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21.
Fertility status of soils of three wetland types in Akwa Ibom State, Nigeria, was investigated. The wetland types are Inland Valley (IV), Flood Plain (FP) and Mangrove (MG). The soils have silt-clay ratios above 0.15 and 0.25 indicating that they are of young parent materials with low degree of weathering and possible weatherable minerals for plant nutrition. The pH of the soils was near neutral (>6.4) when wet but extremely acid (>3.5) when dried indicating that the soils are potential acid sulphate soils. Organic matter content was high with mean values of 12.59, 6.03 and 3.20% for IV, FP and MG soils, respectively. Total N (nitrogen) was low except in IV soils where the value was above the 0.30% critical level. The C:N ratios were narrow with mean of 20.90, 12.17 and 12.12 for IV, FP and MG soils, respectively. The contents of basic cations [Calcium (Ca), Magnesium (Mg), Potasium (K) and Sodium (Na)] were low while acidic cations [Aluminium (Al) and Hydrogen (H)] were high. The Ca:Mg ratios were below the optimum range of 3:1 to 4:1 required for most crops. The Mg:K ratios were above 1.2, below which yields of crops like corn and soybean may be reduced. Effective cation exchange capacity (ECEC) was below the 20 cmol/kg. Percent base saturation was low (<38) indicating that the soils are potentially less fertile. Exchangeable Al and percent Al saturation were high, above 60% in IV and FP soils. Electrical conductivity was above the critical value of 2 dsm−1 while exchangeable sodium percentage was less than 15. Available Phosphorus (P) and low, <10 ppm and free Fe2O3/clay ratios were <0.15. Positive correlation existed between silt and ECEC, implying that silt contributed to nutrient status of the soils. Generally, fertility status of the soil is low and would require maintenance of adequate organic matter, application of lime and organic and inorganic fertilizers, drainage and irrigation if the land is to be used for intensive/sustainable crop production. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   
22.
Forest management in south eastern Nigeria has changed hands from the forest communities to foreign technology. As a result the sustainable, conservative and cyclical use that characterised the communities that lived in balance with their forest resources are no longer practised. Consequently, a great deal of the region's valuable timber trees has been lost and the environmental influences of the forest grossly reduced. The local communities have not only been deprived of a multitude of non-timber forest resources upon which they depend for their survival and well-being but have also lost their knowledge of traditional forest management. Although these consequences are far-reaching, the neglected majority in the rural areas bear the brunt. To save what is left of the once vast forest areas, communities in and around the biome need to be empowered to manage their forest resources. Empowerment will challenge their responsibility and their ability to function for the common good—themselves, the State and the world at large.  相似文献   
23.
This study examines the present environmental and socio-economic status of Adiabo Community in Odukpani Local Government Area of Cross River State against the background of the proposal of the Cross River State Government to site a tourism resort in the community. The paper utilizes participatory appraisal techniques to document information on the existing environmental and socio- economic structure of the study area. It also analyses the potential effect of the proposed tourist resort on the community dwellers and finally recommends strategies to ensure the sustainability of the proposed project and livelihood activities of the natives in the study area.  相似文献   
24.
Throughout the world, human use of water, and bad planning have led to drier and polluted rivers, lakes, and groundwater resources with dramatic effects on the natural ecosystems. Nigeria's vast freshwater resources are among those most affected by environmental stress imposed by human population growth, urbanization, and industrialization. Disposal and management of wastes in Nigeria present serious environmental problems. The usual methods of waste disposal in the country are: land filling, dumpsites, land spreads, water disposal, and incineration. Each of these methods has serious environmental implications because of their potential to pollute and contaminate underground and surface water bodies in the country. Major cities in Nigeria face serious water pollution crises, in which lack of environmental control of water-dependent activities (including domestic, agricultural, and industrial) play an important part. Fish and marine resources in the country face total collapse or extinction, due to over-fishing and destruction of marine life and natural habitats by pollution of water bodies. Unregulated and excessive use of pesticides for fishing and the deliberate disposal and dumping of toxic and hazardous wastes into water bodies are significant causes of massive fish kills and loss of aquatic life and habitats in the country. The protection of water quality and aquatic ecosystem as a vulnerable resource, essential to sustain life, development and environment is of utmost importance to prevent further pollution and degradation of Nigeria's freshwater resources. Integrating operational measures for safeguarding adequate levels of protection of endemic habitats remains a major challenge. There is therefore a need to examine in tandem the entire range of uses to which freshwater is put, and to design services which neither squander precious resources nor fail to respect other, competing and complementary water needs.This paper attempts to provide an overview of the Nigerian freshwater resources, to assess the pollution status of inland waters, identify the sources of pollution, and infer the consequent effect on fisheries resource. Recommendations were proffered on the strategies to employ to ensure that Nigerian fishery resources are adequately managed in order to address the issue of food security.  相似文献   
25.
This article discusses the decision of the Supreme Court of Nigeria on the constitutional provision dealing with the sharing of revenues derived from natural resources located within the states of the Federation, the ‘derivation principle.’ Although the case relates to the interpretation of a constitutional provision, the arguments of the parties suggest that the real battle was — and still is — about the ownership and control of Nigeria's offshore oil. The article details the legal history and precedents as well as constitutional provisions relevant to the case. Disagreements arose over legal questions such as the seaward boundaries of littoral states (from which oil revenues are derived), and whether a distinction can be made between offshore and onshore oil revenues in applying a 13% constitutionally prescribed derivation principle. The article shows that, in its judgment, Nigeria's Supreme Court relied heavily on rules of international law, while failing to apply existing Nigerian laws and constitutional provision, and argues that the decision might have been different had the court investigated and invoked the legislative history of the provision in question, as required in Nigerian law. Furthermore, it is argued that the court was wrong to disregard the provision of the law which had abolished any distinction between onshore and offshore natural resources in the application of the derivation principle. The article concludes that the legal tug of war is set to continue for some years.  相似文献   
26.
This paper presents the findings of a baseline study undertaken to evaluate the natural radioactivity levels in soil, sediment and water samples in four flood plain lakes of the Niger Delta using a hyper pure germanium (HPGe) detector. The activity profile of radionuclides shows low activity across the study area. The mean activity level of the natural radionuclides 226Ra, 232Th and 40K is 20 ± 3, 20 ± 3 and 180 ± 50 Bq kg−1, respectively. These values are well within values reported elsewhere in the country and in other countries with similar environments. The study also examined some radiation hazard indices. The mean values obtained are, 76 ± 14 Bq kg−1, 30 ± 5.5 ηGy h−1, 37 ± 6.8 μSv y−1, 0.17 and 0.23 for Radium Equivalent Activity (Raeq), Absorbed Dose Rates (D), Annual Effective Dose Rates (Eff Dose), External Hazard Index (Hex) and Internal Hazard Index (Hin) respectively. All the health hazard indices are well below their recommended limits. The soil and sediments from the study area provide no excessive exposures for inhabitants and can be used as construction materials without posing any significant radiological threat to the population. The water is radiologically safe for domestic and industrial use. The paper recommends further studies to estimate internal and external doses from other suspected radiological sources to the population of the Biseni kingdom.  相似文献   
27.
Enhanced concentrations of Fe, Zn, Mn, Pb, Cu, Cd and total hydrocarbons (THC) determined in fish samples from the Cross River system, Nigeria have been associated with clinical defects (nausea, headache, hepatitis, body rashes) observed in coastal residents who are the major consumers of the fish species. Fish samples were collected from ten locations with varying degrees of exposure to human activities. Heavy metal concentrations in fish followed the sequence: Fe>Zn>Mn>Pb>Cu>Cd with the highest concentration of 243 g/g (Fe) wet weight occurring in Tympanotonus sp. Fe levels were significantly (P<0.001) higher than other metals analysed. The sequence in total hydrocarbon concentrations according to fish species was in the order of O. niloticus (55.1 g/g) > E. fimbriata > P. elongatus > Portonus sp. > C. nigrodigitatus > Tympanotonus sp. Generally, the demersal species showed a marked potential for tolerating high levels of heavy metals while the pelagic species showed preference for the accumulation of hydrocarbons. The degree of contamination depended on pollutant type, fish species, sampling location, trophic level and their mode of feeding. The persistent accumulation and tolerable potential of Tympanotonus, Portonus and P. elongatus suggest that they might be effectively utilized as self-integrating indicators for time-series monitoring of the rate of recovery of the impacted ecosystem by heavy metals. Possible sources of pollutant include leachates from municipal dumps, used crankcase oils from fluvial discharges (mechanic workshops) and occasional oil spills.  相似文献   
28.
29.
Presently, large quantities of waste mobile phones are being generated in Nigeria with a significant proportion in storage. This paper investigated the behavior of consumers in Nigeria towards this waste stream and their willingness to participate in waste mobile phones recycling. This study also assessed the willingness of consumer's to pay for a more ‘environment friendlier’ phone – the so-called ‘green phone’. We performed a principal component analysis with varimax rotation in order to condense some of our questions into a smaller set of factors. We developed a model to estimate and explain the willingness to pay (WTP) a premium for ‘green’ cell phones. The model showed that the significant predictors of willingness to pay extra for green electronics include awareness and concern about the deteriorating environment, age, and the general attitude towards the environment. About 65% of the respondents are either ‘willing’ or ‘very willing’ to drop-off no-longer-in-use electronics at a nearby recycling facility. Majority of the respondents are also very willing to pay a premium for a green phone. Considering the increasing waste generation by this sector, it has become expedient that a recycling program be introduced for these potentially harmful waste materials.  相似文献   
30.
Although numerous studies have been conducted in recent years on energy transitions, they have been predominately developed and applied in industrialized countries. It is however important to examine the applicability of transition theories, as they are currently formulated, beyond OECD countries. This paper analyses renewable energy transitions in Africa, using Nigeria as a case study, to elucidate the analytical and methodological challenges that sustainability transition studies are facing in developing countries, particularly rentier states. In doing so, the paper employs the lens of the multi-level perspective (MLP) on socio-technical transitions - a well-established theory that emphasizes the role of ‘niches’, ‘regimes’ and ‘landscapes’ in instituting transitions. Based on a detailed analysis of Nigeria, we argue for a more nuanced enquiry of the construct ‘regime’ that better accounts for the rentier character of the state including the role of political elites and prevalent client-patron relationships. As such, our paper makes an important contribution to the further refinement and enrichment of the MLP by focusing on the political dimensions of energy transitions.  相似文献   
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