50 % using local knowledge would reduce the total cost to 5,600 Euros. From a
financial point of view, the use of local knowledge is therefore a necessity when only
poor spatial information regarding natural resources is available.
2.4.6 Usefulness and Limitation of Local Soil Knowledge
Our studies confirmed the usefulness of PRA tools in identifying local soil knowledge, comprising soil types, their properties and suitability, and soil maps. Based on
long-term observations and experience, which are difficult to acquire using scientific
methods, local soil knowledge enables one to identify ‘hotspots’ in terms of vulnerability and susceptibility for using site specific and site adapted measures. Local soil
knowledge relies on a certain, spatially limited realm of experience, especially
during soil suitability assessments, because they are based on a holistic approach
and long-term observations, which provide helpful hints for further assessments
based on scientific analysis. However, local soil knowledge is applicable for
extrapolating only on a conditional basis. Local soil units span a larger area and
do not comprise spatial variations, but this fact should not necessarily be considered
a disadvantage, because the traditionally scientific soil mapping approaches also
have disadvantages because the collected information is, strictly speaking, point
data. The integration of both approaches in our view, means the production of
suitable and from a user perspective, acceptable, soil maps for land-use planning
purposes. Taking local soil knowledge into consideration also helps to prevent
inappropriate decisions being made in terms of land-use planning, such as the
promotion of rubber in Son La as described above. Due to its holistic characteristics,
local soil knowledge includes natural as well as socio-economic contexts, and;
hence, can help to remedy the shortcomings described by Minh (2010) and, as a
consequence, help to establish socially accepted agricultural production systems.
2.5 Development of Soils on Limestone in Tropical
Southeast Asia
Limestones are generally rather scarce in tropical areas, and this is especially true for
the savannah areas of South America and Africa. Though in Southeast Asia limestone
areas occur rather frequently, covering about 10 % of the region, or around
215,000 km
2 (Mouret 2004).
6 The main reason for this is the fact that Southeast
Asia did not belong to the old Gondwana Southern Continent and so contains a series
of Paleozoic and Mesozoic rocks which have been tectonically translocated. The
6 This section was written by Karl Stahr, Ulrich Schuler, Petra Erbe, Mehdi Zarei, Gerhard
Clemens, Volker Haering and Ludger Herrmann.
2 Beyond the Horizons: Challenges and Prospects for Soil Science and Soil. . .
77
financial point of view, the use of local knowledge is therefore a necessity when only
poor spatial information regarding natural resources is available.
2.4.6 Usefulness and Limitation of Local Soil Knowledge
Our studies confirmed the usefulness of PRA tools in identifying local soil knowledge, comprising soil types, their properties and suitability, and soil maps. Based on
long-term observations and experience, which are difficult to acquire using scientific
methods, local soil knowledge enables one to identify ‘hotspots’ in terms of vulnerability and susceptibility for using site specific and site adapted measures. Local soil
knowledge relies on a certain, spatially limited realm of experience, especially
during soil suitability assessments, because they are based on a holistic approach
and long-term observations, which provide helpful hints for further assessments
based on scientific analysis. However, local soil knowledge is applicable for
extrapolating only on a conditional basis. Local soil units span a larger area and
do not comprise spatial variations, but this fact should not necessarily be considered
a disadvantage, because the traditionally scientific soil mapping approaches also
have disadvantages because the collected information is, strictly speaking, point
data. The integration of both approaches in our view, means the production of
suitable and from a user perspective, acceptable, soil maps for land-use planning
purposes. Taking local soil knowledge into consideration also helps to prevent
inappropriate decisions being made in terms of land-use planning, such as the
promotion of rubber in Son La as described above. Due to its holistic characteristics,
local soil knowledge includes natural as well as socio-economic contexts, and;
hence, can help to remedy the shortcomings described by Minh (2010) and, as a
consequence, help to establish socially accepted agricultural production systems.
2.5 Development of Soils on Limestone in Tropical
Southeast Asia
Limestones are generally rather scarce in tropical areas, and this is especially true for
the savannah areas of South America and Africa. Though in Southeast Asia limestone
areas occur rather frequently, covering about 10 % of the region, or around
215,000 km
2 (Mouret 2004).
6 The main reason for this is the fact that Southeast
Asia did not belong to the old Gondwana Southern Continent and so contains a series
of Paleozoic and Mesozoic rocks which have been tectonically translocated. The
6 This section was written by Karl Stahr, Ulrich Schuler, Petra Erbe, Mehdi Zarei, Gerhard
Clemens, Volker Haering and Ludger Herrmann.
2 Beyond the Horizons: Challenges and Prospects for Soil Science and Soil. . .
77