Farmers' initiatives in land husbandry: promising ... - Prolinnova

Technical Report No. 27
ASSESSMENT
Costs and benefits
Musyoka calculates that production of his main crop, maize, doubled after the runoff harvesting system
was introduced – due mainly to the extra moisture available. Increased farm income is an associated
benefit. It is estimated that soil loss approximately halved. Supplementary benefits recorded include
increased fodder production.
An approximate construction input of just over 100 days per hectare is stated for the hand labour involved.
That represents the infrastructure of bunds and channels. Other costs (equipment, seedlings etc) are
minimal. The annual requirement for maintenance is estimated at 10 person days per hectare. This is less
in a dry year, but can be much more due to damage caused by extra runoff during heavy rains. Clearly,
while it is a low external-input system, this is a relatively expensive technology, and particularly demanding
on labour. Nevertheless because the system is directly linked to increased production, these are costs
which can be recovered quickly. The benefits compared with investment costs are recorded to be ‘positive’
in the short term and ‘very positive’ in the longer term.
Adoption
The farmer has designed systems for two neighbours: indeed the main channel from the road passes
through the farm of one of these, with whom he works co-operatively. The total adoption is recorded to
be around 40 farmers. They are all now harvesting runoff from tracks or hillsides in this vicinity. However,
several of those who have taken up his initiative have not managed to guide the runoff water through the
farm as effectively as Musyoka has done.
Research needs/ possible improvements
One improvement regarding adoption of the system would be to assist farmers in layout and design.
These road runoff harvesting systems can be very effective, but if not well designed or managed may lead
to high maintenance requirements and an increased erosion hazard. An idea for improving Musyoka’s
system, from the WOCAT data collectors who visited him, is that he could make his channels shallower
to allow more water to spillover into his fields, rather than it being lost through deep infiltration. In terms
of research, this is one of the systems most in need of validation and full description, as water harvesting
is extremely important in the drylands of Kenya. And here is a system that works.
Concluding comments
In conclusion, this is an initiative that demonstrates the great potential of runoff harvesting in semi-arid
areas. It has been designed, put into practice, and further improved by a farmer on his own. There have
been plenty of project initiated water harvesting systems promoted in semi-arid regions of Kenya (and
sub-Saharan Africa more generally: Critchley et al, 1992), but these have often been criticised for being
outside the capacity of the land users. Musyoka has demonstrated that this need not be the case.
WOCAT data collection: Patrick Kirimi; Peter Mukungi, MOARD
Extra Information: Kenya PFI team; Mwarasomba and Mutunga (1995)
WOCAT Reference: KEN 22
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