SOIL PROPERTIES AND THEIR EFFECT ON SOME BIOLOGICAL ACTIVITIES IN ABU SUBERIA VALLEY- ASWAN, EGYPT.

The present study includes combined soil and biological aspects of Abu Suberia valley. Twelve representative soil surface samples, down to 20 Cm.were collected and subjected to detailed soil analyses.
The obtained results reveal that, soil texture ranges from sand to heavy clay , CaCO3 content is widely variable (0.08-7.21 %) and OM content is extremely low ( 0.02- 2.47 %). pH is neutral to mildly alkaline. The soil samples are non-saline to saline, mostly non-saline. The cationic composition is mostly dominated by Na+ or Ca++ while the anionic composition is mostly dominated by Cl-. Cation exchange capacity ranges widely from (2.43-38.08 me/100 g soil) with the higher capacity due to clay mineral type and content. Exchangeable cations are dominated with Ca++. Available P ranges from (0.82-4.77 me/Kg soil). The mineralogy of clay fraction is dominated by kaolinite as identified by XRD.
Data of biological investigation showed that the total counts of bacteria, fungi, yeast, actinomycetes, thermophilic bacteria, cellulolytic bacteria, nitrifying and denitrifying bacteria range from 22.4x106 to 284x106, 10x103 to 27.x103, 6x102 to 20x102, 9x103 to 19x103, 31x103 to 48x103, 0.90x104 to 1.82x104, 38.0x104 to 121.0x104 and 30.0x102 to 65.0x102 CFU/g dry soil, respectively. The biological activities of the concerned enzymes were also recorded and interpreted.
Statistical evaluation reveals that soil OM, pH, ECe, Ca++, Na+, Cl-, SO4-- and exchangeable Na are correlated well with total counts of most bacteria, fungi and actinomycetes. Also, OM is correlated with dehydrogenase, alkaline phosphatase and urease.