SIERRA LEONE maq 4ª.indd - agrilife - Europa

7 Conclusions
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may actually benefit from market interaction.
The review of the literature concerning these
issues indicates several technical alternatives
which require a more detailed evaluation from
a socio-economic point of view (Cornell et al.,
2007). Although the socio-economic assessment
of technology and agronomic issues escapes
the scope of the present report, agronomic
practices that are seen as relevant to address
the challenges in Sierra Leone are briefly
discussed. Some experts argue for the benefits
of “conservation agriculture” which consists
in a series of techniques aiming at minimise
soil disturbance via maximising year round soil
cover (with residue from previous crops or a
cover crop), minimising hoeing / tilling, and
rotating crops to discourage pests, and improve
soil health (soil structure) 50 . Another approach
in seeing the future of slush and burn consists
in preventing its decline by creating a financial
value for the carbon stored in forests, trough
offering incentives for developing countries to
reduce emissions from forested lands and invest
in low carbon paths to sustainable development51 .
From this perspective, agro-forestry practices
could also be included in order to support large
populations who harvest fruit, leaves, bark,
gums and resins leaving the forest structure
more or less intact (ibid). In addition, trees
provide multiple benefits such as nitrogen fixing,
mulching, fodder, fuel wood, food, medicines,
among other uses which can serve to diversify
the income sources of (semi)subsistence
farming. In this respect, it is also highlighted
by the author the crucial importance of
communities having entitlement and benefiting
from the management of their natural resources,
so that they become the key custodians thus
ensuring sustainable exploitation practices.
Other authors (Egashira et al., 2006) argue
for slash and mulch as a technique to prevent
soil from degradation (so common under slash
50 Theo Dillaha Program Director of the SANREM CRSP and
Professor of Biological Systems Engineering at Virginia
Tech in http://www.ourfutureplanet.org/news/331
51 Yemi Katerere, Head of the UN-REDD Programme in
http://www.ourfutureplanet.org/news/331
and burn practices). According to the authors,
putting sufficient amounts of fallen tree leaves
mixed with livestock excretions on the top of
soil, followed by a cover of weeds, rice straws
and maize stalks, activates small animals and
microorganisms in soil hence improving soil
structure and soil fertility status suitable for crop
production. Ultimately, enrichment of organic
matter in the soils increases the water holding
capacity in the ground.
According to Cornell et al. (2007) alternatives
to the slash and burn system may be clustered
into three groups:
(i) Poverty alleviation alternative. Consists
in providing jobs, incomes, and social
services to growing populations; specifically,
orienting poor people to relocate off farming
and/or out of the forested areas (i.e. offering
livelihood possibilities others than shifting
cultivation).
(ii) Improving productivity and subsequently
economic returns on cultivated land under
slash and burn systems; the objective is to
limit the growth of the area under shifting
cultivation. Methods include use of improved
seeds, increased use of fertilizers both
minerals and manure. Concerning fertilizers,
while the first is difficult to realise since
it implies increasing imports, the second
might be a more sustainable alternative once
cattle species adapted to local environment
(trypanosome-tolerant) are introduced,
supported and widespread.
(iii) To increase the area devoted to modern,
intensive farming, thus producing enough
food to feed growing populations. It should
be noted however that the mechanisation
requirements (e.g. due to the high density
of multi-cropping and/or agro-forestry) may
not be possible or sustainable at all in the
tropics. Therefore this alternative may only
be partially applied.