الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The current work aims at following up the changes that may occur in
availability as well as uptake of some micronutrients (Fe, Mn, Zn and Cu) by
barley plants grown on some calcareous soils of Egypt upon treating these soils
with some organic wastes. To fulfil the purpose of this study, surface soil
samples (0-30 em) varying in their content of CaC03 were collected from three
locations along Cairo-Alexandria desert road. The first location is about 100 Krn
from Cairo, the second is adjacent to EI-Noubaria Seed Company and the third
location is EI-Noubaria Agricultural Research Station. The organic wastes used
in the current work were sewage sludge taken from EI-Gabal El-Asfar Sludge
Station, town refuse taken from Egyptian Organic Manure Plant (Shoubra) and
biogas manure supplied by Moshtohor Biogas Research Station.
An incubation experiment and a greenhouse one were conducted.
In the incubation experiment, each of the organic wastes was mixed with
100 g portions of the investigated soils at a rate of 2 % under controlled
conditions (30°C and either of two moisture levels, i. e. 60 % or 100 % of the
F. C.). Samples of the incubated soils were taken after 1, 2, 4, 6 and 8 weeks
and extracted by AB-DTPA then Fe, Mn, Zn and Cu were determined.
In the greenhouse experiment, plastic pots packed with the investigated
soils were grouped in four sets. The first set was used as a control {without
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mixing with organic wastes), the second, third and fourth ones were mixed (at
a rate of 2 %) with sewage sludge, town refuse and biogas manure, respectively.
The pots were cultivated with barley for a period of 60 days, thereafter plants
were cut above the soil surface and oven dried at 70°C to determine their dry
weight and micronutrients content of Fe, Mn, Zn and Cu.
The following is a brief summary for the results obtained:
(1) Soils contents of Fe, Mn, Zn and Cu extracted with AB-DTPA increased
as a result of incubation with sewage sludge, town refuse or biogas
manure. In all the investigated calcareous soils and under both the studied
moisture contents, sewage sludge was the most effective organic waste in
enriching soil with micronutrients compared to the town refuse or the
biogas manure which showed the lowest effect.
(2) Increasing period of incubation resulted in increases in soils contents of
AB-DTPA extractable Fe, Mn, Zn and Cu, however, the increase was
dependent on type of the organic waste, soil properties and period of
incubation.
(3) Increasing the moisture content at which the investigated soils were
incubated with the organic wastes from 60% to 100% of the F.C.
increased the AB-DTPA extractable Fe, Mn, Zn and Cu. Extractable Fe
was affected by increasing soil moisture mo,re than the extractable Mn
whereas the extractable Zn was the least affected nutrient by increasing
soil moisture content. (4) Interaction effect between sewage sludge and moisture content equivalent to 100% of the F.e. resulted in the highest values of Fe, Mn, Zn and Cu.