EURASIAN JOURNAL OF SOIL SCIENCE

172-181

Authors: Ivona Nikova, Venera Tsolova, Bisser Hristov, Aleksandar Zdravkov, Kalin Ruskov

The chemical composition of soils spread in the Bobov dol valley was studied in order to reveal the natural and anthropogenic patterns of Cd and Co spatial distribution. A sampling procedure based on the irregular grid of points and validated analytical methods were used in the field and laboratory studies. It is found that Cd content varies from 0.21 to 0.90 mg kg-1 in studied soils and the average value of 0.55 mg kg-1 coincides with concentration demarcating soil pollution (0.5 mg kg-1). Co content ranges from 2.22 to 15.76 mg kg-1 and in 70 % of sampled points exceeds the natural background content of 7.8 mg kg-1 found in local rocks. Still, Cd enrichment of studied soils is more significant than Co’s with coefficient of Clarke concentration of 3.67. Hence, the secondary deposition of studied elements as a result of the Bobov dol Thermal power plant air emissions is verified by results obtained. The spatial distribution of Cd and Co is featured with an altitudinal gradient in deposition and a trend of quantitative depletion in the South of Plant. Soil organic matter and pH have no influence on the content and spatial distribution of studied elements. Elements iron affinity governs their geochemical linkage in soils although cobalt occurs allied with aluminum and titanium.

192-200

Authors: Coşkun Gülser, İmanverdi Ekberli, Feride Candemir, Zeynep Demir

Spatial variability of soil physical properties in a cultivated field such as; bulk density (BD), penetration resistance (PNT), saturated hydraulic conductivity (Ks), field capacity (FC) and permanent wilting point (PWP), were determined by geostatistical method. While BD values varied between 1.12 and 1.41 g cm-3, PNT resistance (0.66 to 1.88 MPa), clay content (31.48 to 43.97%), Ks (1.46 to 3.37 mm h-1), FC (30.40 to 39.66%) and PWP (19.22 to 24.42%) values showed variations with soil cultivation. In kriging interpolation for the spatial variability of soil properties, the biggest r2 and cross validation r2 values were determined with spherical model for PNT, Ks, FC values, and exponential model for clay, BD and PWP. Spatial dependences of the properties, except BD, were found to be strong in the field. Ks values significantly increased with increasing BD (0.340*), and decreasing clay content (-0.905**) and PNT (-0.288*) values in the field. Spatial variations of soil physical properties in the field are generally controlled by the particle size distribution as a fundamental factor. Heterogeneity and variation of soil physical parameters in a field due to soil plowing should be taken into consideration for a successful agricultural management.

209-220

Authors: Suleiman Usman

Soil erodibility (K factor) is the most important tool for estimation the erosion. The aim of this study Soil factors and surface soil characteristics are important components of agricultural environment. They support surface and subsurface soils to perform many functions to agriculture and economic human developments. Understanding these factors would aid to the recognition of the values that our soil and land offered to humanity. It is therefore, aim of this study to visualise and examine the soil factors and surface soil characteristics in Kebbi State Nigeria. An Integrated Surface Soil Approach (ISSA) was used in the classification and description of soil environment in the study region. The factors constituted in the ISSA are important components of soil science that theories and practice(s) noted to provide ideas on how soil environment functioned. The results indicate that the surface soil environments around Arewa, Argungu, Augie, Birnin Kebbi and Dandi are physically familiar with the following surface soil characteristics: bad-lands, blown-out-lands, cirque-lands, fertile-lands, gullied-lands, miscellaneous and rock-outcrops.The major soil factors observed hat played an important role in surface soil manipulations and soil formation are alluvial, colluvial, fluvial and lacustrine; ant, earthworms and termite; and various forms of surface relief supported by temperature, rainfall, relative humidity and wind. Overall, the surface soil environment of the region was describe according to their physical appearance into fadama clay soils, fadama clay-loam soils, dryland sandy soils, dryland sandy-loam soils, dryland stony soils and organic-mineral soils.

231-240

Authors: Lotfi Mustapha Kazi-Tani, Abdelaziz Gaouar

Embedded Markov chain (EMC) has long history in geological domains, particularly to define the most representative sequences from statigraphic logs. In other words, what is viewed as a meaningless and disordered stratigraphic layer stack can be reorganized in a meaningful sequence by using EMC. This method was transposed in this paper to obtain soil sequences from data retrieved from soil map made by authors, covering a part of the region of Traras (N.W. of Algeria) and containing 13 major soil types. Each major soil type occupies at least one polygon in the map and allow to establish soil adjacencies, which have been tabulated in a matrix regardless to the direction. Three EMC methods have been tested, Walker, Harper and Türk using Strati-signal software and to erect soil relationship diagrams (SRD) representing the most significant links between soils. Significant test is the main difference between the above mentioned three EMC methods. It has been shown that Harper method is quite insensitive to small number of transitions. Besides, all three methods agreed for one soil sequence made by four soils: lithics leptosols- cambisols chormics- cambisols calcarics- fluvisols representing theoretical catena the most representative to the study area. This soil sequence is relevant to the study region and even to the whole Mediterranean region, and is commanded by the topography and the Mediterranean bioclimate. Walker SRD is the most realistic but the most difficult to interpret because of the high number of soil links, Harper SRD gives interesting results. Although the results didn’t bring something new to the soil interpretation and soil pedogensis but EMC applied to a finer scale may highlights other hidden relationships between soils.

249-254

Authors: Vita Vasilyevna Datsenko, Nataliya Lvovna Khimenko

The experimental data dealing with the effect of heavy metals contained in the technogenic contaminated soils on plant objects under controlled conditions was discussed. The aim of this work is to define the quantitative indicators of copper and zinc potential phytotoxicity, namely germination energy, simultaneous germination and duration of the test plants. It was found that the activity of the test plant growth is linked with copper and zinc complex action. Joint effect of copper and zinc is manifested both in inhibition of lettuce growth and determined, above all, by the nature contamination, soil properties and biological specificity of the test plants.