الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
main objective of this investigation is to study the effect of
some organic fertilizers, i.e. composts, fannyard and .biog
as
manures
on nutrients availability in sandy and clay soils and hence their uptake
by corn plants. TwO pot experiments were carried out under green
house conditions. The first experiment (incubation) was performed to
investigate the chemical availability of N,P and K in the tested soils as
affected by the manuring treatments. The tested manures were applied
at the rate of 2% (WIW) to both tested soils and incubated for 8 weeks.
The soil analyses were run at 0,4,6 and 8 weeks incubation periods.
The second experiment (cultivation) was conducted to study the
combined effect of different manures and NFK fertilizers applied at the
recommended doses on the availability and uptake of N,P, and K by
com plants.
The obtained results reveal the following:
5.1. Incubation experiment:
1) Manures application increased significantly and consistendy
allover the tested periods, both available soil Nand P in the order :
biog
as
M. > compoIT> comp- 1> FYM· On contrarY soil available
K the inducing trend decreased in the order: comp- IT> eomp. I>
FYM > biogas M., with significant differences betWeen any
treatment and each other one.
78 [§ummarY]
2) The application of organic manures increased the soil organic
matter content allover the tested incubation periods, while compost
I followed by compost II were favourite for the sandy soil,
compost II followed by biogas M. were more effective in the clay
soil.
5.2. Cultivation experiment:
1) The addition of different fertilizer sources significantly increased
the dry matter yield of com plants in both tested soils, particularly
the biogas manure which exceeded mostly the other organic
sources and even the mineral source in many cases.
2) The different fertilizer sources increased significantly the N uptake
by com plants (shoots, roots and whole plants) in both tested soils.
The biogas manure followed by the mineral fertilizers source were
the most effective treatments with respect to the increase in N
uptake by com plants after different growth periods (4, 6 and 8
weeks) in both sandy and clay soils.
3) The application of different fertilizer sources increased
significantly the P uptake of com plants in both tested soils.
Results may suggest in general, that biogas M. followed by
compost II were more effective manures in increasing P uptake by
com plants than the other sources, in the sandy soil. Biogas
manure and compost I exceeded the other sources in the clay soil,
while the mineral fertilizers source was the most inferior source.
4) The different fertilizer sources increased significantly the total K
uptake by corn plants in the sandy and clay soils, where compost I
exceeded compost n under the sandy soil conditions, whereas
compost II followed by biogas M. were the most effective under
the clay soil conditions. The mineral fertilizers source was the least
efficient in the sandy and clay soils.
S) The biogas manure followed by compost n were favourite for
increasing the availableN in the sandy soil, whereas, FYM and the
mineral fertilizers source gave the least effect.
As for the clay soil, while the mineral fertilizers source followed
by the biogas M. were the most effective on the level of soil
available N, compost I was the least effective under com growth
conditions.
6) The tested fertilizer sources increased significantly soil available P
allover the growth periods, the sandy soils, recorded higher
efficiency than the clay one allover the growth periods.
7) The different fertilizer sources increased the soil available K in the
sandy and clay soils under com growth conditions. Compost II
followed by compost I were the most effective, while mineral
fertilizers source and/or biogas M. were the least effective for
increasing available K in sandy and clay soils.
8) The application of the different organic manures increased the soil
organic matter content under com growth conditions, the most
effective sources in both soils were compost 1 followed by
compost II.