Hemp absorbs carbon 3-5 times better than conifers, biologists have found

Experts believe that the plant is promising for cultivation in the Urals.
Industrial hemp binds carbon dioxide better than many agricultural crops, and 3-5 times more than coniferous plants per 1 gram of photosynthetic tissue mass, specialists from the Ural Federal University and colleagues from the Ural Federal University found out State Agrarian University. Scientists believe that industrial hemp is the optimal plant for growing in the Urals: it is unpretentious to climate and soil, grows quickly, effectively “seals” carbon dioxide and is a potential raw material for many products.
“We conducted an experiment - we planted the first plants on a carbon farm: five varieties of industrial hemp, which does not contain narcotic substances. These varieties were selected by breeders and officially approved for cultivation in the Russian Federation and included in Rosreestr. From the point of view of the growing season, we started a little late (we planted hemp in the summer, not in the spring), but from the point of view of experimentation and development of the methodology, this is a big start. In addition, we were lucky with the weather, and by October the plants had reached the flowering stage and milky ripeness. In general, in three months the height of the hemp reached more than two meters,” says Mikhail Karpukhin, Vice-Rector for Research and Innovation at USAU.
The ability of hemp to absorb carbon dioxide from the atmosphere was studied using an infrared gas analyzer. The first results of data processing showed that industrial hemp stores carbon dioxide and carbon in biomass very well.
“Hemp leaves have a high rate of photosynthesis - higher than many agricultural crops - up to 70-80 micromoles of CO2 per 1 m2 of leaf surface per second, which is 3-5 times higher than coniferous woody plants. This is more than 100 liters of pure CO2 absorbed by 1 m2 of leaves during the growing season. At the same time, industrial hemp plants can grow on 1 m2 of soil, which in total in the middle of the season will form a leaf surface of more than 2-3 m2,” explains Irina Kiseleva, HEAD of the Department of Experimental Biology and Biotechnology at UrFU.
The process of photosynthesis produces organic matter. Part of this substance - mobile fractions: simple carbohydrates, amino acids, proteins - is used in the metabolism of the plant itself. And part of the products of photosynthesis goes into the formation of complex substances - cellulose, lignin - which are not metabolized by the plant itself, but are stored for a long time in tissues.
“The first substances quickly enter during plant respiration and decompose with the release of carbon dioxide, while the second “seal” carbon. So, according to preliminary estimates, in hemp, less than 1/3 of the carbon is exhaled back and 2/3 is stored in the form of difficult to decompose substances,” adds Irina Kiseleva.
Industrial hemp is a plant suitable for growing in the Urals, experts believe. Firstly, it is unpretentious - it adapts to the Ural climate and soil. Secondly, it grows quickly, produces good biomass and effectively stores carbon. Thirdly, today more than 2.5 thousand products have been invented that can be produced from hemp.
“Hemp biomass can be used to create long-term carbon storage products and can be used to create all kinds of things. It is widely known that military uniforms for the Chinese army are made from fabrics using hemp fiber in the same way as banknotes. Hemp stems are traditionally used to make ropes and ropes. They can also be used to create chipboard. Hemp is also used to make pressed biomass, which resembles plastic in its properties. The plant can be used to make environmentally friendly dishes, such as wood fiber or bamboo. In general, they can be used in completely different ways,” lists Irina Kiseleva.
UrFU biologists consider hemp as the basis for biochar - environmentally friendly charcoal for enriching soil and growing crops. In this way, the carbon accumulated in hemp can be stored in the soil for a long time.
“Our goal—both for science and for business partners—is to develop a carbon-negative farming system: select productive plants that effectively absorb carbon and replace certain crops that are not carbon-negative,” adds Mikhail Karpukhin. “So next year we plan to plant hemp in the spring. We also want to compare it with other tall crops: corn, sunflower, oilseed flax. We will share the data we receive with regions with similar climate and soil.”

Information
Scientists are studying the properties of industrial hemp as part of the project - the Ural-Carbon carbon test site. Scientists are studying dark-coniferous and light-coniferous forests and other natural communities for their ability to sequester carbon. To enhance the process of carbon sequestration from the atmosphere, plants with the greatest potential are selected. Planting such plants, among other measures, will help not only achieve carbon neutrality, but also sell greenhouse gas emissions credits.
In February 2021, the Russian Ministry of Education and Science launched a pilot project to create carbon testing sites in the regions of the country for the development and testing of carbon balance control technologies. In the fall, the Ural-Carbon carbon testing site in the Sverdlovsk region became one of the first testing sites launched in the country. Also, one of the first sites were created in the Chechen Republic, Krasnodar Territory, Kaliningrad, Novosibirsk, Sakhalin and Tyumen regions.
The Ural-Carbon test site is represented by taiga forests, since forest lands make up 70% of the territory of the Sverdlovsk region, and the taiga is one of the most significant reservoirs of carbon flow from the atmosphere due to photosynthesis and its long-term storage. Research sites are the Kourovsky Astronomical Observatory of UrFU and the Ural Training and Experimental Forestry Enterprise of the Ural State Forestry University. The project also involves the Ural State Agrarian University, the Ural State Mining University, the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences, the Institute of Industrial Ecology of the Ural Branch of the Russian Academy of Sciences, the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences and the Botanical Garden of the Ural Branch of the Russian Academy of Sciences.

Source: Press service of the Federal State Budgetary Educational Institution of Higher Education Ural State Agrarian University