The article specifies the features of humus accumulation in the soil profiles of one-loess terraces in order to clarify their classification belonging. The objects of the study were soils of varying degrees of hydromorphism on one-loess terraces of river's left-bank on the territory of Sumy, Poltava and Kharkiv regions within the limits of the Forest-Steppe of Ukraine. Methods of research: traditional field description of soil morphological characteristics; analytical determination of the total content of humus, content of granulometric fraction <0.01 mm (physical clay) and exchange cations; calculations of the parameters of humus accumulation and humus redistribution in the soil profile by the coefficients of profile accumulation of humus (CPAH), relative accumulation of humus (СRAH) and regression of organoprofile (CROP); field observations of groundwater seasonal ripples by wells. It is shown that the polygenetic nature of the soils in one-loess terraces is due to the specific dynamics of soil formation factors. The influence of the groundwater pulsing level on the soil morphogenesis and the intensity of humus accumulation have been determined. The expediency of application of parametrizated estimations in the diagnostics of soils with discussion genesis has been proved. The identified of podzolization processes in semihydromorphic and hydromorphic soils based on content and distribution of exchange cations in profile as a consequence of the periodic settlement of forest vegetation on the territory of first-loess terraces. As a result was clarifscation the genetic status of the soils of one-loess terraces and establishment of their belonging to the overtypical and typical levels of the pedosphere organization.

The ecological-genetic status of soil is determined by the course of the soil-forming process and is the main factor in optimizing the agricultural use to achieve a sustainable state. The definition of a qualitative indicator of this status (KVAG) is developed in Ukraine and is characterized as costing and resource intensive. To solve the problem, it is proposed to replace agrochemical methods with less costly magnetic ones. The purpose of the study is to show the informativeness of geophysical methods for the indication of the process of pedogenesis on the example of chernozems podzolized of Kharkiv region. We used the standardized studies of determination of organic carbon content, determination of the particle size distribution of soil, and pH analysis. The characteristic of the sampling site on the slope was performed by determining the erosion hazard index. The mass-specific magnetic susceptibility of soil (MS) was determined and then calculated. The study sites were located at the area of distribution of chernozems podzolized in the northern part of Kharkiv district and the central part of Pechenigy district of Kharkiv region. Soil genetic identity has been determined initially at the large-scale survey map and refined by field studies. The erosion processes complicated the soil study at the slope. We registered high informativeness of MS for the indication of genetic status. MS is relevant to use not only within a single agrocenosis, but also in agrolandscapes for soils which pedogenesis is complicated by hydromorphism. The experiment was performed at one-lane terrace of the Siverskyi Donets River, where soils of varying degrees of hydromorphism are developed. Magnetic methods have significant outlook for their application in soil studies. The example of the podzolized soils investigation of Kharkiv region shows the possibility of the identification of hydromorphic processes in the lower part of the soil profile (decrease of the values of MS compared to the background). The example of the arable land shows the possibility of replacing the high-cost determining of the humus content by much cheaper MS as the indicator of ecological-genetic status of soil (KVAG). The correlation coefficient between the KVAG and KVAMS (based on the MS measuring) is: ρ = 0.901.

No abstract

No abstract

The territory of Novgorod-Siversky Polissia is characterized by natural conditions as a province of mixed forests, where soddy-podzolic soils of low fertility have formed on loamy sandy and sandy deposits. However, on the high plateau the Desna River valley right bank, there are Novgorod-Siversky and Ponornitsky loessial islands with fertile dark-colored soils (Opillia). They were formed in rather damp and cool conditions, which is natural for the forest zone. However, their landscapes by the property of the components have a forest-steppe nature. On the plateau, in the Novgorod-Siversky Opillia, eolian loessial is located, which led to the formation of dark gray podzolized soils and chernozems leached and podzolized mainly with a humus-degraded arable layer. On sufficiently large areas near localities Pontornytsya, Pokoshychi and Desnianske there was happened loessivation and silt-loam sandy. Fertile gray forest soils were formed here – a kind of Opillia region. During the large-scale survey and mapping of Ukraine's soils in 1957–1961, dark-colored soils of loessial islands were defined predominantly as dark gray podzolized. However, our recent studies have proved the widespread distribution of leached chernozems and podzolized opіlsky chernozems. On strongly eroded slopes of the right-bank native shores, we have remnants of the suboak forest, which indicate the forest-steppe nature of the landscapes. In virgin areas, unlike sandy areas, a thick bean-grass-mixed grass cover, including indicators of forest-steppe. The Opillia area with chernozems and other dark-colored soils is a major agrarian resource of the region. But gray forest soils also belong to the most valuable land in Polissia. On gray forest soils, cereal crops are grown by 4–5 centners per hectare higher than those on typical of the Polissia sod-podzolic soils. Loessial islands are common in southern part of Novgorod-Siversky Polissia, in particular, on the Desna River valley right bank. Landscapes are diverse in properties of components – the nature of loessial species, geological foundations, features of soil cover and relief. They are united by forest-steppe features of soil cover, the presence in the central part of Opilia – fertile dark-colored soils, including chernozems with signs of relic steppe phase in their development, meadow-steppe composition of herbaceous cover on virgin areas and the presence of remnants of the suboak forest. These are large fragments of the Forest-Steppe in Polissia, which have a high natural resource.