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

Pasture on smallholder farm in Bomet county

ACTIVE

HABITAT Smallholder pasture management and biodiversity in the Kenyan highlands

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

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

My Publications

Assessing land use changes and agricultural practices in highland valley-bottom wetlands in Taita Hills, Kenya

  • Gubamwoyo, S.
  • Hein, T.
  • Heiskanen, J.
  • Kisha, D.G.
  • Pellikka, P.
  • Gruber, G.
  • Omondi, V.A.
  • Leitner, Sonja
  • Weigelhofer, G.
  • Mwamodenyi, J.M.
  • Obonyo, A.O.
  • Gettel, G.M.
ILRI publication cover

Beyond default estimates: developing system-specific Tier 2 enteric methane emission factors for rangeland cattle in Kenya

  • Gurmu, Endale Balcha
  • Kiprotich, Linus
  • Kagai, Jesse
  • Solomon, A.
  • Leitner, Sonja
  • Marquardt, Svenja
  • Merbold, Lutz
  • Ndungu, P.W.
  • Arndt, Claudia

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.
ILRI publication cover

CIRNA project inception meetings held in Uganda and Kenya

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

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

Greenhouse gas emissions from soils and animal manure

  • Leitner, Sonja