Characteristics, genesis and classification of a basin peat soil under negative human impact in Turkey

Abstract

The objective of this research was to investigate the morphology, genesis and classification of organic soils formed on depression and flat land around Lake Yenicaga, west-central Turkey. Formation of the area has been influenced by tectonic and karst processes. This peatland is important in this area due to its extensive use as a horticultural plant growth medium resulting from positive physical and chemical properties. Organic soils in the study area were formed in nutrient-rich conditions and it is classified as typical basin peat. Four representative pedons were excavated in the study area based on extensive observations performed with random grid method using an auger. Samples were taken from horizons in each profile for laboratory analyses. Organic matter contents ranged from 12.5 to 91.5% across all four pedons. Fiber contents were between 4.3 and 91.5%, and N ranged from 0.56 to 2.19%. Cation exchange capacity ranged from 37 to 222 cmol kg(-1), bulk density from 0.09 to 0.78 g cm(-3), lime from 0.15 to 2.62%. The pH and EC(e) values ranged from 5.38 to 7.92 and 0.50 to 3.80 dS m(-1), respectively. Sand, silt and clay contents of the organic soils ranged between 0.75-3.92, 40.70-74.77 and 24.15-57.30%, respectively. Differences in organic soils were found to depend on the environment, botanical origins, decomposition degrees, and groundwater composition. The organic soils of the research area were classified in the typic, hemic and hydric subgroups of Medifibrists (Soil Taxonomy 1999).