Baocheng Chen

Genetic characteristics and taxonomic classification of Fimic Anthrosols in China

Abstract The genetic and developmental characteristics of Fimic Anthrosols derived from several types of parent soils in China, and the relationships between Fimic Anthrosols, different vegetable-cultivated soils and parent soils were studied. As the degree of soil ripening increased, there were tendencies toward increases in concentration of organic matter, many nutrient elements and the water-resistant crumb-granular structure. Significant variations in the vertical distribution of the nutrients were found in the soil profiles due to the soils being at different ripening stages. The typical characteristics of these Fimic Anthrosols were great accumulation of organic matter, intensive enrichment of available phosphorus and high intensity of microbial activity. Also evident were increasing tendencies toward increases in the total and available content of Zn, Pb, Cu and other metal elements. Heavy metal analyses and correlation relationships suggested that Zn, Pb and Cu are the main contaminant elements in Fimic Anthrosols and in vegetable-cultivated soils with different ripening stages. The thickness of the fimic epipedon, the contents of available P and organic matter can be regarded as the diagnostic criteria for the classification of Fimic Anthrosols in Chinese Soil Taxonomy. Recognition of the distinct of anthropedogenic fimic processes proved essential in the proper classification of vegetable-cultivated soils. These investigations established a theoretical basis for the scientific and quantitative classification of the Fimic Anthrosols.