I am an ecologist and biogeochemist working on carbon and nitrogen cycling in natural and agricultural ecosystems. I investigate nutrient transformations and nutrient losses via gaseous emissions and leaching, with a special focus on greenhouse gas emissions (CO2, CH4, N2O). Currently, my research focuses on options for soil and manure management that reduce nutrient losses to improve livestock productivity and help achieve climate change mitigation and adaptation. I also investige options for circular, sustainable manure management that consider animal and human health and organic fertilizer quality, while also being feasible for smallholder farmers. Furthermore, I work on ecosystem carbon cycling and sequestration using novel tools such as Eddy Covariance towers. I work in mixed crop-livestock systems and rangelands and am currently involved in projects in Kenya and Uganda

My Projects

CIRNA

ACTIVE

CIRNA - CIRcularity of Nutrients in Agroecosystems and co-benefits for animal and human health

ESSA - Earth observation and environmental sensing for climate-smart sustainable agropastoral ecosystem transformation in East Africa

ACTIVE

ESSA - Earth observation and environmental sensing for climate-smart sustainable agropastoral ecosystem transformation in East Africa

My Blog Posts

A dairy farm in the Kenyan highlands (ILRI/Birgit Habermann)

ILRI News

CIRNA project inception meetings held in Uganda and Kenya

Healthy grassland soils support lush vegetation

ILRI News

How much carbon can Kenyan grasslands store in their soils? Insights from the CarboGrass Project

boxes

Mazingira Centre – a role model for environmental research infrastructure in Africa

cows in lake

Environmental externalities and greenhouse gas emissions from water pans and bomas in pastoral systems

bomas

Digging into Bomas

My Publications

Bringing together measurements and data science for better nitrous oxide emission accounting in data-poor regions

  • Harris, E.
  • Barthel, M.
  • Leitner, Sonja
  • Ouma, T.
  • Agredazywczuk, P.
  • Otinga, A.
  • Njoroge, R.
  • Oduor, Collins
  • Oluoch, K. C.

Beneficial and unsafe plant species within selected grazing areas in Bomet County: HABITAT Project – Harnessing Pasture Biodiversity and Productivity

  • Matheka, Kennedy W.
  • Leitner, Sonja
  • Kinuthia, Kelvin
ILRI publication cover

CIRNA project inception meetings held in Uganda and Kenya

  • Wanyama, Ibrahim
  • Leitner, Sonja
  • Slater, Annabel

Greenhouse gas emissions from soils and animal manure

  • Leitner, Sonja

Machine learning based gridded/ digital soil mapping for Kapiti Research Station and Wildlife Conservancy, Kenya

  • Cherotich, Fredah
  • Leitner, Sonja
  • Pearce, F.
  • Rufino, Mariana C.
  • Quinton, J.
  • Dhulipala, Ram
  • Salavati, M.
  • Gluecks, Ilona V.
  • Whitbread, Anthony M.
  • Paliwal, Ambica

Determination of GHG Emission Factors for Livestock in Pastoral/Agropastoral Areas of Ethiopia and Kenya

  • Balcha, E.
  • Kagai, J.G.
  • Kiprotich, L.E.
  • Saya, N.
  • Hedenou, C. M. E. H.
  • Graham, Michael
  • Hammond, James
  • Leitner, Sonja
  • Merbold, Lutz
  • Arndt, Claudia