Sustainable environmental resource utilisation: a case study of farmers’ ethnobotanical knowledge and rural change in Bungoma district, Kenya

This paper examines farmers’ ethnobotanical knowledge, innovation and rural change, and indicates one way in which indigenous technical knowledge complementing scientific knowledge may be documented for use by development planners and agencies. This paper firstly identifies plant species recognised as resources by farmers, and considers the value of these resources. Secondly, the paper documents and assesses the ethnobotanical knowledge associated with the utilisation of plant species, before turning to examine how plant resources are defined by use and culture. It also demonstrates that some components of ethnobotanical knowledge have potential for the sustainable development of plant species. The study shows that farmers have started to domesticate some of the ‘traditional’ plants, and new crops have been introduced associated with corresponding innovations in local agricultural systems. Since the farmers have a relatively strong tradition in natural resources conservation, this study suggests that it will be possible to introduce community-based gene banks linked to formal or government facilities. The paper demonstrates that it is important to combine and interweave ‘modern’ and indigenous knowledges to produce a more realistic and sensitive understanding and management of natural environmental resources for sustainable development.     

The transfer of agricultural technology and the development of small-scale farming in rural Africa: Case studies from Ghana, Sudan, Uganda, Zambia and South Africa

In many developing countries, research institutions or centres have been established to develop and/or adapt technologies that would help agricultural development. This is particularly true in Africa where national efforts have been supplemented with international research institutes. Although some modest progress has been achieved in improving agricultural technology, on the whole, the improvement record is not quite encouraging among the small-scale farmers. In many areas, either there are no improved technologies, or where they exist, are unacceptable by farmers. However, where useful technologies exist, their spread has been very limited and where they have been adapted, the benefits only accrue to a small segment of the community. The logical question posed is: why and how do we find ourselves in the current situation? This paper considers the view that to understand fully why the available technologies have remained largely at the research centres, there is need to examine the whole process of research, development, dissemination and utilization of agricultural technology. It is significant to investigate the structural constraints and prospects under which those involved in the process work, their motivations and the interactions between different groups. The traditional ‘top-down’ of development strategy should be supplemented with farmers' indigenous knowledge, and programmes encouraging transfer of agricultural technology should include institutional support. Only by the identification of farmers' environmental and resource utilisation, preferences, socio-economic circumstances and constraints can a development programme of optimum meaning to farmers be devised and implemented with success.     

Environmental Resources, Population and Sustainability: Evidence From Zimbabwe

This paper examines four issues central to the relationships between environmental resources, population and sustainability in Zimbabwe. First, the conceptualisation of population-resource interrelationships and sustainability. Second, the legal basis of land use practices and origins of land use conflict within and between Zimbabwe's main population groups. Third, the demographic threats to sustainable resource development and the impact of the Structural Adjustment Programmes (SAPs) on rural and urban communities. Fourth, the dynamics of population change and environmental resource use constraints including resettlement and land redistribution or reform programmes. It is concluded that the relationships between environmental degradation and population pressure are complex. Sustainable environmental resource use to supply basic livelihoods can be achieved if appropriate technical expertise or backup is provided to the population. Developing and implementing sustainable resource development strategies in Zimbabwe requires attention to socio-economic and political challenges.     

Heat capacities of Tschermak substituted Fe-biotite

Six members of the annite–siderophyllite join were synthesized in a three step process – crystallization of biotite from gels, decomposition of the fine-grained biotite under oxidizing conditions and resynthesis of Fe-Al biotite with planned compositions from these products – producing biotite crystals with thicknesses of up to 10 μm. The biotite was characterized by microprobe, electron microscopy and X-ray diffraction. Heat capacities of these biotites were measured with a DSC (differential scanning calorimeter) over the temperature range 143 to 623 K. Using a least-squares technique, the data were fitted to a c_p-polynomial, c _p =k ₀+k ₁ T ^−0.5+ k ₂ T ⁻²+k ₃ T ⁻³. In the temperature range 143 to 250 K, heat capacities of the different annite–siderophyllite members decrease linearly with increasing Al content. At higher temperatures, however, the c_p-polynomial of biotites with intermediate composition (except Ann₇₉Sid₂₁) exhibit a steeper slope than those of other biotites. This produces positive excess heat capacities in the annite–siderophyllite join at higher temperatures. The activity-composition data of the same binary derived from phase equilibrium experiments (Benisek et al. 1996) and the data of this study suggest two compositional regions along this join, with different extent of deviation from ideality. One at X _Sid < 0.3, characterized by a small deviation, one at X _Sid > 0.3 showing a higher nonideality, resulting in a discontinuity visible at this composition. Powder IR-spectra of these solid solutions were measured with a FTIR-spectrometer and used to calculate heat capacities according to the vibrational model of Kieffer (1979). The comparison of the vibrational function with the c_p-polynomials shows that the vibrational function reproduces well the DSC-data of the siderophyllite-poor and -rich members, but deviates for intermediate compositions, where the excess heats of mixing occur. With increasing Tschermak vector, the tetrahedral rotation angle α increases from 0 to 13° for annite to siderophyllite, respectively. At the composition of the discontinuity, this rotation angle α reaches a value of ∼8^∘. The processing of ∼300 chemical data of natural biotites indicates that over 90% of them have a tetrahedral rotation angle that lies between 7 and 9°. It would appear that biotites with these structural characteristics are most stable. Received: 27 August 1998 / Accepted: 10 November 1998     

Heat-capacity measurements and absolute entropy of ɛ-Mg2PO4OH

The low-temperature heat capacity of -Mg₂PO₄OH was measured between 10 and 400 K by adiabatic calorimetry. No phase transition was observed over this temperature range. A relative enthalpy increment of 22,119 J mol^–1 and an absolute entropy value of 127.13±0.25 J mol^–1 K^–1 at 298.15 K are derived from the results. The low-temperature heat-capacity data are compared with the DSC data obtained from 143 K to 775 K and show marginal differences in the common temperature range. The latter data are fitted by the polynomial

Solubility of corundum in supercritical water

Isothermal (670–700°C) solubility of corundum in supercritical water, within the stability range of corundum as a phase of the system Al₂O₃-H₂O, has been determined by the weight loss method. Experiments were performed in the pressure range 2.5 to 6 kbar in cold seal hydrothermal equipment at 670 ± 5°C using gold tubing. The overall uncertainty of the solubility values obtained was 8%. Experiments in the pressure range 10 to 20 kbar were performed in a piston cylinder apparatus at 700°C using sealed gold capsules held by supporting steel containers. The overall uncertainty of the solubility values obtained was estimated to be 10%.All data could be fitted by the linear equation S_[ppmAl2O3] = ?12.37 + 7.24 · p[_kbar] with correlation coefficient r = 0.9963. Separate fits of hydrothermal and piston cylinder results yielded a small difference between the two data sets, which is due rather to the experimental uncertainty than to the small temperature difference.     

The state and peasant farmers’ leverage in Kenya

Limited capitalist development has meant that social classes in independent Sub-Saharan Africa are comparatively weak and the peasant farmers are the weakest of all. Isolated and divided, imbued with ethnic as opposed to class or broad policy consciousness, the peasant farmers may be politically unruly, but they are usually at the mercy of those in power. A by-product of peasant farmers political weakness in Africa generally is their economic exploitation by the state and dominant classes in the form of low prices for agricultural goods coupled with high prices for the manufactured products and a relatively high preference for urban over rural investment. Self-help initiative in Kenya is a politically valuable as a semi-autonomous peasant farmer-based institution oriented towards state policy. But self-help initiative is not a simple instrument of any class or the state. It is a contested terrain and embraces all the contradictions of the Kenyan political economy. Self-help has been a useful development strategy for peasant farmers. The Kenyan case study points to the need to examine what peasant farmers are doing for themselves, how they unite, form coalitions and manipulate state structures to their advantage. Finally, there are important struggles taking place quietly in the rural areas, the outcomes of which are by no means certain.     

Socio-economic factors influencing sustainable water supply in Botswana

The paper examines the socio-economic and political issues of sustainable water supply in Botswana. It pays particular attention to the actual and potential role of economic instruments. Water consumption occurs both in a market and non-market contexts (producer = consumer). Due to rapidly increasing water demand and the fact that the "easy" solutions to increase water supply have largely elapsed, Botswana is concerned with water shortages which may hamper peoples basic needs and industrial development in the future. Other sustainability concerns relate to the environment (pollution), social factors (equity and affordability) and economic considerations (cost recovery and efficiency). Prices, costs and the value of water are instrumental in striking a compromise between these goals. Trends in pricing and their relationship with costs and resource value are presented, and the impact of prices and subsidies on water demand and supply reviewed in order to assess their contribution towards a sustainable equilibrium. There is a substantial scope to improve the performance of economic instruments such as price subsidies and tax relief. The long-term marginal costs calculated in the Botswana National Water Master Plan contribute to prices approaching the costs of water production, but it excludes the environmental considerations. Resource scarcity is partly reflected where it increases the water supply costs; the indirect use and non-use values and external impacts are not incorporated in the water charges. Higher prices would increase the economic feasibility of water recycling and water harvesting and generate investment capital needed for the expansion of the water supply systems. Government subsidies may discourage efficient resource use. It is generally concluded that there is need for greater emphasis on re-use of waste water and control of the demand by harmonizing fees or tariffs between urban and rural areas as far as non-essential use is concerned; and provide more incentives for large-scale consumers to increase water use efficiency and sustainability.