Soil Organic Matter Composition of Arenosols in Western Rhodopes Mountain, Bulgaria

The paper studies soil organic matter in sandy soils from Western Rhodopes region,which fall within the territory of Pazardzhik district of the South central planning region inBulgaria. Brief information on the morphological characteristics of the soils established so farand their initial studies are presented. The composition of soil organic matter is determined byanalysing its extractable (soluble) fractions and insoluble residue. The humus content ofstudied soils is discussed by comparison with soils of the same soil type and those withsimilar stage of development of soil-forming processes. The state of soil organic matter isevaluated according to various indicators related to the degree of humification, the state ofhumic acids and the type of humus in surface horizons.