Agriculture Reference
In-Depth Information
for small-farmer choices. Section 14.4 elaborates on the role of faith-based fram-
ings of agricultural knowledge and the potential of this perspective, highlighting
the significance of mindsets that shape the choices farmers perceive. Following this,
we consider the literature on the diffusion of innovations in Section 14.5. Finally,
in Section 14.6, we introduce the innovation systems perspective and address the
growing recognition of the importance of stimulating and assisting local innovation
networks and platforms.
14.2 PERCEPTIONS OF SOIL FERTILITY
The soils of sub-Saharan Africa are notorious for their levels of degradation, a major
impediment to agricultural productivity in the region. Soil nutrients have been mined
or are carried away by rain or wind, creating a soil system with scarce nutrients and
little water-holding capacity. Consequently, declining soil fertility is a major concern
across many parts of sub-Saharan Africa (Vanlauwe et al. 2006; Swift and Shepherd
2007; Giller et al. 2009). The agricultural scientist or extension agent often frames
this issue from an agroecological standpoint, citing nutrient deficiency, low soil
organic matter, water stress, and high erodibility as limiting factors in soil fertility
and crop production. The current practices of the small farmer, such as overgrazing
and continuous cropping without nutrient replacement, are targeted as improper soil
management practices that further exacerbate these agroecological issues (Vanlauwe
et al. 2006; Kolawole 2013). Mitigating the loss of nutrients has proved to be a sig-
nificant challenge as the rate of input intensity for inorganic fertilizers is estimated to
be between 8 and 12 kg ha
−1
compared with an average of 83 kg ha
−1
for all develop-
ing countries (Mwangi 1997). Owing to the expense and the inaccessibility of these
inorganic inputs, alternative approaches that build on traditional low-cost soil fertil-
ity management are being promoted.
Despite the apparently obvious nature of these problems, farmer knowledge and
perception of soil health and fertility often differs from that of research scientists
and extension agents (Gray and Morant 2003). In a study to assess farmer perception
and knowledge of soil fertility in Ethiopia, Corbeels et al. (2000) note that scientists
often quantify soil fertility by nutrient chemical composition, without giving much
consideration to physical properties. From a scientific perspective, soil fertility refers
to the ability of the land to produce consistent, high crop yields that can be achieved
through inputs of inorganic fertilizer or biological nitrogen fixation. In contrast, the
small farmer defines fertility by a series of easily observable factors quite distinct from
the technical focus imposed by the scientists and extension agents. From a farmer's
perspective, the soil characteristics affecting plant growth of most interest are indi-
cated by soil color, crop yield, water-holding capacity, foliar color, and the presence
of indicator weeds. One of the most important factors for the Ethiopian farmers was
soil color, which reflects otherwise hidden parent material and determines specific
soil characteristics (Corbeels et al. 2000). These findings were repeated for studies of
farmers in Zambia (Ajayi 2007) and Ghana (Dawoe et al. 2012).
Scientists and farmers have the potential to enrich one another's knowledge of
soil fertility and improve on the capacity for innovation. Indeed, Schuler et al. (2006)
found that collaboration between farmers and soil scientists significantly increased
