, an area with a very high rate of environmental pollution.
Here, Tommaso Picella, 70 years old, and his 34 year old nephew Andrea Sylos Calò, have decided to convert their business into a hemp plantation intended for the creation of textile fibers or for construction. A choice made to avoid the death of a land whose contamination has made it unusable for food purposes.
