Journal Articles

Socio-Economic Factors Influencing Solid Waste Management in Urban Centres of Nandi County

Wed, 01 Jan 2025 00:00:00 GMT

Socio-Economic Factors Influencing Solid Waste Management in Urban Centres of Nandi County Meli, James; Sumukwo, Joel; Lagat, Kiplimo Rapid population growth, urbanization, industrialization and economic development have resulted in the generation of big volumes of solid waste in Nandi County. Yet solid waste is an economic commodity that may not be optimally allocated through the market mechanism. Most attempts to solve waste problems in Kenya focus on supply-side of waste disposal and collection, which have not been successful. This study examines the following objectives: Assess the effects of education, age, and gender on management of solid waste; evaluate how household incomes influence SWM in Nandi County; examine various policy options in management of urban solid waste in Nandi County. This study is guided by utility theory which provides a valuable framework for understanding and analyzing decision-making processes related to waste management practices. Data were collected through stratified sampling of 380 respondents, where interview guides and questionnaires were applied. Key findings reveal that gender and income levels are significant predictors of solid waste generation. High-income earners (KSh. 91,000–100,000 monthly) are the largest waste generators, while low-income earners (<KSh. 30,000) cumulatively generate less. Industrial and packaging-related waste accounts for 37% of corporate waste, followed by tea waste (20%) and market waste (15%), reflecting the dominance of manufacturing and agricultural trade in the region. A multiple regression analysis proved that gender, and monthly household income, collectively explained up to 50% of the variation of solid waste management. These results indicate the need for development of gender-specific strategies and policies that are oriented to income disparities, to improve solid waste management. The study recommends offering incentives for minimization of waste disposal such as waste-to-energy practices for tea companies and establishment of affordable recycling facilities for low-income households and informal sector players.

Economic Value of Solid Waste for Improved Solid Waste Management in Nandi County, Kenya

Thu, 01 May 2025 00:00:00 GMT

Economic Value of Solid Waste for Improved Solid Waste Management in Nandi County, Kenya Meli, James; Sumukwo, Joel; Lagat, Kiplimo Due to rapid population growth and urbanization Nandi County is experiencing challenges of managing urban solid waste especially as this is an economic commodity that may not be optimally allocated through the normal market mechanism system. This is because supply-side management practices have failed and hence there is need for demand-oriented approach. The objectives of this study include; assessing the WTP for improved management of solid waste; evaluate potential income opportunities in managing waste; and provide policy implications. The study used a sample size of 380 households through stratified sampling procedures. Interview guides and questionnaires were used in data collection. Results show that only 27% of individual residents and 18% of corporate organizations paid for these services while the rest (73% and 82% respectively) cannot internalize environmental degradation. High income households expressed the highest willingness to pay (WTP) of 60%. On average respondents WTP is Ksh. 300 monthly for improved services, while corporates had WTP of KSh. 1,000. Regression analysis showed that gender, education level, and household income were significant predictors of WTP. The study concluded that gender, education level, and household monthly income significantly influence individuals' willingness to pay for improved solid waste management in Nandi County. It recommends strengthening regulations to enforce proper waste disposal and introduce equitable tariff structures. Expanding participation through affordable rates will help achieve economies of scale, ensuring sustainable financing for waste management services

Influence of pH Variation on Lead Uptake and Accumulation in Raphanus raphanistrum and Brassica napus Grown in Spiked and Limed Agricultural Soils of Moiben Sub-County, Kenya

Fri, 01 Aug 2025 00:00:00 GMT

Influence of pH Variation on Lead Uptake and Accumulation in Raphanus raphanistrum and Brassica napus Grown in Spiked and Limed Agricultural Soils of Moiben Sub-County, Kenya Barno, Faith; Gelas, Simiyu; Mulei, Josephine This study assessed Pb uptake and distribution in Raphanus raphanistrum (RR) and Brassica napus (BN) grown in agricultural soils from Moiben Sub-County, Kenya, under three soil treatments: Pb-spiked soil (to ≈1000 mg/kg), non-spiked soil, and spiked soil amended with lime (to achieve pH≈7.4). Pb concentrations were quantified using Atomic Absorption Spectrophotometry (AAS), and the Bioaccumulation Factor (BAF) was calculated for roots, stems, leaves and seeds. Data were analyzed using SPSS v25. Descriptive statistics (means, standard deviations) were computed for Pb concentrations in soil and plant tissues. One-way ANOVA tested differences among treatments (control, spiked, limed), with Tukey’s HSD applied for post hoc comparisons. Results showed that Raphanus raphanistrum accumulated mean Pb concentrations of 1043.80 ± 18.34 mg/kg in spiked soils, 25.49 ± 0.39 mg/kg in non-spiked soils, and 548.24 ± 17.75 mg/kg in spiked and limed soils. Brassica napus followed a similar trend, with significantly higher Pb accumulation in spiked compared to non-spiked soils, while liming reduced uptake by nearly 50%. In both species, roots exhibited the highest BAF across treatments, while stems consistently recorded the lowest. In spiked soils, the accumulation trend was roots > seeds > leaves > stem, whereas in limed soils it shifted to roots > leaves > seeds > stem, with overall BAF values reduced to <1. Although liming effectively reduced Pb uptake, both Raphanus raphanistrum and Brassica napus accumulated Pb levels in edible parts above FAO/WHO permissible limits (0.3 mg/kg for leafy vegetables, 0.1 mg/kg for root/tuber crops, and 0.2 mg/kg for cereals and oilseeds), raising concerns over food safety. The findings highlight the influence of soil

Assessing Status of Agroecological Biodiversity in Smallholder farming: Evidence from FAO TAPE Tool Localization in Busia County, Kenya

Fri, 01 Aug 2025 00:00:00 GMT

Assessing Status of Agroecological Biodiversity in Smallholder farming: Evidence from FAO TAPE Tool Localization in Busia County, Kenya Kerubo, Suzzette; Otinga, Abigael; Njoroge, Ruth; Ongeri, Lilian; Ambale, Vincent Agroecological biodiversity is the variety and variability of above ground organisms, that is crops, livestock, trees, and activities considered under agricultural systems. This study investigated the extent of above ground agroecological biodiversity among small-scale farmers in Busia County. Agroecological diversity (above ground) was measured using four indicators of the FAO's Tool for Agroecology Performance Evaluation-TAPE: crop, livestock, tree, and activity diversity. Administrative wards were purposively selected where a sample size of 210 was sourced. Households were randomly selected, top 35 households, within those administrative wards. For administrative wards with less than 35 households, snowballing was conducted to reach the required number of households. Snowballing was also conducted to households that were unavailable and to those who did not give consent. Data was collected through structured questionnaires and administered to respondents by trained enumerators. The results revealed that the agroecological biodiversity scores recorded: 40.5%, 31.25%, 45.5%, and 41.75%, for crops, livestock, trees, and activities, respectively, with an overall score of 39.75%. This interprets to unsustainable extent of practice, reflecting missed opportunities to harness agroecological biodiversity. Farmer education and technical extension by up to date standardized trained officers on agroecological biodiversity can be strengthened through mass media, agricultural shows, and farmer school centres. Additionally, promoting practical guidance on integrating locally appropriate species and practices can help unlock the full extent and adoption of agroecological biodiversity.

Spatial–Temporal Influence of Sand Dams on Chemical and Microbial Properties of Water from Scooping Holes in Degraded Semi-Arid Regions

Fri, 01 Sep 2023 00:00:00 GMT

Spatial–Temporal Influence of Sand Dams on Chemical and Microbial Properties of Water from Scooping Holes in Degraded Semi-Arid Regions Churu, Harrison; Kamau, Solomon; Ngetich, Wilson; Magiroi, Keziah; Alkamoi, Bonface; Kebeney, Syphyline; Wamalwa, Fred; Mumo, James Communities in semi-arid lands use sand dams to enhance access water during the dry seasons. However, there is limited information on the quality of water derived from these sand dams, especially in degraded lands where storm surface runoff poses contamination risk. Thus, this study aimed at assessing the spatial–temporal variations in water quality of sand dams in Chepareria, West Pokot County in Kenya. Water samples were collected from scooping holes across 18 purposefully selected sand dams. Results obtained showed significant differences in water quality based on a sand dam’s age and location of the scooping holes, but the magnitude of these differences differed with specific properties. For instance, in recently constructed sand dams (<1 year), scooping holes near the sand dam wall had lower pH values (8.5) than holes scooped a distance from the sand dam wall (9.2). For total dissolved solutes and microbial properties, sand dam age had the greatest impact, over the location of the scooping holes. For example, water obtained from <1 year old sand dams had significantly higher TDS with an average value of 100.3 mg L−1 . The thermotolerant coliforms (TTC) exceeded the maximum allowable levels recommended by The World Health Organization. Thus, water obtained from these sand dams should be treated before consumption. Finally, sand dams meant for domestic water harvesting should be protected. Shallow wells with appropriate aprons for effective protection against contamination should be installed to enhance abstraction of safe water from sand dams.

A Review on Challenges and Opportunities in Management of Soils of Arid and Semi-Arid Regions of Kenya

Sat, 01 Jan 2022 00:00:00 GMT

A Review on Challenges and Opportunities in Management of Soils of Arid and Semi-Arid Regions of Kenya Nyuma, Henry Tamba; Churu, Harrison Arid and semi-arid lands occupy currently 88% of arable land mass in Kenya, a region with significant diversity of production systems and economic opportunities. However, these areas are characterised by low and erratic rainfall, hence challenges to agriculture and socioeconomic development in the wake of an increasing population and the impacts of climate change. This review seeks to identify key challenges and opportunities associated with the management of agricultural soils in these arid and semi-arid communities. Arid and semi-arid regions in Kenya are dominated by 10 soil types; Solanchaks, Solonetz, Cambisols, Arenosols, Leptosols, Vertisols, Fluvisols, Phoezems, Calcisols, and Gypsisols. Among the main soil fertility challenges in these soils are moisture stress, high erodibility, and low organic matter content, salinity, and sodium toxicity, the deficiencies of mainly N, P, Zn, and Fe, hence the vulnerability of over 14 million inhabitants to the shocks of low crop and pasture production. Moreover, the adoption of soil conservation practices remains low as existing soil fertility management technologies have been criticized for being too abstract and not providing context and site-specific solutions. Improving soil fertility and moisture levels enhances soil ecosystem functions and food and pasture production in these regions. Encouraging farmers to join soil and water conservation groups, while providing economic incentives, could potentially accelerate the adoption of soil and water practices at the farm level through pulling resources together. Future research to validate a site and context-specific integrated soil fertility improvement technologies for these soils is evitable to enhance soil functions, agricultural production and livelihood at house hold level.

Drivers of Gully Erosion and its Socio- economic and Environmental Effects in a Tropical Semi-arid Environment

Fri, 01 Mar 2024 00:00:00 GMT

Drivers of Gully Erosion and its Socio- economic and Environmental Effects in a Tropical Semi-arid Environment Churu, Harrison; Kamau, Solomon; Ng’etich, Wilson; Magiroi, Keziah; Alkamoi, Bonface; Kebeney, Syphyline; Wamalwa, Fred; Mumo, James Gully erosion is a form of severe land degradation, which is more pronounced in semi-arid and arid environments due to their vulnerable ecosystems. Establishing the causes and effects of gully erosion is therefore fundamental in policy formulation and resource allocation for up-scaling context-specific gully mitigation and rehabilitation measures. Thus, this study aimed at assessing the causes and effects of gully erosion in semi-arid region, in the North-West part of Kenya. A cross-sectional survey, field measurements, laboratory analysis, focus group discussions and key informants’ interviews were used to collect data on drivers and effects of gully erosion. Descriptive statistics and content analysis were used to analyze the data. From the findings, 60 % of the respondents reported deforestation as the main driver of gully erosion. Further, 37 and 34 % of the respondents reported surface runoff and steep slopes, respectively, as major drivers of gully erosion. Soils in the region had a high dispersion ratio, with values of between 0.3 and 0.9, making them highly erodible. About 66 and 55 % of the respondents reported that the major effects of gully erosion were reduction in arable land size and death of livestock due to fatal falls, respectively. Approximately 14 ha of arable land and 1,483,600 Mg of sediment have been lost to gully erosion at the rate of about 2,410 Mg ha-1 over a period of 45 years. The average growth rate and density of gullies in the study site stood at 154 Mg ha-1 yr-1 and 0.7 km km-2, respectively. Four people and about 100 cattle had died due to fatal falls into the deep gullies. Thus, there is an urgent need to rehabilitate existing gullies while mitigating occurrence of new gullies in the study area. This would convert existing badlands into hotspots of biodiversity.

Enhancing Sorghum Productivity in Acidic Soils Through Lime– Fertilizer Synergism: Agronomic, Economic, and Composite Performance Analysis

Sat, 01 Nov 2025 00:00:00 GMT

Enhancing Sorghum Productivity in Acidic Soils Through Lime– Fertilizer Synergism: Agronomic, Economic, and Composite Performance Analysis Rotich, Edwin Kiprono; Oloo, Peter Kisinyo; Opala, Peter Asbon; Odundo, Gudu Samwel Sorghum productivity in Western Kenya is severely constrained by acidic soils, particularly Ferralsols and Acrisols prone to aluminum toxicity and phosphorus fixation. This study assessed the performance of limeintegrated fertilizer treatments under smallholder conditions using a randomized complete block design across three sites. Sorghum grain yield (SGY), agronomic efficiency (AE), nutrient uptake efficiency (NUE), and gross margin (GM) were measured alongside the formulation of a composite Performance Index (PI) designed to simulate both physiological and economic effects. We developed a composite Performance Index to integrate agronomic and economic outcomes, enabling balanced evaluation of lime–fertilizer strategies across acid-prone sites. The PI incorporated weighting scenarios reflecting equal and smallholder-adjusted preferences. Results showed that lime enhanced AE (up to 55%), NUE (up to 34.6%), and SGY ≥ 1.8 t ha⁻¹ across sites, with intermediate fertilizer rates yielding superior performance. GM exceeding $450 ha⁻¹ and benefit–cost ratios over 2.0, demonstrating strong economic viability, Lime + N37.5P13 consistently outperformed other treatments, offering agronomic–economic balance and robust PI ranking across sensitivity models. Radar and contour plots identified optimal combinations and revealed trade-offs between efficiency and yield. These findings support lime as a foundational input rather than a supplemental one, and advocate for context-driven ISFM strategies aligned with smallholder realities. The PI framework offers a flexible and empirically grounded tool for sustainable intensification decisions in acid soil systems.

Soil-Plant Nutrient Dynamics and Fertilizer Use Efficiency in Maize & Desmodium Cropping System

Wed, 01 Oct 2025 00:00:00 GMT

Soil-Plant Nutrient Dynamics and Fertilizer Use Efficiency in Maize & Desmodium Cropping System Odera, Irine Akinyi; Otinga, Abigael Nekesa; Njoroge, Ruth; Mutua, Scholastica Soil fertility decline and inefficient nutrient use remain major challenges limiting maize productivity in the arid and semi-arid lands (ASALs) of Kenya. This study evaluated the effects of integrating farmyard manure (FYM) with inorganic fertilizers on soil properties, nutrient uptake, yield performance, and efficiency indices in sole maize sole desmodium and maize-desmodium intercrop systems under field conditions in Keiyo North. The experiment consisted of six fertilizer substitution ratios (0-0, 25-75, 50-50, 75-25, 100-0, and 0-100% farmyard manure-inorganic N equivalence) arranged in a randomized complete block design with four replications. Soil chemical parameters (NH₄⁺, NO₃⁻, pH, N, P, and C), plant nutrient uptake, and agronomic and recovery efficiencies were assessed. Results showed that combined farmyard manure – inorganic treatments, particularly 25-75 and 75-25, significantly improved soil nutrient status, enhanced N and P uptake, and increased maize and desmodium yields compared to sole applications. Farmyard manure -rich combinations improved moisture retention and microbial activity, sustaining nutrient release, while inorganic fertilizers ensured rapid early growth. Intercropping enhanced biological nitrogen fixation and nutrient recovery, leading to higher agronomic efficiency and resilience under moisture-limited conditions. The findings underscore that partial substitution of inorganic fertilizers with farmyard manure, coupled with maize-desmodium intercropping, offers a sustainable pathway to enhance soil fertility, nutrient use efficiency, and productivity in arid and semi-arid lands farming systems.

Nutrient dynamics and decomposition of agroforestry litter in acidic soils of Uasin Gishu County, Kenya

Tue, 01 Apr 2025 00:00:00 GMT

Nutrient dynamics and decomposition of agroforestry litter in acidic soils of Uasin Gishu County, Kenya Nyuma, Henry; Njoroge, Ruth; Otinga, Abigael Multiple forms of biomass, including litter, herbaceous, and woody biomass emanating from agroforestry systems, have numerous environmental and socioeconomic benefits, including improved soil health, biodiversity, carbon sequestration, and diversified income. These benefits are crucial to sustainable production. Despite agroforestry's significant contribution to sustainable food production, less attention is given to litter mass decomposition and its mechanisms of nutrient release and cycling. A study to assess the influence of agroforestry litter quality on decomposition and nutrient release in acidic soils of Uasin Gishu County, Kenya, was conducted at the University of Eldoret. The hypothesis was that the litter type of three agroforestry species - Gliricidia, Leucaena, and Sesbania - affects the rate of decomposition, nutrient release pattern, and the chemical characteristics of acidic soils. Results from the study revealed a significant (P≤0.05) influence of agroforestry litter type and initial litter quality on the rate of decomposition and nutrient dynamics in the order of Sesbania > Gliricidia > Leucaena. Sesbania showed superior litter quality, recording the highest OC (48.1%), N (25.9 g kg-1 ), and Cu (0.35 ppm), and the lowest concentration of lignin (18.0%), cellulose (24.0%), and the lowest C:N, L:N, L:PP, L:P:N, and L:N:P ratios, hence the highest rate of decomposition (k=0.04). Nutrient release was in the order of Fe=Cu>K>Ca>Mg=Mn>N=Zn>P for Gliricidia, Ca>Cu>K=Mn>P>Zn>N for Leucaena, and Ca>Cu>Mn=Mg>P=K>N>Zn for Sesbania. Although there were no significant differences in nutrients released from the three litter types, Sesbania recorded the fastest release of N, P, Cu, and Mn, contributing about 3.2% SOC, 25.5 kg P ha-1 , and 11.4 kg K ha-1 to the soil. Mean soil enrichment (ER=1.1, 1.5, and 2.5) for SOC, P, and K, respectively, indicates the potential of agroforestry litter mass of Sesbania sesban in nutrient cycling. These findings provide insights into the crucial role of agroforestry litter in the cycling of macro and micronutrients, hence enhancing soil ecosystems and sustainable production. However, further studies involving different litter types in multiple agroecological zones are needed to assess the impacts of other environmental factors on nutrient release mechanisms in acid soils.