Abstract:
Structural soil aggregates and stability of such aggregates has a tremendous impact on managing the cracking clay soils that belong to the soil order vertisols that are existing in the central clay plain of the Sudan. There are also recent soils belonging to the soil order Entisols that occur in association with the cracking clays. Therefore, soil plant relationship, fertility and biological activities are manifestations caused due to soil aggregate. The importance of knowledge gained from such experience would assist land user manipulate management practices in different agro-ecological zones of the Sudan ranging from arid to wet monsoon climate to cope with teporal changes of climate. The objective of this study is to identify the effect of the contents of clay and calcium carbonate on formation of soil aggregate to embark upon appropriate land management practices.
The study covered 4 areas, 2 out of which are occurring in west Omdurman and Alkadroo, belonging to the soil order Entisols (recent soils). The remaining 2 areas are in Soba and Shambat representing cracking clays of the order Vertisols. Soils samples were collected from six sites each consisting of fixed depth intervals of 0-20 and 20-45cm, totaling 48 samples. Soil samples were analyzed at the laboratories of soil science along with statistical analysis at the College of Agricultural Studies of Sudan University of Science and Technology SUST, Studies revealed that the clay content has increased soil aggregation in the four areas. The correlation with calcium carbonate was insignificant at Alkadroo, Soba and Shambat due to interaction with Exchangeable Sodium Percentage ESP. on the contrary, at west Omdurman, an exception exists in that calcium carbonate significantly correlated with Index of Structure increasing aggregate.
