Impact of Land-use Change on Ecology, Resource Productivity and Adaptive Strategies of Smallholder Agro-Pastoralists in Machakos-Makueni Districts, Kenya
Abstract
Semi arid areas in Kenya are experiencing socio-economic processes leading to land
subdivisions and subsequent changes in land-use patterns. Changes in land-use negatively
affect the ecological resource base through replacement of native plant species, loss of
wildlife habitats and reduced quality and quantity of water. A study was therefore carried
out to analyze the impact of land subdivision and shifts from commercial ranches to
smallholder agro-pastoral production systems on the ecological resource base, resource
productivity and agro-pastoral adaptive strategies in Machakos and Makueni Districts.
Ecological studies involved sampling for vegetation and soil attributes in 2 nonsubdivided
cooperative ranches and 3 subdivided ranches with transects cutting across
smallholder farms (SMFs). Vegetation and soil samples were analysed for vegetation
attributes and physical and chemical properties, respectively, using standard methods.
Household survey involving 90 households was also carried out to determine impact of
the land-use change and land subdivision on resource productivity and characterize the
agro-pastoral adaptive strategies given the shifts. Data for household output and income
was analysed using log-log regression models. The SMFs had significantly higher
(p:S0.05) frequency and biomass production for annuals grass species while the ranches
had higher (p:S0.05) percent ground cover and biomass production for perennial grasses,
forbs and litter. This indicated that SMFs were more degraded than the ranches probably
due to the attendant continuous cultivation and overgrazing. Significant decline (p:S0.05)
in important soil chemical properties was recorded in the SMFs, particularly nitrogen,
phosphorus, magnesium, manganese and sodium levels. Soil Organic carbon (SaC)
significantly reduced (p:S0.05) with increasing period of subdivision and settlement.
There was a significant (p:S0.05) and positive relationship between land size and
household output, suggesting that continued fragmentation of land in the rangelands
could cause significant decline in household output. In addition, the results show that
households in the study were operating below the optimal level of production and would
more than double their output if they doubled their inputs including land. Trends in
household returns indicated increased returns with increase in land size. In spite of land
subdivision" early planting, use of drought resistant crops, predation control and feed
conservation were some of the important agro-pastoral adaptive strategies in the study
area. But, unreliable rainfall, access to land and water, acquisition of skills, shortage of
pasture and predation were the main factors influencing shifts in the adaptive strategies.
Fragmentation of ranches and change in land-use to smallholder agro-pastoral production
systems in the area should be done in tandem with adoption of technologies that will
allow exploitation of land-based resources without compromising on the ecological
integrity in the long run. Therefore, there is need to determine land use and size
thresholds that will not affect land productivity to meet minimum household
requirements of the agro-pastoral system. Furthermore, due to the trends in land
degradation in the SMFs, there is urgent need for development of appropriate
technologies that would contribute to reversing the degradation trends and increase land
productivity in the area.
Citation
Masters of Science in Range ManagementPublisher
University of Nairobi Department of Land Resource Management and Agricultural Technology (LARMAT) 2009