Characteristic of soils along toposequence on limestone mountain footslope | ลักษณะดินตามลำดับภูมิประเทศบริเวณที่ลาดเชิงเขาหินปูน

Characteristics of soils along footslope of limestone mountain were studied in farmer field used for growing sugarcane in Wangdong subdistrict, Muang district, Kanchanaburi province. There were eight locations selected, comprising lower footslope (ND-1), upper lower footslope (ND-2), lower middle footslope (ND-3), middle footslope (ND-4),upper middle footslope (ND-5), erosional lower upper footslope (ND-6), lower upper footslope (ND-7), and upper footslope (ND-8). This study aimed at investigating the relationship of soil characteristics and their position on footslope. Soil morphological, physical and chemical properties were examined and analyzed based on standard methods. All soils studied were classified as Aquic Haplustalf (ND-6), Inceptic Haplustalf (ND-3), Calcic Haplustalfs (NDs-1, 2, 4 and 5) and Typic Haplustalfs (NDs-7 and 8). The position on the landscape had no relationship with soil classification units but land surface form and break of the slope reflected a difference in their classification at subgroup level. Their effective depth ranged from 52-163 cm. Soils formed form colluvium of limestone located on the upper footslope were deeper than those derived formed local alluvium and situated on lower position of the footslope. Landscape position also had a relationship with clay content. Soils on the upper and middle footslope had greater amounts of clay (306-700 g/kg) than did those on the lower position (232-532 g/kg). Soil chemical properties rarely showed clear association with the landscape position. All soils were composed of moderately low to low organic matter content and calcium tended to decrease in soils on the upper footslope where cation exchange capacity tentatively increased.