Carbon cycles in different states through the earth, waterways and the atmosphere. Currently too much carbon exists as gas in the atmosphere. Extensive, continuously increasing carbon emissions are the main reason why the temperature on Earth keeps rising.
Reducing emissions alone is not enough to prevent climate change. In addition to this, carbon has to be sequestered back into the soil.
Returning carbon into the soil is the only known way to reverse climate change. However, carbon sequestration is needed for other purposes as well: food security, nutrient-rich food and the soil’s ability to absorb moisture. In terms of reversing climate change and carbon sequestration, farmers are not the problem; they are the solution.
Returning carbon into the soil is the only known way to reverse climate change.
During photosynthesis, plants capture carbon dioxide from the air and break it down into carbon compounds and oxygen. Plants release the oxygen into the atmosphere and use some of the carbon compounds to grow, while taking the rest into the soil through their roots.
Simply put, if the soil is healthy, it retains carbon permanently for plants, microbes and mycelia to use for growth. Microbes and mycelia release nutrients from the soil for plants to use.
As such, carbon sequestration means that carbon dioxide is removed from the air and retained in the soil. Permanent carbon sequestration occurs underground through collaboration between roots, fungi and microbes.
• Interview with Dr. Christine Jones, “SOS: Save our Soils” in the Acres USA journal
• carbon sequestration as a controller of climate change (in Finnish)
At Qvidja, cattle and horses participate in rotational grazing. This means that a fairly large herd grazes on a certain section of a pasture for a short time before the herd is moved to another location. This way, the animals will always have good fodder to eat and each section has time to grow back before the next feeding time. The herb moves from one section to another approximately every ten days.
The impact of grazing on carbon sequestration has produced interesting results on the global scale. A correctly proportioned number of ruminants can improve the activity of the soil. Additionally, there is some evidence that microbes in the soil are able to eliminate cattle’s methane production by feeding on methane.
• about ruminants, methane and carbon sequestration
Carbon sequestration on fields
At Qvidja’s fields, which span 140 hectares, carbon is sequestered through agro-forestry as well as crop and plant rotation.
Agro-forestry means that trees and bushes are planted among crops. This efficiently improves the ratio of fungi and bacteria in the soil. This ratio is an integral part of biological activity. It is also essential to carbon sequestration.
As such, agro-forestry systematically combines forestry with the production of food and raw ingredients as well as with maintaining the prerequisites for biodiversity. The purpose is to research which combinations of trees, grazing and cultivation help to maximise these goals. Qvidja’s cultivated agro-forestry segments are used, for example, to create combinations that produce woodchips in order to generate the levels of bioenergy that the farm needs.
Plant rotation means that plants with different characteristics are continuously cultivated in turns on field segments. Its basic purpose is to retain the growth potential of the soil. Additionally, plant rotation is used, for example, to prevent the proliferation of plant diseases and pests, increase the humus content of the soil, utilise biological nitrogen sequestration and facilitate the management of intrusive plants.
Crop rotation is based on a plan, which is created for field segments for a certain time period in order for plant rotation to be successful. When crops are rotated, the same plant species is cultivated no more than two years in a row and no more than for two years in any five-year period. Plants that are susceptible to diseases and other plants in the same family are cultivated no more than once in the same location in the course of one crop rotation period.
Crop rotation determines the growth potential of the soil.
As such, crop rotation aims at
• avoiding soil degradation
• reducing plant protection problems
• preventing pests from breeding
• reducing the amount of intrusive plants
• using the nutrient content of the soil in a balanced way
• about the ratio of fungi and bacteria in the soil on the blog called Pohjoinen permakulttuuri (in Finnish)
• about glomalin on the Swansea Biochar website and the blog called Small things considered
• about carbon sequestration on fields through MEF
Uneven-aged forestry management helps to sequester carbon
The Qvidja estate boasts 650 hectares of forests. It will be taken care of by following the principle of uneven-aged forestry management, which promotes biodiversity of nature.
Uneven-aged forest management is the opposite of even-aged forest management: instead of clear cutting, it allows for the forest to grow so that trees are continuously growing. The forest is cut following the high thinning principle, which means that instead of the entire forest, only the largest and economically most mature tree trunks are cut. Saplings and smaller trees are left to grow.
This is the most economic cutting method. The felling yield is higher than in low thinning, as low thinning leads to lower economic value due to the felling of pulpwood. High thinning enables the collection of valuable timber, while clearing space for the remaining trunks and new saplings to grow. The forests provide an even yield and the rate of return on capital invested in the forest remains high. Economic risks decrease, because there is no need to invest in tilling, saplings, planting and nursing the saplings.
With uneven-aged forest management, the soil’s ability to sequester carbon is higher than with even-aged forest management, because there is more carbon in the forest and the soil. Thanks to the trees of various sizes and ages, the ecosystem in the forest stays more diverse than in cultivated forests. It even looks different than even-aged forests: the landscape value of the forest also increases. The living conditions of game will improve, with mushrooms and berries being a familiar sight due to the lack of clear cutting or tilling.
The more diverse forests are, the better they serve all the various ways to use them.
• about carbon sinks in forests (in Finnish)