Abstract

Despite efforts to increase agricultural production sustainably in sub-Saharan Africa, large gaps remain between actual and potential yield of food crops. Adding biochar to degraded cropland soils in the African tropics has significant potential to enhance crop productivity. Biochar-based farming can also mitigate climate change, through soil carbon storage. This study involved six smallholder farms at sites in eastern, central, and western Kenya that are characterized by different pedo-climatic conditions. We examined the response of non-fertilized and fertilized maize monoculture to three dosages of biochar that are realistic for domestic production by farmers at each of the sites over four growing seasons. Commonly available biomass wastes in each agro-ecosystem (coconut shells, coffee husks, maize cobs) were used as feedstock for biochar, which was applied at 1, 5, and 10 Mg ha(-1) at the start of the experiment. Across seasons and fertilizer treatments, maize grain yield (dry matter) showed consistently positive responses, with an average increase of 1.0, 2.6, and 4.0 Mg ha(-1), respectively, above the control for the three biochar application rates. Absolute responses of maize grain yield to specific biochar doses were similar across the four investigated seasons and replicate farms within sites, and uncorrelated to yield levels in the control treatment. Here, we show for the first time that yield response to biochar decreased with increasing application rate, indicating that it may be better to spread a given amount of biochar over a large area rather than concentrating it to a smaller area, at least when biochar is applied along plant rows at rates >= 1 Mg ha(-1), as in our experiment. This study demonstrated that application of biochar, locally produced from available biomass residues, is a promising approach to enhance agricultural production and carbon storage on smallholder farms under a wide range of pedo-climatic conditions in Kenya.

Keywords

Agricultural intensification; Biochar farming; Fertilizer use; Food security; Maize production; Smallholder farmers; Soil carbon sequestration; Soil fertility; Sub-Saharan Africa

Published in

Agronomy for Sustainable Development
2022, Volume: 42, number: 4, article number: 63
Publisher: SPRINGER FRANCE

SLU Authors

• Kätterer, Thomas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Karltun, Erik

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Nyberg, Gert

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

• Sundberg, Cecilia

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    
  • Royal Institute of Technology (KTH)

• Röing de Nowina, Kristina

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • CGIAR System Organization

Sustainable Development Goals

End hunger, achieve food security and improved nutrition and promote sustainable agriculture
Ensure sustainable consumption and production patterns


UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1007/s13593-022-00793-5

Permanent link to this page (URI)

https://res.slu.se/id/publ/119963