J. Ellis-jones et A. Tengberg, The impact of indigenous soil and water conservation practices on soil productivity: Examples from Kenya, Tanzania and Uganda, LAND DEGR D, 11(1), 2000, pp. 19-36
Farmers in many parts of Africa use indigenous soil and water conserving (I
SWC) practices as an integral part of their farming systems. Farmers have d
eveloped such methods which have maintained productivity and contributed to
long-term sustainability, while introduced measures have often been reject
ed or simply failed to achieve their technical objectves,
This paper examines the strengths and weaknesses of some ISWC practices in
Kenya, Uganda and Tanzania. An evaluation has been carried out based on far
mers' evaluation criteria as well as criteria identified by researchers, Fa
rmers' criteria are often based on the quality of their natural resources (
farmers are more likely to conserve those soils that will give the highest
return on the:ir investment), the resource level of the household (particul
arly income levels and labour availability), cropping intensity as well as
cultural traditions related to age, education and gender. Of great importan
ce, however, is the need to maintain or increase soil productivity. Methods
that conserve moisture, reduce soil erosion, maintain soil fertility and i
ncrease productivity, which are socially acceptable and economically viable
, are those which farmers favour. ISWC practices often have these qualities
but farmers have not always been able to adjust the techniques to rapid ch
anges in farming systems and increasing intensity of land use.
Soil productivity and economic modelling indicate that although yields decl
ines are lower when traditional technologies are used, long-term productivi
ty remains a problem. There is an urgent need to work closely with farmers
to improve and develop traditional SWC techniques, Copyright (C) 2000 John
Wiley & Sons, Ltd.