The Effect of Clay Content and Land Use on Dispersion Ratio at Different Locations in Sulaimani Governorate—Kurdistan Region—Iraq
- 1 Department of Soil and Water Sciences, Faculty of Agricultural Sciences, Sulaimani University, Sulaimani, Iraq
Abstract
Land use changes from natural ecosystems into managed ecosystems resulted in negative impact on soil structure and quality. The purpose of this study was to determine the influences of different land-use types on physical and chemical properties of soils in Sulaimani governorate. Land use systems including natural forest, pastureland and agriculture were identified. Ten of soil samples were collected from the 0 - 30 cm depth, and some soil physical and chemical properties of soil were determined. The land use alters from forest to agriculture resulting in significant decrease in organic matter, calcium carbonate and soil surface area and with this change, dispersion ratio affected on the physical property. The value of DR was highest in the Zrguezi Gawra cultivated with Cucumber and the lowest value in Dukan is 13%, and correlation coefficient between dispersion DR with sand, silt and bulk density is positive, value is (0.4979, 0.0126 and 0.7536) respectively, and with clay and specific surface area (SSA) the correlation coefficient value is (-0.7281 and -0.4466).
- Paige-Green, P. (2008) Dispersive and Erodible Soils—Fundamental Differences. SAIEG/SAICE Problem Soils Conference, Midrand, November 2008, 59-67.
- Maharaj, A and Paige-Green, P. (2010) The Impact of Inconsistencies in the Interpretation of Soil Test Results on the Repeatable Identification of Dispersive Soils. Proceedings IAEG2010, Auckland, September 2010, 389-392.
- Maharaj, A. (2010) Preliminary Observations of Shortcomings Identified in Standard Tests for Dispersive Soils. Proceedings IAEG2010, Auckland, September 2010.
- Maharaj, A. (2011) the Use of the Crumb Test as a Preliminary Indicator of Dispersive Soils. Proceedings of the 15th African Regional Conference on Soil Mechanics and Geotechnical Engineering, Maputo.
- Maharaj, A. (2012) Problems Associated with the Chemical Analysis If Dispersive Soils. Proceedings of the 2nd European Conference on Unsaturated Soils (E-UNSAT 2012), Naples, 1-3 June 2012, 433-437.
- Walker, D.J.H. (1997) Dispersive Soils in KwaZulu-Natal. Unpublished M.Sc. Thesis, University of Natal, Durban.
- Elges, H.F.W.K. (1985) Problem Soils in South Africa—State of the Art. The Civil Engineer in South Africa, 27, 347-353.
- Gerber, F.A. and Harmse, H.J. von M. (1987) Proposed procedure for identification of dispersive soils by chemical testing. The Civil Engineer in South Africa, 29, 397-399.
- Gu, B. and Doner, H.E. (1993) Dispersion and Aggregation of Soils as Influence by Organic and Inorganic Polymers. Soil Science Society of America Journal, 57, 709-716. http://dx.doi.org/10.2136/sssaj1993.03615995005700030014x
- Heil, D. and Sposito, G. (1993) Organic Matter Role in Illitic Soil Colloids Flocculation: I. Counter Ions and pH. Soil Science Society of America Journal, 57, 1241-1246. http://dx.doi.org/10.2136/sssaj1993.03615995005700050014x
- Igwe, C.A. (2001) Clay Dispersion of Selected Aeolian Soils of Northern Nigeria in Relation to Sodicity and Organic Carbon. Arid Land Research and Management, 15, 147-155. http://dx.doi.org/10.1080/15324980151062788
- Islam, K.R. and Weil, R.R. (2000) Land Use Effects on Soil Quality in a Tropical Forest Ecosystem of Bangladesh. Agriculture, Ecosystem & Environment, 79, 9-16. http://dx.doi.org/10.1016/S0167-8809(99)00145-0
- Lahore Pour, Sh. (2004) The Effect of Grazing Intensity on the Physical and Chemical Properties of Soil in Charandsummer Pastures in Kurdistan. M.Sc. Thesis, Range Management, Tarbiat Modares University, Tehran, 68.