الفهرس 
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Abstract
The study was carried out to:-
1. Study the effect of humic acids isolate sources on
a- These humic acids content of total acidity and functional.
b- The elemental composition of the isolated humic acids.
2. Study the effect of some neutral salts i.e., NaCl, CaCl2 and FeCl2
applied at different rates on plant growth and its chemical
composition.
3. Study the effect of humic acids different in their chemical
composition on plant growth and its chemical composition.
4. Study the interaction of both neutral salts and humic acids onplant
growth and its chemical composition.
5. Study the effect of the used neutral salts on humic acids utilization
by plant.
The used three humic acids in these study were isolated from three
different sources. The first source was alluvial soil (HAS) which was
collected from surface layer (0-20 cm) of Experimental Farm, Faculty of
Agriculture, Shebin El-Kom, Minufia University. The second source was
pouderette (HAP) which taken from sewage sludge station, El-May,
Minufia Governorate. The third source was prepared compost of clover
straw (HAC). The isolated three humic acids were purified and analyzed
for their elemental composition for C, H,O,P and N (%) were ranged
between 43.85 - 46.54, 5.28 - 6.15, 44.21- 47.44, 0.63 - 0.85 and 2.25 - 2.98, respectively and some atomic ratios. i.e., C/H, C/O, C/N and C/P
were calculated ranged between 7.57 – 8.30, 0.92- 1.55, 16.25 – 20.66
and 66.44 – 74.76, respectively. Also, these acids were analyzed for its
content of (meq/100g) of total acidity and some functional groups. i.e.,
COOH, total – OH, phenolic – OH and alcoholic – OH were ranged
between 580.4 - 710.50, 270.1-330.4, 445.8-527.6, 310.3-380.1, 135.5-
182.5, respectively.
Three humic acids isolated from alluvial soil (HAS), podritte (HAP)
and compost (HAC) were used in this study at five application rates.i.e.,
0, 10, 20, 40 and 100 mgkg-1.
In this study three neutral salts of NaCl, CaCL2 and FeCl2 where
each of those salts was applied at rates of 0, 250, 500, and 1000
mg kg-1
.
A 540 plastic pots with 20 cm inter diameter and 18 cm depth were
used in this study. Each pot was filled by 1 kg of clean and dried prepared
sand. Each pot was planted by 12 grains of barley (Hordium vulgar L. )
variety Giza 123 and irrigated every three days using Hoagland solution
alternated with tap water to obtain the moisture content at 60 % of water
holding capacity. After 10 days of planting, the plants of each pot were
thinned at 8 plants. After 21 days of planting, the pots were divided into
three main groups (180 pot /main group ) representing the main factor or
humic acids (HAS, HAP and HAC) treatments. The pots of each main
group were divided into equal five sub groups (36 pot for each sub
group) which treated by one rate of humic acid (0, 10, 20, 40 and 100
mgkg-1 ). At the same time, the pots of each subgroup were divided into
three subgroups representing the treatment of neutral salts (NaCl, CaCl2,
and FeCl2 ). Finaly the pots of each sub-sub group were divided into
equal four groups ( 9 pot for each group ), where the pots of each final group were treated by one concentration of the used neutral salts. i.e., 0,
250, 500 and 1000 mgkg-1. The studied treatments were arranged in
completely block design with three replicates. After 42 days of planting,
the plants of each pot were taken as a whole, cleaned gently from sandy
particles using current tap water and divided into shoots and roots fresh
weights (g /pot ) of both shoots and roots were recorded. Then plant
materials were oven-dried at 70 OC for 48 hrs and weighted to obtain on
dry weights (g/pot ) for both shoots and roots. The dried plant materials
were fined and kept in glass bottles for its chemical analysis.
The obtained results may be summarized in the following points.
1. Humic acids properties.
· The high content (%) of C, H and P were found in HAS and the
lowest values were found in HAC. On the other hand, the high
content (%) of O was found in HAC and the lowest one was found
in HAS. Also the highest content (%) of N was found in HAP
followed by that found in HAC.
· The ratios C/H and C/P of the three humic acids increased in the
following order : HAC > HAP > HAS. This order according to C/N
ratio was HAS > HAC > HAP. The three tested humic acids
characterized by high ratios of C/O and the following the order :
HAS > HAP > HAC.
· There are wide range of the three tested humic acids content (meq
/100 g ) of total acidity, the highest content (710.5 meq/100g ) was
found with HAC and the lowest one (580.4 meq /100g ) was found
with HAS. The content ( meq /100g ) of COOH in the three humic
acids represent the predominant functional group compared with
other groups, were these humic acids may be arranged according to
the content of COOH as follows : HAC > HAP > HAS. Similar wide variations in the three humic acids content of total – OH,
phenolic – OH and alcoholic - OH groups (meq/100g),where the
highest content was found with HAC followed by that recorded
with HAP.
2. Fresh and dry weight yield (FW and DW ).
· Increasing rate of added humic acids individually was associated
by an increase of FW and DW (g/pot ) of both shoots and roots of
barley plants treated by different application rates of the used
chloride salts. The highest yield of both FW and DW of shoots and
roots were found with the plants treated by HAC. The found
increase of FW and DW of shoots and roots as a result of humic
acids applications were significant.
· Under all treatments of humic acids, both FW and DW of
shoots were higher than those of roots. Similar trend also was
found with individual treatments of NaCl, CaCl2 and FeCl2.
· Increasing rates of added NaCl decreased FW and DW of
both shoots and roots. Individual applications of CaCl2 increased
FW and DW of both shoots and roots up to application of 500
mg/kg, but all application of FeCl2 were associated by an
increasing of both FW and DW of barley plants (shoots and roots).
· In the combined treatments of humic acids and neutral salts,
the highest FW and DW of both shoots and roots were found in the
plants treated by FeCl3 with HAC.
· At each application rate of NaCl, CaCl2 and FeCl2, RC(%) values
of both FW and DW of both shoots and roots were varied from
acid to another, where the tested humic acids takes the order :HAC > HAP > HAS according to the found values of RC for both
FW and DW of shoots and roots.
· At the same rate of added humic acid, RC values of FW were
higher than those of DW for shoots and roots of barley plants.
· The plants were treated by NaCl gave low RC values for both
FW and DW and become more lowest at high application rates
specially with low application rate of humic acids. Also, the
highest RC values of FW and DW were recorded with application
rate at 1000 mg kg-1. While reversal trend for RC values were
found in the plants treated by FeCl2.
· Agronomical efficiency values AE of humic acids which
calculated as mg humic acid /kg plant materials were decreased
with the increase application rates of humic acids. This trend was
found for both FW and DW of shoots and roots under different
treatments of the three neutral salts.
· At the same rate of added humic acids and according its AE
values, these acids may be arranged in the following order HAC >
HAP > HAS. All AE values of humic acids individual treatments
for FW for both shoots and roots were higher than those of DW.
Also, all AE values of FW and DW for shoots were higher than
those of roots.
· With the three humic acids, AE values of FW and DW of shoots
and roots were decreased with the increase rate of added NaCl and
increased with the increase of added CaCl2 up to 500 mg/kg and
FeCl2 up to 1000 mg/kg, mostly.· Humic acids applications in combination with CaCl2 reduced Ca
concentration and increased its uptake by shoots and roots this
trend was more clear at high application rate of CaCl2.
c-Iron (Fe) content.
· Individual and combined treatments of humic acids and FeCl2 at
different application rates were associated by an increase of Fe
uptake (mg/pot ) by shoots and roots of barley plants, but Fe
concentration (mg/kg) in both shoots and roots was decreased with
the increase of added humic acids at the same treatment of FeCl2.
· At the same treatment of either of humic acids or FeCl2
individually or in combination, Fe concentration and uptake by
shoots were higher than those of roots.
4. Effect of humic acids on neutral salts utilization.
· Utilization rate (%) of Na, Ca and Fe by both shoots and roots
were decreased with the increase rate of added NaCl, CaCl2 and
FeCl2 as alone, where those values were increased with the
increase of added humic acids individually or in combination with
the tested neutral salts.
· At the same application rate of neutral salts, the highest Na, Ca and
Fe U (%) for both shoots and roots were found in the plants treated
by HAC followed by those in the plants treated by HAS. At the
same treatment of humic acids or / and neutral salts Na, Ca and Fe
U by shoots were higher than those of roots.
· With both shoots and roots and at the same treatment of humic
acid the found utilization for those three elements takes the order :
CaU > FeU > NaU. Also under all the studied treatments, Na, Ca
and Fe U of shoots were higher than of roots.