Keragaman bahan organik dan tekstur tanah berdasarkan kedalaman pada tanah aluvial dari brebes

Abstract

"Alluvial Soil" is soil formed from alluvial sediient that originated from mud transported and deposited by flood. Most of materials of the mud are derived from eroding soils or streambanks and contain an appreciable organic material. The alluvial sediment is deposited through a repeated sedimentation process that resulted in an irregular texture and organic-C content throughout the layers. Such alluvial sediment is regarded as recent sediment (Soil Taxonomy, 1999). The soils formed from this recent alluvial sediment, therefore, would be juvenile soils, which are among others characterized with an irregular texture and organicC content throughout the solum. In Soil Taxonomy (1999), organic-C content that decreases irregulary with depth or that is 0.2 % or more at a depth of 125 cm are used as determining characteristics of sub order Fluvent and subgroup Fluventic. However some data of tropical soils show that the content of soil organic-C of 0.2 % or more at a depth of 125 is also common for soils formed from non-alluvial parent materials. The objective of this research, therefore, is to collect data of organic-C of soils developed on floodplain from recent alluvium to clarify if the value of 0.2 % organic-C content at a depth of 125 cm is too low for the above use.