Diversity and Fertility of Soils in Doi Inthanon Area, Chiang Mai Province

Abstract

The diversity and fertility of 15 soils in the Doi Inthanon area of Chiang Mai province was studied using standard methods for field investigation and laboratory analysis, to characterize differences in their morphology, their physical and chemical properties and to assess their fertility levels. The soils occupied areas from 1,276 up to 1,563 m (above sea level, ASL) with slope ranging from 1 to 62%. Most soils were deep to very deep and acidic, with sand and silt dominating fine earth and a presence of an argillic horizon in all soils. They showed diversity in color, pH, presence of colluviated materials and depth of weathered materials within the profile. Their fertility levels were slightly different, but mostly medium in the upper part and medium or poorer in the layer between 30 and 100 cm. High organic matter content played an integral part in enhancing soil fertility level in all soils, combined with high amounts of available potassium in some soils. A small amount of bases and high values of exchangeable acidity signified the low base saturation percentage, which, in turn, had a negative impact on soil fertility levels in this area of Inthanon.