Characteristics of Volcanic Ash Soils from Southern Part of Mt. Tangkuban Perahu, West Java
No Thumbnail Available
Date
2012-12-18
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Balai Besar Penelitian dan Pengembangan Sumberdaya Lahan Pertanian
Abstract
Description
Three soil pedons developed on young andesitic volcanic ash with high mineral deposit and high P retention, granular soil structure, high porosity, and low bulk density, were differentiated based on their morphological, physical, chemical and mineralogical characteristics. Pedons 1 and 3 are discontinue or bisequm pedons characterized by the presence of more contrast colour and new buried materials on layer 4, while pedon 2 isrelatively younger than pedons 1 and 3. Mineralogical composition of pedons 1 and 3 is very different compared with pedon 2. Pedons 1 and 3 have high total porosity resulting in easy to the soil leaching. Pedon 2 with higher bulk density tends to be more compact although its soil texture is light, indicating soil character of Andisols from this young volcanic material. High P retention and low base saturation may bring about high Pfertilizer need. Pedons 1 and 3 have lower feldspar content as K sources compared with pedon 2, while the content of opaque minerals is higher in pedons 1 and 3 indicating more developed pedons. The top layer of pedon 1 has lower opaque minerals but higher hornblende than pedon 3 due to different land use. The presence of alophane minerals in pedon 1 and 3 can be detected from the results of Selective Dissolution Analysis, but they do not detected on X-ray diffraction patterns. In pedon 2, however, alophane minerals show convex diffraction patterns. Based oncharacteristics of their soil physics, chemistry, and mineralogy, pedons 1 and 3 were classified as Thaptic Hapludands, and pedon 2 as Typic Melanudands. The increase of P availability on the three pedons can be done by P fertilization and liming to accelerate substitution of Al-P to Ca-P and increase of soil pH.