PhD Thesis      [Total: 14 ]

Trials towards treating water and soil polluted due to some anthropogenic activities

Gamal Osman Alshiekh, 2007

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Contamination of soil and water by various pollutants( synthetics and organic) such as pesticides, polyaromatic hydrocarbons as well as the heavy metals, etc. have caused imbalance in the natural functioning of the ecosystem. Soils can naturally reduce mobility and bio availability of heavy elements as they are retained in soil by sorption, precipitation and complexation reaction. This natural attention process can be accelerated by addition of amendments converting the soluble form to more geochemically stable solid phases. On the other hand, algae have been proved to play an important role in purification and removal of trace elements from wastewater.The current study represents trials towards ameliorating soils and waters polluted with heavy metals due to anthropogenic activity.In situ soil decontamination incubation experiments were executed. Two soil samples from El-Gabal El-Asfar farm and El-Saff regions polluted due to irrigating them with sewage water and industrial wastewater, respectively were incubated with either poultry manure, compost El-Khalil (organic amendments), bentonite, rock phosphate or calcium carbonate (inorganic amendments) at a rate of 2% after being mixed thoroughly in pots of 200 g soil capacity. Soil samples were taken to represent the different amendment treatments as well as the different incubation periods and extracted with EDTA, the Ni,Co and Cd were determined in EDTA-extracts using an Atomic Absorption Spectrophotometer, Perken Elmer (Model 2380).A wastewater experiment was conducted on two wastewater samples collected from the effluents of El-Gabal El-Asfar station and the industrial wastewater at El-Saff. These wastewater samples were inoculated with either of Scenedesmus obliquus, Chlorella vulgaris or spirulena plantensis algae. The inoculated as well as the control wastewater samples were incubated at 28 2C0 under light of 4000 lux intensity (14 h light followed by 10 h darkness) for periods of 7,15 and 21 days beyond which Ni, Co and Cd were determined. The most important obtained results could be summarized in the following :- 1-Effect of poultry manure: •EDTA-extractable amounts of Ni, Co and Cd were decreased in both the investigated soils due to amending these soils with poultry manure at a rate of 2%. The decrease was more obvious by increasing time of contact between the applied amendment and the investigated soils. •Although it was found that the removed amounts of the studied metal ions from both the investigated soils followed the descending order : Ni>Co>Cd, yet the corresponding removal percentage values followed the descending order Co>Ni>Cd all over the periods of incubation. •Values of the removal capacity of poultry manure seemed highest with Ni, lowest with Co and came in-between for Cd, however, these values were generally higher in El-Gabal El-Asfar poultry manure amended soil than in El-Saff poultry manure amended soil. 2- Effect of El-Khalil compost:- •Application of the compost could minimize value of EDTA-extractable Ni, Co and Cd in both soils under study especially by increasing period of incubation, yet such an effect was more obvious in El-Gabal El-Asfar soil than El-Saff soil. * Sorbed amounts of Ni, Co and Cd in El-Gabal El-Asfar soil exceeded obviously the corresponding ones in El-Saff soil. On the other hand, sorption (removal) percentages of the concerned metal ions in El-Saff soil exceeded obviously the corresponding values in El-Gabal El-Asfar. •Removal capacity of the compost for Ni, Co and Cd was of higher values in El-Gabal El-Asfar soil than in El-Saff soil. 3- Effect of bentonite :- •Values of EDTA–extractable Ni, Co and Cd from both the bentonite-amended soils decreased progressively with increasing period of incubation. Consequently, it was found that values of sorbed Ni,Co and Cd increased with increasing time of contact between the investigated soils and bentonite.Absolute values of sorbed Ni were the highest whereas those of Co were the lowest while those of Cd were in-between, however, sorption percentages of Co were shown to be highest withing the first and second periods of incubation in El-Gabal El-Asfar soil and over the whole period in El-Saff.Removal capacity of bentonite for Ni was higher than for Co and Cd over the studied periods of incubation which were characterized by increasing the removal capacity by progressing time except for Co whose one remained almost constant over the different periods of incubation. 4- Effect of rock phosphate:- •Increasing time of contact between the studied soils and rock phosphate caused values of EDTA-extractable Ni,Co and Cd to decrease progressively with increasing period of incubation.The sorbed (removed) amounts of Ni,Co and Cd increased with prolonging time of contact between rock phosphate and soils and hence removal percentages of Ni,Co and Cd by the rock phosphate–amended soils increased with time. According to those percentage values, the studied metal ions followed the descending order:Cd>Ni>Co. This sequence characterized both the studied soils over all periods of incubation except for the 75 day period in El-Gabal El-Asfar soil where removal percentage of Cd highly exceeded that of Co which slightly exceeded that of Ni.El-Gabal El-Asfar soil could adsorb values of Ni, Co and Cd higher than El-Saff soil did, however, sorption percentages of the metal ions under study were relatively higher in El-Saff than El-Gabal El-Asfar soil except for Cd after 75 days where its sorption percentage in El-Gabal El-Asfar soil was higher than in El-Saff soil.The removal capacity of rock phosphate for studied metal ions increased with time of contact between rock phosphate and soils. 5- Effect of calcium carbonate:- •Increasing time of contact between soils and CaCO3 reduced progressively the amount of EDTA-extractable Ni,Co and Cd. The reduced amounts seemed highest with Ni, lowest with Co and came in-between with Cd.Sorbed amounts of these elements increased with time of contact following the descending order:Ni>Cd>Co regardless of type of soil. Values of removal capacity increased with time to be in the following descending order:Ni>Cd>Co. 6- Effect of algae on ameliorating the wastewaters:- •Algea could succeed in reducing concentrations of Ni,Co and Cd in the studied wastewaters.The used algal species could be arranged according to the mean values of removal percentage of Ni in the following descending order: Scenedemun > Chlorella > Spirulina. The corresponding sequence according to the removal percentage of Co and Cd followed the descending order : Chlorella > Scenedemun > Spirulina. The efficiency of fungus regardless of its species on removing Ni from the studied wastewaters was lower than the corresponding ones on removing Co and Cd


Trials towards treating water and soil polluted due to some anthropogenic activities

Gamal Osman Alshiekh, 2007

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Contamination of soil and water by various pollutants( synthetics and organic) such as pesticides, polyaromatic hydrocarbons as well as the heavy metals, etc. have caused imbalance in the natural functioning of the ecosystem. Soils can naturally reduce mobility and bio availability of heavy elements as they are retained in soil by sorption , precipitation and complexation reaction. This natural attention process can be accelerated by addition of amendments converting the soluble form to more geochemically stable solid phases. On the other hand, algae have been proved to play an important role in purification and removal of trace elements from wastewater.The current study represents trials towards ameliorating soils and waters polluted with heavy metals due to anthropogenic activity.In situ soil decontamination incubation experiments were executed. In these experiments, two soil samples from El-Gabal El-Asfar farm and El-Saff regions polluted due to irrigating them with sewage water and industrial wastewater, respectively were incubated with either poultry manure, compost El-Khalil (organic amendments), bentonite, rock phosphate or calcium carbonate (inorganic amendments) at a rate of 2% after being mixed thoroughly in pots of 200 g soil capacity. The pots were wetted to field capacity and incubated at room temperature for different incubation periods i.e. 0,25,50 and 75 day and moisture content was maintained constant at field capacity throng daily application of distilled water. Soil samples were taken to represent the different amendment treatments as well as the different incubation periods and extracted with EDTA, the Ni, Co and Cd were determined in EDTA-extracts using an Atomic Absorption Spectrophotometer, Perken Elmer (Model 2380).A wastewater experiment was conducted on two wastewater samples collected from the effluents of El-Gabal El-Asfar station and the industrial wastewater at El-Saff. These wastewater samples were inoculated with either of Scenedesmus obliquus, Chlorella vulgaris or spirulena plantensis algae. The inoculated as well as the control wastewater samples were incubated at 28 2C0 under light of 4000 lux intensity (14 h light followed by 10 h darkness) for periods of 7,15 and 21 days beyond which Ni, Co and Cd were determined. The most important obtained results could be summarized in the following :- 1-Effect of poultry manure: •EDTA-extractable amounts of Ni, Co and Cd were decreased in both the investigated soils due to amending these soils with poultry manure at a rate of 2%. The decrease was more obvious by increasing time of contact between the applied amendment and the investigated soils. •Although it was found that the removed amounts of the studied metal ions from both the investigated soils followed the descending order : Ni>Co>Cd, yet the corresponding removal percentage values followed the descending order Co>Ni>Cd all over the periods of incubation. •Values of the removal capacity of poultry manure seemed highest with Ni, lowest with Co and came in-between for Cd, however, these values were generally higher in El-Gabal El-Asfar poultry manure amended soil than in El-Saff poultry manure amended soil. 2- Effect of El-Khalil compost:- •Application of the compost could minimize value of EDTA-extractable Ni, Co and Cd in both soils under study especially by increasing period of incubation, yet such an effect was more obvious in El-Gabal El-Asfar soil than El-Saff soil. * Sorbed amounts of Ni, Co and Cd in El-Gabal El-Asfar soil exceeded obviously the corresponding ones in El-Saff soil. On the other hand, sorption (removal) percentages of the concerned metal ions in El-Saff soil exceeded obviously the corresponding values in El-Gabal El-Asfar. •Removal capacity of the compost for Ni, Co and Cd was of higher values in El-Gabal El-Asfar soil than in El-Saff soil. 3- Effect of bentonite :- •Values of EDTA – extractable Ni , Co and Cd from both the bentonite-amended soils decreased progressively with increasing period of incubation. Consequently, it was found that values of sorbed Ni, Co and Cd increased with increasing time of contact between the investigated soils and bentonite. •Absolute values of sorbed Ni were the highest whereas those of Co were the lowest while those of Cd were in-between, however, sorption percentages of Co were shown to be highest withing the first and second periods of incubation in El-Gabal El-Asfar soil and over the whole period in El-Saff •Removal capacity of bentonite for Ni was higher than for Co and Cd over the studied periods of incubation which were characterized by increasing the removal capacity by progressing time except for Co whose one remained almost constant over the different periods of incubation . 4- Effect of rock phosphate:- •Increasing time of contact between the studied soils and rock phosphate caused values of EDTA-extractable Ni, Co and Cd to decrease progressively with increasing period of incubation. •The sorbed (removed) amounts of Ni , Co and Cd increased with prolonging time of contact between rock phosphate and soils and hence removal percentages of Ni, Co and Cd by the rock phosphate –amended soils increased with time. According to those percentage values, the studied metal ions followed the descending order:Cd>Ni>Co. This sequence characterized both the studied soils over all periods of incubation except for the 75 day period in El-Gabal El-Asfar soil where removal percentage of Cd highly exceeded that of Co which slightly exceeded that of Ni. •El-Gabal El-Asfar soil could adsorb values of Ni , Co and Cd higher than El-Saff soil did, however, sorption percentages of the metal ions under study were relatively higher in El-Saff than El-Gabal El-Asfar soil except for Cd after 75 days where its sorption percentage in El-Gabal El-Asfar soil was higher than in El-Saff soil. •The removal capacity of rock phosphate for studied metal ions increased with time of contact between rock phosphate and soils. 5- Effect of calcium carbonate:- •Increasing time of contact between soils and CaCO3 reduced progressively the amount of EDTA-extractable Ni,Co and Cd. The reduced amounts seemed highest with Ni, lowest with Co and came in-between with Cd. •Sorbed amounts of these elements increased with time of contact following the descending order:Ni>Cd>Co regardless of type of soil. •Values of removal capacity increased with time to be in the following descending order:Ni>Cd>Co. 6- Effect of algae on ameliorating the wastewaters:- •Algea could succeed in reducing concentrations of Ni,Co and Cd in the studied wastewaters. •The used algal species could be arranged according to the mean values of removal percentage of Ni in the following descending order: Scenedemun > Chlorella > Spirulina * The corresponding sequence according to the removal percentage of Co and Cd followed the descending order : Chlorella > Scenedemun > Spirulina * The efficiency of fungus regardless of its species on removing Ni from the studied wastewaters was lower than the corresponding ones on removing Co and Cd


Improving the efficiency of potassium fertilization in some Egyptian soils

Khaled Abd El-Lattif, 2007

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This work aims to study some different methods that can be used to improve the efficiency of potassium fertilization in sandy and clay soils of Egypt. Three sources of potassium fertilizers (i.e. mineral-K, Feldspar-K and compost rich in-K) were added as single, dual or in a combine form as well as inoculation seeds of faba bean with or without potassium dissolving bacteria, represent the different suggested ways in this study. Material and Methods : This work included three main factors. Three experimental factors were inoculation with/ or without K-dissolved bacteria Bacillus circulans (KDB), treatments of potassium fertilizer types (seven treatments as well as control) and the rates of their application (three rates). All pots received the basic doses of N & P mineral fertilizers. Potassium fertilizer types were added as 50%,75% and 100% of the recommended dose (R D). Seeds of broad bean plants (Vicia Faba. L), cv.Giza 843 variety, used in this study as indicator plant. Results: The obtained results could be summarized as follows:- ** Inoculation with Bacillus circulans recorded, in the two soils, higher straw, seeds and biological yields as well as higher nutrients uptake than the non- inoculation treatments. Increasing rate of any form of K- fertilizer increased the yields of faba bean and nutrients content of straw and seeds comparing with the control treatment. Generally, the profitable treatments were those treated with Mineral-k, feldspar-K or mixture between them at high rate of fertilization under inoculation with Bacillus circulans. The economic ability of the experimental treatments, through calculation of the differences between costs of production (L.E/fed) and incomes profits (L.E/fed) to obtain the net gain or return (L.E/fed) treatments, to choose the best treatments which gave the highest financial return (L.E/fed)


Studies on the improvement of some characteristics of soil irrigated with agricultural dranage water.

Mohamed El-Saed, 2006

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A field experiment was conducted out on reclamation of a saline-alkali soil by agricultural drainage water (Nasr El-Din drain). The average values of EC and SAR among the experimental work were 1.91 dS/m and 6.68, respectively. This work was conducted at Mounshaet Bakhaty village, Shebin El-Kom district, Menofia Governorate to asses the efficiency of reclamation using different local amendments such as gypsum “G”, sulphur “S”, organic matter “FYM” and sand “d”. These amendments were applied individually or in a combination, where gypsum application rate was 5 ton/fed., sulphur, 1.0 ton/fed, organic matter (FYM) 20 m3/fed and sand 20 m3/fed., then the experimental plots were irrigated to leach the excess of soluble salts. Maize and wheat seeds were sowing through summer and winter seasons and the yields were harvested and recorded. The pre-leaching values of soil parameters before reclamation were: EC: 8.3 dS/m, others were; ESP: 17.2, pH: 7.9 in the surface layer (0-30 cm). The obtained results could be summarized as following: 1- Effect of amendments application on soil chemical properties:  A great reduction in soil salinity values were recorded after the application of soil amendments being 54.3% under (G+S+FYM+d) treatment after wheat compared to the control.  Soil acidity (pH) slightly decreased from 8.15 to 7.75 under the application of (G+S+FYM), (S+FYM+d) and (G+S+FYM+d) in the same value.


Studies on the chemical forms of some micronutrients in soils and their relation to plant

Hoda Saeid, 2006

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Studies on the chemical forms of some micronutrients in soils under consideration and their relation to plant, especially those bounded with organic and inorganic soil constituents, was the main purpose of this study. Three different soil types were selected to represent the Nile alluvial, calcareous and sand. Two experiments were carried out, the first was conducted to study the behaviour of Fe, Mn, Zn and Cu added separately to the studied soils under different incubation periods. The treatments were 5, 10 and 20 mg Fe/kg soil in the form of FeSO4; 2.5, 5 and 10 mg Mn/kg soil in the form of MnSO4; 2.5, 5 and 10 mg Zn /kg soil in the form of ZnSO4 and 0.5, 1.0 and 2.0 mg Cu/kg soil in the form of CuSO4. The soils were watered with distilled water to field capacity and allowed to equilibrate at intervals 1, 15, 30 and 45 days. After each incubation period, the soils were fractionated for different forms of micronutrient fractions (exchangeable, carbonate, Fe-Mn oxides, organic and residual). The second experiment was conducted to study the effect of the previous treatments on the plant growth (dry matter yield) and the contents of micronutrients uptake by corn plants. The results could be summarized as follows: 1. Incubation experiment: - Increasing the levels of Fe to the different soils was associated with a progressive increase in the chemical forms of Fe, i.e., exchangeable, carbonate, Fe-Mn oxides, organically bound and residual fractions at any incubation period. Fe in the sandy soil was detected in Fe-Mn oxides and exchangeable fractions, while in the calcareous soil was detected in carbonatic fraction. So, Fe in these two soils was potentially bioavailable because it presents as exchangeable and carbonates fractions, which was readily available for plant uptake. However, in the Nile alluvial soil an enrichment amount of Fe was found in organical and Fe-Mn oxide fractions. The amount of Mn bounded with Fe-Mn oxides and residual forms were greater than that bounded with exchangeable, carbonate and organic forms. In sandy soil Mn was detected in exchangeable fraction, while it was detected in carbonate and organic fractions in the calcareous and Nile alluvial, respectively. So, Mn in these soils was potentially bioavailable. Zn was detected in exchangeable, carbonate and organic fractions in the sandy, calcareous and Nile alluvial, respectively. So, Zn in sandy and calcareous soils was potentially bioavailable. The application of Cu was more effective for increasing the organic form of Cu in the Nile alluvial soil than the other soils. The amount of Cu bounded with residual form was higher, compared to those bounded with exchangeable, carbonate, Fe-Mn oxides or organic forms. 2. Greenhouse experiment: - Application of the studied micronutrients to the Nile alluvial, calcareous and sandy soils had a markedly effect on the dry weight of corn. The greatest growth of corn was recorded at 20, 10, 10 and 2 mg / kg soil for Fe, Mn, Zn and Cu, respectively. Fe was more effective for increasing the corn yield and sandy soil was responded to micronutrients application more than the Nile alluvial and calcareous ones. The addition of the different levels of Fe, Mn, Zn and Cu to the Nile alluvial, calcareous and sandy soils caused a marked effect on the contents of Fe, Mn, Zn and Cu in corn plants. The highest amounts of Fe, Mn, Zn and Cu were found in the Nile alluvial soil, while the lowest one was found in the calcareous soil.The effects of chemical forms of micronutrients on their uptake by corn exhibited that organic, Fe-Mn oxides, exchangeable and carbonate forms were stronger influence on the uptake than the total concentration in soils. The maximum increases in Fe, Mn, Zn and Cu bounded with different fractions (exchangeable, carbonate, Fe-Mn oxides, organic and residual fractions) were detected at the highest levels of micronutrients. The sequential extraction used in this study is useful to indirectly assess the potential mobility and bioavailability of micronutrients in different soils. Assuming that bioavailability is related to solubility, then Fe, Mn, Zn and Cu bioavailability decreases in the order: exchangeable > carbonate > Fe-Mn oxides > organic > residual. Based on the above mentioned, it could be assumed that Fe, Mn, Zn and Cu in the non-residual fractions are more bioavailable than micronutrients associated with residual fraction. The most important chemical forms influencing the uptake of Fe by corn plants in sandy soil were Fe-Mn oxides and exchangeable fractions. While, carbonate fraction in calcareous soil was the most important fraction for Fe uptake by corn plants. The most important fractions influencing the uptake of Mn by corn plants in Nile alluvial, calcareous and sandy soils were organic and Fe-Mn oxides; carbonate; and Fe-Mn oxides and exchangeable fractions, respectively. The most important chemical fractions influencing the uptake of Zn by corn plants in the Nile alluvial, calcareous and sandy soils were organic and Fe-Mn oxides; Fe-Mn oxides and carbonate; and exchangeable and Fe-Mn oxides, respectively.


A comparative study of nitrogen and micronutrients application and their effect on onion yield and yield components

Mohamed Badr Bayoumy, 2006

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A field experiment was conducted at Demo, El-Fayoum Governorate during two successive seasons 2003/2004 and 2004/2005 to study the effect of different sources and rates of nitrogenous fertilizer and folia spray of Fe and Zn on growth, yield and storage ability of bulb onions. Three forms of nitrogenous fertilizers (ammonia anhydrous, ammonium sulphate and urea) were applied at three rates (80, 100 and 120 kg N/fed). Plant samples were taken from the different treatment during the growing season. Plant growth was expressed by measuring dry weight of leaves and bulbs. The chemical analysis of leaves and bulbs includes the determination of N, P, K, Fe, Zn, chlorophyll, total soluble solids, carbohydrate and pungency. The obtained data are summarized as follows:  Dry weight of leaves and bulbs differed significantly with different sources of nitrogen during both seasons of this study. In this respect, application of 120 kg N/fed as ammonia anhydrous in combination with micronutrients gave the highest dry weight of leaves and bulbs compared with other treatments.  Nitrogen, phosphorus and potassium uptake of different plant parts, i.e. leaves and bulbs were significantly increased with increasing nitrogen rate. The maximum values in this connect were obtained with ammonia anhydrous, ammonium sulphate and urea, respectively.  Application of Zn or Fe, alone or in combination caused a significant increase of N, P and K uptake during the growing seasons. A high increase was recorded with (Zn+Fe).  Zn and Fe concentration in leaves were significantly increased with increasing N rate.  Application of Zn, Fe and their combination increased the concentration of Zn and Fe by leaves of onion plant.  Chlorophyll a, b and total chlorophyll were increased by increasing N application rate.  The best treatment which produced the highest concentration of chlorophyll was the application of 120 kg N/fed as ammonia anhydrous.  The micronutrients application as foliar spray on plants led to significant increases in chlorophyll a, b and total chlorophyll (a+b) during both seasons of study compared with the untreated treatment. The maximum values of photosynthetic pigments were connected with mixture of Fe+Zn.  The highest total soluble solids (TSS) in bulbs were obtained by ammonia anhydrous application. While urea gave the lowest total soluble solids (TSS).  The total soluble solids (TSS) were decreased by increasing application rate of N.  The best treatment which produced the high (TSS) concentration during the whole growth period was the application of 80 kg N/fed as ammonia anhydrous.  The carbohydrates percentage in bulbs was significantly increased as a result of application of N-fertilizer. The highest values were obtained as a result of using micronutrients as foliar spray treatments during both seasons.  The highest pungency concentration in bulbs was obtained with ammonium sulphate application.  The lowest pungency concentration with urea application.  The most effective treatments which produced bulbs with lowest moisture percent throughout the whole storage period was the application of 80 kg N/fed as ammonium sulphate.  The highest loss in moisture particularly during the first five months of storage and in turn keeps bulbs from sprouting and decay was the application of 120 kg N/fed as urea.  Application of micronutrients gave significant decreases in weight loss during the storage period.


Retention and release of some heavy elements in polluted soils

Ragab Badr, 2005

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The current study aims at throwing some light on reactions that control retention and release of some heavy elements in soils polluted with these elements. The study involved adsorption-desorption reactions of each of Cd and Pb. These reactions were studied using three surface soil samples differing in their physical and chemical properties. The samples under study were taken from Ismalia, Giza and Nubaria to represent the alluvial, the sandy and the calcareous soils, respectively. Adsorption-desorption reactions were studied also on a clay mineral (montmorillonite), humic acid and calcium carbonate to correspond the different separates forming the soil material. Different concentrations of Pb in the form of Pb(NO3)2 and Cd in the form of Cd(CH3-COO)2.2H2O were prepared and their solutions were adjusted at pH 6.5 using either NH4OH or NHO3 acid. The adsorption experiments were conducted using certain weight of soil, the clay mineral, humic acid or CaCO3 in bottles received a series of final Cd concentrations namely 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0 and 5.0 ug ml-1 or Pb concentrations corresponding to 2.5, 5.0, 7.5, 10.0, 20.0, 30.0 and 40.0 ug ml-1. The suspensions were shaken, centrifuged and Cd and Pb were determined in the supernatants. Desorption experiment was conducted on the Cd and Pb previously enriched samples using DTPA solution. The amounts of Pb and Cd desorbed were determined. Fitting the obtained data to adsorption isotherm equations was a matter of concern. Also, the effect of the different soil components on adsorption-desorption reaction was investigated


Studies on plant tolerance to salinity

Mamdouh Mohamed- Ali Badr, 2005

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The present research work was conducted to find out a relation between plant salt tolerance and its chemical composition especially its content of proline amino acid which is thought to take part in increasing tolerance of plant against salinity of plant growth media. Such approach is very important and urgent to improve plant growth under conditions of shortage of water available for leaching salts out of the growth media and/or the absence of an adequate drainage system to carry the leached salts out of the plant root zone. To fulfill the purposes of this investigation, a series of pot experiments were conducted on different varieties of sunflower under different types of four salinities i.e. nonsaline-nonsodic (normal), saline-nonsodic, nonsaline-sodic and saline sodic conditions. The used soils samples were taken from Dammitta governorate at a depth of 0-30 cm. Polyethylene pots were packed with the soils under investigation at a rate of 10 kg per each in a complete randomized block with twelve replicates. Each pot received basal applications of N, P and K corresponding to 0.4g N, 0.3 g P2O5 and 0.48 g K2O in the forms of ammonium sulfate (20.6% N), superphosphate (15% P2O5) and potassium sulfate (48% K2O), respectively. Eight seeds of each of the used sunflower varieties which are Fedok, Iroflor and Giza 2 were planted in each pot, thinned after 7 days from seed emergence to 4 seedlings pot-1. The pots were watered weekly to maintain their moisture content at 70% of the water holding capacity. The growing plants were sampled at the vegetative, flowering and fruiting stages. Some growth parameters i.e. stem diameter, yield of seeds, disc diameter, 1000 seed weight were recorded. Subsamples of the dried plant materials were digested. Na, Cl, N, P, K, Fe, Mn, Zn, and Cu were determined in the digests. Likewise, free proline amino acid was determined. Seeds contents of oil and N, P, K, Fe, Mn, Zn, and Cu were determined. The obtained results could be summarized in the following- The dry matter yields of the different varieties of sunflower plant were adversely affected by salinity and/or sodicity of soil, however, sodicity seemed to be more negative effect on dry matter yield than salinity especially at the fruiting stage. At all stages of growth, dry matter yield of Giza 2 was less affected by salinity and/or sodicity than Iroflor and Fedok. On the other hand, Fedok variety gave higher dry matter yield than Iroflor and Giza 2 when the plants were grown on normal soil. Such a finding illustrates that dry matter yield of relatively salt resistant plants was less affected by salinity than relatively salt-sensitive ones. Fedok variety gave higher stem diameter, plant height and leaf area index than the other two varieties when the plants were grown on the normal soil. These parameters were adversely affected by salinity and/or sodicity, however sodicity had a more obvious effect. Yet, it is worthy to indicate that Giza 2 gave higher values for these parameters than Iroflor and Fedok varieties when they were grown in salt-affected soils. This finding was true at the different stages of growth. Contents of Na+ and Cl- in different varieties of sunflower plants at the different stages of growth increased in the salt-affected soils to values higher than the corresponding areas of the plants grown on the normal soil. Na and Cl contents of Fedok and Iroflor varieties were higher than that of Giza 2 at all the studied stages of growth in all the studied soils. However Na and Cl contents under saline and/or sodic conditions were higher than those under normal conditions. Na and Cl concentrations in Fedok and Iroflor varieties were usually higher than that in Giza 2 variety at all growth stages. The relatively salt-sensitive varieties (Fedok and Iroflor) had more Na and Cl than the relatively salt-resistant one (Giza 2). Proline content in the sunflower plant varieties grown on the salt affected soils, especially the sodic ones was higher than the corresponding proline content of the plant varieties grown on the normal soil. It was higher in the relatively salt-tolerant variety (Giza 2) than in the relatively salt-sensitive ones (Fedok and Iroflor). Values of N and P content and uptake by the plants grown on the salt-affected soils were lower than the corresponding values of the plants grown on the normal soil. Fedok and Iroflor varieties were affected by the depressive effect of salinity on N content and uptake than Giza 2 variety. This was true at all the plant growth stages. A general depressive effect of salinity and/or sodicity (with sodicity being more effective) was noticed on K content and uptake by the plants grown on the salt-affected soils. The effect was more pronounced in the sodic soils. This was true at all stages of growth. Moreover, values of K content and uptake were higher in the relatively salt, tolerant varieties than the salt-sensitive one. A depressive effect of salinity and/or sodicity on values of the micronutrients (Fe, Mn, Zn and Cu) content and uptake was noticed at all stages of growth of all the studied varieties of sunflower plants. The effect of sodicity seemed to be more obvious than that of salinity. These effects were more noticeable on Fedok and Iroflor varieties than Giza 2. Values of seeds yield of all grown varieties decreased due to salinity and/or sodicity with sodicity being of higher effect than salinity. However, it is importance to indicate that Giza 2 variety was less affected with salinity and/or sodicity than Fedok and Iroflor. Taking into consideration, yield components i.e. disc diameter, 1000 seed weight and seed oil content, it was noticed that they were the highest values in Fedok variety grown on the normal soil. However, values of yield components of the three varieties decreased due to salinity or sodicity. Sodicity seemed to be more depressive effect on these values than salinity. Giza 2 variety was affected to a lesser extent with salinity and/or sodicity than other two varieties. Upon grown sunflower plants on the normal soil, N, P and K contents in seeds of Fedok variety were slightly higher than their contents in Iroflor or Giza 2, however the differences among the studied varieties were not significant. Under conditions of the saline and saline-sodic soils N, P and K contents of Giza 2 variety exceeded slightly the corresponding ones of Fedok and Iroflor varieties. The superiority of Giza 2 variety over the other two varieties with regard to seeds contents of N and K was more obvious than in case of the sodic soil. Soil salinity or sodicity was accompanied with a decrease in Fe, Mn, Zn and Cu contents in seeds of all the investigated sunflower plant varieties as compared with the corresponding contents of these varieties when they were grown on the normal soil. The plants contents of the micronutritive elements were more depressed in the plants grown on the sodic soils than the saline ones. The depressive effect of salinity and/or sodicity was more obvious on Fedok and Iroflor varieties than in Giza 2


Role of growth promoting substances producing microorganisms on tomato plant and control of some root rot fungi

Ebtsam Morsy, 2005

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A number of 261 bacterial isolates were obtained from different plants rhizosphere. High percentage of these isolates produced indole acetic acid (IAA), siderophores and hydrogen cyanide. Only 31 isolates in-vitro antagonized R. solani or F. solani, the causative agents of tomato root rot, but varied greatly in their in-vivo antagonistic activities and effects on shoot and root dry weights. Most efficient four isolates against R. solani and F. solani had also the potential to produce considerable amounts of IAA, gibberellins, siderophores and hydrogen cyanide. These isolates were identified as strains of Bacillus subtilis (three strains 47, 82 and 104) and Pseudomonas synxantha (one strain 95). Optimization of carbon, nitrogen sources, aeration and incubation period for mass production by selected strains were studied. Highest growth yield for B. subtilis 47, 82, 104 strains was obtained when grown on King’s medium (containing glycerol and peptone), supplemented with 0.1 g/L tryptophan, at 30 ºC for 72 h, initial pH 7.2 and shaking speed 150 rpm. The same growth conditions favoured highest mass production by Ps. synxantha 95 except that peptone of the medium was replaced by yeast extract. In a pot experiment, inoculation with selected strains- in soil infested with root rot fungi- antagonized R. solani and F. solani and promoted tomato growth and fruit yield. Such beneficial effect was more pronounced by repeated inoculation up to four times. These treatments favoured highest survival rates, greater proliferation of rhizosphere microflora, higher dehydrogenase activity in the rhizosphere, and considerable enhance in nutrients (NPK) uptake. It is recommended to use these strains as a common biocontrol practice in agriculture.


Soil water table depth in its relation to soil and water management and to crops productivity under different drainage conditions in meddle Delta soil

Abdel-Gelil El-Araby, 2004

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content as an attempt to monitor the irrigation time and as an approach for soil workability using the simple measure of the water table depth. 4- quantify the effect of the soil water table depth, through the distance from the drain, on the crop yield and water use efficiency, under different drainage conditions. To achieve the aim of this study, two sites were selected to represent the different drainage conditions, i.e. adequate (site 1) and inadequate (site 2) subsurface drainage system. The selected two sites located at Ebiar village in Kafr El-Zayat district, El-Gharbia Governorate. At each site, observation wells were installed along a line perpendicular of three laterals. Observation wells were located at a distance of 1/8, 1/4 and 1/2 the drain spacing (40 m). The two sites were cultivated, in agricultural cycle, with wheat and corn crops during the two successive growing seasons of 1998/1999 and 1999/2000. The experiment was arranged in split split plot design with three replicates. The main plot was assigned as the drainage status; adequate and inadequate drainage. The subplot was the distance from drain (lateral) which were 5, 10 and 20 m. The sub-subplot was assigned as the plant growth stages. Each plot was 2m×2m (4m2). In each site disturbed and undisturbed soil samples were collected from soil profiles every 30 cm depth until 60 cm. Each site was represented by two profiles. One profile above the drain pipe and the other in the midway between each two laterals for comparison. The soil samples were used to determine the main physical and chemical soil properties. Water table depth was recorded daily between every two irrigations cycle during the growing seasons of wheat and corn crops. Rate of water table drawdown, the frequency distribution of water table and the relative ground water depth were calculated to evaluate the ground water table and the performance of the drainage system. Also drain discharge was measured during all irrigation cycles and some hydrological parameters such as drainable intensity factor and the effective porosity were calculated. The hydraulic conductivity and the pore size distribution were also determined. The measurements of the soil water table depth (WTD) were made simultaneously with the soil moisture content (MC) at 5, 10 and 20 m distance from drain during the growing seasons of wheat and corn for each study site. Also the soil moisture content at the lower plastic limit (LPL) for the surface soil layer (0-30 cm depth) was determined. Finally, some vegetative growth parameters, yield and yield components, water consumptive use (Cu) and water use efficiency (WUE) of wheat and corn crops were determined for the two sites along the two years study period. The obtained results can be summarized in the following: 1. Evaluation parameters of the WTD fluctuation, rate of drawdown, relative depth and the frequency distribution of the WTD, depend mainly on the drainage conditions and the distance between the drains. Consequently, these parameters are good indicator to evaluate the efficiency of the subsurface drainage (tile drainage) average values of each of the studied parameters of the ETD were greater under the adequate drainage conditions than that under the inadequate one. 2. Higher WTD due to the inadequate drainage conditions, resulted in low values of the studied hydrophysical properties of the soil. Average values of drainage intensity factor "a", saturated hydraulic conductivity "K", effective porosity "f", quickly drainable pore "QDP" and slowly drainable pore "SDP" were about 2.2 and 2.0, 1.26 and 1.4, 2.1, 1.4 and 1.6 times greater under the adequate drainage conditions than that under the inadequate one. Whereas average value of WHP and FCP were, respectively, lower 0.92 and 0.87 times under adequate drainage conditions than the inadequate one. Average values of these soil properties were, also, found to be decrease with increasing the distance from drains to the mid-distance between them. 3. The poor conditions for plant growth resulting from the inadequate drainage conditions are responsible for average crop production losses equal to 31.6 and 43.2% of the production under the adequate drainage conditions, respectively, for grain yield of wheat and corn crop. The average grain yield for the two seasons of study was 2.59 and 3.49 ton/fed., respectively, for wheat and corn crops under the adequate drainage conditions. While it were 1.77 and 1.98 ton/fed., respectively, for the same two crops. Also the undesirable soil properties due to the higher WTD obtained at 20 m distance from the drains, are responsible for grain yield losses equal to 29.1 and 26.7% of the yield obtained at 5 m distance from drains where WTD is always more deeper relative to that at mid-distance from drains, respectively, for grain yield of wheat and corn. The average grain yield of the two seasons was 2.51 and 3.14 ton/fed., respectively, for wheat and corn at 5 m distance from drains. While it was 1.78 and 2.3 ton/fed., respectively, for the same two crops at 20 m distance from the drains. 4- The seasonal water Cu of wheat and corn under the adequate conditions was about 15.6 and 16.7% more than that under the inadequate one. Values of the Cu decreases as WTD decrease as well as that of the WUE. The WUE of wheat and corn grains were, respectively, 1.42 and 1.5 times more under adequate drainage conditions than that under the inadequate one. 5- The predicted W.T.D at the soil MC, in the root zone depth, which meets the irrigation time could be used as a new approach fast and easy for irrigation timing of wheat and corn crops under the conditions of the studied area. According to this approach, irrigation interval was about 23 and 27 days for wheat crop under adequate and inadequate drainage conditions. The corresponding values for corn crop were about 16 and 17 days, respectively for the same two sites. Also, the prediction of the WTD at the moisture content (MC) of the lower plastic limit (LPL), in the tillage soil depth (0-30 cm), could be used as an approach for soil workability using the simple measure of the WTD. According to this approach the suitable time for field operations is the time at which WTD reach 113 cm under wheat and 95 cm under corn, for the adequate drainage conditions. And at which WTD reach 72 and 63 cm, respectively, for wheat and corn under the inadequate drainage conditions. The average workability timing duration, after an irrigation event varied between about 13 and 18 days, respectively, for corn and wheat in site (1) cultivated under adequate drainage. While it varied between about 15 and 20 days, respectively, for corn and wheat cultivated under inadequate drainage conditions in site (2).


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