Table 2.8 Local soil types using farmers’ soil quality assessments in the Bor Krai research area,
north-west Thailand, with corresponding stocks of total Nitrogen (Nt) and available bases
(S-value) based on farmers’ evaluations
Local soil classes
WRB-soil types
Quality
evaluation
Stocks Nt
kg m
À2
Evaluation
a
S-value
mol m
À2
Evaluation
b
Black soil
h
1.21
h
136
h
STD/n
0.275/9
33/9
Hard red soil
h
1.00
mh-h
49
m
STD/n
0.258/6
11/6
Soft red soil
mh
0.95
mh
89
mh
STD/n
0.034/2
28/2
Mixed hard red-black soil
m
0.85
mh
258
vh
STD/n
0.023/2
84/2
Mixed yellow-black soil
m
0.85
mh
66
mh
STD/n
0.174/3
12/3
Yellow and orange soil
l
0.5
l
30
m
STD/n
0.084/3
10/3
Acrisols
1.09
h
50
m
STD/n
0.314/3
8/3
Alisols
1.00
mh-h
88
mh
STD/n
0.243/8
40/8
Luvisol
1.13
h
193
h
STD/n
0.378/2
7/2
a
Nt (kg m
À2
): 0.1–0.25 ¼ low, 0.25–0.5 ¼ moderate, 0.5–1 ¼ moderate high, 1–2 ¼ high
b
S-value (mol c kg m
À2
): 1–10 ¼ low, 10–50 ¼ moderate, 50–100 ¼ moderate high, 100–200 ¼
high, >200 very high
Table 2.9 Calculated costs of the two soil mapping approaches and for eliciting local knowledge –
based on local salaries
Soil mapping by
augering
a (excluding
lab-analysis)
Soil survey using a transect
mapping approach
b (including
lab-analysis)
c
Local
knowledge
d
Scale
<¼ sub-watershed
(1:10,000)
<¼ sub-watershed (1:10,000)
sub-watershed
commune
area
Required
sampling
points per
sq. km
400
5–(8)
0
Costs in Euros
e
2,000
650 (125/pit)
350
a
According to Schlichting et al. (1995)
b
According to Schuler (2008)
c
Laboratory expenses based on Herrmann (2005)
d
Including labor costs for a 1.5 day workshop, with one senior (SR) and one local junior researcher
(YR), one translator (T) and six farmers (F), compiling a local soil map
e
For computing labor costs in €/day: €100 for SR, €20 for YR, €10 for T, and €6 for F
76
K. Stahr et al.