Agriculture Reference
In-Depth Information
Population
growth
Lack of
investment in
conservation
Poverty
Globalization
Land manager
decisions
Policies
Intensification
Soil degradation
Te chnology
Culture and
religion
Land cover
conversion
(urban sprawl,
deforestation)
Psychological
factors
FIGURE 7.4
Human dimensions affecting soil degradation.
7.3 FORMS OF SOIL DEGRADATION AND LAND
MANAGEMENT AS PROXIMATE CAUSE
In agroecosystems, soil degradation is indicated by a loss of soil fertility (Majule
2003; Reed 2008). Soil fertility includes the ability of the soil to supply essential
nutrients in the right amounts and at the right time to produce desired results (Rowell
1993). It also includes the quality of soil physical properties (soil structure) such as
the arrangements of soil granules and the pore spaces between them (Marshall and
Holmes 1979; Boix-Fayos et al. 2001; Ayres et al. 2009).
Since our interest in this chapter is the human dimension that drives soil degra-
dation, we focus on forms of degradation that result from human activities. These
include forms relating to soil chemical properties such as nutrient depletion, chemi-
cal contamination, and salinization, and structural properties such as compaction,
waterlogging, and erosion. As will be described below, each of these forms of deg-
radation has proximate causes related to land management (direct drivers). Land
management choices of particular relevance for soil degradation have been described
in three broad categories: lack of investment in conservation, intensification of agri-
cultural management, and conversion of land cover.
7.3.1 L
ack
of
I
nvestment
In
c
onservatIon
Lack of investment in conservation contributes to soil degradation. Although a vari-
ety of best management practices (BMPs) and projects to protect soil have been
developed for agricultural practices in a wide range of contexts, underinvestment
remains a problem worldwide. In fact, entire fields of study have developed around
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