Adeniyi Gbadegesin

Avoiding the mistakes of the past: towards a community oriented management strategy for the proposed National Park in Abuja-Nigeria

Abstract In recent times, the roles of local participation in what was previously perceived as pure public- service delivery has come to the forefront of policy debate and academic research. In this connection, this paper focuses on the roles of local communities in the management of protected ecosystems using the proposed Abuja national park as a case study. Based on the analysis of the results of a socio-economic survey of the communities in the study area, the paper argues that the sustainable conservation of the proposed park can only be achieved if a management scheme that will integrate, empower and involve the local communities in the planning and implementation of the park management programme is put in place. The paper suggests a collaborative strategy such as that of the Co-ordinated Resource Management which has the features of promoting an atmosphere of open communication, ensuring voluntary participation of stakeholders and guaranteeing decisions by consensus rather than those that enforce decisions using legal and political means.

Soil properties in the metropolitan region of Ibadan, Nigeria: implications for the management of the urban environment of developing countries

This paper examines the variation in the properties of surface soils from the rural, through sub-urban, to the urban zones of Ibadan metropolitan area, south-west Nigeria. Soils were sampled at 0–20 cm depth in the northern part of the metropolis. Statistical techniques were used to compare the data obtained in the three zones. The results of the analyses clearly show that the mean values of nine out of the eighteen soil properties analysed differed significantly between the three zones. In particular, the concentration of two of the three heavy metals analysed in the study, that is, zinc and lead were higher in the urban zone than in the other two zones. The accumulation of heavy metals in the soils of the urban environment of developing countries requires urgent attention from environmentalists and urban development planners. It is important to prevent such heavy metals leaching into the underground water supply, and, to minimise the health risks to both humans and animals that depend solely on this source of water supply.

On the suitability assessment of the forest and savanna ecological zones of south-western Nigeria for maize production.

Abstract A combined ecological and economic approach was used to assess and compare the productivity of 44 maize farms located in two different ecological zones in south-western Nigeria. First, the technique of investigation involved, the identification of the ecological parameters in particular soils and climatic variables that significantly influence the crops production in the two zones; secondly, it involves the estimation of the costs and revenues accruing from cultivating a hectare of land for maize production for each ecological zone. Using a rating procedure developed in this study, four parameters were used to assess the sampled maize farms in the two ecological zones: nitrogen, phosphorus, number of rainy days and Gross Margin Analysis. The results of the assessment indicate that it is more profitable to produce maize in the savanna zone than the forest zone. In addition, all the farms sampled in the savanna zone but only 65% of the farms in the forest zone were rated fairly suitable to very suitable for maize production.

Urban Vulnerability to Climate Change and Natural Hazards in Nigeria

Climate change and global warming have attained global dimensions with the recurrent discussions at the United Nations (UN) and in other international meetings. Global climate change, driven largely by anthropogenic activities, is a growing threat to human wellbeing in developing and industrialized nations alike. Significant harm from climate change is already occurring, and further damages are likely (Gwary 2008; Barnett/ Adger 2007; CHGE 2005; IPCC 2001a). Extreme weather events resulting in hurricanes, windstorms, tornadoes, droughts, fires, floods and other weather-related hazards account for a large proportion of the increased losses from natural disasters over the last decades. More alarming even than the size of past losses is the trend for losses to increase. More than 1.5 million people died in the past two decades because of extreme climatic events, and more than ninety per cent of those deaths have occurred in developing countries (IFRC-RCS 2002; Munich Re 2003).

Soil rating for crop production in the savanna belt of south-western Nigeria

Abstract A method for grouping soils for specific purposes is presented using the example of maize in the savanna ecological zone of south-western Nigeria. The technique involves two important stages. The first is the identification of the crucial soil properties influencing maize production in the study area while the second is the actual rating of the soils based on the relevant soil properties identified. Using an index of soil variable contribution to the growth and yield of maize in the area, only two soil properties, the organic matter and the available moisture contents of the soils, contribute significantly (58·4% and 13·1%, respectively) to the growth and yield of the crop, out of the twenty soil parameters analysed. With respect to the second stage, six soil productivity classes ranging from A (Excellent) to E (Poor) were arrived at as far as maize production in the area is concerned. The assignment of scores to the two soil properties used in rating the soils was based on their relative contribution to the growth and yield of the crop. However, the results of the application to, and comparison of the rating scheme with, 29 local soil series previously assessed for rainfed maize production by Murdoch et al. (1976), largely indicate that, after carrying out the special purpose soil classification, there is still the need to engage in capability assessments of the land using other environmental parameters apart from the soil attributes.

A method for identifying soil properties influencing crop yield: the example of maize in the Savanna Belt of South-western Nigeria

Abstract This paper describes a method of identifying the crucial soil properties influencing yields of crops, using the example of maize in south-western Nigeria. The method involves first, the examination of the relationship between soil properties and the maize parameters using the simple bivariate correlation analysis and the multiple regression model. It also involves, in part, the computation of an index of soil variable contribution to maize prediction in order to identify the crucial soil properties influencing the yield of the crop. In the current study, the multiple regression model reduces the 20 soil properties analysed to the 14 that have made significant contributions to the crops prediction. The 14 variables were later reduced to two using the maize-prediction index. The index has the merits of being very simple to compute and the ability to reduce the numerous variables to few significant ones as far as the crop under investigation is concerned.

Water Use and Seasonal Differences in Maize Performance in the Transitional Humid Zone of Nigeria

ABSTRACT Maize (Zea mays) was grown in four consecutive (wet and dry) seasons in two years at the experimental fields of the International Institute of Tropical Agriculture, Ibadan, Nigeria. Water use of maize and yield responses in the humid forest-Savanna transition zone of Nigeria were assessed using drainage lysimeters which were irrigated daily depending on the evaporative demand of the atmosphere. Results show significant differences (p < 0.01) in water use, yields and yield components between the seasons and the years. Seasonal averages of water used from sowing to harvest were 363 mm and 271 mm for the wet and dry seasons, respectively. These are equivalent to mean water use efficiency (WUE) of 122 g and 176 g of water per gram dry matter for the wet and dry seasons, respectively. Significant yield differences were recorded between the wet (7.6 t ha−1) and dry (3.8 t ha−1) seasons and between the first (6.6 t ha−1) and second (4.8 t ha−1) years, respectively. Also, the lysimeter surfaces gave superior maize yields when compared to the rain-fed plots. Two years average lysimeter yields were 9.1 t ha−1 and 4.3 t ha −1 for the wet and dry seasons, respectively, compared to rain-fed plots yields of 5.6 and 3.3 tonnes ha−1 during the same period. The result shows a significant yield response irrespective of the season, to increased water input from higher rainfall amount, distribution or supplementary irrigation.

Effects of land clearing methods on the properties and productivity of an Alfisol in south-western Nigeria

SummaryThis study investigated the impact of manual and mechanical land clearing methods on the soils and the yield of maize in a part of the rainforest belt of south-western Nigeria. The results of the study revealed that the mean values of such soil properties as the organic matter, bulk-density, total porosity, soil moisture and to some extent the exchangeable actions in the mechanically cleared farms differed significantly at (P ≥ 0.05) from those in the manually cleared farms and the rainforest vegetation used in the control plot. There was no significant difference in the average yield of maize for the three years for which records were available.

River Bank Erosion Control Measure Effects on Soil Physical and Chemical Properties in the Niger Delta Area of Nigeria

Abstract This paper evaluates the effectiveness of the use of synthetic fibres for river bank erosion control as it affects soil physical and chemical properties in the Niger Delta area of Nigeria. The method of investigation involves a comparison of the mean values of the soil physical and chemical properties in three different zones of the study area. Zone 1 or the controlled zone is the zone where the erosion control measure is constructed and successful. Zone 2 or the uncontrolled zone is also affected by river bank erosion but without a control measure. The third zone is a forest zone about 80 years old and located in a relatively undisturbed environment free from any erosion menace. In order to evaluate the effectiveness of the control strategy adopted in the area, an analysis of variance (ANOVA) test was used to compare the mean values of soil physical and chemical properties in the three zones. In addition, the mean values of the soil properties in zones 1 and 2 were expressed as a percentage of the forest zone equilibrium in order to assess the extent of soil depletion caused by the erosion. The ANOVA results indicate that there is a significant difference in eight out of the 11 soil properties analysed (at p ⩾ 0.05) in the three zones. In addition, the analysis also reveals that there is an improvement in the soil nutrient status as a result of the erosion control strategy adopted in the study area. For instance, all the soil nutrient properties attained over 80% of the forest equilibrium level in the areas under the erosion control measure (zone 1). By contrast, only three soil properties attained up to 50% of the forest equilibrium level in zone 2.