Lithologic discontinuity in Andisols on tea plantation area in West Java, Indonesia

Abstract

Tea plantation areas are normally found on Andisols developed from volcanic eruptions. Volcanic eruptions can occur within several periods, resulting in a sequence of soil layers that can differ in every period and produce lithologic discontinuity in the soil profile. Lithologic discontinuities were investigated in Andisols on Ciater Tea Plantation in Ciater, West Java, Indonesia. Andisols in this area developed from the eruption of Mt. Tangkuban Parahu, Mt. Dano and Mt. Tampomas derived from two geological formation, the Qyd (Middle Holocene) and Qyt (Early Holocene). The objective of this research was to investigate the lithologic discontinuity of Andisols in Ciater Tea Plantation through macromorphological observations from four profiles in this location. The results showed that there were lithologic discontinuities in all profiles, indicated by unusual changing color detected by Munsell Soil Color Chart and increasing organic carbon content in certain depth. Some A buried horizons (Ab) were found, indicated that the underlying soils had developed from the parent material of the earlier eruption period than the overlying horizons. Detailed analyses of mineralogical and element in sand and silt fraction were needed to have the more accurate information of lithology discontinuities. Instruments like X-Ray Fluorescence Spectrometry and Visible Near-Infrared Diffuse Reflectance Spectroscopy can be explored to investigate the lithologic discontinuity.