الفهرس 
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Abstract
The study was carried out using salt-affected soils to study the effect of gypsum or sulfur, each individually or in combination, on the soil chemical properties and its content of nutrients, as well as its effect on the growth and content of barley plants (Hordeum vulgare L.), cultivar variety Giza 123).
from each soil, five surface (0-30) cm were collected from different sites, good mixed and analyzed for its chemical and physical Properties as well as its content of available nutrients and trace elements.
In this study two soil amendments were used. The first was the elemental sulphur (ES) as a chemical amendment with purity of 99% and pH of 6.8 The second was gypsum (G) as a natured amendment (CaSO42H2O) which obtained from Agricultural Research Station,Sokha, Kafr ElShikh Governorate. The purity of the used G was 85%. This study was carried out as a pots experiment on barley plant (Hordeum vulgare L.), as a test plant. Seeds of barley ware obtained from Agricultural Research Center (ARC) Egypt. The studied treatments were: -
Soil types include five soils (So1, So2, So3, So4 and So4) varied in the physical and chemical properties especially their EC (dSm-1) values.
Elemental sulphur (ES) which applied at four application rates So (0.0%), S1(0.05%), S2(0.10%) and S3(0.20%).
Gypsum (G) application which carried out at three application rates i.e G0 (0.0%), G1(0.04%) and G3(0.08%)
The studied treatments, including soil salinity and applications of elemental sulfur and gypsum, were arranged within the experimental units in a 3-way completely randomized block design with three replicates.
All pots were irrigated at moisture content of soil field capacity (60%). As well as these pots were manured by compost at rate of 5%.
At the same time the pots ware fertilized by ordinary super phosphate at a rate of 0.13gkg-1. The applications of compost, super phosphate and elemental sulphur and gypsum ware carried out before planting and good mixed with the pots soil. Both N and K fertilizers ware applied at recommended doses of barley plants (g.kg-1) as ammonium nitrate 33%N and potassium sulphur (48%k2O)
After 72 days of planting, the plants of each pot ware harvested above the soil surface, weighted oven dried, weighted and analyzed for the content of some nutrients and trace elements.
Aftar harvesting, soil sample was taken separately from each pot and analyzed for its chemical composition and the content of available nutrients and trace elements.
The obtained data may be summarized in the following points:
The studied five soils have an EC value varied between 2.80 dSm-1 (S4) and 5.40 dSm-1 (S3)
Soil pH varied between 7.19 and 7.78 in soil 2 and 5 respectively, while the content of OM varied between 2.36 and 0.37% in soil1 and 5 respectively, ESP were varied between 10.47 and 17.38 in soil 1 and soil 5, respectively Na was varied from 19.50 to 29.0 meq.L-1 in soil 1 and soil 5.
The predominant soluble cations in the five soils were Na+, while the predominant soluble anion was CL-1
All soils have a low and moderate content of both macro- and micro- nutrients as well as the content of some trace elements.
The five soils have a clay texture class.
A- Effect of soil properties on dry matter yield of barley plants (BDW).
According the found BDW the cultivated soils take the order soil2>soil1>soil3>soil4>soil5.This trend means that, BDW was decreased with the increase in soil EC dSm-1. The relationship between BDW gpot-1 and soil EC may be explained by this equation.
BDW = 6.06 – 0.82 EC (r=0.92)
Increasing in soil pH of the studied soils reduced BDW (gpot-1). where their reeducation was BDW= 38.8 -4.65 pH (r=0.71)
As well as increasing in the soil content (meq.L-1) of soluble Na+ and Cl- resulted in decrease of BDW (gpot-1), where these two relations may be described using the following two equation:
BDW=5.83- 0.10 Na+ (meq. L-1) (r=0.93) in the case of Na+
BDW= 5.91- 0.09 Cl-1 (meq.L-1) (r=0.92) in the case of Cl-
These two equations and the two varied of correlation coefficients show a similar decrease effected of both Na+ and Cl- on BDW.
B. Effect of gypsum and sulphur applications on barley dry weight (BDW)
-Individual applications of gypsum especially at high application rate (0.08%) resulted in a significant increase of BDW under the five soil conditions under study for example, BDW in the plants grow in soil 5 was increased from 1.13 gpot-1 with zero gypsum and sulphur (G0 and S0) applications to 1.35 gpot-1 in the same soil with the treatment of S0 and G3 recorded increase percent of 17.391.
-Individual applications of sulphur especially at high applications in all soils under study resulted in a signification increase of BDW. For example, BDW of barely plants planted in soil5 was increased from 1.13 gpot-1 with the treatment of G0 and S0 to 2.11 gpot-1 recorded increase percent of 83.478
-More significant increases of BDW were found with the plants growing in the soils with the combined applications of G and S especially at their high application rates (G2 and S3). For example, BDW of the plants grown in soil5 was increased from 1.15 gpot-1 with G0 and S0 treatment to 2.52 gpot-1 for the plants cultivated in the same soil treated by G2 and S3 together with increase percent of 123.478.
C. Effected of gypsum and sulfur applications on nutrients contents of barley plants.
1- Nitrogen (N) content.
The soils under study have a moderate effect on N concentration (%) in barely plants which ranged between 0.13 and 0.10% with different treatments under study.
With all treatments of G and S individually and in combination and according the found N (%) in barley plants the cultivated soils takes the order soil 2> soil 1> soil 3 >soil4 >soil5.This order is in harmony with pH of the studied soils as well as with these soils content of organic matter.
On the other hand, N uptake by barely plants in the five soils varied from 2.89 to 6.91mgpot-1 with a mean of 4.24 mgpot-1, where the highest uptake was found in the plants planted in soil2 and the lowest was found in the plants cultivated in soil 5.
Nitrogen uptake by barley plants significant increased as a result of added S increase where its uptake varied from 2.89 mgpot-1 in soil 5 to 6.04 mgpot-1 in soil2 with mean of 4.24 mgpot-1.
Individual application of gypsum led to a signification increase in both N concentration (%) and uptake (mgpot-1) by barely plants grown in the five soils varied in their salinity. For example, N uptake by barley in soil2 was increased from 2.60 mgpot-1 with the treatment of S0 and G0 to 7.31 mgpot-1 with the treatment of S0 and G2 .
The data also show that, the effectiveness of sulphur and gypsum application for promoting nitrogen uptake. For example, in soil 2, the highest mean nitrogen uptake (12.42 mgpot-1) was observed at the 0.2% and 0.08 % application level for both sulfur and gypsum, respectively, while in soil 4, the highest mean nitrogen uptake (9.38 mgpot-1) was observed at the 0.05% sulfur and 0.04 % gypsum application.
Moreover, the data indicate that the combined application of sulfur and gypsum can have a significant effect on nitrogen uptake in barley plants, with the highest mean nitrogen uptake observed at the 0.1% sulfur and 0.08% gypsum application levels. For example, in soil 2, the combined application of sulfur and gypsum at the 0.1% and 0.08% application levels resulted in a mean nitrogen uptake of 12.42 mgpot-1, which is higher than the mean nitrogen uptake observed with either sulfur or gypsum alone at any application level in the same soil.
2-Phosphorus(P) content
The properties of the studied soil have a significant effect on P(%) of barley plants, where according to this content, the experimental soils takes the order soil5>soil4>soil2>soil1>soil3.
Furthermore, the results suggest that the response of P uptake to sulfur and gypsum additions also varies depending on soil type. For example, in soil 1 and soil 2, the highest P uptake values are observed at 0.1% sulfur and 0.08% gypsum.
Furthermore, the results suggest that the optimum sulfur and gypsum application rates for maximum P uptake in soils vary among soils. For example, in soil 1 and soil 2, the highest P uptake values are observed at 0.1% sulfur and 0.08% gypsum, while in soil 3, soil 4, and soil 5, the highest P uptake values are observed at 0.2% sulfur and 0.04% gypsum.
Regarding the effect of adding elemental sulfur, the results suggest that P uptake generally increases with increasing levels of sulfur, although the magnitude of the increase varies depending on the specific soil sample. For instance, in soil 1, the P uptake increases from 5.80 mgpot-1 to 10.79 mg/pot as the rate of sulfur increases from 0.0% to 0.2%. Generally, the mean P uptake throughout all soil samples increased from 5.13 to 10.77 mgpot-1 as the rates of sulfur increases from 0.0 to 0.2%.
In respect to the effect of gypsum treatments on P uptake (mgpot-1), the results indicate that, the P uptake generally increases with increasing levels of gypsum, although the magnitude of the increase varies depending on the specific soil sample.
For instance, in soil 1, the P uptake increases from 7.03 mgpot-1 to 9.71 mgpot-1 as the gypsum addition rate increases from 0.0% to 0.08%. General, mean of P uptake in all soil samples increased from 5.97 mgpot-1 to 9.14 mgpot-1 as the rate of gypsum increases from 0% to 0.08%.
3-Potassium (K) content
The plants content (%) of K with all S and G applications varied widely from soil to another. The results indicate that the combined applications of gypsum and sulfur generally enhance K uptake compared to the application of either amendment alone, although the magnitude of the increase varies depending on the specific soil sample and the added rate of gypsum and sulfur used. For instance, in Soil 1, the application of 0.0 % gypsum and 0.10% sulfur results in a K uptake from 1.25 mg/pot, which is higher than the uptake observed with either amendment alone.
As well as their soil5 has the highest K % in the barley plants, with a value of 1.54%, while Soil3 has the lowest K %, with a value of 1.34%. A variation in K uptake by the plants across the different studied soils, soil2 has the highest K uptake, with plants taking up 63.45 mg/ pot, while soil4 has the lowest K uptake, with plants taking up only 28.93 mg per pot.
The mean K uptake of all soils was is 40.83 mgpot-1, that increase with increasing the level of sulfur added to the soil, the K% of barley plants increases. For instance, in Soil1, the mean K% of barley plants increases from 1.32 at 0% sulfur to 1.48 at 0.2% sulfur.
As increase in the level of gypsum added to the soil increases, the mean K% of barley plants shows a slight increased. For example, in soil1, the mean K% of barley plants increases from 1.33 at 0% gypsum to 1.48% at 0.08% gypsum. This trend is also observed in other soils. However, the observed trend is not statistically significant, given the LSD value for gypsum at a 0.05 level of significance, which is 0.1.
As increased the level of sulfur added to the soil, the mean K uptake of barley plants also increases. For example, in soil1, the mean K uptake of barley plants increases from 34.81 mg per pot at 0% sulfur to 56.47 mg per pot at 0.2% sulfur. This trend is also observed in other soils.
There is no clear trend in the mean K uptake of barley plants with increasing levels of gypsum. For example, in soil1, the mean K uptake of barley plants is 41.15 mg per pot at 0% gypsum, and it increases to 52.52 mg per pot at 0.08% gypsum, but it decreases to 51.23 mg per pot at 0.04% gypsum.
This trend is not consistent across the other soils. In some soils, such as soil2 and soil4, the mean K uptake of barley plants increases with increasing levels of gypsum.
4-Sulfur (S) content
The data shows that, S % values for studied soils varied with values ranging from 0.406 to 0.487 %. The highest S % value was observed in soil 5 (0.487), followed by soils 2 and 4 (0.480 and 0.483%).
Sulfur uptake in studied soils, varied with values ranging from 9.229 to 21.016 mgpot-1. The highest sulfur uptake was observed with soil 2 (21.016 mgpot-1), followed by soil 1 (16.083 mgpot-1). The lowest sulfur uptake was observed in soil 5 (9.229 mgpot-1). The higher sulfur uptake observed in soils with lower salt concentrations (soils 1 and 2) On the other hand, the lower sulfur uptake observed in soils with higher salt concentrations (soils 4 and 5).
Increasing the amount of gypsum applied to the soil increases the sulfur content of the barley plants. When no gypsum applications, the sulfur content of the barley plants was 0.44 %. However, while its values with 0.04% and 0.08%gypsum.
Increased to 0.47% and 0.49%, respectively. The data shows that increasing the amount of gypsum applied to the soil results in a higher sulfur uptake in barley plants. When no gypsum was added to the soil, the sulfur uptake by the barley plants was 10.80 mg/pot. However, when 0.04% gypsum was added to the soil, the sulfur uptake increased to 13.61 mg/pot. Moreover, the sulfur uptake increased to 15.24 mg/pot when 0.08% gypsum was added to the soil.
Additions of sulfur had a positive impact on S% in all soils tested. As the sulfur rate increased from 0.0 to 0.2 %, there was a corresponding increase in S% in all soils. However, the impact of sulfur on S% varied depending on the soil type. Soils 5, 4, and 2 had higher S% values compared to soils 1 and 3.
In addition, S application had a significant increase effect on S uptake by barely plants grown in soils varied in their salinity. The highest sulfur uptake was observed in soil 2 at the highest sulfur rate of 0.2%, with a value of 27.81 mg/pot. Soil 4 also showed a significant increase in sulfur uptake as the sulfur rate increased.
5.Lead (Pb) content
Lead concentration and uptake (mg/kg and mgpot-1) are higher in soils with higher salinity, such as content in soil 2 and soil 3, compared to soils with lower salinity, such as soil 4 and soil 5. However, there are some exceptions, such as soil 1, which has a lower salinity but a higher Pb mg/kg than soil 4 and soil 5.
The experimental saline soils can be arranged according their effect on Pb concentration (mg/kg) in the barley plant as the following order: soil 3 > soil 5 > soil 4 > soil 2 > soil 1 and as Pb uptake (mgpot-1) as the following order: soil 2 > soil 1 > soil 3 > soil 4 > soil 5.
In general, gypsum application increased Pb (ppm) and uptake mgpot-1 by barley plant in most soils, except for soil 4 and soil 5, where the highest gypsum rate (G3) decreased Pb (mg/kg) and uptake (mgpot-1) in barley plants compared to the control (Go).
6-Cadmium (Cd) content
All five saline soils have cadmium concentrations in barley above the average level of 0.1 mg/kg, but below the animal feed limit of 0.5 mg/kg. This means that these soils have different effects on Cd accumulation in barley plants. Lead uptake by barley plants grown in different saline soils is very low, where its ranging from 0.0003 to 0.0005 mgpot-1.
The mean Cd content of barley plants increased with increasing sulfur applications in all soils.
The data also show that, indicating that sulfur enhanced the uptake of Cd by the plants.
The highest Cd content was observed with the plants in soil 5 with treatment S3 (0.1968 mg/Kg), while the lowest Cd content was observed with the plants in soil 2 with treatment
The statistical results show that sulfur treatments have significant effects on Cd. This means that there are differences among the treatments in terms of Cd (mg/Kg).
The results reveal that, the mean Cd uptake of barley plants increased with increasing sulfur applications across all soils.
The highest Cd uptake was observed in soil 2 with treatment S3 (0.0007 mgpot-1), while the lowest Cd uptake was observed in soil 4 and soil 5 with treatment S0 (0.0002 mgpot-1).
The statistical analysis shows that gypsum treatment has a significant effect on Cd uptake in barley plants. This means that, there are significant differences among the mean Cd uptake for different gypsum treatments where a significantly different between G0 and G1, G0 and G2, and G1.
D-Relationships between nutrients uptake and soil chemical properties
There are as negative correlation between nitrogen uptake and soil properties such as pH, EC, K+, Na+, Mg++, Ca++, Cl-, and HCO3-. Higher levels of some soil properties were associated with higher P % in barley plants. On the other hand, the correlation coefficients for P uptake (mgpot-1) were negative. Saline soil chemical properties have a well effect (positive or negative) in K content (% and mgpot-1) The positive or negative of the correlation coefficient indicates the direction of the relationship between the two variables. A positive correlation coefficient suggests that as one variable increases.
The other variable also tends to increase, while a negative correlation coefficient suggests that as one variable increases, the other variable tends to decrease.
Such as a weak positive correlation for S content with pH (0.06), EC (0.19), K+ (0.26), Na+ (0.10), Mg++ (0.28), Ca++ (0.54) and SO4-- (0.10), indicating that these soil properties have little influence on the sulfur content of barley plants in saline soils.
There is a negative correlation between sulfur uptake and most of the soil properties, except for pH and Ca++. The strongest negative correlation is with SO4-- (r = -0.700), followed by Na+ (r = -0.674) and HCO3- (r = -0.685). The weakest negative correlation is with EC (r = -0.651) and Cl- (r = -0.651). The positive correlation with pH (r = 0.058) and Ca++ (r = 0.542) is weak and moderate, respectively.