EURASIAN JOURNAL OF SOIL SCIENCE

179-190

Authors: Ekaterina Chebykina (Maksimova) , Ivan Alekseev , Evgeny Abakumov

SOM stabilization rates were estimated in the soils of Antarctic region in case of influence of ornithogenic factor. Soils in large penguin clusters, near nests of Stercorarius sp., as well as soils located in geochemically subordinate positions (also often are visited by birds) were found to be characterized by an increased content of carbon and nitrogen with a rather narrow ratio of C/N. The pH values decreased in ornithogenic soils due to the organic acids that produced plants (mosses, Deschampsia antarctica) inhabit these soils and the decomposition products of the organic matter guano. The amount of CO2, in general, released over the entire experiment period is quite large for both ornithogenic and non-ornithogenic soils. CO2 emission rates were the highest in ornithogenic soils. Ornithogenic soils of the studied area are characterized by the most stabilized organic matter. Thus, the avifauna favors and increases the rate of the mineralization process by several times. An acceleration in the organic matter mineralization rate leads to an increase in nutrients amount available to plants, as in the case of the studied soils. The quality of initial SOM is of a great importance in post-ornithogenic environments. Therefore, further researches of CO2 emissions rates are needed to characterize post-ornithogenic dynamics and develop an approach to model this process.

199-206

Authors: Adenike Fisayo Komolafe , Christianah Olubunmi Kayode , Dorcas Tinuke Ezekiel-Adewoyin , Olufemi Emmanuel AyanfeOluwa , David Ogundeji Ogunleti , Aderemi Isaiah Makinde

This study evaluated the effect of two plant materials (Panicum maximum and Tridax procumbens) composted with cow dung, with or without Trichoderma asperellum inoculation on soil properties and yield of celosia in 2014 and 2015. The treatments were tridax-based compost without Trichoderma (TBC), tridax-based compost with Trichoderma (TTBC), panicum-based compost without Trichoderma (PBC), panicum-based compost with Trichoderma (TPBC) and control (no compost). All compost were applied at 240 kgN/ha. The design was RCBD with three replicates and data analyzed using ANOVA at α0.05. Results showed that compost enhanced growth, nutrient uptake and yield of celosia. In 2014, highest fresh weight (57.09 t/ha) was obtained from plant treated with TPBC, which compared favourably with TTBC TTBC (57.00 t/ha) but significantly higher than TBC (43.85 t/ha) and PBC (47.32 t/ha) while control gave the least significant value (20 t/ha). A similar trend was obtained in 2015. This infers that plants that received inoculated compost gave better yield compared to uninoculated compost. Post-cropping soil chemical analysis revealed that compost improved soil N, P, K and organic C. This shows that Trichoderma inoculated compost could be better than the uninoculated compost for celosia production in an Alfisol.

215-221

Authors: Zeynep Demir

The present research was conducted to assess the effects of vermicompost (VC) treatments under different soil moisture contents on consistency limits of sandy-clay-loam (SCL) soils in which lettuce (Lactuca sativa var. crispa) was cultivated in a greenhouse. Liquid limit (LL), plastic limit (PL), plasticity index (PI), consistency index (Ic) and clay activity (A) values were investigated. Three different VC doses (0, 2.5 and 5% w/w) were applied at 3 different soil moisture contents (100% FC-field capacity, 50% FC and 25% FC). Experiments were conducted in 3 replications over 27 experimental plots (3×3x3). Increasing LL and PL values were observed with increasing VC doses. The greatest LL (46.6%) and PL (37.7%) values were obtained from the 5% VC treatment under high soil moisture content (100%FC) and the lowest LL (35.0%) and PL (23.0%) were obtained from the control treatment under low soil moisture content (25%FC). LL had significant correlations with VC (0.848**), PL (0.904**), PI (0.565**), Ic (0.668**) and A (0.548**). Ic had significant correlations with VC (0.815**), PL (0.417*) and PI (0.740**). As compared to the control treatments, Ic values increased by 13.0% and 21.9% respectively with 2.5% and 5% VC treatments. Ic values were greater than 0.75. Therefore, it was observed that the sandy-clay-loam soils could be cultivated without any structural deformations at FC or higher moisture contents with vermicompost application. Moisture content upper limits for optimal tillage without any structural destructions were suggested as 26.8%, 34.9% and 36.9% for 0%VC, 2.5%VC and 5%VC treatments, respectively. Present findings indicated that VC treatments extended the range of moisture for workability.

236-242

Authors: Lyudmila Sudina , Sergey Kolesnikov , Tatiana Minnikova , Kamil Kazeev , Svetlana Sushkova , Tatiana Minkina

The present study was performed for the ecotoxicity assessment of the bismuth (Bi) effect on the biological indicators of soil condition: total number of soil bacteria, catalase activity, dehydrogenases activity and germination of Radish seeds and length of the Radish roots. Three soil types with significantly different resistance ability to heavy metal pollution were studied: Haplic Chernozems Calcic, Haplic Arenosols Eutric and Haplic Cambisols Eutric.Soil contamination of Bi was simulated in the lab (3, 30 and 300 mg kg-1 dry weight). Changes in the biological parameters of the soil were assessed at 10 day treatment. The data obtained showed that the soils contaminated with Bi in South Russia generally characterized by oppression of the biological properties. The total number of bacteria and enzymatic activity (catalase and dehydrogenases) decreased over the Bi contamination. The indicators of phytotoxicity (germination of radish seeds) increase when bismuth 3 and 30 mg kg-1 is added to the soil. The degree of deterioration in biological properties depends on the concentration of Bi in the soil and the period of time after the onset of pollution. Resistance of soil types to Bi pollution can be described by the following decreasing series: Haplic Chernozem Calcic > Haplic Arenosols Eutric > Haplic Cambisols Eutric. The following regional maximum permissible concentrations (rMPC) of Bi have been proposed: Haplic Chernozem Calcic – 8.5 mg kg-1, Haplic Arenosols Eutric – 2.2 mg kg-1 and Haplic Cambisols Eutric – 1.8 mg kg-1.

251-258

Authors: Ruslan Suleymanov , Mikhail Yakimov , Peter Liebelt , Pavel Shirokikh , Azamat Suleymanov , Evgeny Abakumov , Ilgiza Adelmurzina , Elvera Bakieva , Ilgiz Asylbaev

The article presents the results of complex research (research was conducted in 2019) of the Botanical natural monument territory “Pine forest near Venetsiya village” (Russia). In 2007, part of the nature monument territory was destroyed by a hurricane, resulting in massive windfall. The purpose of the research was to study the processes of evolution of natural complexes (vegetation and soil cover) in the areas affected by the hurricane. Classification of vegetation was done according to the Braun-Blanquet and Kopečký and Hejný approaches. NDVI (Normalized Difference Vegetation Index) was used to estimate the amount of photosynthetically active biomass. Changes in morphological, physical and chemical properties were studied in the soil cover. The conducted research showed that the vegetation of the natural monument is represented by relict pine and broad-leaved pine forests. Under the pine canopy linden and birch are dominated. In the herb layer grow in various combinations of nemoral and boreal species. Soil cover is represented by Gray-humus (Umbric Luvisol). There is a strong transformation of vegetation in the areas damaged by the hurricane in 12 years (2007-2019). There is an active formation of highly productive herbaceous vegetation and renewal of deciduous stands, which leads to an increase in biomass (confirmed by changes in NDVI). The terminal stage of the restoration succession will be the formation of secondary deciduous and mixed nemoral forests. The active development of grass vegetation leads to the formation of a sod horizon on the surface of the soil with a thickness of about 14 cm. There is also an increase in the content of organic carbon, alkaline-hydrolyzable nitrogen and mobile phosphorus, the value of electrical resistivity increases and acidification of the soil solution.