Abstract
Author studied the oxidation-reduction potentials of the profiles of orchard and tea garden soils and the results are summarised as follows : 1) Orchard soil (alluvial) The potential had a close relation with tree growth and fruit production, i. e., poor soil showed always lower potential than richer soil and this is more distinct in the deeper horizon of the profile. 2) Tea garden soil (alluvial and diluvial) The potentials of both poor and rich soil were studied, and as shown in 1), poor soil showed lower potential than richer soil again. 3) From these results, it will be concluded that the low productivities of orchard and tea garden soils may be partly attributed to the reduced state in the soil
