Isolation and Characterization of Nitrogen Fixing Rhizobia from Cultivated and Uncultivated Soils of Northern Tanzania

Soil bacteria1 called rhizobia are gram-negative capable to colonize the soil immediately surrounding roots under the influence of the plant “rhizosphere” and reduce atmospheric nitrogen into the form available to plants through nitrogen fixation process. Nitrogen is the most limiting and supplied nutrient to most plants, and the determinant of plant growth. Legumes differ with most plants because they have access to nitrogen from both mineral and symbiotic sources. Small-scale farmers who are the major legume producers in Africa rarely apply fertilizers during legume production. Hence, the crop is largely dependent on fixed nitrogen from native nitrogen fixers. Isolation of rhizobia for legume production has been given a little attention in Africa due to inadequate research or negligence of researchers and unawareness of its potential in legume production as well as lack of an intention from skilled personnel to popularize the technology. Evaluation of effectiveness of isolated rhizobia is essential for inoculants preparation, host specificity recommendation and symbiotic effectiveness. The isolation, determination of their population in the soil and assessing factors affecting their population and testing the effectiveness of native nitrogen fixers with respect to right trap host crop are given a special attention in this review.

Impacts of Synthetic and Botanical Pesticides on Beneficial Insects

Sustainable methods to control insect pests that affect crop yield have become a great challenge to mainly smallholder farmers. Beneficial insects in agricultural fields play an important role in natural pest control and pollination. The use of synthetic and botanical pesticides has detrimental effects to both natural enemies and pollinators in agricultural fields. The pesticides affect the survival of a range of life cycle stages, reductions in reproductive capacity, changes in the suitability of hosts for parasitising or predation, reduced emergence of parasitoids from sprayed host eggs and cause direct mortality. This has caused a serious menace to biological control agents and pollinators. When natural enemies are reduced, even more serious consequences may result for pest population dynamics which include the phenomena of resurgence and eruption of secondary pests. The decrease in pollinators reduces agricultural productivity. This review aims at exploring the side effects of synthetic and botanical pesticides on beneficial insects to give the basis for research on the negative impacts of synthetic and botanical pesticides on these insects. This information will assist in optimizing the use of pesticides in integrated pest management programmes by employing more sustainable and ecosystem benign practices such as the use of right dosage and selective pesticides in agricultural fields.

The Potential of Common Beneficial Insects and Strategies for Maintaining Them in Bean Fields of Sub Saharan Africa

Beneficial insects provide natural ecosystem services such as biological control of pests, soil formation, nutrient cycling and pollination of plants. Beneficial insects include pollinators important in the essential pollination process of all plants, and natural enemies of pests such as parasitoids and predators which are important in the suppression of pest damage to crops. Knowledge on management techniques to attract beneficial insects in the agricultural fields is a way forward to enhance agro ecosystems for increased crop production. Therefore, proper understanding and identification of natural enemies, as well as pollinators in agricultural fields, is essential in promoting biological control and pollination activity. Natural enemies and pollinators, within legume fields, play a key role in ensuring sustainable production, especially in smallholder farms. There is a limited understanding of beneficial insects and the ecosystem services they offer to the agricultural production process in much of sub-Saharan Africa. This paper reviewed and provided existing knowledge on beneficial insects in bean fields. This will give the basis for research on beneficial insects in bean fields and practices that encourage their populations.

Yield and Fiscal Benefits of <i>Rhizobium</i>Inoculation Supplemented with Phosphorus (P) and Potassium (K) in Climbing Beans (<i>Phaseolus vulgaris</i>L.) Grown in Northern Tanzania

Both field and green house experiments were intended to investigate and evaluate the outcome of rhizobial inoculation supplemented with P and K on climbing beans production in northern Tanzania. The results obtained indicated that, inoculation using Rhizobium inoculants supplemented with fertilizers significantly (p ≤ 0.001) improved both vegetative and yield parameters of climbing beans varieties compared with control treatment. The economic analysis in rhizobium alone revealed a profit of US$ 2350 compared with control treatment with US$ 1558 profit, which was finally reflected in higher percentage increase over control and higher marginal rate of return (MRR). Thus, the use of Rhizobium inoculants supplemented with P and K increased climbing beans yield and the economic analysis performed based on total revenue and variable costs reflected an improvement in economic well being of a small hold farmer of northern Tanzania.

Theoretical Design of Complex Molecule via Combination of Natural Lawsone and Synthetic Indoline D131 Dyes for Dye Sensitized Solar Cells Application

The dye sensitized solar cells (DSSCs) have been extensively studied due to their low production cost and simple fabrication process. Dye co-sensitization broadens the absorption spectrum of the sensitizer;thus enhances light harvesting efficiency;and contributes to the improvement of the DSSCs overall efficiency. In this study we performed theoretical design of complex molecule (C45H32N2O4) through combination (esterification reaction) of the natural dye lawsone and synthetic metal free indoline dye D131. The excitation energies, vibration spectra, molecular structures, electronic absorption spectra and electron transitions in individual dyes and complex molecule were investigated using density functional theory (DFT) and time dependent density functional theory (TD-DFT) B3LYP5 methods, with 3-21G, 6-31G and 6-31G(d,p) basis sets. The UV-Vis absorption spectra of the individual dyes and their mixture in chloroform solution were measured using spectrophotometer. For the complex formation reaction, enthalpy, entropy and Gibbs free energy were calculated and the results indicated the reaction was endothermic and non-spontaneous. Electron density distribution of the frontier and adjacent molecular orbitals and energy levels alignment were used for analysis of the electronic spectra and mechanism of transitions. The results indicated that the designed complex molecule satisfied the requirements for good photosensitizer of DSSCs.

Extrapolations on the Use of Rhizobium Inoculants Supplemented with Phosphorus (P) and Potassium (K) on Growth and Nutrition of Legumes

Land scarcity and poor farming management practices has resulted in to intensive agriculture which rendered most of the soil in sub Saharan Africa depleted in essential plant nutrients. High prices of chemical fertilizer are crucial bottleneck toward increasing production of legumes and other food crops in most countries found in sub-Saharan Africa. Nitrogen, phosphorus and potas-sium are among the most limiting nutrients for plant growth as they play different but crucial roles in the plant physiological processes. These macronutrients are fundamental components of cell building blocks including genes and chromosomes. This review intend to show the vital roles played by rhizobial inoculants supplemented with phosphorus and potassium in enhancing growth, yield, photosynthesis, nodulation, nutrient uptake and nitrogen fixation of legumes.

Non-Isothermal Degradation and Thermodynamic Properties of Pine Sawdust

The study of non-isothermal kinetics analyzed the reactivity of pine sawdust, while the thermodynamic properties analyzed energy consumed and released from the pine sawdust. The kinetic parameters were determined by analyzing mass loss of pine sawdust components by using Thermogravimeric analyzer. The cellulose has the highest conversion rate of 9.5%/min at 610 K compared to hemicellulose and lignin, which are 5%/min at 600 K and 2%/min at 800 K, respectively. The activation Energy for cellulose, hemicellulose and lignin was 457.644, 259.876, and 89.950 kJ/mol, respectively. The thermodynamic properties included the change of Gibbs free energy for cellulose and hemicellulose, which were -214.440 and -30.825 kJ/mol respectively, their degradation was spontaneous in forward direction, while change of Gibbs free energy for lignin was 207.507 kJ/mol, which is non-spontaneous reaction. The positive value of change of entropies for the active complex compounds formed from hemicellulose and cellulose is less stable, while the active complex compounds of lignin are characterized by a much higher degree of arrangement since its change of entropy is negative. The kinetic and thermodynamic properties show that pine sawdust is a good candidate for production of char since it is easier to remove hemicellulose through thermal process.

Mobile Application for Research Knowledge Sharing and Dissemination: The Case of Nm-Aist Univeristy Tanzania

The utilization of mobile and web applications has surpassed all other platforms in terms of disseminating researchers’ knowledge among diverse communities throughout the world. The current method of disseminating researchers’ knowledge to the communities in the Arusha region in Tanzania is through meetings, workshops, and focus group discussions held by researchers, agricultural extension officers and community members after every three months or during field study. Yet the strategy is inefficient and ineffective in practice. The purpose of this study was to determine the most efficient and successful method of disseminating knowledge in communities. The study began with a qualitative phase, utilizing an interpretive technique and a qualitative multiple case study research design. The Arusha region in Tanzania was selected as a case study where different social activities were undertaken, including farming, livestock keeping, tourism activities and fishing. Individual participants were interviewed by using a semi-structured questionnaire. In addition, focus group discussions were conducted to gather more information regarding the needs of the mobile application. Through the implementation of the application, the second phase of the study led to the development of a mobile application that includes community members, agricultural extension officers, and researchers that will enable anyone to install the application on their mobile phones to access knowledge regarding activities undertaken in Arusha. According to the findings of the first phase of the research, a substantial percentage of community members own mobile phones, and hence a mobile application would be sufficient. The research also found that most researcher-community interactions occur at the data collection and intervention assessment (field trials) stages. Hence, the mobile application will benefit community members, district agricultural, irrigation, and cooperative officers (DAICO), and researchers.

Allelopathic Effect of Seed and Leaf Aqueous Extracts of <i>Datura stramonium</i>on Leaf Chlorophyll Content, Shoot and Root Elongation of <i>Cenchrus ciliaris</i>and <i>Neonotonia wightii</i>

Pot experiment was carried out to determine the allelopathic effects of Datura?stramonium on leaf chlorophyll content, root and shoot elongation, fresh and dry weight of two wild plant species: Cenchrus ciliaris and Neonotonia wightii. Different concentrations (0%, 25%, 50%, 75% and 100%) from seed and leaf extracts of D. stramonium were used to investigate the allelopathic effects of D. stramonium on growth of tested species.?The total chlorophyll content of N. wightii was significantly reduced in all plants treated with both aqueous seed and leaf extracts of D. stramonium. In C. ciliaris, the total chlorophyll content was also significantly reduced for those plants treated with aqueous seed extract and leaf extract from D. stramonium. Relative to the control treatments, there was greater reduction in root and shoot length which was observed in higher concentrations of aqueous seed and leaf extracts. Fresh and dry weight of tested species significantly decreased after being treated with both seed and leaf aqueous extracts of D. stramonium. It was found that the allelopathic effect of aqueous seed and leaf extracts from D. stramonium on tested species was concentration-dependent. The inhibitory effects on all tested species increased as the concentration of both extracts increased from 0% to 100%. This study concluded that aqueous seed and leaf extract of D. stramonium have allelopathic effects on leaf chlorophyll content, root and shoot length, fresh and dry weight of grass (C. ciliaris) and legume (N. wightii) species.

Influence of <i>Bradyrhizobium japonicum</i>and Phosphorus on Micronutrient Uptake in Cowpea. A Case Study of Zinc (Zn), Iron (Fe), Copper (Cu) and Manganese (Mn)

The field and screen house experiments were carried out in the 2013 cropping season to assess the effects of B. japonicum inoculation and phosphorus supplementation on the uptake of micronutrients in the cowpea. The experiment was laid out in a split plot design where the main plots comprised two inoculation treatments (with and without B. japonicum inoculation) and sub plots included four different levels of phosphorus (0, 20, 40, and 80 kg P/ha). The results showed a significant improvement in the uptake of micronutrients in the B. japonicum inoculated treatments over the control. Phosphorus supplementation (40 kg P/ha) also showed a significant increase in the uptake of some micronutrients while decreasing the uptake of Zn in some plant organs. There was also a significant interaction between B. japonicum inoculation and phosphorus in the root uptake of Zn for the field experiment.

Effects of <i>Bradyrhizobium japonicum</i>Inoculation and Supplementation with Phosphorus on Macronutrients Uptake in Cowpea (<i>Vigna unguiculata</i>(L.) Walp)

The current study was conducted to assess the effects of phosphorus supplementation and Bradyrhizobium japonicum inoculation on the availability and uptake of N, P, K, Mg, Ca and Na on cowpea. The experiment was laid out in a split plot design where the main plots comprised two inoculation levels (with and without inoculation of B. japonicum ) and sub plots contained four different levels of phosphorus (0, 20, 40, and 80 kg P/ha). The results indicated that B. japonicum inoculation and phosphorus supplementation significantly improved the uptake of N, P, K, Mg, Ca and Na in different cowpea tissues such as roots, pods, shoots, and whole plant relative to the control. The results also indicated that there was a significant interaction of B. japonicum and phosphorus on the uptake of sodium in the roots and whole cowpea plant in the screen house. Rhizobia inoculation and supplementation of phosphorus at 40 kg P/ha resulted in the improved uptake of the most elements over other treatments tested.

On Development of Platform for Organization Security Threat Analytics and Management (POSTAM) Using Rule-Based Approach

The integration of organisation’s information security policy into threat modeling enhances effectiveness of security strategies for information security management. These security policies are the ones which define the sets of security issues, controls and organisation’s commitment for seamless integration with knowledge based platforms in order to protect critical assets and data. Such platforms are needed to evaluate and share violations which can create security loop-hole. The lack of rules-based approaches for discovering potential threats at organisation’s context, poses a challenge for many organisations in safeguarding their critical assets. To address the challenge, this paper introduces a Platform for Organisation Security Threat Analytic and Management (POSTAM) using rule-based approach. The platform enhances strategies for combating information security threats and thus improves organisations’ commitment in protecting their critical assets. R scripting language for data visualization and java-based scripts were used to develop a prototype to run on web protocol. MySQL database management system was used as back-end for data storage during threat analytic processes.

Online and Offline Android Based Mobile Application for Mapping Health Facilities Using Google Map API. Case Study: Tanzania and Kenya Borders

The evolution of technology in 1990s resulted in the enormous growth of smartphones and the propagation of mobile applications (App) that marked new opportunities for healthcare centers and medical education. Apps have altered health services from patient’s health monitoring to specialist’s appointments and consultations from specialized health facilities. It can be argued that a healthy society can bring forth sustainable economic development to its full potential while an unhealthy society cannot. However, a free movement of people, labour and right to residence which was built across East Africa (EA) borders enabled Tanzania and Kenya borders to have enormous interactions. Subsequently, increase the risk of highly communicable diseases such as Tuberculosis and Sexually transmitted infections in such a way that medical attention is unavoidable along the borders. Statistically, Android Operating System (OS) owns 83% of Africa’s mobile OS market. In addition, 25,794,560 internet users reported by Tanzania Communications Regulatory Authority (TCRA) together with the 22.86 million internet users provided by Kenya Digital which is equivalent to 46% and 43% of internet penetration in year 2020, disclose the need for Android mobile application for mapping health facilities both online and offline using Google map API, which will solve residents’ need to healthcare services on the presence or shortage of internet connections;using either Swahili or English language via Smartphone devices. The App incorporates Monitoring and Evaluation (M & E) tool for tracking application usage which will ease Admin’s task to generate daily and monthly reports in Excel and Comma-Separated Values (CSV) formats. The developed system received positive feedback from EA citizens and residents in the Arusha region and Namanga border crossing where 90.2% of the system evaluation conducted between Dec 2020 and Apr 2021 agreed upon App usage.

The Potential of Using Indigenous Pesticidal Plants for Insect Pest Control to Small Scale Farmers in Africa

Pesticidal plants are scientifically proven for their effectiveness in controlling insect pests. Their activity is enhanced by active compounds contained, which are known for their repellant and antifeedant potentials to the insects. Use of pesticidal plants by local small scale farmers has been a point of concern following information that majority of farmers do not widely use pesticidal plants despite of an indigenous knowledge that they possess. Improvement of the technologies used by local farmers in previous times, that are easy and effective need to help farmers abstain from the use of synthetic pesticides that are detrimental to the environment and to their own health. This paper reviews the potentiality of pesticidal plants to small holder farmers. It also gives the status of pesticidal plants use, their possible effectiveness against insect pests, persistence as well as the knowledge that indigenous people possess in their use. Again, the paper suggests the need for more instrumental research on practical improvement of indigenous knowledge on the use of pesticidal plants with scientific evidences.

Oldoinyo Lengai Volcanic Ash for Removal of Hydrogen Sulfide and Ammonia from Biogas

Oldoinyo Lengai mountain located in Northern Tanzania is the only active natrocarbonatite volcano with unusually alkali-rich natrocarbonatites which are not found elsewhere in the world. Volcanic ash formed earlier during eruptions was collected from different sites along the mountain, and its potency to adsorb hydrogen sulfide (H2S) and ammonia (NH3) from biogas was investigated. The samples were calcinated at different temperatures (550℃ - 850℃) and were characterized by X-ray florescent, scanning electron microscopy and X-ray diffraction techniques. The on-site adsorption experiments were conducted at the biogas digester at ambient conditions. The calcinated ash was packed into the reactor bed, biogas allowed to pass through the adsorbent, and the inlet and outlet concentrations of H2S and NH3 were measured. The height of the site where the adsorbent was taken from, calcination temperature, biogas flowrate and mass of the adsorbent were variable parameters and found to influence greatly on the efficiency of H2S and NH3 removal. The efficiency is increased with calcination temperature raise and mass of adsorbent and decreased with flowrate increase. The samples collected from the top site of the mountain and calcinated at 850℃ exhibited the best sorption performance.

Allelopathic Effect of Aqueous Extract of Argemone mexicana L on Germination and Growth of Brachiaria dictyoneura L and Clitoria ternatea L

The present study was conducted in the laboratory to investigate the allelopathic effect of Mexican poppy (Argemone mexicana L.) to the germination and growth parameters of two native species Brachiaria dictyoneura L and Clitoria ternatea L. Different concentrations of leaf and seed aqueous extracts from Argemone mexicana (0%, 25%, 50%, 75% and 100%) were evaluated. Results showed that seed germination, root length, shoot length, seedling length, fresh weight and dry weight of B. dictyoneura and C. ternatea seedlings were significantly reduced by leaf and seed extracts compared with control treatments. Roots were more affected than shoots;and leaf extract was more suppressive than seed extracts. From the results, it is concluded that leaf and seed extracts have some allelochemicals with inhibitory effect on germination and growth of the tested plant species.

Isolation and Molecular Characterization of Elite Indigenous Rhizobia Nodulating Phaseolus bean (Phaseolus vulgaris L.)

Nowadays application of biological nitrogen fixation (BNF) through rhizobia inoculums is highly promoted as a solution to solve the problem of poor soil fertility in areas where legumes are cultivated. This is due to the fact that, rhizobia enhance nitrogen fixation, induce disease resistance, reduce heavy metal in the soil, facilitate bioavailabity of iron in soil and is environmental friendly. To get rhizobia strains which are suitable for inoculants production, isolation and molecular characterization of elite rhizobia are highly needed. Molecular characterization acts as a spark plug for discovery of many microbes including Rhizobia. Multi Locus Sequence Analysis (MLSA), 16S rRNA gene sequence analysis, DNA-DNA hybridization and SDS-PAGE analysis of the whole-cell proteins are the molecular techniques mostly used in characterizing rhizobia. But before deciding to use or not to use rhizobia inoculants in certain areas, knowing the population size of indigenous rhizobia found in that area is very important, because this is a major factor which determines inoculums responses as well gives clues on which areas need or do not need inoculation. The Most Probable Number (MPN) method is mostly used in enumerating rhizobia population of the soil. Given that, in most of the developing countries, including Tanzania, Biological Nitrogen Fixation (BNF) technology is not fully flourished;more efforts in isolation, molecular characterization of elite rhizobia and estimation of indigenous rhizobia population in various areas are required.

Modelling the Suitability of Pine Sawdust for Energy Production via Biomass Steam Explosion

Biomass material as a source of fuel is difficult to handle, transport, store, and utilize in its original form. To overcome these challenges and make it suitable for energy prodution, the material must be pre-treated. Biomass steam explosion is one of the promising pretreatment methods where moisture and hemicellulose are removed in order to improve biomass storage and fuel properties. This paper is aimed to model the suitability of pine saw dust for energy production through steam explosion process. The peak property method was used to determine the kinetic parameters. The model has shown that suitable operating conditions for steam explosion process to remove moisture and hemicellulose from pine sawdust. The temperature and pressure ranges attained in the current study are 260 -317 ℃ (533 -590 K), 4.7 -10.8 MPa, respectively.

Geochemistry of Potentially Toxic Elements in Soil and Sediments of a Tanzanian Small-Scale Gold Mining Area

Small-scale gold mining is linked to significant environmental pollution by potentially toxic elements (PTEs). However, research on the pollution caused by such mining activities remains insufficient especially in developing countries. In the present study, a systematic investigation assessed the pollution and level of ecological risk of PTEs in soil and stream sediments in an active small scale gold mining area of Isanga, in Nzega, Tanzania. Samples amounting to 16 soil and 20 sediment were gathered from the study area and analyzed for five PTEs concentrations (As, Cd, Cr, Hg and Pb) using the AAS method. The contamination level and ecological risk were assessed using several pollution indices. The results suggest that the assessed environmental systems of the Isanga mining area and its vicinities are lowly contaminated by PTEs and have a low potential to pose ecological risks. Hg and Cd with mean concentrations of 0.09 mg/kg and 0.26 mg/kg respectively were found to be the most enriched PTEs in soil, compared to their average continental crust concentrations (0.056 mg/kg and 0.102 mg/kg respectively). The levels of the evaluated PTEs in the study area are susceptible to increase over time if proactive steps are not taken to control mining and waste disposal activities.

Assessing the Ethnobotanical Uses, Harvesting Practices, and Conservation Awareness of Warburgia ugandensis in Northern Tanzania

Warburgia ugandensis is unsustainably harvested commercially, threatening its survival and potentially leading to local extinction in its native range areas in Northern Tanzania. Our study aimed to assess the extent of harvesting of W. ugandensis in Northern Tanzania, ethno-botanical uses, community perceptions of species utilization, and conservation measures across its native range in Northern Tanzania. From each of the 128 randomly selected grids, we laid down a sampling plot measuring 100 m × 100 m (1 ha) for the identification, and collection of data on the extent of harvesting of W. ugandensis. Additionally, we interviewed 221 respondents using open-ended questionnaires to gather data on ethno-botanical uses, perceptions of product utilization, and conservation measures. We analyzed the data using descriptive statistics and Kruskal-Wallis tests. Our findings reveal significant variation in the extent of harvesting, with Mt. Ketumbeine experiencing the most severe harvesting while Mt. Kilimanjaro holds the highest number of intact trees. Community knowledge of the medicinal uses of W. ugandensis was highest in Mt. Kilimanjaro, particularly for treating gastrointestinal disorders, coughs, and malaria. Perceptions of species utilization were very high in Mt. Gelai and Mt. Monduli, while Mt. Kilimanjaro, Ketumbeine, and Longido showed more variability. Awareness of W. ugandensis conservation measures was high in Mt. Kilimanjaro, compared to the rest of the species’ native range areas. Therefore, our study findings underscore the urgent need for targeted conservation initiatives, particularly in regions like Mt. Ketumbeine and Mt. Longido, where W. ugandensis faces the severe extent of harvesting.