Abstract:

Poor soil fertility in smallholder farming systems in sub-Saharan Africa is recognised as a
major factor responsible for low per capita food production and escalating food insecurity.
Increasing food production in most smallholder farming systems requires intensification with
nutrient inputs. Targeting nutrient management interventions to heterogeneity can greatly
enhance the use efficiency of the scarce nutrient inputs and can help in identification of ‘best
fits’ (most suitable options for niches within the systems). This thesis aimed at contributing to
understanding how to target nutrient management options to heterogeneity for improved crop
production in the Teso farming system in eastern Uganda.
Land use change analysis between 1960 and 2001 showed that 48 -78% more land was
brought into cultivation and disappearance of communal grazing lands. Productivity of the
farming system is also low. Population growth, political-instability-mediated collapse of
institutions that supported production and marketing of cotton, and cattle rustling account for
the changes in land use and productivity of the system. Balances of N, P and K were positive
on larger farms (LF) and negative on the medium farms (MF), small farms with cattle (SF1)
and without cattle (SF2), but were negative at the crop scale on all the farm types. Livestock,
crop yield, labour availability and access to off farm income are the sustainability indicators
in the system.