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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722


vol. 22, nr. 4 (2008)

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Soil properties influencing water-dispersible clay and silt in an Ultisol in southern Nigeria
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C.A. Igwe, O.N. Udegbunam
Department of Soil Science, University of Nigeria, Nsukka, Nigeria

vol. 22 (2008), nr. 4, pp. 319-325
abstract Soil degradation such as soil erosion by water is directly linked to water-dispersible clay (WDC) in the soil. Ten locations in an Ultisol in southeastern Nigeria were sampled for analysis. In each locations 2 samples were collected viz; 0-20 and 20-40 cm depth. The aim was to measure the water-dispersible clay and silt and determine the easily measured soil properties that influence clay dispersion in the soils. The soils investigated are porous, high in soil bulk density and low available plant nutrient. Soils are all within the acid range in pH while the soil organic carbon (SOC) contents are low. The exchangeable Ca2+ and Mg2+ contents of the soils dominated the exchange complex. Values of WDC are between 60 and 120 g kg-1 with a mean value of 73 g kg-1. Also water-dispersible silt (WDSi) ranged from 10-190 g kg-1 with a mean of 66.5 g kg-1. These results indicate that pH, SOC, exchangeable Ca2+, exchangeable acidity (EA), CEC, sodium adsorption ratio (SAR), the clay and silt contents of these soil are the soil factors that influence the water-dispersible properties of the soils. The modifications of the regular management procedures of the soils through the addition of soil organic matter will check the rate of WDC in the soils and that will accordingly check the high degradation rate of the soils.
keywords microaggregates, erodibility, clay-dispersion, soil organic carbon, sodium adsorption ratio