saeedeh Nateghi; Rostam Khalifehzadeh; Mahshid Souri; Morteza Khodagholi
Abstract
Soil organic carbon is one of the most important indicators of soil quality. The purpose of this study is to study the spectral and non-spectral behaviors of soil in order to estimate the organic carbon of topsoil using factor analysis and multiple regression methods in the semi-steppe rangelands of ...
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Soil organic carbon is one of the most important indicators of soil quality. The purpose of this study is to study the spectral and non-spectral behaviors of soil in order to estimate the organic carbon of topsoil using factor analysis and multiple regression methods in the semi-steppe rangelands of Asuran, Semnan province. Soil sampling was performed using stratified random sampling method. After creating a map of homogeneous units in the area, in each homogeneous unit according to its area, several sampling points were selected completely randomly. A total of 145 sampling points were collected. At each sampling point, a composite soil sample (a mixture of 9 observations) was taken. Soil organic carbon was measured using Valkyli-Block titration method. Data of 114 samples were used to calibrate the model and data of 31 samples were used to validate it. The results showed that the correlation of spectral variables obtained from Landsat OLI sensor with surface soil organic carbon is higher than non-spectral variables obtained from 1: 25000 topographic maps. Also, the results of factor analysis by principal component analysis with eigenvalues greater than one showed that the total cumulative variance explained by 14 variables was equal to 90.2%, which was explained by three factors. The regression equation generated by the three extracted factors had suitable potential for predicting surface soil organic carbon (R2 = 0.59). The root mean square error (RMSE) of the proposed model was calculated to be 0.3.
Leila Zandi; Reza Erfanzadeh; Hamid Joneidi-Jafari
Abstract
This study aimed to determine the effect of land use changes from rangeland to horti-agricultural lands on the most important qualitative characteristics of soil such as total soil carbon and particulate organic matter, in Salavatabad region, Sanandaj. In the present study, one rangeland, two cultivated ...
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This study aimed to determine the effect of land use changes from rangeland to horti-agricultural lands on the most important qualitative characteristics of soil such as total soil carbon and particulate organic matter, in Salavatabad region, Sanandaj. In the present study, one rangeland, two cultivated pea lands, two cultivated wheat lands and two gardens were selected in growth season in the end of spring, 2014. Forty two soil samples were taken randomly and systematically from the study region. Then, soil micro- and macro aggregates were separated using 0.25 mm and 2 mm sieves. Total soil carbon and particulate organic matter of soil samples were measured in the laboratory. The results showed that land use changes from rangeland to horti-agriculture significantly decreased total carbon and particulate organic matter in micro-aggregates. While total carbon and particulate organic matter in macro-aggregates was not changed by land use changes from rangeland to horticultural land. We suggested that if rangeland will be converted into agricultural land, horticultural land is the best for land use changes.
Roya Vazirian; Hamid Reza Asgari; Majid Ownegh; Chooghi Bairam Komaki
Abstract
Understanding the relationship between soil and plant is essential for reclamation of degraded lands. In order to investigate the relationship between Atriplex halimus density with carbon sequestration the rangeland of Incheborun was studied. Soil samples were collected randomly by Auger in the depth ...
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Understanding the relationship between soil and plant is essential for reclamation of degraded lands. In order to investigate the relationship between Atriplex halimus density with carbon sequestration the rangeland of Incheborun was studied. Soil samples were collected randomly by Auger in the depth of 0-30 cm of the soil profile in three different plant densities (<200, 200-400 and >400 stand per hectare) with 30 replications. The data were subjected to ANOVA using statistical software SPSS 21.0. Means were separated by T-test at P≤0.5. The results of this research showed that the soil organic carbon have ranging from 0.48 to 0.64 (with an average of 0.56%) in Atriplex plantation areas, while the organic carbon have ranging from 0.03 to 0.12 (with an average of 0.078%) in the control region.Therefore, plantation measures caused significant difference in soil organic carbon contents per unit area in Atriplex plantation areas as compared to that observed in the control area. Sequestered carbon in per unit is 26.27, 27.85 and 30.66 ton/ha respectively for low, medium and high Atriplex density areas. The results indicated that the rate of organic carbon as well as soil carbon sequestration increased with plant density. There were no significant difference among sequestered carbon and soil organic carbon values under those three different levels of densities, while significant difference were observed between three plantation areas and control area.
