L1 /
10
CH3041
PRELIMINARY
ASSESSMENT
• Soil : auger (> 5 cm) samples of soil
(1kg) taken at every 50 cm down to 2m
or at every change in horizon. » 4 holes / ha.
(1kg) taken at every 50 cm down to 2m
or at every change in horizon. » 4 holes / ha.
• pH is measured directly with soft soils or
mixed to a paste.
soil:water 1g:5mL
pHField £ 4 actual ASS
mixed to a paste.
soil:water 1g:5mL
pHField £ 4 actual ASS
•Peroxide test : small volume of soil and
30% peroxide (pH checked at 4.5) are added
to a test tube and the pHField-ox is measured
after 1 hour along with the severity of rxn.
30% peroxide (pH checked at 4.5) are added
to a test tube and the pHField-ox is measured
after 1 hour along with the severity of rxn.
Clays & loams pHField-ox
< 3 indicates ASS.
Organic
matter (mangrove muds) &
MnxOy minerals interfere!
MnxOy minerals interfere!
ISFET
Stainless Steel
Stainless Steel
