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T. V. Prokof’eva O. A. Varava S. N. Sedov A. M. Kuznetsova 《Eurasian Soil Science》2010,43(4):368-379
At present, many parts of river valleys, including floodplains, are being actively used for urban construction. This leads
to the disturbance of normal functioning of the valleys; alluvial deposits and soils become buried under the thickness of
various anthropogenic materials. Four profiles of typical urban soils (urbanozems) developed on the floodplain of the Moskva
River and its small tributaries have been studied. The macro- and micromorphological characteristics (including data of submicroscopic
studies) and the chemical and physicochemical properties of these soils are analyzed. It is shown that the influence of ground-water
on the anthropogenically transformed soils of floodplains and low terraces is preserved even upon the cessation of regular
flooding. The substitution of urban pedosedimentogenesis for alluvial pedosedimentogenesis has a gradual character with a
transitional stage of simultaneous occurrence of both processes. Clayey and clayey-calcareous infillings in the middle-profile
horizons and newly formed phosphates of iron and calcium in the lower horizons affected by the groundwater can be considered
typical diagnostic features of the urban-alluvial pedogenesis. 相似文献
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The origin of red clayey soils developed on limestones has been largely questioned. We have analyzed thick red soils on Eocene-Pliocene
limestones of the Yucatán peninsula (with detail in the Kantunil Kin area). The morphological, geochemical and mineralogical
characteristics were interpreted as a record of pedogenesis and geomorphic dynamics during the Quaternary. Sand fraction mineralogy,
the Zr/Ti ratio and ternary diagrams of Trace elements (Ti-Y-Zr, La-Th-Sc and Zr-Th-Sc) indicated a mixed origin of the soil
parent material; volcanic and granitic/metamorphic components, redeposited by eolian transport. Within the soil matrix, primary
minerals were transformed by weathering and caused desilication with the accumulation of kaolinitic clay. Reworked pedofeatures
were originated from different soil bodies eroded. In the lower part of the profiles, we described the zone of carbonate leaching
front, were the clay translocation in suspensions and posterior coagulation is more probable than the migration of elements
in solutions and posterior synthesis. 相似文献
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G. lvarez Arteaga N.E. García Caldern P.V. Krasilnikov S.N. Sedov V.O. Targulian N. Velzquez Rosas 《Geoderma》2008,144(3-4):593-612
The soils of montane cloud forests (MCF) are still insufficiently studied. A number of researchers report Podzols to be the main soil group for MCF ecosystems; however, a great deal of contradictory data exists. We studied an altitudinal sequence of soils formed on ferrous chlorite shale under natural MCF vegetation in Sierra Juárez, Southern Mexico, from 1500 to 2500 m asl. The soils of the upper part of the toposequence were Folic Stagnic Podzols, with inclusions of Folic Stagnosols in local depressions, while the soils of the lower part of the toposequence were Folic Cambisols (Humic, Hyperdystric). All the soils in the toposequence were extremely acid, and had thick organic surface horizon. Mineral horizons of all soils were poor both in exchangeable and total reserves of bases; the bases were concentrated mainly in organic topsoil. With decreasing altitude both the thickness of albic horizons, the depth of the maximum acid oxalate-extractable Fe and Al concentrations, and the difference in clay content between the eluvial and illuvial horizons decreased. In the upper part of the toposequence the composition of soil clays was similar to that of parent material (chlorite and mica), with some mixed-layered 2:1 minerals. However, gibbsite and kaolinite were also present in the soils of the other site within the same upper MCF belt. The phenomenon was ascribed to parent material heterogenity. In the medium and lower parts of the toposequence gibbsite and kaolinite were the dominant minerals. We consider that the main pedogenic processes in the study area are raw humus accumulation, weathering in situ, podzolization, and iron reduction due to water stagnation in mineral topsoil. The intensity of weathering decreases, while the extent of water stagnation increases with altitude. To a great extent the genesis and altitudinal distribution of the soils in the MCF depends on parent material. 相似文献
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Apple cultivars from the VNIISPK breeding program are characterized for sugar content in fruit. It is shown that many VNIISPK apple cultivars exceed widespread control cultivars in the studied trait. The results of studies for the development of apple cultivars with higher content of sugar in fruit are given. The features of domination and transgressions have been studied for the content of sugar and soluble dry substances in fruit of hybrid apple seedlings. 相似文献