Although there has been increasing research on the adoption of agroforestry technologies over the last decade, few such studies have
assessed uptake over a long period and many are based on a single snaphot in time. Furthermore, most of these studies have mainly
looked at non-adopters and adopters: only recently have social scientists considered testers. A further category of users neglected in
adoption studies has been re-adopters of technologies. Studying this group provides an interesting and more nuanced understanding
of adoption and re-adoption. Methodologically, most adoption studies use quantitative methods and fail to link their findings to wider
socio-economic, political and institutional settings. This paper presents a study of the dynamics of improved tree fallow use by farmers in
Siaya and Vihiga districts of western Kenya over a period of eight years. It uses both qualitative and quantitative data to critically discuss
the motivations of adopters, testers/rejecters and re-adopters. The results show that the process of adoption is highly dynamic and variable
with farmers planting improved fallows and discontinuing or re-adopting them due to a whole range of factors, of which soil fertility
improvement is just one. These factors included incentives from projects, the tying of adoption to credit programmes, prestige,
participation in seminars/tours and the availability of a seed market from projects promoting improved fallows. Farmers planting
improved fallows for such reasons may be termed ‘pseudo-adopters’. There were significant differences in adoption between the two districts,
with more farmers in Siaya planting improved fallows than in Vihiga. A majority of farmers in Vihiga (53%) who were given seed
never planted improved fallows, even though they had been exposed to the technology. Some 40% of farmers in Siaya and 38% in Vihiga
planted improved fallows but later rejected them. This has some important implications for research and development. For improved
fallow technologies to be attractive to farmers, they must provide other tangible economic benefits besides soil fertility improvement.
This presents a challenge to researchers who must better attune themselves to the needs and demands of farmers if they wish to see their
research findings widely adopted.