A soil solution for containing climate change?
Carbon Action is a joint pilot project of the Finnish Meteorological Institute, Baltic Sea Action Group (BSAG) and Sitra. This story explains what the project is all about. Finnish Meteorological Institute Research Professor Jari Liski and Baltic Sea Action Group's Chairwoman of the Board Saara Kankaanrinta provide the answers.
What is the goal of the Carbon Action project?Jari:The goal of the project is to find out what methods can be used to fix carbon from the atmosphere into agricultural soil in order to curb climate change and how effective these methods would be. Of the many possible methods, forestation and land use are the only ones worthy of attention, as the other methods involve technical problems and the costs would rise to high.Another goal of the project is to expand and diversify Finnish research on the topic and to strengthen the status of this research internationally. The project's scientific research is being coordinated by the Finnish Meteorological Institute, with participating organisations including the University of Helsinki, Natural Resources Institute Finland (Luke) and the Finnish Environment Institute (SYKE). Baltic Sea Action Group (BSAG) is responsible for overall project management, for agricultural work and for impact work. This project is therefore a Finnish pilot project in which multidisciplinary top-level research engages directly with the practical grass-roots level.
Saara:Reducing emissions from agriculture is of top importance also for the Baltic Sea, because it is still producing over half of the eutrophic load. Repairing the soil is the most significant action to take, because emission reductions are thus made on the field. Nitrogen, phosphorus and carbon should not end up in streams, rivers, lakes or the sea. On the other hand, we know that climate change is strongly impacting the Baltic Sea. The project is therefore doubly effective, and it has both a local and global dimension to it.
How much carbon dioxide emissions can be fixed into the soil and what significance does this have for climate change?
Jari:Reducing climate change in accordance with the goals of the Paris Climate Agreement requires the removal of carbon dioxide from the atmosphere in addition to reductions in emissions. Fixing carbon dioxide into the soil and using forests as carbon sinks are the most important and cheapest ways to remove carbon dioxide from the air. According to the calculations made, developing the carbon store in agricultural soil could remove 2–3 billion tonnes of carbon from the atmosphere per year. This is equivalent to between 20 and 30% of current fossil carbon emissions. The soil is already the second largest carbon store on the planet, with the seas being the largest: Organic substances in the soil store more carbon than is contained in all the planet's plants and the atmosphere combined. The majority of the soil's carbon is stored in the surface layer which is about one metre thick and is therefore the layer which agriculture, grazing and forestry directly impact.
Saara:
The soil's potential is often assessed conservatively and under the conditions of the prevailing ‘efficient agriculture' methods. Monocultures, the forgotten importance of biological fertility and synthetic production inputs have shown over the decades how effectively they bring about destruction, not efficiency. In contrast, by using sustainable agricultural practices and working in cooperation with nature's power it is possible to maximise photosynthesis and microbe activity. At the same time, biodiversity is increased, carbon storage grows and agricultural output is also improved.
How can the soil's carbon-fixing capacity be improved?
Jari:Carbon fixing can be increased on the one hand by increasing the amount of carbon transferred from the atmosphere to the soil as a result of plant growth and on the other hand by ensuring that the carbon stays in the soil. The flow of carbon from the climate to the soil can be strengthened, for example, by keeping agricultural lands covered in plant growth during the whole growing season or by using cover crops and growing deep-rooted plants. The carbon in the soil can be prevented from escaping by, for example, avoiding powerful tilling which breaks the structure of the soil and by using soil conditioners which promote the formation of permanent carbon forms.
Saara: It is important to think of biodiversity as one of the methods on offer. Nature functions best and at full strength when there is a wide range of plant species in the field and there is both crop rotation and organic soil conditioners in use. These, in addition to minimal tilling of the soil, are the requirements for good soil functioning.
What is the importance of microbes for fixing carbon into the soil?
Jari:The microbes in the soil, primarily mushrooms and bacteria, extract nutrients from the dead plant matter that enters the soil and at the same time break down this plant matter. In this process, the breathing of the microbes produces carbon dioxide – which is then released from the soil back into the atmosphere – as well as other organic compounds which can be fixed into the soil for centuries or even millennia. For the purpose of soil carbon fixing, it is cheaper if the microbes produce a lot of compounds for fixing into the soil. Understanding microbe activity is of central importance for carbon fixing.
Saara:Maximising photosynthesis involves feeding as much liquid carbon and sugars as possible into the underground organism network. Mycorrhizas are the underground internet and railways, which transport information, nutrients and carbon. Microbes do the work in the soil; without them there is no carbon sequestration and no activity at all. The goal is to obtain as large a store as possible of permanent carbon. According to current understanding, humus is composed mainly of dead microbial biomass. In the Carbon Action project, we are seeking to increase understanding of and develop practices for engaging with the interaction between plants, microbes and the soil.
How is the soil's carbon-fixing capacity currently being taken into consideration in agriculture?
Jari:The large significance of organic matter for soil fertility is certainly known. Current agricultural practices have nevertheless led to a situation where the amount of organic carbon in agricultural land is decreasing almost everywhere on the planet, including in Finland. Paying attention to the amount of carbon and organic matter in the soil is cost-effective in terms of both agricultural productivity and climate impact.
Saara: In a monoculture, artificial manures are given directly to the plant in usable form, and thus the work of microbes is not needed. In this way, the huge carbon-fixing potential is wasted, and the conditions for farm profitability are lost as well. What is needed is a significant paradigm shift and large changes in farm practices.
What are the concrete measures being carried out on farms as part of this pilot project?
Jari:Practices for increasing the soil's carbon storage, such as avoiding powerful tilling of the soil and using cover crops. In the participating farms, attempts are made to integrate these into the farm's agricultural practices. In addition, the farms in the experiment are to keep a record of their activities so that the amount of carbon fixed into the soil can be calculated.
Saara:In addition to avoiding tilling of the soil, there are many other concrete actions that can be taken, such as- increasing photosynthesis by lengthening the growth period- increasing photosynthesis by increasing harvest size- the correct selection of species and strains- planting deep-rooted plants and repairing the soil structure- the use of fertiliser and soil conditioners- planting arboreal plants
Changes should also be made in grazing or the agricultural uses of grasslands. Grazing should also be made use of for carbon fixing, in which case we can speak of rotation grazing.
What is the Yasso model?Jari:Yasso is a model developed by the Finnish Meteorological Institute for describing the carbon cycle in the soil. The Yasso model is used very widely in a variety of contexts. It is a permanent part of the German Max Planck Instituut's climate system model, which is used for global climate change simulations in the IPCC reports and elsewhere. Yasso has been used by eight European countries to produce their national greenhouse gas inventories as required by the United Nations Framework Convention on Climate Change. In addition, Yasso is part of many other calculation systems in Finland and abroad. In the Carbon Action project, the Yasso model will be further developed, particularly for use in making reliable assessments of carbon fixing in agricultural land.
Why is the project so significant in many ways?
Jari:The purpose of the project is to combine the different research disciplines which are needed for using soil carbon fixing to reduce climate change. Another special feature is the close and concrete cooperation with real-life agricultural activities.
Saara: The cooperation between different fields of science is truly essential in such a broad project, and equally essential in global cooperation. In few projects is it possible to impact so directly on so many important matters, including Baltic Sea emissions, reversing climate change, increasing diversity, and sustainable food production.
What stage is the project in at the moment?
Jari:The project began last autumn. During the winter, research plans have been made, extra funding has been obtained and some measurement preparations have been made. A diverse range of measurement and research activities are just now getting under way as the growing season begins.
Saara:The project is open to everyone, so anyone who is interested can still get in touch with us. We have received registrations from interested farmers and we are already planning training and activities for the summer. The project has also gathered interest at the global level. I believe that Finland can be a pilot country in this and can show how different experts and different practices can engage with each other and, most of all, how environmental protection can be about concrete action and real work in the field.