BC-Department of Environmental Sciences

Permanent URI for this collection

https://repository.ku.ac.ke/handle/123456789/7902

Browse

Now showing 1 - 20 of 54

Adoption and adaptation of nutrient replenishment technologies by farmers in Kirege sub-location of Central Kenya
(African Crop Science Society, 2003) Mucheru-Muna, M.; Muriu, F.; Kung'u, J.B.; Karega, R.; Njuki, J.
Soil erosion, continuous cultivation, reduced land productivity, population pressure on land, low income, inappropriate and inadequate use of farm inputs such as fertilizers are some of the interrelated problems experienced by smallholder farmers in central Kenya highlands. These problems have been manifested in increased food insecurity in the area over the years. In an effort to address these problems research on soil nutrient replenishment technologies has been widely carried out in the area. Positive results(soil fertility improvement) have been reported from the use of tithonia, calliandra, leucaena, mucuna and crotalaria biomass. These technologies have been introduced to farmers in this area through participatory demonstration trial and on-farm trials to ensure that farmers benefit from knowledge generated through research. By the end 2003 short rains, two hundred and six (206) trained farmers had tested the soil nutrient replenishment technologies. A research was conducted to establish the criteria used by trained farmers of varying age and gender in their decision to adopt soil nutrient replenishment technologies. The study found out that farmers had adopted and adapted the soil replenishment technologies that were initially introduced to them. Use of calliandra and leucaena asincorporation materials had increased by 11% from the testing stage while 16% of the farmers preferred using the two tree species asfodder supplements. Preference of using calliandra had increased from 7% at the testing stage to 17%. Increased crop yield and otherfarmers’ experiences on improved soil fertility significantly influenced the farmers’ overall rating of the soil nutrient replenishmenttechnologies
The African Network for Soil Biology and Fertility: New Challenges and Opportunities
(Academy Science Publishers, 2004) Mugendi, D.N.; Bationo, A.; Kimetu, J.; Ikerra, S.; Kimani, S.; Odendo, M.; Silver, M.; Swift, M.J.; Sanginga, N.
Soil fertility degradation has been described as the single most important constraint to food security in sub-Saharan Africa (SSA). Soil fertility decline is not just a problem of nutrient deficiency but also of 1)Inappropriate germplasm and cropping system design. 2) Interactions with pests and diseases. 3) The linkage between poverty and land degradation. 4) Often perverse national and global policies with respect to incentives, and 5) Institutional failures. Tackling soil fertility issues thus requires a long-term perspective and a holistic approach. The African Network for Soil Biology and Fertility (AfNet)of Tropical Soil Biology and Fertility institute of CIATwhose ultimate goal is to strengthen and sustain stakeholder capacity to generate, share and apply soil fertility management knowledge and skills to contribute to the welfare of farming communities is devoted to overcoming this challenge. This African-wide network has over 200 members from National Agricultural Research and Extension Services (NARES) and universities from vanous disciplines mainly soil science. social science and technology exchange. This paper is an highlight of AfNet's main activities which include: Network field research activities. information and documentation. training and capacity building.
Agroforestry for Land and Water Management in Kenya
(School of Environmental Studies and Human Sciences, Kenyatta University, 2007) Mugendi, D.N.; Waswa, B.; Mucheru-Muna, M.; Mugwe, J. N.
A groforestry is an age-old practice that contains a strong element of r\management. It is a collective name for land-use systems and technol . where woody perennials are deliberately used on the same land-management u as agricultural crops and/or animals. This can either be in a spatial arrange or in rotation, with economic and ecological interactions between the trees crops. In a review by Franzel (2002), agroforestry is defined by Leaky (1996)as dynamic, ecologically based, natural resource management system that sus ' and diversifies production for improved economic, social and environme benefits for farmers, through the integration of trees in the agricultural landsc Trees in this system provide fuel wood, fodder, fruit (productive functions) as as fencing and shade (service functions). A strict scientific definition of agrofore should stress two characteristics common to all forms of agroforestry and sepa .from other forms of land use, i.e., Deliberate growing of woody perennials in the same unit of land as agricult crops and/or animals There must be significant interaction (+ve or -ve) between the woody and non-woody component (either ecological or economical)
Application of Ecosystem Modelling in Environmental Management in Kenya
(School of Environmental Studies and Human Sciences, Kenyatta University, 2006) Olukoye, Godfrey Alati
Ecosystems are dynamic entities made up of several interactive biotic and abiotic factors that determine their production and productivity levels. Equally complex are the ecological processes that govern ecosystem structure and function, the inherent variability in biophysical processes and the interactions between ecological, economic and social processes. Models that seek to guide policy decisions need to capture this complexity. Equally important, managers should give due consideration to the prevailing economic, socio-cultural, legal and political factors that may be relevant when making appropriate management decisions. Although the management of ecosystems is difficult, various models have been developed that aid in decision making for sustainable ecosystem management. For example, conceptual models that incorporate the interactions of climate, plants and herbivory are important in understanding land use dynamics. Further, establishing a balance in ecological and economic functioning of resources such as vegetation in an ecosystem is difficult but ecosystem models have the capability to simulate such complex scenarios to arrive at appropriate resource management. Simulations help in the diagnosis of strengths and weaknesses of an ecosystem and compare it with other alternatives so that improvements may be prescribed (Upton, 1989). Despite this advantage, simulations and their use in resource management especially in developing countries is rare
Assessment of farmers' perceptions of soil quality indicators within smallholder farms in the central highlands of Kenya
(Springer, 2007) Mairura, F.S.; Mugendi, D.N.; Mwanje, J. I.; Ramisch, J. J.; Mbugua, P. K.
A study was conducted to determine farmers' perceptions of soil quality and soil management practices that influenced soil fertility within farmers' fields in Chuka and Gachoka divisions in central Kenya highlands. Soils were characterized by farmers after which they were geo-referenced and sampled at surface depth (0-20 ern) for subsequent physical and chemical analyses, to determine differences within farmers' soil quality categories. Special attention was given to agricultural weed species. Indicators for distinguishing productive and non-productive fields included crop yield, crop performance, soil colour and soil texture. A total of 18 weed species were used to distinguish between high and low soil categories. Significant differences among soil fertility categories implied that there were qualitative difference in the soils that were chacterised as different by farmers. Fertile soils had significantly higher pH, total organic carbon and exchangeable cations, with available-N being significantly different in Gachoka. Factor analysis on 15 soil properties identified 4 factors that explained 65% of the total variance in soil quality. Soil fertility and crop management practices that were investigated indicated that farmers understood and consequently utilized spatial heterogeneity and temporal variability in soil quality status within their farms as a resource to maintain or enhance agricultural productivity.
Assessment of Occupational Safety Concerns in Pesticide Use Among Small-Scale Farmers in Sagana, Central Highlands, Kenya
(Springer, 2011) Mureithi, P.; Waswa, F.; Kituyi, E.
Small-scale farmers in Sagana area of central Kenya constitute a population at risk due to intensive use of pesticides in the production of mainly horticultural crops for commercial purposes. This chapter examines the main causes of pesticide hazards and risks, barriers to taking risk reduction measures and cues to adopting safety behaviour when dealing with pesticides. Data were collected by the use of interviews conducted in 2006/2007 from a sample of 140 farmers. Perception scales were developed from interview items and were ranked along a modified three-point Likert scale. Analysis of the items and scales showed that farmers had fairly high levels of perceived risk, perceived severity and perceived benefits of taking action to mitigate pesticide hazards. Results from this study showed that farmers are still susceptible to pesticide-related dangers notably due to resignation to fate, perceived high cost of purchasing protective gear and lack of adequate training in the use and handling of pesticides. Further, contrary to conventional thinking, farmers' education had limited positive effect to safety behaviour when handling pesticides. The challenge to policy and practice towards safe use of pesticides lies in issues of farmers' economic survivability, perceptions and attitudes, along the whole chain from pesticide procurement, storage, farm application and disposal.
Available technologies to replenish soil fertility in East Africa
(Springer Netherlands, 2007) Mugendi, D.N.; Okalebo, J. R.; Othieno, C. O.; Woomer, P. L.; Karanja, N. K.; Semoka, J.R.M.; Bekunda, M. A.; Muasya, R. M.; Bationo, A.; Mukhwana, E. J.
Low inherent soil fertility in the highly weathered and leached soils largely accounts for low and unsustained crop yields in most African countries. But in particular, the major nutrients, nitrogen (N) and phosphorus (P), are commonly deficient in these soils. This scenario of nutrient depletion is reflected in food deficits and hence the food aid received continuously, specifically in sub-Saharan Africa. Undoubtedly, substantial efforts have been made in the continent to replenish the fertility of degraded soils in attempts to raise crop yields, towards self-sufficiency and export. Such efforts consist of applications of both organic and inorganic resources to improve the nutrient status of soils and enhanced nutrient uptake by crops, provided that soil moisture is adequate. Overall, positive crop responses to these materials have been obtained. Thus in the East African region, maize (staple) yields have been raised in one growing season from below 0.5 t/ha without nutrient inputs, to 3–5 t/ha from various nutrient amendments at the smallhold farm level. However, in spite of the positive crop responses to nutrient inputs, farmers are generally slow to adopt the soil fertility management technologies. In this paper we review the impact of some technologies, focussing the use of nutrient resources of different characteristics (qualities) in relation to improved crop yields, with an overall goal to enhance technology adoption. Thus, inorganic resources or fertilizers often give immediate crop responses, but their use or adoption is rather restricted to large-scale farmers who can afford to buy these materials. Organic resources, which include crop residues, water hyacinth and agroforestry shrubs and trees, are widely distributed, but they are generally of low quality, reflecting the need to apply large quantities to meet crop nutrient demands. Moreover, most organics will add N mainly to soils. On the other hand, phosphate rocks of varying reactivity are found widely in Africa and are refined elsewhere to supply soluble P sources. The recently developed soil fertility management options in East Africa have targeted the efficient use of N and P by crops and the integrated nutrient management approach. Some people have also felt that the repackaging of inputs in small, affordable quantities, such as the PREP-PAC described in this paper, may be an avenue to attract smallhold farmers to use nutrient inputs. Nonetheless, crop responses to nutrient inputs vary widely within and across agroecozones (AEZs), suggesting specificity in recommendations. We highlight this observation in a case study whereby eight soil fertility management options, developed independently, are being tested side- by-side at on-farm level. Farmers will be empowered to identify technologies from their own choices that are agronomically effective and economically friendly. This approach of technology testing and subsequent adoption is
Bioproduction Systems and their Environmental Implications
(School of Environmental Studies and Human Sciences, Kenyatta University, 2006) Shitanda, D.
Bioproduction is a new term that has been coined to refer mainly to the agricultural processing and animal/ fish production systems of the agricultural industry. These two sectors are very critical for many African countries, which depend heavily on agriculture for their daily livelihood and foreign exchange earnings. Although Africa has few agro-based industries, the rapid growth in population places a high demand on the same. This in turn brings in the aspect of environmental degradation, through the potentially high levels of waste production. For purposes of this book, a waste is any material discarded by society because it has fulfilled its useful purpose and is no longer wanted or cannot be utilized. It is a superfluous material with little or no worth that results from production processes. As such, a waste is a pollutant. Someof the main agro-based industries in the Eastern region of Africa that have significant effect on the environment include the coffee, tea, sugar, lumber, paper, sisal,and tanning industry. However, it is also common to see much agricultural produce especially fruit go to waste in many agro-ecosystems in different parts of Africa. Mangoes, paw paws, bananas, cabbages, milk, cassava and potatoes fall in this category. Processing of such produce is likely to emerge as a perfect initiative towards food security and job creation in rural areas. This will in no doubt be accompanied with increasing volumes of wastes and hence higher risks of environmental degradation. Africa has the highest number of animals especially cattle and goats. Animal production is done mainly using the traditional systems where the animals are fed in open fields with minimal control and consideration of the environment. However, as land continues to become scarce, the need for more intensive animal production systems is unavoidable. Already most peri-urban residences are characterised by zero-grazing units in cities like Nairobi, Kampala and Oar salaam. Such intensive modern systems optimise production but their impact on the environment is enormous due to high concentration of wastes, use of chemicals and modern equipments. The aim of this chapter is therefore to highlight some of the critical concerns within the bioproduction industry that correlate highly with the environmental issues in the East African region
Changes in Soil Organic Matter as Influenced by Organic Residue Management Regimes in Selected Experiments in Kenya
(Springer Netherlands, 2007) Waswa, B. S.; Mugendi, D.N.; Vanlauwe, B.; Kung'u, J.B.
The failure to understand the dynamics of soil organic matter (SOM) is a major limitation to the sustainability of smallholder production systems that predominantly relied on organic resources for the maintenance of soil fertility. This study evaluated the influence of organic resource management on SOM in three selected experiments in central and western highlands of Kenya. Results showed that soil carbon (C), nitrogen (N) and carbon-13 (13C) values in the three experiments were depending on the amounts of the organic residues applied as well as the duration of application indicating that organic residue management practices have a profound impact on the final contribution to the SOM pools. Kabete experiment had the narrowest C, N and 13C values pointing to its young age as well as the low quantity of the organic residues applied. On the other hand, Embu experiment had soil C values above the critical level of 2.0% indicating a positive effect of continued application of organic residues. In all the three sites, aggregate mineral fraction (MF) size distribution were dominated by macroaggregates (250–500μm and >500 μm) which on average accounted for about 72%, 65% and 69% of the dry soil weight for Maseno, Kabete and Embu experiments, respectively. Similarly higher proportions of aggregate light fractions (LF) C and N were observed in macroaggregate fractions for the three experiments with organic treatments having higher proportions. The 13C signatures of the LF in the macroaggregates (>250 μm) were more negative as compared to the 13C values in the microaggregate (53–250 μm) LF suggesting a more C contribution from C3 vegetation to the most recently incorporated SOM pool
Climate Change and Crop Yield in Sub-Saharan Africa
(Springer International Publishing, 2015) Baaru, M. W.; Gachene, Charles K. K.; Karuma, Anne N.
Recent scientific evidence shows that crop yields in many Sub Saharan Africa (SSA) countries are likely to be severely affected by climate change. Reliance on rainfall in this region increases the vulnerability of cereal systems to climate change and variability. In large parts of SSA, maize (Zea mays L.) is the principal staple crop, covering a total of nearly 27 M ha, and yet maize yields remain the lowest in the world, stagnated at less than 2 Mg ha−1. Calculated and simulated analyses for SSA show that crop yields will decline by more than 10 % by 2055. The effect of climate change on crop yields is mainly attributed to: increased frequency of extreme events; effects of elevated CO2(where studies project crop yield increases of 5–20 % at 550 ppm CO2); interactions of elevated CO2 with temperature and rainfall as well as with soil nutrients; and increased vulnerability to weed competition, insect pests, and diseases. However, several studies show that rainfall and water availability limit agricultural production more than temperature in SSA. The projected rainfall would increase by 2–4 % in Eastern Africa, but decrease by 5 % in Southern Africa during the main crop growing seasons. Temperatures are likely to increase throughout SSA by 2050, but the combination of increasing temperatures and low seasonal rainfall in Southern Africa suggest this region will be particularly vulnerable. Some of the crop models used for predicting the effect of climate change on yields are limited by their ability to predict effects of climatic events that lie outside the range of present-day variability. In addition, comparisons between models for the same setting have sometimes given differing results. This review paper shows that, for most of the SSA countries, the data required for assessing long-term effect of climate change on crop yield are lacking, that most of the models do not cater to assessment at the household level, and that no single approach can be considered as adequate. Therefore, a clear need exists for collaboration among different scientific disciplines for the development of agriculture in SSA in a changing climate.
Communication Channels Used in Dissemination of Soil Fertility Management Practices in the Central Highlands of Kenya
(Routledge, 2013) Mucheru-Muna, M.; Kimaru-Muchai, S. W.; Mugwe, J. N.; Mugendi, D.N.
Developing Agroforestry Curricula: A practical Guide for Academic Institutions in Africa and Asia
(World Agroforestry Centre, 2005) Rudebjer, P. G.; Temu, A. B.; Kung'u, J.B.
We promote the view that agroforestry is not only a set of practices, but also about the processes in society that influence, and are influenced by, those practices. Recent advances in participatory approaches are heavily influencing rural development paradigms and, in consequence, must also influence agroforestry teaching. By seeking the participation of farmers and other stakeholders, institutions are able to develop and deliver more relevant education programmes. We endorse and recommend the participatory approach here. Institutions use the terms 'subject', 'module' and 'course' interchangeably to describe the components of an education programme. For the purpose of clarity, we consistently use the term 'subject' in this guide. The term 'curriculum' is here used to describe all the teaching and learning content and processes that lead to a desired competence in learners. Thus we interpret 'curriculum' as a much wider concept than merely course subject matter. While agroforestry is taught in tropical, subtropical and temperate regions, this guide primarily targets users in developing countries, particularly those in Africa and Asia. However, institutions in other regions may also find it useful. The guide is organized into five Chapters. In Chapter 1, our introduction briefly looks back at agroforestry innovations over the past 25 years, and discusses different concepts o£ agroforestry and multifunctional landscape mosaics. We then look at the different scales of agroforestry research and development. Global experiences in agroforestry education are summarized in Chapter 2. After an overview of the history of agroforestry education, we discuss the diverse teaching approaches employed at different technical and professional levels. We then point out some of the common shortcomings of existing curricula. Finally, we briefly explore how the job market for agroforestry graduates has developed. Chapter 3 presents some commonly used methods for curriculum development. The participatory method is then discussed in some detail, because experience suggests that the participation of farmers, employers and other stakeholders helps create more relevant and applicable curricula. Agroforestry curriculum development is then discussed in Chapter 4. Based on the various processes available, we suggest a set of seven requirements for the planning and implementation of a curriculum development project. Methodologies for a simple training needs analysis and a stakeholder analysis are also provided. In Chapter 5, we present a framework for agroforestry curricula. This is intended to guide the content development within an agroforestry education programme, subject or topic. At the centre of the framework are farmers' decisions related to the agroforestry production cycle: overall management, the products and services produced, and the use and marketing of these outputs. We present a model of how these decisions are influenced by biophysical and socioeconomic conditions, and how agroforestry practices may impact on people and landscapes. We also discuss risks and potential challenges, and how policies and governance relate to agroforestry. Finally, we offer some additional resources. Firstly, we present Internet resources related to agroforestry, natural resources management and education. Secondly, Annex 1 presents a quick reference summary of the complete agroforestry curriculum framework.
Dissemination of Integrated Soil Fertility Management Technologies Using Participatory Approaches in the Central Highlands of Kenya
(Springer Netherlands, 2011) Mugendi, D.N.; Mugwe, J. N.; Mucheru-Muna, M.; Karega, R.; Muriuki, J.; Vanlauwe, B.; Merckx, R.
Declining soil fertility and productivity is a critical problem facing smallholder farmers in the central highlands of Kenya. A study to improve soil fertility and farm productivity within the smallholder farming systems in the area was carried out from 2003 to 2006. The specific objectives were to identify farming system constraints, evaluate and disseminate potential integrated soil fertility management (ISFM) interventions using participatory approaches, assess achievements and impacts, and document learning experiences emanating from the methodologies used. The participatory approaches used were Participatory Rural Appraisal (PRA), mother–baby approach (with emphasis on demonstration), farmer groups, stakeholders planning meetings, village training workshops, cross-site visits and participatory monitoring and evaluation. The core problems identified were low crop and fodder yields that were caused by erratic rainfall, soil erosion, low soil fertility and small land sizes. There was high participation of farmers in all the partnership activities, and this possibly contributed to the high uptake of the technologies for testing by farmers whereby after only 2 years a total of 970 households were testing the new technologies. Maize yields at the farm level increased by more than 150% following use of the new ISFM interventions and about half of the farmers within the groups planted close to 500 trees propagated in the group nurseries. We recommend that pathways to reach more farmers should concentrate on demonstrations, farmer training grounds, field days and farmer groups and that a policy framework should be put in place to impart appropriate skills in ISFM to the extension workers.
Economic Environmental Valuation
(School of Environmental Studies and Human Sciences, Kenyatta University, 2007) Wawire, N. H. W.; Thuo, A.D.M.
This chapter attempts to place a monetary value on environmental resources describing various methods of valuing an environmental resource with respect to costs and benefits. This is because externalities do arise from production and consumption of goods and services that are not accounted for in a competitive market due to market failure (Stiglitz, 1988; Hyman, 1996 and Kolstad, 2000). Marketsfail if prices do not communicate the society's needs and constraints accurately, thereby understating the services provided by an environmental resource. In the worst scenario, prices do not exist to send a signal about the value ofa resource within the environment.
Effect of Organic Inputs and Mineral Fertilizer on Maize Yield in a Ferralsol and a Nitisol Soil in Central Kenya
(Springer Netherlands, 2011) Mucheru-Muna, M.; Mugendi, D.N.; Pypers, P.; Mugwe, J. N.; Vanlauwe, B.; Merckx, R.; Kung'u, J.B.
Declining land productivity is a major problem facing smallholder farmers in Kenya today. This decline primarily results from a reduction in soil fertility caused by continuous cultivation without adequate addition of external nutrient inputs. Improved fertility management combining organic and mineral fertilizer inputs can enable efficient use of the inputs applied and increase overall system’s productivity. Field trials were established at three sites in distinct agro-ecological zones of central Kenya (one site at Machang’a and two sites at Mucwa with different soil fertility status) aiming to determine the effects of various organic sources (tithonia, lantana, mucuna, calliandra and manure) and combinations with mineral N fertilizer on maize grain yield during four consecutive seasons. In Machang’a site, sole manure recorded the highest maize grain yield across the four seasons. In Mucwa poor site, sole tithonia gave the highest maize grain yield during the four seasons, while in Mucwa good site, sole calliandra gave the highest maize grain yields. Generally, the maize grain yields were lower in the treatments with fertilizer alone compared to the treatments with organics across the three sites in the four seasons due to the poorly distributed rainfall. In Machang’a during the SR 2004 and SR 2005 seasons, the treatments with integration of organic and mineral fertilizer inputs were significantly higher than treatment with the sole organics; however, in Mucwa good and poor sites, generally the treatments with sole organics did better than the ones with integration of mineral N fertilizer and organics with the exception of the mucuna treatment which did significantly better in the integration compared to the sole application.
Energy for Sustainable Development
(School of Environmental Studies and Human Sciences, Kenyatta University, 2006) Kirubi, C.
The concept of sustainable development refers to development that 'meets the needs of the present without compromising the ability of future generations to meet their own needs' (WCED, 1987). This has social, economic and environmental dimensions. The way energy is produced and used plays an essential role in all the three dimensions. Current primary energy sources are shown in Figure 3.1. The energy system today is heavily dependent on the use of fossil fuels (coal, oil and gas), which together account for 80%of global primary energy consumption (Johansson and Goldemerg, 2002). It is clear that countries differ significantly in the structure of their energy consumption (Figures 3.2-3.4). Fossil fuel consumption accounts for 83%of the energy consumed in industrialized countries and 93% in the transition-economy countries, but only 70%in developing countries. In contrast biomass represents only 3.4% of primary energy used in industrialized countries, is virtually non-existent in countries in transition, and accounts for 26% of energy used in developing countries. Nuclear energy is also significant in industrialized countries (where it is the source of 11% of primary energy) and countries in transition (5%), but makes only a minor contribution in developing countries (1%). The figures also highlight the extreme inequalities in per capita use among groups of countries. Industrialized countries use 4.7 tons of oil equivalent (toe) per capita, in contrast to developing countries, which use only 0.78% toe per capita; the world average is 1.6 toe per capita.
Environment and Sustainable Development A Guide for Higher Education in Kenya
(School of Environmental Studies and Human Sciences, Kenyatta University, 2007) Makokha, K.; Muthiane, N.
Over the last five decades the world has witnessed a number of significant and unprecedented environmental problems on scales not witnessed before, such as environmental deqradation and pollution, loss of biodiversity, 'global warming and climate. Emerging environmental problems like HIV/AIDS poverty, and invasive species (for example water weeds in inland water bodies) pose a real challenge to economic development and sustainable living in poor countries. The most disturbing fact about environmental problems is that they are mainly human-caused. These problems are exemplified by increased pollution in all forms, wanton destruction of forests, depletion of the ozone layer, global warming, disposal of toxic wastes and garbage, extinction of numerous species of both flora and fauna, among others. These problems are attributed to many causes, such as technology, poverty, poor governance, and civil wars among others. Whatever the specific cause, these problems herein collectively referred to as 'environmental crisis' are intricately connected and have implications of up to global proportions on development.
Environment and Sustainable Development Nexus
(School of Environmental Studies and Human Sciences, Kenyatta University, 2006) Waswa, F.; Otor, S.C.J.; Mugendi, D.N.
To appreciate the link between the environment and sustainable development, one needs to understand the basic concepts within ecology. While numerous literatures exists on this subject, ecology generally refers to the scientific study of the inter-relationships between living things and their biotic and abiotic environment, which determines the distribution and abundance of organisms in an environment (Krebs, 1985). On the other hand, the environment according to Kenya's Environmental Management and Coordination Act (EMCA) 1999 includes the physical factors of the surroundings of human beings including land, water, atmosphere, climate, sound, odour, taste, the biological factors of animals and plants, and the social factor of aesthetics, and includes both the natural and the built environment. In essence the environment may be viewed as the totality of nature and its components. Current thinking no longer views ecology as a subdivision of biology, but acknowledges that it has emerged from its roots in biology to become a separate discipline that integrates organisms, the physical environment, and humans on the premise that everything on earth operates in cycles, and all life is connected (Odum, 1996). Various specializations in ecology have emerged and will continue to emerge as humans continue to discover new areas in the environment for utilization. As an emerging specialisation, and based on the role of humans as the greatest force in shaping and being shaped by the environment, human ecology is the study of humans as they relate to the environment. It includes the study of the impact of humans on the environment and vice versa, as a basis for informed and accountable decision-making about resource use and development towards sustainable societies. Prior to the development of ecological thinking, science had been reductionist and concerned with compartmentalizing things in order to understand them. To the contrary, ecology is holistic and requires a study of the whole, which is often more than the sum of the parts. Ecology thus involves many branches of science and must inevitably adopt an interdisciplinary and integrated approach, which in essence simulates diversity and the inter-dependence of nature and its components. It is on this basis that mainstreaming sustainability thinking in education has gained momentum within the international community (UNEP, 2006).
Environmental Philosophy, Education and Sustainable Development Nexus
(School of Environmental Studies and Human Sciences, Kenyatta University, 2007) Ndaruga, Ayub Macharia; Kerich, Richard
Since the United Nations Conference on Human Environment, of 1972, governments have made it a policy to integrate sustainable development concerns in national agenda at all levels. The universities globally have responded by creating diverse courses focusing on various aspects of sustainable development using both multidisciplinary and interdisciplinary approaches. The education for sustainable develop mentis a relatively recent concept and not all educators and programmes. have embraced it adequately. It is however important to note that all courses have the potential to address sustainable development issues. It is therefore crucialthat all learning institutions make deliberate efforts to mainstream education forsustainable development in all their activities. The international community has made tremendous efforts to address emergent environmental challenges. Conferences held by experts and governments have called for greater innovations and investment of more resources in sustainable development activities and education. Conferences such as Stockholm, Belgrade, Tbilisi,Rio and the recent Johannesburg Summit represent deliberate and focused advances to address global environmental crises. Following the diverse deliberations and recommendations from various conferences, the decade between 2005-2014 has been identified as the United Nations Decade of Education for Sustainable Development (DESD). This decade is dedicated to recognition of the valuable role of education in developing sustainable societies. The decade is intended to champion the re-orientation of all education toward sustainable development. This impliesthat sustainability thinking be streamlined in all activities and at all levels of decision-making in learning institutions.
Evaluation of the Potential of using Nitrogen Fixing Legumes in Smallholder Farms of Meru South District, Kenya
(Springer, 2007) Mugwe, J.; Mugendi, D.N.; Odee, D.; Otieno, J.
Soil fertility depletion in sub-Saharan Africa is a big constraint to increased food production to feed the ever-growing human population. Use of legumes to improve soil fertility is an option in the central highlands of Kenya and this study evaluated soil characteristics on farms and screened effectiveness of five rhizobia strains on four legumes. Soilssampled from 31 farms showed that the soils were generally acidic with more than 50% of the farms having pH inthe range of extremely acidic and strongly acidic (pH < 5.0). Organic carbon was low «2%) on most farms and total nitrogen was deficient with more than 80% having <0.2% N while P ranged from 1.3 to 15.8 ppm with more than70% of the farms being critically deficient in P. Nodulation on Mucuna pruriens and Crotalaria ochroleuca was observed to be variable within farms with individual farms having fewer nodules per plant than on-farm researcher managed trial. Consequently trials to evaluate effectiveness of rhizobia strains were conducted under glass house conditions. Results showed that KWN35 and TAL 1145 were highly effective on C. calothyrsus and L. trichandra and not on C. ochroleuca. Crotalaria ochroleuca nodulated effectively only with CP354 and NGR457. The NGR 457was highly effective on all the legume plants while NGR185 was only effective on L. trichandra. These studies showed that performance of legumes among the smallholder farms was likely to vary due to varying soil characteristics and that them could be potential for improving legume performance within the smallholder farms through inoculation.

Browse

Browsing BC-Department of Environmental Sciences by Title

Results Per Page

Sort Options