Abstract:
The soils of the farm investigated in this study occupy an area of about 121
feddans. The land is mainly an experimental and demonstration farm owned
by the College of Agricultural Studies, Sudan University of Science &
Technology at Shambat. This area lies within the arid climate which is
characterized by a very hot and humid summer, a mild and dry winter and
marked seasonal variations in both rainfall and temperature. During these
Months the highest rates of evaporation take place. The solid geology of the
area is mainly composed of Nubian Sandstone covered by a relatively thick
continuous formation of Nile alluvium deposits which form flat depositional
plains. The natural vegetation of the area was disturbed as the area is
continuously put under cultivation. The soils alluvium deposits were
classified into recent alluvium; sub recent alluvium (old levees and bars) and
old alluvium clay plain deposits. Although the soils are intensively cropped
for teaching and research purposes, but adequate information regarding the
physical and chemical properties of the soils under investigation were
lacking, and no detailed soil map has ever been compiled. In the present
work a detailed investigation was made to characterize the soils. Due to the
soil variability in the area, a detailed survey with a high density of soil
observations was adopted. Six profile pits and thirty augers have been fully
described and sampled for the determination of important physical and
chemical properties. Among these salinization, alkalization processes,
potential soils fertility and soil water regime were examined. Results of
laboratory determinations are discussed in chapter six. The field
observations and laboratory findings were used for study of soil genesis and
the compilation of a detailed soil map of the area. The estimation and
mapping of salts and alkali in the surface soil of the farm were also carried
out. For this purpose surface soil samples have been analysed for soil
reaction, salinity, sodium adsorption ratio and exchangeable sodium
percentage. Soil mapping units were separated according to differences in
profile characteristics, taking into account the arrangement of stratification,
textural variations and features of alluvial development. Laboratory results
were also utilized in the differentiation between soil mapping units. Special
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suitability assessment was carried out and accordingly land suitability maps
were produced for the investigated study area. The soils of the farm lie
within suitability class S1 (Highly suitable) and S2 (Moderately suitable) with
limitations of salinity, sodicity, permeability and texture. Since the study was
designed as applied research, the recommendations outlined are related to
future research studies and as well to agricultural practices to improve soil
performance. These include implementing proper soil tillage operations and introducing
.adequate fertilization programs to improve soil quality