Soil In Sudan Research Articles

Biodegradation of Crude Oil Contaminated Soil in Sudan Using Sudanese Plant Acacia seyal Del

Phytoremediation is an environmental technology in which plants are used for decontamination of organic and inorganic pollutants from soils and water. Acacia seyal Delile was tested for it is ability to degrade crude oil contaminated soil in four concentrations 0.5, 1, 1.5 and 2% (w/w) of crude oil. Plant parameters, degradation percentage, retention time and bacterial count were calculated. Results showed that at the end of the growth period of A. seyal Del no such adverse effect was observed on the shoot length and it is better than that of the control at the 2% concentration by the end of the growth period. This result highlights the ability of A. seyal Del to grow under stress of oil contamination. A. seyal root length has substantially increased at two and four month’s interval and no significant difference was observed at these two intervals. A. seyal Del shoot biomass was significantly (p<0.05) negatively affected by crude oil at four month intervals, Root weight of A. seyal Del have decreased steadily. Degradation percentage was found to be in the range between 49-54%. Penadecane is the first compound appear in most cases and the retention time was between 13.7-32.9 min. Number of compounds detected in the rhizosphere those were 57, 70 and 167 compound after two, four and six month of growth respectively. Viable count of the dominant bacteria showed that there is no significant different between concentrations (P=0.699), also there is no significant difference between intervals (P=0.08) in bacterial number. This study reveals the visibility of using tropical plant Acacia seyal in crude oil degradation.

Impact of Salinity and Sodicity on Crop Growth and Physicochemical Properties of Some Aridisol and Vertisol Soils in Sudan: A Review

Comprehensive field and laboratory studies were undertaken toinvestigate the performance of some crops on salt-affected soils in Sudan.To separate salinity and sodicity indicators some laboratory studies wereconducted on soils equilibrated with mixed NaCl-CaCl 2 solutions. Therelative hydraulic conductivity (RHC) or diffusivity increased withincrease in total salt concentration (C) and decrease in exchangeablesodium percentage (ESP). A dispersion index (DI), a swelling index (SI),shrinkage volume and modulus of rupture increased with increase in ESPand decrease in C. The data showed a highly significant linear decrease inRHC with increase in DI or SI. The threshold salt concentrations (THC),which gave 75% of the highest RHC, and ESP relationships, wereobtained for samples from an Aridisol and a Vertisol soils.. The salinityprofile obtained after intermittent leaching with water suggested thepresence of a desalinized zone followed by a salinized one with thehighest salt concentration below the wetting front. The depth of thedesalinized zone increased significantly with increase of the amount ofwater stored (r2 = 0.968) and the length of the wetting front (r2 = 0.974).Soil amendments promoted salt leaching in the following order: Sand>chicken manure> water hyacinth> gypsum> dry sewage> farm yardmanure> control. Cumulative evaporation (E) for the various amendments

Evaluating the Antagonistic Potential of Actinomycete Strains Isolated From Sudan's Soils Against Phytophthora infestans.

Soil microorganisms play crucial roles in soil fertility, e.g., through decomposing organic matter, cycling nutrients or through beneficial interactions with plants. Actinomycetes are a major component of soil inhabitants; they are prolific producers of specialized metabolites, among which many antibiotics. Here we report the isolation and characterization of 175 Actinomycetes from rhizosphere and bulk soil samples collected in 18 locations in Sudan. We evaluated the strains’ metabolic potential for plant protection by testing their ability to inhibit the mycelial growth of the oomycete Phytophthora infestans, which is one of the most devastating plant pathogens worldwide. Most strains significantly reduced the oomycete’s growth in direct confrontational in vitro assays. A significant proportion of the tested strains (15%) were able to inhibit P. infestans to more than 80%, 23% to 50%–80%, while the remaining 62% had inhibition percentages lesser than 50%. Different morphologies of P. infestans mycelial growth and sporangia formation were observed upon co-inoculation with some of the Actinomycetes isolates, such as the production of fewer, thinner hyphae without sporangia leading to a faint growth morphology, or on the contrary, of clusters of thick-walled hyphae leading to a bushy, or “frozen” morphology. These morphologies were caused by strains differing in activity levels but phylogenetically closely related with each other. To evaluate whether the isolated Actinomycetes could also inhibit the pathogen’s growth in planta, the most active strains were tested for their ability to restrict disease progress in leaf disc and full plant assays. Five of the active strains showed highly significant protection of potato leaves against the pathogen in leaf disc assays, as well as substantial reduction of disease progress in full plants assays. Using cell-free filtrates instead of the bacterial spores also led to full protection against disease on leaf discs, which highlights the strong crop protective potential of the secreted metabolites that could be applied as leaf spray. This study demonstrates the strong anti-oomycete activity of soil- and rhizosphere-borne Actinomycetes and highlights their significant potential for the development of sustainable solutions based on either cell suspensions or cell-free filtrates to safeguard potatoes from their most damaging pathogen.

Review on Potassium Research in Sudan: Past, Present and Future Prospects

The objective of this review is to explore the possibility of changing the old perception among agriculturist from various disciplines that Sudanese soils are rich in potassium, this article reviewed the work that had been conducted on potassium in soils of Sudan since 1927.Hereby, potassium did not receive the worth attention in Sudan agricultural system. This article reviewed the work that had beenconducted on potassium in soils of Sudan since 1927. However, research work on soil potassium status and response of crops to the applied potassium is little. Early studies showed that some crops, like cotton and wheat, did not respond to the added potassium, however, sugarcane, banana, potato, and sweet potato crops responded well to the addedpotassium. Nevertheless, it is evident that application of potassium is a key factor in crops growth and quality. Accordingly, to improve crop production in Sudan, research for enhancing utilization of potassium element is needed. Many possible research for future directions have been suggested in the final part of this article.

A Review on Reclamation and Management Practices of Wind Erosion and Salt – Affected Soils of Sudan

Wind erosion and salt–affected soils are predominant desertification processes in Sudan, particularly in the northern part, and have adverse impacts on agricultural lands in the arid and semi-arid lands characterized by erratic rainfall, high temperature, high wind velocity and consequent high rates of evapotranspiration. The main objective of this paper is to present research review on combating, control, reclamation and management practices in areas affected by wind erosion and salt–affected soils. The study showed that the principal measures for controlling wind erosion depends on minimizing certain conditions that can be accelerated wind erosivity (winds ≥ 5.4 m/sec) and vice versa maximizing soil erodibility by creation a suitable condition for generate of non–erodible soil particles (NEP) versus soil surface detachment and transport by wind. Wind erosion research requires high financial support, thus this cost should be borne by government. The strategy of management practices of saltaffected soils aimed to sustain a level of salinity tolerable to the cultivated crops through good manages to water and crop. Assessment and mapping of wind erosion and salt-affected soils is urgent need to determine the inherent risk in the affected areas included in investment map of agricultural land capabilities of the country. Encourage studies on stabilizing soil particles by various natural or synthetic cementing and flocculation materials which are friendly to soil environment to increase NEP on the soil surface. Practical programs on reclamation of salt–affected soils should be included in national development programs and national strategy for scientific research in the State.

English

The rising antibiotic resistance is urging researchers to explore for new forms of antibiotics, notably from soil microorganisms such as Bacillus species. This study aimed to screen Bacillus strains from soil samples in Sudan for antifungal activity and to review relevant compounds from members of the genus in the literature. Out of 10 isolates from soil in Sudan, the strain JS6 (DSM 28831) was found active against representative zygomycete fungi and consequently subjected to thorough identification and chemical analyses of secondary metabolites. Confirmation of the initially identified Bacillus spp. was done using 16S rDNA gene sequence analysis which indicated a novel species (accession MF099872) that is closely related to Bacillus siamensis, Bacillus amyloliquefaciens, and Bacillus nakamurai. The crude culture-free filtrate and both chloroform and ethyl acetate extracts authenticated the initial antifungal activity of this strain, which exceeded that of amphotericin B, a standard antifungal agent. GC-MS results of the extracts revealed 32 compounds which included long-chain fatty acids, fatty acid methyl esters, alkaloids, and alcoholic compounds. Seven biologically active compounds were identified from Bacillus spp. strain JS6 and are equally found in the literature originating from plant or microbial sources. In the literature, these compounds show various activities such as antifungal, antioxidant, hypocholesterolemic, nematicide, pesticide, antiandrogenic, flavour, haemolytic, alpha reductase inhibitor, and other antimicrobial activities. The analysis identified a major unique antifungal peak (rt, 23.142; area, 25.36%) as 5,10-Diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d]pyrazine, a heterocyclic aromatic organic compound, that has been previously detected in Lactobacillus casei. Key words:  Bacillus species, chromatography, TLC, GC-MS, soil, aromatic organic compounds.

ДОСЛІДЖЕННЯ МЕТОДАМИ БАГАТОВИМІРНОГО СТАТИСТИЧНОГО АНАЛІЗУ НАБРЯКАЮЧИХ ҐРУНТІВ ЯК ОСНОВИ ФУНДАМЕНТІВ ІНЖЕНЕРНИХ СПОРУД У СУДАНІ

A new way to study swollen soils as the basis for foundations by methods of mathematical statistics, including cluster, factor and correlation-regression analyses has been proposed in the article. Normative values of the strength characteristics of these soils depending on their physical properties and degree of swelling, application limits, predominant factors and correlations between different indicators of soil properties have been established according to the results of these analyzes. A method of the study area zoning, leading to possible differential application of soils normative characteristics, as well as proposals for designing foundations on swollen soils have been developed. The methods were tested on the soils of Sudan.

Predicting Soil Cation Exchange Capacity in Entisols with Divergent Textural Classes: The Case of Northern Sudan Soils

Cation exchange capacity (CEC) is an important soil property because it affects the assimilation of nutrients and buffers against soil acidification. Thus, knowledge of CEC is considered key to developing agricultural and environmental models for land management planning. However, in developing countries such as Sudan, there is a lack of soil CEC data due to the absence of research projects and funding to develop this information. Therefore, this research was conducted to predict CEC for large areas using specific soil physical characteristics, including soil texture and saturation percentage (SP), for which there is potentially available data. To achieve this goal, the properties of 430 soil samples (301 for training and 129 for validation) were obtained from the soil database of the Soil Survey Administration, Ministry of Agriculture, Sudan, which had different soil depth intervals (0–0.3 m, 0.3–0.6 m, 0.6–0.9 m, 0.9–1.5 m, and >1.5 m) from Entisols in the Northern State of Sudan. The data were stratified into homogeneous groups based on the textural classes of the main soil order. Then, regression models were performed and evaluated using the coefficient of determination ( R2), standard error of the estimate (SEE), and root mean square error (RMSE). The results indicated that in individual Entisols and textural classes, the combined soil covariates silt, clay, and SP were the best properties to predict CEC values ( R2 ranged from 0.86 to 0.99). The regression models did not provide statistically significant results for the silty clay loam textural class ( R2 ranged from 0.01 and 0.35). The findings of this modeling study could be applied to other Entisols worldwide with divergent textural classes, which could be used to verify the suggested CEC pedotransfer functions and/or improve them. This would help farmers correctly design soil management plans and prevent acidification issues if combined with other soil properties data.

Isolation and Identification of Streptomyces spp. from Desert and Savanna Soils in Sudan.

The purpose of this study was to investigate streptomycete populations in desert and savanna ecozones in Sudan and to identify species based on 16S rRNA gene sequences. A total of 49 different Streptomyces phenotypes (22 from sites representing the desert and semi-desert ecozone; 27 representing the savanna ecozone) have been included in the study. The isolates were characterized phenotypically and confirmed using 16S rRNA gene sequence analysis. The two ecozones showed both similarities and uniqueness in the types of isolates. The shared species were in cluster 1 (Streptomyces (S.) werraensis), cluster 2 (Streptomyces sp.), cluster 3 (S. griseomycini-like), and cluster 7 (S. rochei). The desert ecozone revealed unique species in cluster 9 (Streptomyces sp.) and cluster 10 (S. griseomycini). Whereas, the savanna ecozone revealed unique species in cluster 4 (Streptomyces sp.), cluster 5 (S. albogriseolus/ S. griseoincarnatus), cluster 6 (S. djakartensis), and cluster 8 (Streptomyces sp.). Streptomycetes are widely distributed in both desert and the savanna ecozones and many of these require full descriptions. Extending knowledge on Streptomyces communities and their dynamics in different ecological zones and their potential antibiotic production is needed.

Occurrence of hydrocarbon-utilising bacteria in oil-polluted arid soils in Sudan

Occurrence of hydrocarbon-utilising bacteria in oil-polluted arid soils in Sudan

English

This study was carried out to isolate and identify indigenous bacteria associated with pesticides heavily contaminated soil in Sudan. The samples were collected from pesticides contaminated soil in different locations. The predominant bacterial isolates were then purified by subculturing on selective media. Seven isolates were selected based on their capability to degrade pesticides and three of them having the highest performance in biodegradation of frequently reported pesticide contaminants were subject to identification by molecular tools using 16S rDNA gene sequence analysis. Amplification of 16S rDNA gene was done from genomic DNA and sequenced. Construction of phylogenetic tree was done after aligning of multiple sequences. The results reveal that the three bacterial isolates are Bacillus cereus ATCC 14579, Bacillus subtilis subsp. inaquosorum KCTC 13429 and Bacillus safensis FO-36b. This is the first record of pesticides biodegradation by B. safensis FO-36b which can be considered as a novel contribution in this field. Since these strains were found effective and are living naturally in an environment heavily contaminated with pesticides, therefore, they might have potential in removing pesticides from contaminated soils, especially soils of pesticide stores and dumping sites in developing countries.   Key words: Bacillus, gene sequencing, pesticides-polluted soil, Sudan.

English

Sandy desert soil in Sudan are characterised by low content of organic matter, small water holding capacity and low crop productivity. Methods to enhance crop productivity on these environments, such as land application of composts, are of great importance. Field experiments were conducted on a sandy soil to determine the effects of two types of composted manures on growth and yield of two sorghum varieties grown under rainfed conditions. Two sorghum cultivars (Butana and Arfa Gadmak were sown under chicken manure (CM) compost (5 t ha-1), CM compost with NPK (36 kg ha-1), farm manure (FM) compost (20 t ha-1), FM compost with NPK (36 kg ha-1), CM compost with FM compost (1:1, wt/wt, 12.5 t ha-1), CM and FM composts with NPK (36 kg ha-1), only NPK (36 kg ha-1) and control (no composts or NPK). Application of composts increased organic soil carbon by 50% and available phosphorous (P) between 43 to 105%, whereas, pH and bulk density were decreased by 2 and 6%, respectively. Soil moisture contents in compost treated plots were 56–98% higher than control plots. Mixing compost with NPK increased leaf area index over NPK alone by 28% but the highest values were found in plots treated with chicken compost or integrated with NPK compared to NPK application alone. Incorporation of compost increased dry matter yield compared to control by 17–53% and increased grain yield by 1.8 to 3.1 fold in both sorghum varieties. Grain yield from plots treated with NPK, sole chicken compost or combined with NPK were similar for both varieties in both seasons. In general, the trend of grain yield of sorghum was in the order of NPK = chicken compost with NPK = chicken compost = farm manure compost with NPK  mixed compost with NPK = farm manure  control. In conclusion, integrating composts with NPK improved fertility of sandy soils, sorghum growth and yield. © 2020 Friends Science Publishers

English

This study aimed at investigating the effect of consortia of three types of indigenous bacteria (Corynebacterium sp., Sphingobacterium gobiense and Kocuria flava) and earthworm (at 5 and 10 earthworms/kg soil) and their combination on the percentage removal of chlorpyrifos from chlorpyrifos contaminated soil in Sudan. Silt soil (Gerf soil) samples were mixed with known concentration of chlorpyrifos (450 mgkg-1) and incubated for various exposure periods (3, 7, 15 and 45 days) with the bacterial consortia alone, low and high densities of earth worm and their combinations under laboratory conditions. Remaining chlorpyrifos residues were measured by gas chromatograph equipped with flame ionization detector. Degradation rates and half-lives were found to follow biphasic model with an initial fast rate of disappearance followed by a second phase of slow disappearance. All treatments caused significant (PE‚0.05) effect on the degradation rates of chlorpyrifos compared to the control. The bacterial consortia alone induced the highest effect (73.83%) on the percentage removal of chlorpyrifos, followed by the bacterial consortia plus high density of earth worm (71.22%). Earth worm alone induced the least effect on the rate degradation of chlorpyrifos (64.27 and 66.49% for the high and low concentrations respectively). Based on this finding indigenous bacterial consortia represent a promising bioremediation agent for treatment of chlorpyrifos contaminated soil and therefore may deserve further investigation under different experimental conditions as well as validation of results under real contaminated soil conditions. Key words: Sudan, earthworm, indigenous bacteria, chlorpyrifos.

Photodegradation of endosulfan and pendimethalin in sunlight

The potential of sunlight photolysis in remediation of pesticide-polluted soils in Sudan is reported. The common pollutants endosulfan (alpha- and beta- isomers) and pendimethalin were exposed to sunlight over glass and soil surfaces and the periodically drawn samples were analyzed by GC-ECD and GC-MS. Photo-degradation followed biphasic model. The half-lives of direct photolysis of the two pesticides over glass and soil surfaces ranged between 1.840-6.720 d and 2.711 to 9.760 d respectively. The respective values for indirect photolysis of the two pesticides with β-carotene over glass surface were 0.846-1.605 d and for benzophenone 1.050-1.626 d. Values for soil β-carotene sensitized photolysis of the two pesticides were 2.260-3.158 d while the corresponding values for benzophenone sensitized photolysis on soil were 1.193-2.880 d. Meteorological factors did not show significant impact on photolysis rates. Despite the significant decrease in starting material in direct no photoproducts were detected. However, many photoproducts were detected on the indirect sets. Photo-degradation efficiency can be arranged in the order benzophenone > β-carotene > direct exposure.

Photodegradation of chlorpyrifos, malathion, and dimethoate by sunlight in the Sudan

The potential of sunlight photolysis in remediation of pesticide-polluted soils in Sudan was studied. Chlorpyrifos, malathion and dimethoate, common pollutants, were exposed to sunlight over glass and soil surfaces with periodic samples drawn for GC and GC-MS analysis. Photo-degradation followed a biphasic model. Alpha half-lives of direct photolysis over glass surface range between 1.99 and 9.36 days while the range in soil surfaces is 1.88–10.77 days. Respective values for indirect photolysis with β-carotene are 0.96–2.40 days whereas for benzophenone are 0.38–2.37 days (not including malathion as starting material was completely lost after 3 days). Values for soil β-carotene sensitized photolysis are 0.85–4.02 days while respective values for soil benzophenone sensitized photolysis are 0.88–3.74 days. Metrological factors did not have a significant impact on photolysis rates. No photoproducts detected in direct photolysis. However, many photoproducts were detected on the indirect sets. Photo-degradation efficiency can be ordered as; benzophenone > β-carotene > direct exposure.

Ecological and Bioengineering Studies for Stabilizing the Wad Medani‐Sennar Roadside Slope Linking the Gezira and Sennar States

The erosion of the highway embankment slope′s soil along the Wad Medani‐Sennar road is a significant issue, as there are many traffic accidents on this road, with an average of 15 to 25 fatalities per annum. It was thus decided to investigate this issue to find a method to protect slope from erosion on this road and to provide new approaches to slope erosion knowledge gap in Sudan. An engineering survey was carried out, followed by geotechnical studies, experimental work and interviews with academic experts regarding native vegetation in the survey area. These include measuring the eroded parts of the road; studying cross‐ sections of the road; soil experiments to check the strength, compaction and particle size distribution; and a native vegetation survey to check for suitable plants that could be used to control the slope erosion. It was found that an appropriate bio‐engineering method to stabilize the slope soil against erosion due to rainfall was to cultivate the grasses Cynodon Dactylon and Vetiver on the slopes. In conclusion, that using native vegetation for eco ‐protection, was an excellent solution to the problem based on the climate, native vegetation, and type of soil in Sudan and it reduces the accidents.

Biodegradation of Chlorpyrifos, Malathion, and Dimethoate by Three Strains of Bacteria Isolated from Pesticide-Polluted Soils in Sudan

This study was done to identify pesticide-biodegrading microorganisms and to characterize degradation rates. Bacillus safensis strain FO-36bT, Bacillus subtilis subsp. inaquosorum strain KCTC13429T, and Bacillus cereus strain ATCC14579T were isolated from pesticide-polluted soil in Sudan, separately incubated with each pesticide with periodic samples drawn for GC and GC-MS. Pesticide biodegradation followed a biphasic model. α and β half-lives (days) of chlorpyrifos, malathion, and dimethoate in B.safensis culture were 2.13, 4.76; 2.59, 5.66; and 9.5, 11.0, respectively. Values in B.subtilis and B.cereus cultures were 4.09, 9.45 and 4.33, 9.99 for chlorpyrifos; 2.99, 5.36 and 2.43, 4.71 for malathion; and 9.53, 15.11 and 4.16, 9.27 for dimethoate. No metabolite was detected in B.subtilis cultures, whereas a few were detected from B.safensis and B.cereus cultures. Bacterial efficiency can be ordered as B.safensis > B.subtilis > B.cereus for chlorpyrifos and B.cereus > B.subtilis > B.safensis for malathion and dimethoate.

Assessment of Calcimetric and Titrimetric Methods for Calcium Carbonate Estimation of Five Soil Types in Central Sudan

Despite the CaCO3 estimation using titration method was not reliable, but up to the present time, some soil laboratories in Sudan still used this method. The objective of this study was to compare and assess the results of calcimetric and titrimetric methods of quantitative estimation for soil calcium carbonate of different soils in Sudan. 26 soil samples from five soil profiles were collected from different climatological and ecological regions in central Sudan. CaCO3 equivalent was estimated using calcimeter and titration methods in order to find accurate, rapid and suitable method for soils of Sudan. The results revealed that there are no significant differences between calcimeter and titration methods for calcium carbonate estimation in all studied samples except in samples from Gedaref area. We concluded that when the Calcimeter method used for CaCO3 estimation, the differences between one person and another in detecting titration end point would be avoided, rapid and accurate results would be obtained compared to titration method. Additionally, time would be saved; fewer amounts of chemicals would be used. From this study, we highly recommend using calcimeter method for CaCO3 estimation for soils of Sudan.

Mobility of total petroleum hydrocarbons in Shambat soil in Sudan

Purpose – A laboratory experiment was conducted in the soil laboratory in the Department of Environment and Environmental Pollution, Environment and Natural Resources Research Institute, National Centre for Research. The purpose of this paper is to study the movement of crude oil through soil column. Design/methodology/approach – Polyvinyl chloride columns were filled with Shambat soil, amended with three concentrations of light crude oil (0.16, 0.32, and 1.28 ppm), obtained from Petrodar Oil Company. Soil samples were taken from 5 and 10 cm depths after two, 14 and 28 days from crude oil addition. At each sampling date, the recovery of petroleum hydrocarbons measured. Findings – The results obtained indicated that high by significant differences among the different concentrations, different depths and different sampling durations. Moreover, the downward mobility of petroleum hydrocarbons decreased with increasing crude oil concentration. Originality/value – Results of the experiment revealed the importance of studying the fate and mobility of total petroleum hydrocarbons (TPH) in soils in order to facilitate a proper reclamation practice specially in oil polluted sites.

Assessment of the role of compost in remediation of CD-contaminated soil in Sudan

Assessment of the role of compost in remediation of CD-contaminated soil in Sudan