Can Local Nutrient-Circularity and Erosion Control Increase Yields of Resource-Constraint Smallholder Farmers? A Case Study in Kenya and Uganda
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Date
2021
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Cleaner Production
Abstract
As many regions in sub-Saharan Africa, the border region of Kenya (KE) and
Uganda (UG) has faced a declining soil fertility for decades, resulting from
soil erosion, intensely managed agricultural soils due to population pressure
and small inputs of mineral and organic fertilisers. With limited financial
means, farmers need measures and/or technologies that effectively reduce
nutrient losses or increase inputs at a low cost. In this study, four such
measures are in focus, namely erosion reduction practices, vermicomposting
of animal manure, collection of human urine in jerry cans and, collection of
human excreta in urine-diverting dry toilets. Current soil nutrient balances
in five districts in the Sio-Malaba-Malakisi River Basin and the potential
of these measures to reduce the soil nutrient deficit are studied using the
method of material flow analysis and the software STAN. Furthermore, crop14
nutrient-response functions are used to determine their potential impact on
maize harvests. Overall, results reveal that there exists a non-negligible and
exploitable potential of local resources to reduce the soil nutrient deficit,
improve harvests and in turn food security of the smallholder farmers in the
region. Soil nutrient deficits could be reduced by 20 — 30 %, 23 — 42 % and
9 — 15 % for nitrogen (N), phosphorus (P) and potassium (K), respectively.
Subsequently, maize harvests could be increased by 8 – 40 %, depending on
the applied technology and area. This research provides useful insights for
agricultural extension workers, politicians and researchers alike, highlighting
that simple and easily available technologies can harness similar amounts
of nutrients as more complex and expensive ones if all specific technology
constraints are adequately incorporated in the analyses.
Description
Keywords
Material Flow Analysis, Nutrient Circularity, Erosion, EcoSan, Urine Collection, Vermicomposting, Crop-Nutrient-Response
Citation
A. Amann, M. Herrnegger, J. Karungi et al., Can local nutrient-circularity and erosion control increase yields of resource-constraint smallholder farmers? A case study in Kenya and Uganda. Journal of Cleaner Production (2021), doi: https://doi.org/10.1016/j.jclepro.2021.128510.