susceptible to erosion (Baboule et al. 1993) This
erosion is accentuated by a rapid increase in the
agricultural population due to population growth
and migration (M’biandoun and Olina 2007).
Although biophysical and demographic factors
are in part responsible for land degradation in
SSA, inappropriate land-use practices mainly
related to cotton development have accelerated
the rate of harm (Ngondjeb et al. 2014).
On the other hand, for nearly 20 years, a
series of projects have been promoting conservation agriculture with the support of donors in
order to sustainably improve the agricultural
production of vulnerable farms in the SSA (Abou
et al. 2006). Given the known and potential
negative effects of soil erosion, governments in
Cameroon have been undertaking different policies and strategies to address soil degradation as
part of poverty reduction and environmental
conservation efforts. This is particularly the case
of the 1994–2002 project “Développement paysanal et gestion des terroirs” (DPGT), followed
by the Eau-Sol-Arbre (ESA) project since 2002.
These projects promote agricultural conservation
techniques including non-tillage practices,
mulching, contour edges, alley farming and terrace construction that reduce the phenomenon of
accelerated erosion and improve the organic
status of soils (Thevoz 2000). Generally, however, efforts so far to promote the technologies
have had insignificant impacts on increasing the
adoption of different soil conservation practices.
As a result soil erosion remains an intractable
challenge to the area.
The limited success of various conservation
practices suggests the need to explore the problem areas in implementing conservation activities. Most studies focus on the on-farm effects of
the soil erosion but for public policy to address
the challenge of soil erosion a comprehensive
assessment of off-site impact is needed. This
research aims at tackling this problem by
assessing the off-site impacts of erosion and the
value of avoiding this effect from society’s point
of view. Hence, our study provides the necessary
inputs in designing possible intervention
strategies.
The SSA of Cameroon is one of the most
vulnerable areas for the off-site impacts of soil
erosion, including proximate property damage,
run-off and sedimentation of Lake Lagdo and
Lagdo Dam, habitat degradation, and compromising rural road safety (Baboule et al. 1993).
The presence of off-site costs/benefits leads to
market failure or externalities (Barbier 1996;
Boxall et al. 1996; Pretty et al. 2000; Hein 2007).
These impacts are not reflected in market price
since they affect other agents in the community
who do not cause the action. The failures of the
market to take account of this cost encourage
actions that are not economically optimal for
society as a whole. Bekele (2003) noted that this
externality has implications for soil problems,
especially in developing countries i.e. farmers
lack sufficient incentive to consider the off-site
impacts of their practice. This aggravates the
problem further and leads to non-optimal
resource use and allocation. The need to control
the problem through appropriate mechanisms
also requires an assessment of the value of the
resource.
The change in land use practices generates
multiple benefits as environmental, societal and
cultural externalities (Zhang et al. 2007; Nijkamp
et al. 2008). The economic assessment of the
environmental benefits of agriculture requires a
thorough understanding of the environmental
services through the lens of environmental economics. When referring to environmental services, environmental economists do not rely on
the functions that natural capital can fulfil, but
rather on the environmental benefits that human
activities can generate (Chevassus-au-Louis et al.
2009; Swinton et al. 2007). In this study, we
frame positive externalities of production as
service-externality, as opposed to servicefunction of the ecological approach (Gillis et al.
1998) and service-delivery of the services
approach (Gadrey 2000; Aznar and PerrierCornet 2003).
The environmental service is therefore
understood here as a positive externality of production resulting from human activity or also
identified with an unintentional relationship
94
D. Y. Ngondjeb and E. Ayuk
erosion is accentuated by a rapid increase in the
agricultural population due to population growth
and migration (M’biandoun and Olina 2007).
Although biophysical and demographic factors
are in part responsible for land degradation in
SSA, inappropriate land-use practices mainly
related to cotton development have accelerated
the rate of harm (Ngondjeb et al. 2014).
On the other hand, for nearly 20 years, a
series of projects have been promoting conservation agriculture with the support of donors in
order to sustainably improve the agricultural
production of vulnerable farms in the SSA (Abou
et al. 2006). Given the known and potential
negative effects of soil erosion, governments in
Cameroon have been undertaking different policies and strategies to address soil degradation as
part of poverty reduction and environmental
conservation efforts. This is particularly the case
of the 1994–2002 project “Développement paysanal et gestion des terroirs” (DPGT), followed
by the Eau-Sol-Arbre (ESA) project since 2002.
These projects promote agricultural conservation
techniques including non-tillage practices,
mulching, contour edges, alley farming and terrace construction that reduce the phenomenon of
accelerated erosion and improve the organic
status of soils (Thevoz 2000). Generally, however, efforts so far to promote the technologies
have had insignificant impacts on increasing the
adoption of different soil conservation practices.
As a result soil erosion remains an intractable
challenge to the area.
The limited success of various conservation
practices suggests the need to explore the problem areas in implementing conservation activities. Most studies focus on the on-farm effects of
the soil erosion but for public policy to address
the challenge of soil erosion a comprehensive
assessment of off-site impact is needed. This
research aims at tackling this problem by
assessing the off-site impacts of erosion and the
value of avoiding this effect from society’s point
of view. Hence, our study provides the necessary
inputs in designing possible intervention
strategies.
The SSA of Cameroon is one of the most
vulnerable areas for the off-site impacts of soil
erosion, including proximate property damage,
run-off and sedimentation of Lake Lagdo and
Lagdo Dam, habitat degradation, and compromising rural road safety (Baboule et al. 1993).
The presence of off-site costs/benefits leads to
market failure or externalities (Barbier 1996;
Boxall et al. 1996; Pretty et al. 2000; Hein 2007).
These impacts are not reflected in market price
since they affect other agents in the community
who do not cause the action. The failures of the
market to take account of this cost encourage
actions that are not economically optimal for
society as a whole. Bekele (2003) noted that this
externality has implications for soil problems,
especially in developing countries i.e. farmers
lack sufficient incentive to consider the off-site
impacts of their practice. This aggravates the
problem further and leads to non-optimal
resource use and allocation. The need to control
the problem through appropriate mechanisms
also requires an assessment of the value of the
resource.
The change in land use practices generates
multiple benefits as environmental, societal and
cultural externalities (Zhang et al. 2007; Nijkamp
et al. 2008). The economic assessment of the
environmental benefits of agriculture requires a
thorough understanding of the environmental
services through the lens of environmental economics. When referring to environmental services, environmental economists do not rely on
the functions that natural capital can fulfil, but
rather on the environmental benefits that human
activities can generate (Chevassus-au-Louis et al.
2009; Swinton et al. 2007). In this study, we
frame positive externalities of production as
service-externality, as opposed to servicefunction of the ecological approach (Gillis et al.
1998) and service-delivery of the services
approach (Gadrey 2000; Aznar and PerrierCornet 2003).
The environmental service is therefore
understood here as a positive externality of production resulting from human activity or also
identified with an unintentional relationship
94
D. Y. Ngondjeb and E. Ayuk