Moscow University Soil Studies Bulletin. 2020. 1.

In hydromorphic soils are important not only sustainable Fe-minerals, defined traditionally in dried soil, but also unstable Fe-minerals, changing the colors of the clay after extracting the sample fr om the soil, as well as — weakening gley signs in the dry season. New indicators are offered for the additional characteristic of Fe-minerals. The first is that it characterizes the interaction of active Fe-minerals with colloids, it is index I: I = CEC/Fe (free), wh ere CEC is the cation exchange capacity. The second indicator is the change in the gley color after drying, assessed by the change in the redness Да*. In Fe-enriched, reduced gley Gr with a low index value (/0,1) and a strong increase Aa* ~ 9 after drying, the green rust is transformed into a brown lepidocrocite. During the humidity decrease, the transition of the reduction gley to the oxidized gley is accompanied by a change in the composition of the green rust: the transformation of fougerite into a trebeurdendite: Fe-ephemera with a higher degree of Fe oxidation and the growth of Да* ~ 3. When oxidized gley Go with the index I = 2—8 is dried, the slow Да* growth is caused by the inhibition of Fe-hydroxide crystallization by colloids. In the “de-ironed” gley Gdf with a high value the index 1= 6—27, the lack of red growth (a* « 0) on drying, is probably due to the Fe clay minerals inertia.

The properties of representative soil profiles of podzols included in the database of the Unified State Register of Soil Resources of Russia are considered. As a result of processing and analysis of the data array (53 measured profiles), the ranges of values of a number of parameters were adjusted. It was found that in most cases the properties of podzols had a wider range of values compared with the estimated profiles given in the literature (thickness of illuvial horizon, humus content in eluvial horizon), at the same time, the range of values of the humus content for the illuvial horizon was narrower. The specificity of the podzols of individual regions obtained by combining of soil provinces of the Map of soil-ecological zoning is revealed. Regularities can be traced in the geography of the profile thickness of these soils, the content of humus and its profile distribution. In Siberian regions humus prevails in the eluvial soil horizon, in the European territory of the country and in Primorye - in the illuvial horizon.

The composition of water extracts of the soil, litter and land litter was studied for the conditions of the nesting places of the gray heron and the control plots in the zone of distribution of gray forest soils of the broad-leaved ecosystems of the Tula area. It has been established that the entry of bird excreta leads to an almost universal degradation of land cover, the formation of specific litters, with a significant influx of large tree litter, which is associated with the nest building process. It is shown that the upper horizons of gray forest soil, litter and litter in nesting conditions are characterized by an increased content of such elements as calcium, potassium and magnesium, and among trace elements - copper, zinc and strontium. Among the anions in the soils and litters of bird nesting sites, an increase in the content of nitrates, phosphates and chlorine was found.

The study of the mineralogical composition of sand (0,25-0,05 mm) and coarse silt (0,05-0,01 mm) fractions revealed a significant lithological heterogeneity of soil forming material on the territory of the Zvenigorod biostation. The predominance of ore minerals in the heavy fractions (up to 42% of the grains) and, to a lesser extent, hornblende and biotite, explains the ironing (significant presence of iron oxides, hydroxides) of the profiles and the brown color of sandy loam soils. This feature, along with the insignificant presence of the clay fraction, admit us to classify texturally undifferentiated soils as ferric-metamorphic soils, and more differentiated - as eluvial soils.

The mineralogical composition of fraction of more then 0,1 mm of podzolic soils of the Kostroma region was studied. One of the debatable versions of finding the boundary between the glacial deposits of the Moscow and Dnieper ages is confirmed. Signs of destructions of minerals are established, this indicates the role of this process in providing mineral elements of the subsurface, which formed on weathered glacial deposits.

The article considers agrochemical factors for cultivation of medicinal plants with focus on biomass increase primarily due to a role of nitrogen and zinc and change in the fractional composition and concentration of carotenoids in Calendula officinalis L. A two-year vegetative experiment with calendula of Kalta variety was carried out. Effects of Zn and Zn supplemented with N intake on morphological changes, blooming and reproduction were studied. Intake of nutrients into above-ground plant parts was studied utilizing a variety of chemical methods. The quantitative and qualitative composition of carotenoids by HPLC was established. The calculated value of the accumulation of carotenoids by plants for the entire vegetation period was performed. Data were subjected to analysis of variance (ANOVA) and means were separated by Duncan multiple range test at P < 0,05 significant level. Factors selected by us in the growing experiment, formed contrasting options which allowed to determine the most effective way to grow medicinal crops on chernozem soil.

We conducted soil zoological studies on the Southern coast of Crimea in the Nikitsky botanical garden and in the natural reserve “Cape Martian”. We found 22 taxonomic groups of large invertebrate soil animals, whose number was up to 1000 spec/m², and biomass - up to 25 g/m², in the artificial stratozems of the garden and in the natural red-colored soils of the reserve. The territory of the Nikitsky garden is characterized by a greater biomass and taxonomic diversity of the soil macrofauna than Cape Martian, but the structure of the communities of the two territories have similarities. Higher biodiversity and biomass in the garden are explained by increased soil moisture due to sprinkling and the mosaic distribution of vegetation in the arboretum. Both territories are characterized by a large internal heterogeneity of the soil population, which is due to the variability of soil properties, which is determined by the differences in the artificial soils of the Nikitsky garden and the gulley erosion of the soils of Cape Martian. These factors, together with the diversity of vegetation cover, affect the heterogeneity of the macrofauna distribution and provide high biological b-diversity of the territory.