AgriChar research group

What we do


Throughout the past two hundred years, the mankind has been emitting increasing amounts of greenhouse gases to the atmosphere and by doing so, likely contributing to the climate change. CO2 is considered to be the most important of the greenhouse gases and new ways to sequester it from the atmosphere are actively looked for. One of the most promising options worldwide for managing the CO2 is to develop sustainable biochar systems. Mixing biomass that has gone through a pyrolysis process, to soil might lead us even to a carbon-negative agriculture. Such a practice is especially promising if taken into account that biochars hold carbon in the soil for hundreds and even thousands of years.

In addition to that, auxiliary effects from adding some biochars to soil might further reduce greenhouse gas emissions as well as bring along desired effects to the environment. These effects include reductions in the fertilizer need by increased nutrient uptake efficiencies, improved soil physical structure as well as decreased nutrient leaching from the fields.

On the other hand, as the biochars once applied to the soils cannot practically be removed from the soil, the question: are they safe? needs to be answered before the practice could be widely adopted. Some of the most crucial gaps in the current scientific understanding of the functioning of biochars in soil and environment and its role for plants are due to the lack of data on:

   i. the long-term (i.e. more than 5 years) effects under field conditions on soil and plant properties;
   ii. studies under boreal conditions;
   iii. the biochar effects on soil biota under field conditions
   iv. changes occurring on the biochar surfaces.

Our research group targets these gaps focusing mainly on the effects of biochar systems on the physico-chemical properties of soil, on soil biota and on the yield formation and nutrition of field crops.

We have also ongoing projects in the areas of, among others, using biochar for re-using the phosphorus in lake sediments and research on recycling industrial fertilizers (e.g. biogas digestate, composts, meat bone meal).

Group members 



The group is led by associate professor (docent) in agroecology, university lecturer in crop science Dr. Priit Tammeorg
 ResearcherID I Google Scholar I ResearchGate I UH research portal


Priit is interested in solutions increasing the sustainability of
agriculture: nutrient recycling, soil fertility, organic farming and biochar. The main focus of his doctoral thesis was to study the effects of biochar use as a soil amendment on soil fertility, earthworms and plant properties in boreal soils. His current work as a PI of the AgriChar group continues along these lines and is focused on exploring the mechanisms of the short and long-term effects of biochar in boreal soils as well as novel ways to recycle nutrients in the agriculture.
 

Visiting Post-Doctoral researcher  Subin Kalu


Subin is a post-doctoral researcher interested in exploring environment friendly solutions. For his doctoral studies, he focused on the long-term effects of biochar for sustainable agriculture in boreal soils. His studies emphasized on the effects of biochar on soil physico-chemical properties, greenhouse gas emissions, as well as plant nutrient uptake in long-term, his doctoral thesis was accepted with distinction in autumn 2022 from University of Helsinki. He was also awarded with two awards for the best doctoral thesis of 2022 (by Suomen Luonnoinvarain tutkimussäätiö and by the Faculty of Agriculture and Forestry).
 
He continues his work as post-doctoral researcher focusing on biochar-nutrient-soil interactions and is working mostly in North Carolina State University but also as a visiting researcher in AgriChar group.
 
 
 
 
Visiting Post-Doctoral researcher Mina Kiani


Mina is a visiting post-doctoral researcher in Agroecology at University of Helsinki and joined the AgriChar group in 2017. She is interested in finding solutions for closing the nutrient leakage from the cycle via reusing lake sediments in agriculture and landscape engineering. She defended her doctoral thesis in 2023 on the topic Closing the phosphorus cycle by recycling lake sediments in agriculture and it was accepted with the highest grade, passed with distinction.
Her current research focuses on comparing different ways of sediments applications to soil to examine nutrient retention in topsoil and to quantify their effects on environment and crops, but also on other ways to recycle phosphorus.



Doctoral student  Jure Zrim


Jure is a D.Sc. student in Agroecology at University of Helsinki, who joined the AgriChar group already for his MSc thesis work in 2015. He is investigating the effects of biochars and recycled organic fertilizers on soil biota in Finnish boreal conditions. His study focuses on medium– and long–term effects of softwood biochars on earthworm and microbial compositions, physicochemical properties of soil and plant growth.









 Doctoral student Mari Unnbom
 

 Mari is a doctoral student in Agroecology at University of Helsinki since May 2022. Mari was a project coordinator in HYKERRYS-projects (2017–2021) where recycled fertilizers were studied in a five-year field experiment in Haltiala, Helsinki. Now she is using the data gathered from HYKERRYS field experiment to study the effects of recycled fertilizers and soil amendments to soil properties, yield formation and plant nutrient uptake. 
Doctoral student Samuel Amoah
 
Samuel is an agricultural scientist with special interests in indoor agriculture, hydroponics and sustainable plant production systems. In his doctoral studies he is currently researching on finding the best practices for using nutrient enriched biochars in boreal conditions.

Doctoral student Jonna Pärssinen

 
 Jonna is a doctoral student working on sustainable ways to grow cranberries, including exploring the potential of biochars in berry production.

Doctoral student Zannatul Ferdous
 


Zannatul is a doctoral student in Agroecology at the University of Helsinki who started her journey in the AgriChar research group in 2023 for her MSc thesis work. Now, she is working on the effect of nutrient-loaded biochar on the nitrogen use efficiency of crops, nitrogen losses, and soil biota in Finnish boreal agriculture and forest ecosystems.



 
 

Doctoral student Zhouyang Tian


Zhouyang has been a doctoral student at the University of Helsinki since September 2024, researching how biochar retains nitrogen in soils, with a focus on retention mechanisms and the effects of field aging.

 
 

 
Doctoral student

Franco is a Doctoral Researcher in the Department of Agricultural Sciences at the University of Helsinki, focusing on sustainable lake restoration. His research explores innovative approaches to lake remediation by integrating sediment removal with nutrient recycling for sustainable agriculture. Franco investigates how nutrient-rich sediments can be reused as phosphorus (P) fertilizer, addressing both eutrophication and the challenge of finite P resources. 



 
 
 
 
MSc student Heikki Sikanen 



MSc student Joni Vihavainen 
  
 
 




MSc student Tatu Puttonen

 
 MSc student Kira Eskelinen
 


MSc student Cecilia Renvall
 

MSc student Faiza Binte Enam
 
 
MSc student Dilruba Yasmin

MSc student Sofi Paatelma
 
Sofi is a MSc student in Global Sustainability with a deep love for nature and all things biochar. She’s currently working at Carbo Culture, where she gets to combine her passion for climate solutions with hands-on impact in the biochar carbon removal space. She is especially interested in how biochar can support sustainable land use and help us build climate-resilient systems. She’s always curious, always learning and always ready to chat about biochar, carbon, or your latest nature adventure!


 
MSc student Jenni Kurvonen
 
 
 
 
 
 
 
 
 
 
 
 
MSc student Tharangi Disnika
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Anna is a laboratory analyst student from Metropolia working as an intern with greenhouse gases.





AgriChar group in summer 2024
Group meeting in autumn 2023


We work in co-operation with several other researchers from the University of Helsinki:


Dr. Asko Simojoki
Dr. Petri Penttinen
Dr. Kristiina Karhu
Prof. emer. Juha Helenius
Dr. Michael Starr  
 Adj. Prof. Frederick Stoddard
Prof. Pirjo Mäkelä
Dr. Olga Tammeorg
Doctoral student Mr. Jukka Kivelä




Former group members


Dr Biar Deng


In spring 2020, Biar finished his D.Sc. on soil fertility and crop yield improvement through inclusion of multipurpose trees (Acacia seyal.L) and biochar application in drylands agrosystems; case study South Sudan. 
 
 
 
Completed MSc. theses: 
  1.   Zannatul Ferdous (The effect of cattle slurry-activated biochar on earthworm community on
    arable soil in Southern Finland)
  2.  Anu Suwal (Effect of lake sediments from range of eutrophic lakes on ryegrass growth and nutrient uptake)
  3.  Tuuli Markkanen (Development of sustainable practices for using lake sediment as growing medium for grass production)
  4.  Suvi Tikka (Effect of biochar on soil aggregate stability, water retention capacity and chemical properties in field nine years after biochar application). 
  5. Topi Kopakkala (Biochar as a planting soil component for urban trees: a short-term study from Hyväntoivonpuisto, Helsinki).
  6. Annukka Kukkola (The effects of biochar and fertilisation strategies on soil fertility and cereal growth on nutrient deficient soil eight years after biochar application)
  7. Eiko Höglund (The effects of biochar on soil biota in temperate and boreal agricultural soils).
  8.  Vilja Jyrinki (Impact of biochars on microbial biomass carbon and soil respiration in forest soils)
  9. Antti Ali-Lekkala (The effect of pinewood biochar on the properties and hydrology of clay loam soil and the growth and development of Pea (Pisum sativum L.) in the temperate climate of southern Finland)
  10.  Niina Välinen (The physicochemical effects of softwood biochar on soil properties and yield formation of pea (Pisum sativum L.) eight years after application in Southern Finland)
  11. Aino Härkönen (The effects of spruce biochar on soil fertility and barley (Hordeum vulgare L.) yield formation eight years after application to nutrient deficient soil)
  12. Samuel Amoah (The effects of biochar on the soil properties and on yield formation of pea (Pisum sativum L) nine years after application) 
  13.  Katariina Hämäläinen (The effects of biochar on soil moisture and nutrient concentrations and yield components of oat (Avena sativa L.) five years after application.)
  14.  Heidi Hovi (Biochar effects in soil properties and on the yield and species composition of grass).
  15.  Jure Zrim (Medium-term effects of biochars on earthworms in two contrasting soils in Southern Finland)
  16. Stefano Caro (Aalto University, Thermochemical Valorization of Waste: Pyrolytic Conversion of Horse Manure)
  17. Pierre Boivin (Plant uptake of biochar nutrients)
  18. Alma Lehti (Effects of biochar on the yield and species composition of grass)
  19. Juho Honkala (Effects of biochar on faba bean yield formation)
  20. Tuure Parviainen (Effects of biochar on earthworms).
  21. Heedo Lee (Availability of biochar-K to plants)
  22. Tero Brandstaka (Effects of biochar on N dynamics)
  23. Chen Xiaoyulong (Effects of biochar on turnip rape yield formation) 
  24. Jarkko Hovi (Effects of biochar on soil particle stability and P-retention)
  25. Chiara Pituello (Plant uptake of biochar nutrients) 
  26. Johanna Muurinen (Assessment of biochar verification methodology)
Former visitors


Visiting senior researcher Dr. Dilfuza Egamberdieva,  visited us in 2022
 
Visiting doctoral student Mohammad Ghorbani, visited us in 2023
 
Visiting doctoral student Elnaz Amirahmadi, visited us in 2023
 
Visiting doctoral student Sharifa Nabavi, visited us in 2023-2024
 
Visiting doctoral student Karel Bartoš , visited us in 2024

 Visiting doctoral student Maryam Nik Qadami Hosseni E, visited us in 2024-2025
 


 
 
 


 Co-operation

University of Helsinki biochar research group works in co-operation with other institutions :

 Estonian University of Life Sciences  
 Natural Resources Institute Finland
 Aalto University 
SJT Sugar Beet Research Centre


Publicity


Our work has been written about in several newspapers and magazines, including:
  1. Science Magazine 2 May 2023 (story covered also by ScienceDaily, Phys.org and Mirage) 
  2.  Bioenergialehti 1 March 2023 
  3.  YLE News, 4 October 2021 (story covered also by ScienceDaily, Phys.org, NewsWise, RitzHerald and Mirage).
  4.  Maatilan Pellervo, December 2019. 
  5.  Karjalainen 4 October 2019
  6.  Tekniikka & Talous 5October 2018
  7. Farmi 4/2018
  8.  Puutarha & kauppa, 9 March 2017
  9.  Ekoelo, February 2015
  10.  Helsingin Sanomat, 22 May 2014
  11.  Energia ja Ympäristö, May 2011   
  12. Yliopistolehti, December 2010  


Funding


We are very grateful for the financial support that makes our work possible.

Our special thanks go to: 
Please contact us by e-mail: priit . tammeorg (at) helsinki.fi.
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