Document Type : Research Paper

Authors

• Mohsen Armin ¹
• hasan rouhipour ²
• Hassan Ahmadi ³
• Ali Salajegheh ⁴
• mohammad Hossein Mahdian ⁵
• vajihe ghorban nia kheybari ⁶

¹ Assistant Professor, Faculty of Natural Resources, University of Yasuj, I.R. IRAN.

² Associate Professor, Research Institute of Forests and Rangelands, I.R. IRAN.

³ Professor of Islamic Azad University, Science and Research Branch, I.R. IRAN.

⁴ Associate Professor, Faculty of Natural Resources, University of Tehran, I.R. IRAN.

⁵ Associate Professor of Soil Conservation and Watershed Management Research Institute, I.R. IRAN.

⁶ Ph.D. Student of Environmental Science, University of Malayer, I.R. IRAN.

Abstract

Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. Also, identification of the critical soil properties affecting aggregate stability is central to understanding where erosion might be located within a catchment as a result of natural patterns in aggregate stability. The objective of this study, which was carried out in surface soils from Taleghan, was to relate aggregate stability to selected soil properties. In this study, based on homogeneity in slope, aspect and lithology work units were prepared, and then by relying on results of geostatistical studies in homogeneous work units in soils of Taleghan watershed, with 3260 hectares in area, 84 points as the soil sampling points were selected. The indices of stability used are the mean weight diameter (MWD) and wet aggregate stability (WAS). Correlation between mean weight diameter and measured properties were extracted using Pearson correlation coefficient and evaluated in terms of their statistical significance. Then based on the results of correlation and using stepwise regression, models of aggregate stability prediction were developed. The unexpected results have been obtained from correlation between soil properties and aggregate stability so that the correlation between aggregate stability and the percentage of Caco3, clay and saturation are negative while that with fine sand and very fine sand are positive. Thus the improvement of aggregate stability and soil erosion control in Taleghan watershed depends on management of these soil properties and soil conservation projects in order to adjust and optimize them

Keywords

• aggregate stability
• soil properties
• Work unit
• Stepwise regression
• Taleghan watershed