The objective of this study was to assess the relationship of the C and N ratio with related to their basic
soil properties in different land use. Agricultural land use was our interested. Within the agricultural areas
themselves, cropping practices have been different depending on agricultural types. Those are divided into
three main crops, including horticulture, field crops and paddy fields. The dissimilar patterns of each
agricultural crop bring to the alterations of land cover, soil properties and further effect to biogeochemical
cycle in soils. Mangrove forest nearby agricultural areas was another land use selected. The reasons were
that (1) the difference of soil parent materials could be controlled and (2) the basic of land use is similar, as
the natural areas.