Behnaz Attaeian; Ali Badrestani; Saeid Khosrobeigi Bozchelui; Mohammad Mehdi Artimani
Abstract
Soil organic carbon as a key factor in soil stability and fertility is considered as one of the important environmental challenges in the context of climate change. The aim of this study was to determine soil organic carbon zonation in Gonbad paired-watershed, Hamedan province. In this research, the ...
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Soil organic carbon as a key factor in soil stability and fertility is considered as one of the important environmental challenges in the context of climate change. The aim of this study was to determine soil organic carbon zonation in Gonbad paired-watershed, Hamedan province. In this research, the information of meteorology, soil science and erosion and sedimentation study of Gombad watershed was used, including the information of 49 profiles in the 0-15 cm soil layer. After collecting data, tests of normality (Shapiro-Wilkα test <0.05), homogeneity of variance, and then the relationship between independent variables and organic carbon were performed using Pearson's linear correlation in SAS software. Also, determining the most effective independent variable using multivariate analysis, PCA factor analysis was used in XlStat 2.1 software. In order to determine the distribution and amount of soil organic carbon in the Gonbad representative watershed, modeling using SVM support vector machine learning algorithms and RF random forest was used in R software.The results showed that 78.18% of soil organic carbon changes depend on four components. Clay and nitrogen percentage were selected as the most effective variables on soil organic carbon content, so that the first component of clay content explained 34% and the second component nitrogen explained 18% of variations. According to the results of the implementation of the SVM and RF Models, the SVM model with a CE factor of 0.86 and RMSE of 0.05 in the test stage is a more accurate model in this study.
Ahmad Godarzi; Soheilasadat Hashemi; Behnaz Attaeian
Abstract
The purpose of this research was investigation of soil physicochemical and particle distribution in three agricultures, rangeland and forest park land use in two surface (0-15 cm) and subsurface (15-30 cm) depths in Oshtorninan city on the Lorestan province. Soil sampling was done in 45 points in three ...
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The purpose of this research was investigation of soil physicochemical and particle distribution in three agricultures, rangeland and forest park land use in two surface (0-15 cm) and subsurface (15-30 cm) depths in Oshtorninan city on the Lorestan province. Soil sampling was done in 45 points in three land use. Some soil physico-chemical properties were determined in laboratory. This experiment was arranged in a factorial manner. The results showed that the change of rangeland use to agriculture has resulted in a decrease in clay content, cation exchange capacity, soil carbon, nitrogen and soil particle size. Changing the land use of pasture to forest park has led to an increase in the amount of clay, silt and soil acidity. Mean comparison showed that there was no significant difference between bulk density and electrical conductivity in the three land uses (p ≤ 0.01). Analysis of the data showed that the soil cation exchange capacity, organic carbon, clay and silt content in three land uses and two depths were significantly different (p ≤ 0.01). Land use factor also showed a significant different on soil sand and lime percentage (p ≤ 0.01). The soil granulation did not change with the conversion of the rangeland in to a forest. Increased organic carbon and soil clay content could be the reason for this. In general, land use change from pasture to agriculture similar to other research is unfavorable, but land use change to forest park has improved clay content, cation exchange capacity and soil organic carbon.
