EURASIAN JOURNAL OF SOIL SCIENCE

64 - 68

Authors: Ciro Gardi, Yusuf Yigini

Soil pH is one of the most important chemical parameters of soil, playing an essential role on the agricultural production and on the distribution of plants and soil biota communities. It is the expression of soil genesis that in turns is a function of soil forming factors and influences all the chemical, physical and biological processes that occur in the soil. Thus it shapes the entire soil ecosystem. Due to any of the above reasons, mapping of soil pH becomes very important to provide harmonised soil pH data to policy makers, public bodies and researchers. In order to obtain a continuous mapping of soil pH for Europe, adopting the digital soil mapping approach, a set of continuously distribute covariates, highly correlated with pH, were selected. The estimate of soil pH was realized using a regression procedure, coupled with the kriging of the residuals. More than 30.000 points on top soil pH (CaCl2) were used, and 27 covariates were tested as predictors. The similar approach was already applied with 12.333 samples to produce a pH map of Europe using European Soil Profile Data in 2008 which compiles several databases from 11 different sources (Reuter et al. 2008). Our study was conducted to update the previous data and maps based on LUCAS (EUROSTAT - Land Use/Cover Area frame statistical Survey), BIOSOIL (Hiederer and Durrant, 2010) and merged database which was used to produce previous soil pH map of Europe (Reuter et al. 2008). We used a compilation of more than 30.000 soil pH measurements from 13 different sources to create a continuous map of soil pH across Europe using a geostatistical approach based on regression-kriging. Regression was based on the use of 27 covariates in the form of raster maps at 1km resolution to explain the differences in the distribution of soil pH in CaCl2 and we added the kriged map of the residuals from the regression model.

75 – 80

Authors: Dan Laurenţiu Stoica, Cristian Valeriu, Patriche, Culiţă Sîrbu, Radu Pîrnău , Bogdan Roşca

Continental saltlands have a high degree of peculiarity amongst European primary habitats and a prominent insular character. The present scientific approach establishes the degree of soil-vegetation correlation in continental slatlands patches as a measure of habitat continuity/fragmentation and soil conservation/degradation. The use of hyperspectral imagery, soil types’ distribution and vegetal associations’ conservation status reveal disturbances in relation with human induced modifications in comparison with normal plant-soil interdependence. Supervised classifications of LANDSAT satellite imagery along with detailed soil maps, ground truth data provided by accurate GPS positioning and field based plants evaluation are used to perform landscape metrics analyses. The landscape metrics approach is meant to find the balance between extent and grain in the case of saltlands habitats analyses and the degree of patches and classes inhomogeneity. These also give an insight of habitats connectivity and/or isolation in relation with land use topology and soil multiplexing. The resulting training sets developed for a representative, protected area in the county of Iaşi enhance the creation of a comprehensive mask to be used for the evaluation of larger areas in the silvan-steppes of North-Eastern Romania. The model is statistically tested to depict the degree of correlation and confidence. The final goal resides in more proper measures elaboration for the mitigation of continental saltland preservation and natural resources exploitation via agricultural and the associated activities.

87 – 91

Authors: Samad Shadfar, Dadvar Lotfollahzadeh

Landslides have been made irreversible damage to urban areas and economic in Iran. In this research, at first, for Investigation of relationship between landslide and sediment yield was recognized some of effective factors on Landslide. These Factors were processed with use of ILWIS and Arc GIS software’s. Landslide hazard zonation was done using Density Area and Index Overlay methods in GIS and evaluated them using Quality Sum index. In after phase, were determined sediment yield in each of them. Finally, occurrence rate landslide investigated in sediment yield zones. The results indicated that, slope, lithology and distance from the hydrographic network have the greatest impact on landslides. Most of the landslides have occurred in the 15-40% slope class, units of conglomerate and marl, and within one km of drainage network. On the other hand, the relationship between landslide frequency and distance of the fault was not a linear relationship and Almost 60 %of landslides have occurred distance of one km of the faults. Evaluation using Quality Sum index showed that the density Area has a more logical answer and as Appropriate method will be introduced in the basin. Investigation of deposition potential in sub-basins showed that Javaherdeh sub basin with 92.74 deposition potential is the first priority. Nedasht and latmohalleh sub basins, each with a deposition potential of 20.08 are the next priorities. Relationship between landslide area and deposition potential were identified as 8/91% of the landslides in the area of low And about 79 percent of landslides are located in high and very high deposition potentials.

98 – 103

Authors: Rıdvan Kızılkaya, İzzet Akça, Tayfun Aşkın, Rezan Yılmaz, Vladimir Olekhov, Iraida Samofalova, Natalya Mudrykh

Insecticides are used in modern agriculture in large quantities to control pests and increase crop yield. Their use, however, has resulted in the disruption of ecosystems because of the effects on non-target soil microorganisms, some environmental problems, and decreasing soil fertility. These negative effects of synthetic pesticides on the environment have led to the search for alternative means of pest control. One such alternative is use of natural plant products such as azadirachtin that have pesticidal activity. The aim of this experiment was to study the effect of soil contamination by azadirachtin (C35H44O16) on dehydrogenase (DHA) and catalase activity (CA) of soil under field conditions in Perm, Russia. The tests were conducted on loamy soil (pHH2O 6.7, ECH2O 0.213 dSm-1, organic carbon 0.99%), to which the following quantities of azadirachtin were added: 0, 15, 30 and 60 mL da-1 of soil. Experimental design was randomized plot design with three replications. The DHA and CA analyses were performed 7, 14 and 21 days after the field experiment was established. The results of field experiment showed that azadirachtin had a positive influence on the DHA and CA at different soil sampling times. The increased doses of azadirachtin applied resulted in the higher level of DHA and CA in soil. The soil DHA and CA showed the highest activity on the 21th day after 60 mL azadirachtin da-1 application doses.

110 – 115

Authors: Füsun Gülser, Ferit Sönmez

Effects of cadmium applications on plant growth and potassium contents of pepper seedlings were investigated in different mixtures of soil:peat ratios. This study was conducted with three different levels of Cd (Cd0=0, Cd1=2.5 and Cd2=5.0 ppm) and three different ratios of soil:peat (Pt0=soil:no peat, Pt10=soil:10% peat and Pt20=soil:20% peat) in a factorial experimental design with three replications. K contents of shoots and some criteria of pepper seedlings such as; shoot and root dry weights were significantly influenced with the soil:peat ratios. Interactions between soil:peat ratio and Cd significantly affected shoot and root dry weights and K contents of pepper seedlings. Application of 20% peat ratio significantly increased shoot dry weight. Mean root dryweights decreased with increasing Cd dose applications. The highest (7.0%) and the lowest (4.1%) K contents in shoots were determined in Pt20Cd2 and Pt0Cd2 applications, respectively. On the other hand, the highest (3.27%) and the lowest (2.12%) K contents in roots were determined in Pt0Cd2 and Pt20Cd0 applications, respectively. Mean Cd contentents in shoots were also significantly reduced with increasing K contents of shoots, especially in the mixture of soil:20% peat ratio.