www.old.international-agrophysics.org / issues

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

vol. 19, nr. 2 (2005)

previous paper back to paper's list next paper
Influence of soil properties on the aggregate stability of a highly degraded tropical soil in Eastern Nigeria
(get PDF)
C.A. Igwe, D. Nwokocha
Department of Soil Science, University of Nigeria, Nsukka, Nigeria

vol. 19 (2005), nr. 2, pp. 131-139
abstract Soil structure of fragile ecosystems should be monitored frequently for soil pore rigidity and aggregate stability. We studied four soil profiles in Eastern Nigeria that are loose, porous, highly weathered and deep in order to characterize their aggregate water stability upon drying and wetting and their relationship with soil properties. Mean-weight diameter of dry aggregates (MWDd) was largely determined by dry-stable aggregates (DSA) between 1-0.25 mm while the mean-weight diameter of water-stable aggregates (MWDw) was dominated by water-stable aggregates (WSA) between 0.5 to <0.25 mm. The permeability rates for the soils indicated that most horizons were within the moderately rapid to very rapid class. The MWDd correlated significantly with saturated hydraulic conductivity (Ks) (r = 0.68). The MWDw correlated negatively with bulk density (r= -0.65). The potential structural deformation index (PSDI) for the soils indicates that soil moisture contents, particle size distribution, soil organic matter (SOM), Ks, bulk density and CEC were soil factors that influenced it. To maintain good soil structure thereby reducing soil degradation, long term fallows or other farming practices that ensure steady maintenance of SOM are recommended.
keywords potential structural deformation, soil organic matter, aggregates stability, permeability