The advent of modern technology and the industrialization of agriculture has allowed humans a life of convenience and comfort, but the result is at the cost of a degraded environment. We have been deforesting, ploughing, and eroding our soils in the name of agriculture; we have also been harming our landscapes with mines, fossil fuel extraction, and using them as waste dump sites. This destructive behavior towards our environment has led to depleted soils and excessive carbon in our atmosphere, among other gases. Our soils are in great need of our attention and care because they can be rescued. There is hope on the horizon because we now know more about soil ecology and its role in the health of our environment. Gathering knowledge about our soils is an important step to combat these challenges. There are many ways to improve soil health, but the focus for this blog will center specifically on implementing hemp as an economic, safe, and natural way to restore soils through carbon sequestration and phytoremediation.
The topsoil layer hosts the most biological activity and the most organic material, which allows for crops and plants to prosper
The Important Role of Soil
Soil is teeming with life, from the microscopic life forms to the macroscopic organisms that we can readily see. Most people tend not to think of soil as being an incredible source of biodiversity; if one were to take a small sample of earth, it would contain 15,000 species of bacteria alone which does not factor in other larger organisms (Center for Food Safety. n.d.). The soil consists of minerals, organic material, water, and air. These are necessary components for plant health and growth. The process of soil formation is very complex and involves a number of different elements such as rain, wind, and temperature shifts that break down rock into smaller particles (Bell, Sullivan, Brewer, & Hart, 2003). Soils always need soil organisms because they generate soil formation. These soil entities include microscopic organisms (e.g. fungi) and larger creatures such as ants and earthworms. Soil formation is important because it creates diverse layers, some of which are crucial for humans. The topsoil layer hosts the most biological activity and the most organic material, which allows for crops and plants to prosper (Bell, Sullivan, Brewer, & Hart, 2003).
The importance of soil is indescribable. Soil performs many functions that provide the ability to sustain life on earth. These include services such as nutrient cycling, water cycling, providing habitats and biodiversity, water filtration, and lastly it supports us with physical stability (Soil Quality for Environmental Health, 2011). Simply put, plants, animals, and humans rely on the soil for providing the structure on which we live, for supplying us food, and perpetuating the natural cycles on earth. Soil also has the dynamic role of sequestering atmospheric carbon, which is an important part of the soil cycle, a fact that scientists have recently discovered. According to the Center for Food Safety, “cultivated soils globally have lost 50-70% of their original carbon content” (2015). There is an opportunity to restore soil carbon levels where it will perpetuate healthy water and nutrient cycles for food and water security.
The focus for this blog will center specifically on implementing hemp as an economic, safe, and natural way to restore soils through carbon sequestration and phytoremediation.
Our planet is facing a climate crisis. Due to human activities that have disrupted the carbon cycle such as the burning of fossil fuels, deforestation, and constant tilling, we are now experiencing an excess of carbon dioxide in our atmosphere (Center for Food Safety, 2015). The carbon cycle refers to the movement of carbon throughout the environment, cycling between a liquid, solid, or a gas. The methods of industrial farming do not promote carbon storage which is evident by the commonly held practices of ploughing and clearing of the forest. However, we can improve how we grow our food without harming the environment, since it “is estimated that as much as one-third of the surplus CO2 in the atmosphere that’s causing climate change has come from agricultural and land management practices” (Marin Carbon Project, n.d.).
As a result of studying the impacts of industrial agriculture and examining what constitutes soil health has helped create the practice termed carbon farming; one approach to restore our soil. It is a technique to “improve the rate at which CO2 is removed from the atmosphere and converted to plant material and soil organic matter” (Marin Carbon Project, n.d.). By cutting down on our dependence on fossil fuels, implementing other regenerative practices for the soil, and cultivating diverse woody perennials and annuals shows how successful we can be at sequestering carbon.
A successful crop that can be utilized in carbon farming is hemp. The fact that hemp grows quickly in a season, can grow in many regions, and its biomass contains a very woody stem and core makes it an excellent option for capturing carbon dioxide. An additional bonus is being able to transform the crop into many goods like paper products and textiles which take pressure off of forests and fiber crops respectively. This allows trees to maintain their carbon dioxide uptake and reduces the need to rely on cotton production which will avoid chemicals and high water inputs. As a result of not needing to manage industrial hemp crops too much, cultivating hemp can be below the average in carbon emissions (Vosper, n.d.).
Phytoremediation refers to the process when plants and soil microbes are used to clean up sites of contamination, toxic spills, and leaks caused by anthropogenic activities (human activities that affect the environment). There are different methods of phytoremediation and it is considered to be accepted as an economically viable method for environmental restoration (Greipsson, 2011). Phytoremediation can be broken down into different processes such as phytostabilization, phytodegradation, phytovolatilization, and phytoextraction. Simply put, the phytostabilization process refers to the ability of certain plants that can absorb and contain toxins within their root system, which helps to prevent the spread of these contaminants. Phytodegradation uses plants that can take up contaminants through their roots and then metabolize them into less toxic substances. Phytovolatilization refers to the process of converting contaminants inside plants into a gaseous state which is then released into the atmosphere. Lastly, phytoextraction utilizes plants that have an accumulative trait to take up toxins from the soil and then stores them into the plant tissues, which can be used as harvestable biomass in certain plants. These natural technologies can be implemented all over the world. It is important to note that these methods take time to remediate contaminated sites, but these methods will leave the surrounding landscape markedly improved as time goes on.
The role of hemp within phytoremediation is relatively well-known at this point. Hemp has the natural ability to take up substances from its surrounding environment. It is believed to be better at cleaning up heavy metals than radioactive substances (Colbert, 2018). Even though heavy metals are naturally occurring elements widely distributed, our human activity has increased the prevalence of these substances due to our agricultural and industrial activities (DalCorso, 2019).
Industrial hemp is a fast growing annual that requires very little inputs in terms of nutrients, water, and pesticides, which makes it an excellent candidate for phytoremediation. When hemp is intentionally planted at sites of heavy metal deposits, it does extremely well functioning as a phytoextractor, where it takes up the various toxic metals through its root system and stores it in its above ground tissues. Therefore, the plants can be harvested annually in order to remove the heavy metal concentration in the soil. Over time the concentration will decrease and the soil will be improved as time goes on. Scientists have studied the results of hemp crops which were used to clean up cadmium, lead, copper, and zinc and found that the crops were still able to grow in concentrated soils with the added bonus of being able to create products from the fibers even though the soil was of poor quality (Young, 2005). These crops would be safe to utilize in construction material such as hempcrete (a natural form of insulation), pressed boards in addition to paper products. However, they would not be able to utilize the seeds or the flowers for human consumption or wear clothing made from textiles derived from those fibers due to the health risks they pose by containing heavy metals.
Natural Solutions for Anthropogenic Environmental Degradation
Despite the fact that we are facing an excess of climate issues as a result of human activities, we can transition away from these destructive practices. We must begin to promote environmental healing strategies, as well as reduce our fossil fuel use. The earth is incredibly resilient. We can all do our part by protecting our ecosystem, which can simply be a matter of restoring soil health. When we invest in our soils, we are investing not only in our future for the health and prosperity of our lives, but also the lives of all living creatures.
Without soil, there would not be food, biodiversity, or physical stability. As we continue to face the challenges of climate change which is triggering widespread ecosystem issues, we can turn to nature to assist us by employing phytoremediation and carbon sequestration as tools to mitigate them. The intentional planting of hemp crops is a practical way to assist in the cleanup of toxic waste sites and polluted landscapes; cultivating hemp also alleviates some of the excess carbon in the atmosphere. When we implement hemp as a tool for regenerating the soil, we can begin to restore our environment.
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Center for Food Safety. (n.d.). The Soil Food Web. https://soilsolution.org/the-soil-food-web/
Center for Food Safety. (2015). Soil and Carbon soil solutions to climate problems (Rep.). Retrieved from https://soilsolution.org/wp-content/uploads/2016/03/soil-and-carbon-report.pdf
Colbert, M. (2018). Radioactive research: is hemp a soil savior?. Hemp. (3).Retrieved from https://thehempmag.com/2018/07/radioactive-research-is-hemp-a-soil-savior/
DalCorso, G., Fasani, E., Manara, A., Visioli, G., & Furini, A. (2019). Heavy Metal Pollutions: State of the Art and Innovation in Phytoremediation. International journal of molecular sciences, 20(14), 3412. https://doi.org/10.3390/ijms20143412
Greipsson, S. (2011) Phytoremediation. Nature Education Knowledge 3(10):7 Retrieved from https://www.nature.com/scitable/knowledge/library/phytoremediation-17359669/
Marin Carbon Project. (n.d.). What is Carbon Farming? Retrieved from https://www.marincarbonproject.org/carbon-farming
Savory Institute. (2015). Restoring Climate [White Paper]. https://savory.global/wp-content/uploads/2017/02/RestoringClimateWhitePaper2015.pdf
Soil Quality for Environmental Health. (2011). Soil Functions: Services Provided by Soil Resources. Retrieved from http://soilquality.org/functions.html
Union of Concerned Scientists. (2008). The Hidden Costs of Industrial Agriculture. Retrieved from https://www.ucsusa.org/resources/hidden-costs-industrial-agriculture
Vosper, J. (n.d.). The Role of Industrial Hemp in Carbon Farming. Retrieved from https://hemp-copenhagen.com/images/Hemp-cph-Carbon-sink.pdf
Young, E. M. (2005). Revival of Industrial Hemp: A systematic analysis of the current global industry to determine limitations and identify future potentials within the concept of sustainability (Unpublished master's thesis). Lund University, Sweden. Retrieved from https://pdfs.semanticscholar.org/bec0/874b2d98b2373c0723c7f909b5f1bff745f3.pdf