Research helps turn fields into carbon sinks

Fields that are green year-round continuously bind atmospheric carbon. Researchers are currently investigating the scope of this carbon sequestration and the effects of weather fluctuation on the phenomenon.

What are your research topics?

I investigate the effects of the soil and plants on climate change, or how the soil and plants bind carbon from the atmosphere and, at the same time, release greenhouse gases back into the atmosphere.

I measure carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) exchange between plants, the soil and the atmosphere, also studying the processes associated with gas production and consumption as well as the factors affecting those processes. I also study which agricultural practices make the soil bind carbon and which measures make the sequestered carbon stay in the soil for a long time.

My research area includes a great many questions: why are trees sources of methane, how do plants as well as bacteria and fungi living in plants affect greenhouse gas production and consumption, and how do the changing climate and extreme weather conditions influence soil and plant processes as well as, through them, climate change?

Where and how does the topic of your research have an impact?

Current cultivation techniques release carbon from fields into the atmosphere, where carbon dioxide warms up the climate. Through research, we are looking into which agricultural practices can curb carbon loss from arable land and turn these fields into carbon sinks. Carbon sequestration and increased carbon concentration in the soil benefit not only the climate, but also farmers. Increased carbon quantities enhance the water economy and productivity of the soil, consequently improving yields.

Knowledge pertaining to the climate effects of various agricultural practices, that is, the sinks and emissions relating to all greenhouse gases, is important for national and international decision-making. Information on the amount of sequestered carbon helps determine the level of political support measures, or the compensation paid to farmers for increased carbon levels in the soil. In the future, carbon sequestered in arable land can potentially even be used for carbon trading.

What is particularly inspiring in your field right now?

I am inspired by the opportunities afforded by measuring devices for making visible the invisible processes of the soil and plants.

Right now, I am particularly excited about studies where we are investigating why tree canopies produce methane in oxygen-rich conditions. We have found that tree branches emit methane in daylight, but not in the dark. We want to understand the reasons for this.

With the help of new, automated measuring devices, we are exploring what kinds of effects changing winter conditions and the freezing and thawing of fields have on carbon in the soil as well as the methane and nitrous oxide emissions from the soil. Together, these elements constitute the climate effects of a field.

We are launching unique measurements encompassing all greenhouse gas exchange (CO2, CH4, N2O) at a new SMEAR-Agri field station in Viikki and in Haltiala, focusing on the study of the climate effects of agriculture.

I am coordinating the construction of the SMEAR-Agri station in Viikki. Already this year, the station will generate continuous measurement data on the climate and air quality effects of grassland farming.

Mari Pihlatie is a professor of environmental soil science at the Faculty of Agriculture and Forestry.

Watch Mari Pihlatie's inaugural lecture as a new professor on 26.5.2021 on YouTube.

Read about the other newly appointed professors.