of soil macropores (through sufficient and adequate organic inputs) had a positive
influence on local infiltration rates. The study proved that WaNuLCAS can be used
to study, understand and explore the management options available in terms of
improving tropical hillside cropping systems threatened by soil degradation.
Moving from the plot-scale to watershed-scale requires the application of
spatially-explicit modeling approaches which commonly build on GIS (Geographic
Information Systems). The recently developed Land Use Change Impact Assessment model (LUCIA) (Marohn and Cadisch 2011) aims to bridge a gap in current
modeling approaches, as it has the capability to simulate overland flows and soil
erosion, soil fertility as a function of soil organic matter and plant available
nutrients, as well as surface cover development and vegetation growth for crops
and tree-based land use systems, in an integrative and spatially-explicit fashion. An
example of a recent LUCIA modeling study is presented in Chap. 10 of this book.
7.5.2 Farmer-Based Approaches
7.5.2.1 Participatory Assessment Approaches
A study by Lippe et al. (2011) in Ban Put, Chieng Khoi commune in north-west
Vietnam used a set of participatory assessment tools to highlight the linkages between
soil fertility degradation and land use change. In the following section, outcomes
from use of the participatory tool referred to as ‘causes and consequences’ – a tool
similar to the commonly known preference ranking technique (Chambers 1994), are
presented, in order to discuss the advantages and disadvantages of using participatory, farmer-based soil degradation assessments. For this purpose, a set of focus
group discussions was organized in January 2008 with 32 farmers from Ban Put. To
reduce output bias, discussions groups were split into younger (18–40 years) and
older (41–65 years) participants, as well as males and females (see also: Lippe et al.
2011 for further details). The results of a previously conducted focus group session on
land use history had pointed to a decline in soil fertility in the area, as a growing
threat. Accordingly, participants described the causes and consequences of the soil
degradation phenomenon, and if possible, provided recommendations on how to
improve the existing farming situation through the use of cards. Cards were tagged
on a A0 paper sheet and grouped together to obtain a superior order (Table 7.5), to be
used as an input in further focus group sessions. When comparing the local
observations and perceptions of farmers with the scientific findings (e.g., Dung
et al. 2008), commonalities were found, such as to “abandon fallow periods results
in soil degradation”. In this study, the participatory assessment approach was able to
confirm or pinpoint the facts observed by farmers in the field more quickly than if
analysed as part of a research study, providing the fundamental background information necessary for the layout for detailed studies of soil degradation and crop yield
response (e.g., Boll et al. 2008). Taken as a whole, the presented study falls in line
256
T. Hilger et al.
influence on local infiltration rates. The study proved that WaNuLCAS can be used
to study, understand and explore the management options available in terms of
improving tropical hillside cropping systems threatened by soil degradation.
Moving from the plot-scale to watershed-scale requires the application of
spatially-explicit modeling approaches which commonly build on GIS (Geographic
Information Systems). The recently developed Land Use Change Impact Assessment model (LUCIA) (Marohn and Cadisch 2011) aims to bridge a gap in current
modeling approaches, as it has the capability to simulate overland flows and soil
erosion, soil fertility as a function of soil organic matter and plant available
nutrients, as well as surface cover development and vegetation growth for crops
and tree-based land use systems, in an integrative and spatially-explicit fashion. An
example of a recent LUCIA modeling study is presented in Chap. 10 of this book.
7.5.2 Farmer-Based Approaches
7.5.2.1 Participatory Assessment Approaches
A study by Lippe et al. (2011) in Ban Put, Chieng Khoi commune in north-west
Vietnam used a set of participatory assessment tools to highlight the linkages between
soil fertility degradation and land use change. In the following section, outcomes
from use of the participatory tool referred to as ‘causes and consequences’ – a tool
similar to the commonly known preference ranking technique (Chambers 1994), are
presented, in order to discuss the advantages and disadvantages of using participatory, farmer-based soil degradation assessments. For this purpose, a set of focus
group discussions was organized in January 2008 with 32 farmers from Ban Put. To
reduce output bias, discussions groups were split into younger (18–40 years) and
older (41–65 years) participants, as well as males and females (see also: Lippe et al.
2011 for further details). The results of a previously conducted focus group session on
land use history had pointed to a decline in soil fertility in the area, as a growing
threat. Accordingly, participants described the causes and consequences of the soil
degradation phenomenon, and if possible, provided recommendations on how to
improve the existing farming situation through the use of cards. Cards were tagged
on a A0 paper sheet and grouped together to obtain a superior order (Table 7.5), to be
used as an input in further focus group sessions. When comparing the local
observations and perceptions of farmers with the scientific findings (e.g., Dung
et al. 2008), commonalities were found, such as to “abandon fallow periods results
in soil degradation”. In this study, the participatory assessment approach was able to
confirm or pinpoint the facts observed by farmers in the field more quickly than if
analysed as part of a research study, providing the fundamental background information necessary for the layout for detailed studies of soil degradation and crop yield
response (e.g., Boll et al. 2008). Taken as a whole, the presented study falls in line
256
T. Hilger et al.