African Journal of Soil Science

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-008, April, 2019. © International Scholars Journals

Full Length Research Paper

Effect of tillage practices on the soil carbon dioxide flux during fall and spring seasons in a Mediterranean Vertisol

R.  Moussadek^1,2*, R. Mrabet¹, R. Dahan¹, A. Douaik¹, A. Verdoodt²,  E. Van Ranst² and M. Corbeels³

¹Institut National de la Recherche Agronomique, BP 415, Avenue la Victoire, 10000, Rabat, Morocco.

²Department of Geology and Soil Science (WE13), Laboratory of Soil Science, Ghent University, Krijgslaan 281/S8, B-9000 Gent, Belgium.

³Systèmes de Culture Annuels, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), France.

Accepted 15 February, 2019

Abstract

In this study, we assessed the effect of conventional tillage (CT), reduced (RT) and no tillage (NT) practices on the soil CO₂ flux of a Mediterranean Vertisol in semi-arid Morocco. The measurements focused on the short term (0 to 96 h) soil CO₂ fluxes measured directly after tillage during the fall and spring period. Soil temperature, moisture and soil strength were measured congruently to study their effect on the soil CO₂ flux magnitude. Immediately after fall tillage, the CT showed the highest CO₂ flux (4.9 g m^-2 h^-1); RT exhibited an intermediate value (2.1 g m^-2 h^-1) whereas the lowest flux (0.7 g m^-2 h^-1) was reported under NT. After spring tillage, similar but smaller impacts of the tillage practices on soil CO₂ flux were reported with fluxes ranging from 1.8 g CO₂ m^-2 h^-1 (CT) to less than 0.1 g CO₂ m^-2 h^-1 (NT). Soil strength was significantly correlated with soil CO₂ emission; whereas surface soil temperature and moisture were low correlated to the soil CO₂ flux. The intensity of rainfall events before fall and spring tillage practices could explain the seasonal CO₂ flux trends. The findings promote conservation tillage and more specifically no tillage practices to reduce CO₂ losses within these Mediterranean agro-ecosystems.

Key words: Tillage, CO₂ flux, seasonal variability, Vertisol, semi-arid Morocco.

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-028, April, 2019. © International Scholars Journals

Review 

A review of non-conventional energy systems and environmental pollution control

Abdeen Mustafa Omer

Energy Research Institute (ERI), Nottingham, United Kingdom.

Accepted 10 February, 2019

Abstract

The massive increases in fuel prices over the last years have however, made any scheme not requiring fuel appear to be more attractive and to be worth reinvestigation. In considering the atmosphere and the oceans as energy sources, the four main contenders are wind power, wave power, tidal and power from ocean thermal gradients. The renewable energy resources are particularly suited for the provision of rural power supplies and a major advantage is that equipment such as flat plate solar driers, wind machines, etc., can be constructed using local resources and without the advantage results from the feasibility of local maintenance and the general encouragement such local manufacture gives to the build up of small scale rural based industry. The key factors to reducing and controlling CO₂, which is the major contributor to global warming, are the use of alternative approaches to energy generation and the exploration of how these alternatives are used today and may be used in the future as green energy sources. Even with modest assumptions about the availability of land, comprehensive fuel-wood farming programmes offer significant energy, economic and environmental benefits. These benefits would be dispersed in rural areas where they are greatly needed and can serve as linkages for further rural economic development. Self-renewing resources such as wind, sun, plants and heat from the earth can provide clean abundant energy through the development of renewable technologies. Virtually all regions of the world have renewable resources of one type or another. Research and development investments in the past 25 years in renewable technologies development has lead to important advances in performance and resulting cost effectiveness. Renewable resources currently account for about 9%-10% of the energy consumed in the world; most of this is from hydropower and traditional biomass sources. Wind, solar, biomass and geothermal technologies are cost effective today in an increasing number of markets and are making important steps to broader commercialisation. The present situation is best characterised as one of very rapid growth for wind and solar technologies and of significant promise for biomass and geothermal technologies. Each of the renewable energy technologies is in a different stage of research, development and commercialisation and all have differences in current and future expected costs, current industrial base, resource availability and potential impact on energy supply. This article discusses the potential for such integrated systems in the stationary and portable power market in response to the critical need for a cleaner energy technology. Anticipated patterns of future energy use and consequent environmental impacts (acid precipitation, ozone depletion and the greenhouse effect or global warming) are comprehensively discussed in this paper. Throughout the theme, several issues relating to renewable energies, environment and sustainable development are examined from both current and future perspectives.

Key words: Energy, renewable energy technologies, energy efficiency, environment, sustainable development, global warming, emissions.

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-005, April, 2019. © International Scholars Journals

Full Length Research Paper

Morphogenetic characterization of soils formed from basement complex rock in the humid tropical rainforest of Nigeria

O. T. Ande

Institute of Agriculture, Research and Training, Obafemi Awolowo University, P. M. B. 5029, Apata, Ibadan, Oyo State, Nigeria. E-mail: [email protected].

Accepted 16 January, 2019

Abstract

The morphogenetic and physico-chemical properties of four soil units occupying different slope facets on a rolling landscape were studied to understand distribution of soils on a typical landscape. The soil colours range from dark brown to reddish brown (10YR3/3-5YR3/3) in the surface and strong brown (7YR4/6) to yellowish red (5YR5/8) in the sub soil. The texture varies from loam/sandy clay loam in the surface to clay/clay loam in the sub soil. The solum was moderately acidic to neutral (5.5 - 8.0) at the surface and strongly acidic to moderately acidic (4.65 - 5.80) in the sub soils. The soils are characterized by low exchangeable bases and cation exchange capacity. Pedon 1 on the crest was classified as Typic Hapludult (Haplic Acrisols). Pedon 2 at the mid slope was classified as Dystric Hapludult (Dystric Luvisol) while Pedons 3 and 4 were classified as Albic plinthudult (Albic plinthosols) and Dystric Haplaquent (Dystric Gleysols) respectively. Pedogenesis was influenced by physiographic positions resulting in different soil types on the landscape. Where similar parent material exists, different soil types were formed due to different exposure to morphogenesis processes such as eluviation, illuviation, deposition, cementation of pedi-sediments and multiple stratification as determined by the position of the pedon on the landscape.

Key words: Morphogenesis, pedoturbation, quartz vein, plinthite, argillic horizon, base saturation.

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-008, April, 2019. © International Scholars Journals

Full Length Research Paper

Balanites aegyptiaca, a potential tree for parkland agroforestry systems with sorghum in Northern Ethiopia

Hailemariam Kassa¹, Kindeya Gebrehiwet² and Charles Yamoah³*

¹Tigray Agricultural Research Institute, Humera Agricultural Research Centre, Humera, P. O. Box 230 Tigray, Ethiopia.

²Department of Land Resource Management and Environmental Protection, Faculty of Dryland Agriculture, Mekelle University, P. O. Box 231, Ethiopia.

³Faculty of Renewable Natural Resources, University of Development Studies, P. O. Box TL 1350 Tamale, Ghana.

Accepted 10 February, 2019

Abstract

Balanites aegyptiaca tree is preferred by farmers in Tigray region of Ethiopia for fuel wood, provision of shade, fodder and as a medicinal plant. This study was conducted to assess soil properties and sorghum yields on farm fields (Limat, Goblel and Korbebite and Endakeshe), where B. aegyptiaca are traditionally retained. At each site, six trees were randomly selected and soil properties and sorghum yields were compared 1) under the tree canopy (0 – 4 m), designated as zone D1; 2) near the tree, (4 – 6 m, D2) and 3) far away from the tree (8 – 12 m, D3). At the Limat site, results indicated that % clay and available P were significantly higher (p < 0.05) at D1 (under the canopy) than D3 (further away from the canopy). Also at the same site, % silt was significantly lower (p < 0.05) at D1 than D3. At Goblel and Korbebite sites, pH was significantly lower (p < 0.05) at D1 and D2 than D3. Apart from these, exchangeable Ca, exchangeable K, organic carbon (OC), cation exchange capacity (CEC), electrical conductivity (EC) and yields were non-significant among the three zones at the sites. Mean moisture levels of all sites at sowing period at D1 (14.36%) was significantly (p < 0.05) lower than D3 (16.32%), but yields were unaffected. Pot studies using soils from the above sites and zones demonstrated similar soil and yields’ patterns. Thus, it may be appropriate to integrate sorghum crops with B. aegyptiaca trees on the same field in a parkland agroforestry system with minimal risk of crop failure.

Key words: Balanites aegyptiaca, parkland agroforestry, sorghum.

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-006, April, 2019. © International Scholars Journals

Full Length Research Paper

Environmental impact assessment of oil and gas sector: A case study of Magurchara gas field

J. B. Alam¹, A. A. M. Ahmed², G. M. Munna¹ and A. A. M. Ahmed³

¹Department of Civil and Environmental Engineering, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh.

²Department of Civil Engineering, Leading University, Sylhet-3100, Bangladesh.

³Department of Business Administration, Leading University, Sylhet-3100, Bangladesh.

Accepted 21 January, 2019

Abstract

This study focuses on the environmental impact assessment of Magurcherra gas field through environmental, socio-economical and meteorological study. The major activities involved are seismic activities, drilling activities, exploration and production. In the case of Magurcherra gas field, improper planning and drilling activities have created explosion and caused huge environmental damage. In order to evaluate the environmental damage due to exploration and drilling activities, checklist of possible environmental impact on the nature, society and socioeconomic activities of the proposed area has been identified by focus group discussion, survey and sample testing. During the observation pollution related with noise found as temporary and minor but the air is observed to be polluted by dust, SPM, SO_x, NO_x, and CO₂ etc. The effects of explosion on the natural forests, land, wildlife, tea garden, infrastructure, local people and tea garden workers, livestock feeding, communication and transport etc are measured. During observation, water quality deterioration by spills and leaks of oil and grease, paints, solvents and chemicals was identified. It was found from the cumulative analysis of the study that the project is environmentally feasible.

Key words: Magurcherra gas, meteorological study, environmental damage, feasible, socio-economical.

African Journal of Soil Science ISSN 2375-088X Vol. 7 (4), pp. 001-009, April, 2019. © International Scholars Journals

Full Length Research Paper

Application of queuing theory to the container terminal at Alexandria seaport

M. E. El-Naggar

Civil Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, Egypt. E-mail: [email protected].

Accepted 09 February, 2019

Abstract

This paper describes a methodology designed to support the decision -making process by developing seaport infrastructure to meet future demand. In order to determine an optimum number of berths at a sea port, the queuing theory is applied in the light of port facilities and activities. The aim is to avoid inadvertent over and under-building. Within this methodology, the movements in port should firstly be analyzed. The waiting time of vessels outside the port and in queue is calculated in accordance with the considered queuing model. The theoretical functions representing the actual vessel arrival and service time distributions are determined. For the economic considerations, cost estimate studies including cost of port and waiting vessels are carried out. Finally, the optimum number of berths that minimizes the total port costs can be decided. Both proposed mathematical and economical models are applied to Alexandria port in Egypt.

Key words: Port capacity, port economy, port modeling, queuing theory.