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Kenyatta University Institutional Repository is a digital archive that collects, preserves and disseminates scholarly outputs of the Institution
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Maize Yield Responses to Soil Organic Carbon under Integrated Soil Fertility Management in Tropical Environments
(Agronomy for Sustainable Development, 2025-10) Laub, Moritz; Corbeels, Marc; MacLaren, Chloe; Ndungu, Samuel Mathu; Mucheru‑Muna, Monicah Wanjiku; Mugendi, Daniel; Vanlauwe, Bernard; Waswa, Wycliffe; Yegon, Rebecca; Six, Johan
To ensure the sustainable management of tropical cropping systems, tracking changes in soil fertility and distinguishing long-term crop yield trends from season-to-season fluctuations are essential. However, a scarcity of long-term datasets for tropical systems has left a gap in understanding how soil organic carbon (SOC, used as a proxy for soil fertility) and yield co-evolve in these systems. Here, we present a unique analysis of maize yield and SOC trends in four long-term experiments in Kenya, conducted under contrasting pedo-climatic conditions. Experimental treatments consisted of yearly applications of organic resources with different C:N ratios (12 to 200) at two quantities (1.2 and 4 t C ha-1 yr-1), with and without mineral nitrogen fertilizer (240 kg ha-1 yr-1). At sites with adequate rainfall (475-600 mm in-season rainfall), long-term maintenance of maize yields and SOC were strongly correlated. Specifically, 74% of the variation in long-term yield trends across sites was explained by the interaction between site and the trend in SOC, increasing to 84% when adding the interaction with the mineral nitrogen fertilizer treatment. In contrast, no significant correlation between yield and SOC trends existed at the driest site (300 mm in-season rainfall). Differences in the strength of the SOC-yield relationships between treatments with and without mineral N fertilizer were significant at only one of the four sites. In addition, seasonal maize yield variability at three of the four sites was strongly influenced by seasonal mean temperature and total rainfall, overriding the effect of site fertility and SOC in any given season. However, the strength of climate effects varied between sites. We conclude that maintaining SOC is important for sustaining maize yields, but this potential can only be fully realized under favorable climatic conditions, particularly sufficient rainfall.
Effect of Teacher Support on Students' Discipline in Public Secondary School in Tharaka-Nithi County
(EdinBurg Peer-Reviewed Journals and Books Publishers, 2025-12) Wachira, Isaac Kiiru; Muchanje, Peter Nyaga; Ndiritu, John
Student indiscipline remains a persistent challenge in many public secondary schools in
Tharaka-Nithi County, undermining academic progress, disrupting learning environments, and
increasing the financial burden associated with repairing damaged school property. While
multiple factors contribute to student behaviour, teacher support has increasingly been
recognized as a critical determinant of learners’ discipline and overall school adjustment. This
study examined the effect of teacher support on students’ discipline in public secondary schools
in Tharaka-Nithi County. Guided by Invitational Theory, which emphasizes the role of
supportive interpersonal relationships in shaping positive student outcomes, the study adopted
a convergent parallel mixed-methods design. The target population comprised students,
teachers, and principals from public secondary schools in the county, from which a sample was
selected using stratified, systematic, and purposive sampling techniques. Data were collected
using questionnaires for students and teachers and interview schedules for principals. The
reliability coefficients for student and teacher questionnaires were 0.831 and 0.731,
respectively, indicating high internal consistency. Quantitative data were analyzed using
descriptive statistics and simple linear regression, while qualitative data were analyzed
thematically. The findings revealed that teacher support had a statistically significant effect on
students’ discipline, indicating that learners who perceive their teachers as caring,
approachable, fair, and academically supportive are more likely to exhibit positive behaviour
and comply with school rules. The study concludes that strengthened teacher–student
relationships play a vital role in fostering disciplined learning environments. It recommends
that schools invest in teacher mentorship programmes, continuous professional development
on positive discipline strategies, and policies that promote supportive and empathetic teacher–
student interactions to enhance discipline in public secondary schools
Transformative Education for the 21st Century: Gender, equity and inclusion in Kenya
(Kenyatta University, 2021-02) Wabwire, Daniel
The Kenyan Government, is a key stakeholder in the education sector, and has the obligation to engage different
actors in ensuring that the gender parity discourse in education translates into praxis. Any gender related
programme, which fails to address a girl child right to education as priority problem area, cannot drive the
transformative education agenda for women. This right is not only a gender issue, but also an equality, equity
and inclusive issue. In order for education in Kenya to be progressively transformative and able to face 21st
century, theory and research methodology are critical. This paper argues that: i) though every child has the right
to education, the most left behind has been the girl child, due to a failed African philosophic educational
discourse, owing to a number of factors; ii) transformative educational discourse must deconstruct the ontology
of the girl - child beyond theoretical and methodological limitations; iii) the philosophical and anthropological
grounding of law, rights(equality) and justice(equity) can be demonstrated from a Thomistic perspective; iv)
Girl-child right to education and the 21st century transformative discourse: equality, equity and inclusion
A Comparative Evaluation of Antibacterial Activity of Metallic Nanoparticle Formulations Synthesized Using a Poly(amic) Acid
(sage journal, 2025-11-06) Obumba, Maxwell; Naumih Noah; Nawiri,Mildred
Water is considered one of the most abundant natural resources, covering the largest proportion of the Earth’s total surface. The availability of clean and safe water for domestic use, however, remains the most important scientific and technological challenge facing humanity presently. Disposal of human organic waste containing large volumes of deadly microbes, including Streptococcus aureus and Escherichia coli, has been cited as the major cause of water pollution and contamination. The increasing prevalence of these antibiotic-resistant pathogens in major water sources presents a critical challenge to public and environmental sustainability. Addressing this challenge calls for the development of novel, effective antimicrobial agents. This study reports the effect of synthesis temperature on the particle size and dispersion, which in turn influence the antimicrobial activity of silver (Ag), gold (Au), and bimetallic silver/gold (Ag/Au) nanoparticles synthesized and stabilized with a biodegradable poly(amic) acid PAA-polymer against S. aureus and E. coli. The synthesis of the different nanoparticle formulations was carried out in two different sets of temperatures: ambient (25 °C) and elevated temperatures (70 °C). The elevated temperature was kept at 70 °C to minimize imidization of PAA to polyimides, a process which occurs at temperatures above 100 °C. This ensured that the stability and structural integrity of PAA were preserved throughout the synthesis process. Nanoparticles synthesized at both ambient and elevated temperatures were characterized by cyclic voltammetry, ultraviolet–visible spectroscopy, and transmission electron microscopy. The results revealed spherical particles sized between 25 and 58 nm, with elevated temperatures yielding smaller, more uniformly dispersed nanoparticles. Elevated temperatures exhibited enhanced antibacterial activity against E. coli and S. aureus using disk diffusion assays. A higher antimicrobial activity exhibited by the bimetallic Ag/Au nanoparticles synthesized at elevated temperatures (Ag/Au NPs-HT) showed superior inhibition zone against E. coli (27.67 ± 1.53 mm) and S. aureus (23.67 ± 0.58 mm), outperforming their counterparts synthesized at ambient temperature (p = 0.0088; for E. coli) and all monometallic nanoparticles (p < 0.0001 for both S. aureus and E. coli). Statistically, Ag/Au NPs-HT exhibited a stronger antimicrobial activity as compared to Vancomycin, a commercial clinical antibiotic against both S. aureus (p < 0.0007) and E. coli (p < 0.0007). These findings highlight a synergistic effect when combining silver and gold and underscore synthesis temperatures as a crucial factor in optimizing the antimicrobial performance of Nobel metal nanoparticles, with potential application in environmentally sustainable and cost-effective water purification systems.
Fiscal Devolution And Technical Efficiency Of County Governments In Kenya
(IOSR-JEF, 2026-01-07) Nyaoko, John Mose; Njaramba, Stephen Githae; Korir, Julius
Several fiscal decentralization and revenue independence programmes have been instituted since independence in Kenya in order to attain technical efficiency in the delivery of public goods and services. Notably, the enactment of the Constitution 2010 ushered in fiscal devolution as the main driver of economic growth through technical efficiency in delivering public goods and services. Technical efficiency is to be attained through reduction in costs associated with allocations and rent-seeking activities as they focus on transparency and allocative efficiency. A smaller and productive government is believed to enhance technical efficiency by reducing wastage of expenditure and raising income growth. However, being responsible for a larger fiscal capacity can offer both challenges and opportunities for local governments in developing countries. As the devolved funds increase to the counties in Kenya, it is expected that technical efficiency would also increase in the county public service provision as more inputs would be available in relatively small size government. Despite the fact that the allocations to counties have been increasing and increased independence through tax assignments, there seems to be no evidence of improved technical efficiency as there has been no significant improvement in provision of goods and services for devolved functions including health and agriculture. There has also been a decline in the county growth domestic product over the years. Additionally, revenue collections at the counties have remained low and declining, despite higher targets that are set by the county governments. The main objective of the study was to measure the technical efficiencies in the counties. Specifically, the study estimated technical efficiency index for the 47 county governments. The model used in the analysis was a Cobb Douglas Stochastic Frontier Analysis to compute the mean technical efficiency. The average technical efficiency across counties is 84 percent, implying an average of 16 percent technical inefficiency. Technical efficiency varies significantly across counties operating between 50 and 90 percent technical efficiency. Based on these findings, the study recommends that counties should optimize resource utilization to close the 16 percent efficiency gap.