Genetic Characteristics And Taxonomic Classification Of The Representative Soils In Zhejiang Province

Variations of the climate, geography, geology and land-use type of Zhejiang province resulted in complexity of soil formation processes, genetic characteristics, and the spatial distribution of soil types. For quantitative classification of the soils, twenty-nine representative soil profiles were collected from different areas of Zhejiang province. The soil profiles included11paddy soils and18forest and upland land soils. Formation conditions of the soils were well investigated and described, and physical and chemical properties of the soils were analyzed.The results obtained in the study were summarized as follow:(1)The18foresty and upland soils under the study had obvious profile differentiation and deep soil depths. With increasing soil depth, soil structure transformed from granular structure to block structure. Soil colors were mainly yellow-brown and red brown, and the surface soil colors were relatively darker. The content of silt made up a large proportion of the mechanical composition. The soil texture varied from loam to sandy loam. The weathering degree of the studied soil varied with different soil-forming conditions, and several profiles formed Argic horizon. The content of organic matter varied from different utilization mode and hydrothermal conditions. The soils were mainly acidic to strong acid with low base saturation. There was significant difference in the content of total iron, owing to the parent materials. Such as it is, Fed/Fet was higher than40%. Suface soils were rich in nitrogen, but low in available phosphoru, while potassium was different with parent material and K fertilization situations. With the rise of elevation, the content of soil clay and Fed/Fet reduced while the content of organic matter, the cation exchange capacity and Feo/Fed increased.(2)The11paddy soils under the study had obvious profile differentiation and most had deep soil depths. With increasing soil depth, soil structure transformed from granular structures to prisms or block. Soil colors were mainly yellow-brown and grayish yellow, and four soils appeared gleyic features with long-term saturating with water. The content of silt made up a large proportion of the mechanical composition. The soil texture was loam. Soils were slightly acidic to neutral and acidification was most obvious. Surface soil accumulated more organic matter. The content of total iron and (Fed-Feo)/Feo increased from the surface to the bottom of soil, contrary to the trend of Feo/Fed and Fep/Fed. Thereinto, seven soils had obvious iron accumulation phenomenon in their hydragric horizons, while four soils had iron leaching sub-horizon. The plough layer of paddy soils’nutrients ranged the same as forest and upland land soils.(3)According to the Keys to Chinese Soil Taxonomy (3rd edition), ten diagnostic horizons and eleven diagnostic characteristics of the soils were characterized. The diagnostic horizons were ochric epipedons, fimic epipedon, anthrostagnic epipedon, albic horizon, LAC-ferric horizon, plinthic horizon, phos-agric horizon, hydragric horizon, argic horizon, cambic horizon. The diagnostic characteristics were L.C.of carbonate rocks, paralithic contact, anthroturbic layer, soil moisture regimes, soil temperature regime, gleyic features, redox features, humic property, ferric property, alic property, base saturation.(4)Types of the soils were classified according to the Keys to Chinese Soil Taxonomy (3rd edition), including five orders (Aanthrosols, Ferrosols, Argosols, Cambosols and Primosols), seven suborders, eleven groups and ninteen subgroups and, thereinto, forest and upland land soils could be sorted into five orders, six suborders, eight groups and thirteen subgroups and paddy soils could be sorted into one order, one suborders, three groups and six subgroups.It was accurate and objective that each representative soil have found their own posizion in Chinese Soil Taxonomy and, therefore, avoiding different classification due to differences in people’s subjective consciousness. And provided scientific basis for soil appraisal, soil management, soil mapping and soil production practices, the data base for the foundation of soil series, at the same time, provided the possibility for the international exchange of soil classification.