Organic Farming

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Adaptive Capacity to Climate Change among Smallholder Farmers’ in Busia County, Kenya
(IOSR Journal of Agriculture and Veterinary Science, 2017-11-30) Agnes Mugure Sorre; Alice Kurgat; Richard Musebe; Benard Sorre
This paper emanates from a study that was carried out to assess smallholder farmers’ adaptive capacity to climate change effects in Busia County. Qualitative and quantitative data was collected from 376 respondents selected using multistage and simple random sampling techniques. Six determinants (financial, social, knowledge and information, institutions and flexible decision making) of adaptive capacity to climate change were assessed using a five point Likert scale. Findings indicated a moderate (2.65) adaptive capacity among smallholder farmers in Busia County. Low adaptive capacity was indicated in financial/economic resources (2.4), but moderate in knowledge/information (2.5), social (2.8), technology and innovation (2.7), institutional (2.8) and informed farming decision making resources. Therefore, low financial and economic resources limit ability to plan, prepare for, facilitate and implement adaptation measures. This paper recommends that development and climate change efforts should focus on climate change awareness and diversification for both on-farm and off-farm livelihood activities.
Aflatoxin B1: Chemistry, Environmental and Diet Sources and Potential Exposure in Human in Kenya
(IntechOpen, 2019-10-05) Lalah, Joseph Owuor; Omwoma, Solomon; Orony, Dora A. O.; Lalah, Joseph Owuor; Omwoma, Solomon; Orony, Dora A. O.
Cancer incidences and mortality in Kenya are increasing according to recent reports and now number among the top five causes of mortality in the country. The risk factors responsible for this increase in cancer incidences are assumed to be genetic and/or environmental in nature. The environmental factors include exposure to carcinogenic contaminants such aflatoxins (AFs). However, the exact causes of the increase in cancer incidences and prevalence in many developing countries are not fully known. Aflatoxins are known contaminants produced by the common fungi Aspergillus flavus and the closely related Aspergillus parasiticus which grow as moulds in human foods. Aflatoxin B1 (AFB1) is most common in food and is 1000 times more potent when compared with benzo(a)pyrene, the most potent carcinogenic polycyclic aromatic hydrocarbon (PAH). Aflatoxins have therefore drawn a lot of interest in research from food safety and human health point of view. In this chapter, the chemistry, synthesis, identification, toxicology and potential human health risks of AFB1 in Kenya are discussed.
An Evaluation Of Farmers’ Perceptions Of And Adaptation To The Effects Of Climate Change In Kenya
(Alanya Alaaddin Keykubat University, Department of Economics and Finance, 2013) Ndambiri, Hilary K.; Ritho, Cecilia N.; Mbogoh, Stephen G.
The study was carried out to evaluate how farmers in Kyuso District have perceived and adapted to climate change. Data was collected from 246 farmers from six locations sampled out through a multistage and simple random sampling procedure. The Heckman probit model was fitted to the data to avoid sample selection bias since not every farmer who may perceive climate change responds by adapting. The analysis revealed that 94% of farmers in Kyuso District had a perception that climate was changing and as a result, 85% of these farmers had responded by adapting. In this regard, age of the household head, gender, education, farm experience, household size, distance to the nearest market, access to irrigation water, local agro-ecology, on and off farm income, access to information on climate change through extension services, access to credit, changes in temperature and precipitation were found to have significant influence on the probability of farmers to perceive and/or adapt to climate change. With the level of perception to climate change being more than that of adaptation, the study suggests that more policy efforts should be geared towards helping farmers to adapt to climate change.
Application of GIS on the Identification of Suitable Areas for Water Conservation Technologies in the Upper Tana Watershed of the Central Highlands of Kenya
(International Journal of Plant & Soil Science, 2019) Nganga B. W.; Nge’tich K. O.; Adamtey N.; Milka K.; Ngetich K. F.
Low adoption of soil water conservation technologies has been one of the main causes for decreased agricultural productivity in the Upper Tana Catchment of Kenya. Proper identification of locations to scale-out the individual technologies necessary to improve water conservation is a key determinant for the rate of adoption. Our main aim was to identify the suitable sites for water conservation technologies using the suitability model created by the model builder function in ArcGIS 10.5® . The model combined the thematic layers of soil texture, slope, rainfall, and stream order, which were acquired from assorted online sources. The factors were converted to raster format and reclassified based on their suitability and were assigned fixed scores and weights by use of multi influencing factor (MIF) method. The suitability evaluation was carried out by use of weighted overlay to produce suitability classes for each of the water conservation technique. The delineated suitability maps indicated that check dams are highly suitable in 50% of the study area. Mulching, on the other hand, is highly suitable for 49% of the study area. Zai pits are highly suitable in 43% of the study area. Majority of the study area is moderately suitable for the use of terraces, covering 41% of the study area. The highly suitable areas for the Checkdams are Machakos, Kitui, Tharaka-Nithi and lower parts of Embu. The highly suitable areas for mulching are Kirinyaga, Murang’a, Nyandarua and Nyeri. The highly suitable areas for the Zai pits are Kitui, lower parts of Tharaka-Nithi and the highly suitable areas for the terraces are Murang’a, Nyeri and Kirinyaga. Furthermore, the results demonstrated the effectiveness of GIS in delineating the suitable areas for the use of water conservation technologies.
Contribution of livestock marketing chains and role played by stakeholders’ knowledge, attitude and practice in spreading cystic hydatidosis to Busia Town, Kenya, 2018
(Cold Spring Harbor Laboratory, 2019-05-14) Ogutu, Henry Joash; Owiny, Maurice; Bett, Bernard; Otieno, Christina
Background Cystic hydatidosis (CH), a neglected parasitic zoonosis, is endemic in many parts of Kenya and could be spread along livestock marketing chains. Poor knowledge, attitude and practices (KAP) enables this spread in remote areas with inadequate public health services. We estimated prevalence, identified possible origin of CH to Busia, Kenya and assessed KAP among cattle owners and abattoir workers.Methods and Principal Findings We conducted a cross-sectional study on slaughtered livestock and interviewed their owners and abattoir workers in Busia in May–June 2018. We used visual observation, palpation and incision to identify cysts. Polymerase chain reaction (PCR) was used for confirmatory diagnosis. Epi Info 7 was used to calculate descriptive and associative statistics. Of 302 carcasses inspected, cysts were visualized in nine (2.98%, 95% Confidence Interval (CI): 1.46–5.78). Fourteen samples were collected and 13 (92.86%) were positive on PCR (sensitivity=92%, specificity=95%). All carcasses with cysts were from West Pokot County, which borders Busia to the north. We interviewed 310 participants: 260 were males (83.87%, 95% CI: 79.19 – 87.69); median age was 41 years (range=21-69). Dogs were kept by 221 (71.99%, 95% CI: 66.55 – 76.87), of which 83 (37.56%, 95% CI: 28.33 – 48.52) improperly disposed of dog faeces. Home slaughtering was practiced by 196 (63.23%, 95% CI: 58.78-69.80), of which 115 (58.67%, 95% CI: 51.44-65.64) were not inspected and 85 (43.37%, 95% CI: 36.32-50.62) fed raw organs to dogs. Adequate knowledge was associated with butcher ownership (P-value = 0.002), age ≥35 years (P-value = 0.002) and higher literacy level (P-value <0.001).Conclusions and Significance There is non-negligible risk of CH in Busia communities which might worsen with time given that the county is connected to endemic areas through livestock trade. Poor KAP by the people on the disease calls for need to implement information, education and communication campaigns to improve KAP on CH in the area.Author summary Cystic hydatidosis is a globally neglected parasitic zoonosis which is endemic in many parts of the world including Kenya. It is majorly a problem among pastoral communities where there is close contact between human, livestock and dogs. Busia County, in Western Kenya is part of a livestock marketing chain between Kenya and Uganda. Animals from high endemic regions in Uganda and Kenya can easily spread the parasite to Busia through improper disposal of their infested organs. Non-pastoral communities like Busia may not have much cumulative experience about the disease though their practices may contribute to the perpetuation of the parasite in their environment. The parasite is gradually spreading to new areas and it is very important to the public health players in Kenya to take action so as to prevent further spread of this disease. Findings from this study show that the disease is no longer limited to pastoral communities only. There is need for the implementation of information, education and communication campaigns to improve the knowledge, attitude and practices of Busia community and other non-endemic regions on the disease.
Earthworms regulate ability of biochar to mitigate CO2 and N2O emissions from a tropical soil
(Elsevier, 2019) Namoi, Nictor; Pelster, David; Rosenstock, Todd S.; Mwangi, Lukelysia; Kamau, Solomon; Mutuo, Paul; Barrios, Edmundo
Soils account for >80% and 20% of the total agricultural N2O and CO2 emissions respectively. Soil management activities that target improved soil health, such as enhancing earthworm activity, may also stimulate further emissions of CO2 and N2O. One recommended strategy for mitigating these soil emissions is biochar amendment. However greater clarity on the interaction between earthworm activity and biochar, and subsequent impact on CO2 and N2O are needed to evaluate the environmental impacts of management practice. We measured N2O and CO2 emissions from a kaolinitic Acrisol in the presence or absence of earthworms, with and without application of two different biochars in a microcosm study. The two biochars were derived from indigenous trees; Zanthoxylum gilletii and Croton megalocarpus, and were tested at three application rates of 5 Mg ha−1, 10 Mg ha−1 and 25 Mg ha−1. Emissions of CO2 and N2O increased by 26% and 72% respectively in the presence of earthworms. In microcosms with biochar and earthworms however, emissions depended on type of biochar and rate of application. With C. megalocarpus, CO2 emission increased with increasing rates of biochar application with 25 Mg ha−1 resulting in higher CO2 fluxes compared to no-biochar control (p = 0.002), while no change was observed with Z. gilletii at the same rate. Nitrous oxide emissions were suppressed at 25 Mg ha−1 for both C. megalocarpus (p = 0.009) and Z. gilletii (p = 0.011). Reduction in N2O flux was however not consistent across biochar types. No change in N2O was observed with 5 Mg ha−1 and 10 Mg ha−1of C. megalocarpus. Biochar from Z. gilletii at 5 Mg ha−1 however led to increase in N2O emissions (p < 0.001). Our findings suggest that earthworms may moderate the effect of biochar, with suppression of N2O emissions occurring at only high biochar application rates, which may occur at the cost of increasing CO2 emissions. These findings contrast with biochar suppressing effect on N2O emissions even at moderate biochar rates of (10 Mg ha−1) when in absence of earthworms, an outcome typical of many laboratory experiments. These findings highlight new interactions among application rate, source of biochar (and hence properties) and earthworms.
Effect of co-digestion with water hyacinth, inoculum concentration and dilution on biogas production of fish waste
(Elsevier, 2023-11-01) Hortence, Ingabire; Maurice, Twizerimana; Arimi, Milton
A report from the FAO (Food and Agriculture Organization) estimates that 9.1 million tons of Fish wastes (FW) are thrown away each year. Water hyacinth (WH) is the most invasive water weed that thrives in freshwater water and has impacts on the environment, ecology, and society. The waste generated is either discarded onto the open ground or disposed into pits which result in environmental pollution and health hazards. FW and WH can be used for biogas production. However, FW digests quickly and produces a lot of ammonia and Volatile fatty acids (VFAs) which inhibit the digestion when digested alone, it has also a low carbon to nitrogen (C/N) ratio; consequently, it is not directly suitable for anaerobic digestion (AD). In this regard, co-digestion with WH (high C/N ratio) prior to AD is necessary. To examine the effects of the operating factors: Substrate ratio (WH: FW), Inoculum concentration (IC) and Dilution, Central composite design (CCD) in Design Expert 13 software was used to design experiments of three factors at five levels which resulted in 17 runs. Laboratory scale experiments were carried out under mesophilic temperature (37 ℃). The maximum biogas with the highest methane content of 68.15% was produced at the substrate ratio of 25:75 g/ 250 mL (WH: FW), 15 g/ 250 mL of IC and dilution of 95 mL. The biogas yield increased by 16.1% and 32.4% compared to pure WH and FW respectively. This implied that the operating conditions were efficient in maximising the biogas yield. FW had a lower C/N ratio; further study needs to consider co-digestion with other higher C/N ratio substrates.
Effects of Carrier Materials and Storage Temperatures on the Viability and Stability of Three Biofertilizer Inoculants Obtained from Potato (Solanum tuberosum L.) Rhizosphere
(Multidisciplinary Digital Publishing Institute, 2022-01-20) Aloo, Becky Nancy; Mbega, Ernest Rashid; Makumba, Billy Amendi; Tumuhairwe, John Baptist
Biofertilizer technology continues to be derailed by the short shelf life of inoculants. The present study investigated the suitability of wheat-bran (WB), rice-husks (RH), farmyard-manure (FYM), bagasse (BG), and sawdust (SD) in the formulation of potato-derived Klebsiella grimontii (MPUS7), Serratia marcescens (NGAS9), and Citrobacter freundii (LUTT5) under refrigerated (8 °C) and room (25 ± 2 °C) storage. The physicochemical properties of the materials were assessed before sterilization and introduction of the inoculants and assessment of their viability for 8 months. Most of the physicochemical properties of the materials varied significantly (p < 0.05). Bagasse supported the maximum growth of MPUS7 (5.331 log CFU g−1) under refrigeration and LUTT5 (4.094 log CFU g−1) under both conditions. Under room storage, the maximum growth of MPUS7 (3.721 log CFU g−1) occurred in WB. Formulations that remained viable under room storage can easily be integrated into existing agricultural distribution systems that lack refrigeration.
Evaluation of Greenhouse Gas Emissions along the Small-Holder Coffee Supply Chain in Kenya
(Journal of Sustainable Research in Engineering , 2015) Maina, Joan.J.; Mutwiwa, Urbanus. N.; Kituu, Gareth. M.; Githiru, M.
Coffee plays an important role in sustaining millions of livelihoods around the world. The production of Arabica coffee is greatly affected by the changing climate. Besides suffering from changing climate, coffee is also a contributor to climate change as a result of greenhouse gases emitted throughout the supply chain. The coffee sector is therefore interested in climate-friendly coffee production methods. Understanding greenhouse gas emissions from the coffee supply chains is important for evaluating options for climate change mitigation within the sector. In this study, data from 108 small scale farmers affiliated to three wet mills in Kenya was used to calculate the carbon footprint of coffee parchment, and identify emission hotspots within different farmer production levels. The results indicate that farmer production level had a highly significant negative impact on carbon footprint (p<0.0001). The carbon footprint decreased with increase in production level. The mean farm level carbon footprints for 1kg of fresh coffee cherries were 0.05 kg CO2e, 0.24 kgCO2e and 0.54 kgCO2e for high, medium and low producers respectively. The main GHG emission hotspot at farm level across all the levels of production was the inputs of organic and inorganic nitrogen (94%). The mean carbon footprint at processing for 1kg coffee parchment was 2.6 kgCO2e. At the wet mills the major emission hotspot was the processing wastewater (97%). Mitigation practices proposed therefore focused on the reduction of emissions from fertiliser use and wastewater treatment.
Examining the Contributions of Maize Shoots, Roots, and Farming Manure to Stable Soil Organic 2 Carbon Pools in Tropical Smallholder
(Elsevier B.V, 2022) Nyamasoka-Magonziwa Blessing; Vanek Steven J.; Ojiem John O.; Fonte Steven J.
Continuous inputs of organic matter are vital for sustaining soil organic carbon (SOC) and productivity of soils in smallholder crop-livestock systems. However, the dynamics of the different inputs i.e. maize shoots, roots and manure used are poorly understood. Along with organic inputs, use of mineral fertilizers can alter the nutrient stoichiometry of organic matter inputs and have implications for SOC turnover. This study sought to understand how maize-based inputs and alterations to nutrient stoichiometry contribute to stable SOC pools. We hypothesized that higher quality litter (i.e., manure) contributes more than maize residues to stable SOC pools and that N, P and S additions, designed to balance the stoichiometry of inputs to reflect the stable fine fraction of soil organic matter (C:N:P:S-10,000:833:200:143) results in greater SOC stabilization. We used a 13C natural abundance approach, where the C4 maize residues were incubated for 11 months to trace C stabilization into different SOC pools within a C3 soil. Contrary to our expectations,we observed greater recovery and stabilization of shoot-derived C (2 X more than manure and 1.63 X more than roots) in the mineral-associated organic matter (MAOM) fraction. Mineral N, P and S additions reduced new C recovery in MAOM by 40% compared to no mineral nutrient’s additions. Our study highlights the importance of residue retention as a strategy to maintain SOC and soil health in smallholder systems, and our results challenge the idea that nutrient additions increase C stabilization of added residues.
Farmers’ Knowledge and Practices in the Management of Insect Pests of Leafy Amaranth in Kenya
(Entomological Society of America, 2019-01-01) Nampeera, Esther L; Nonnecke, Gail R; Blodgett, Sue L; Tusiime, Sharon M; Masinde, Dorothy M; Wesonga, John M; Murungi, Lucy K; Baidu-Forson, Joseph J; Abukutsa-Onyango, Mary O
Amaranth (Amaranthus L.) species are grown for their grain or leaves and contribute to farmers’ livelihoods and nutritional food security. Leafy amaranth (LA) is consumed widely as a vegetable in Kenya. An assessment of current farmers’ knowledge of pest management practices provides information about future educational needs. Six-hundred LA farmers were interviewed, focus group discussions with farmers, and interviews with key informants were completed in four Kenyan counties. The majority (71%) of survey respondents grew LA on less than 0.25 acre (<0.1 ha) and 59.2% were female. Constraints of LA production differed by counties surveyed. Farmers indicated insects and birds were important in Kiambu and Kisumu counties, whereas in Vihiga and Kisii, capital, markets, and land area for production were important. Farmers stated and ranked importance of the insects they observed during LA production. Eighty-seven percent stated aphids (Hemiptera: Aphididae), as a major pest and 96.8% ranked aphids as the number-one insect pest of LA in all four counties. Two other pests of LA included cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) (0.8%) and spider mites, Tetranychus spp (Trombidiformes; Tetranychidae) (0.7%). Forty-two percent of all LA farmers managed aphids, with 34% using synthetic insecticides and 8% using nonsynthetic methods. Biological controls and host-plant resistance were not mentioned. Educational programs that train farmers about integrated pest management (IPM) in LA production are needed. Future research should determine successful IPM strategies for aphids on LA to reduce insecticide use and improve sustainability and nutritional food security for small-landholder farmers and consumers.
Gallium-Induced Perturbation of Zinc Selenide Quantum Dots Electronics
(wiley publishers, 2017) Ndangili, Peter M.; Masikini, Milua; Feleni, Usisipho; Douman, Samantha; Tovide, Oluwakemi; Williams, Avril; Baker, Priscilla; Iwuoha, Emmanuel I.
A rare cationic chemistry of GaIII has been used to modulate the optical and electrochemical properties of selenide quantum dots. Three different types of 3-mercaptopropionic acid (3MPA)-capped quantum dots (ZnSe-3MPA, Ga2Se3-3MPA and Ga-doped ZnSe-3MPA) were synthesized in highly basic aqueous media (pH = 12.12) at room temperature. Three-dimensional emission-excitation matrix spectra (3D EEM), as well as, the ultraviolet visible spectroscopic bands of the Ga-doped ZnSe-3MPA were similar to the average values obtained for ZnSe-3MPA and Ga2Se3-3MPA. Electrochemical studies revealed that gallium-induced vacancies caused a significant enhancement in the conductivity of the Ga-doped ZnSe-3MPA compared to the conductivity of a mixture of ZnSe-3MPA and Ga2Se3-3MPA.
Influence of Agricultural Lime on Soil Properties and Wheat (Triticum aestivum L.) Yield on Acidic Soils of Uasin Gishu County, Kenya
(American Journal of Experimental Agriculture, 2013-07-04) M. A. Osundwa; J. R. Okalebo; W. K. Ngetich; J. O. Ochuodho; C. O. Othieno; B. Langat; V. S. Omenyo
A study was carried out to investigate the influence of agricultural lime (21% CaO) from Koru, Kisumu on soil properties and wheat yield on acidic soils of Uasin Gishu county. Field trials were conducted at Chepkoilel University College farm and in Kipsangui area of Uasin Gishu county. Soils were analyzed to determine their pH, available P and other nutrient levels before treatment application. The experiment was a split plot arrangement with two wheat varieties as the main plots and the lime treatments as the subplots. The two varieties compared were ‘Njoro BW 2’ and ‘KS Mwamba’ characterized as tolerant and moderate tolerant to soil acidity, respectively. Phosphorus and nitrogen were applied as a blanket treatment at the rates of 40 kg P205 /ha and 46 kg N/ha respectively. Lime was applied at the rates of 0.0, 0.5, 1.0, 1.5 and 2.0 t/ha. Soils from the two sites were acidic with low to moderate available P for Chepkoilel and Kipsangui sites respectively. Soil pH and soil available P increased with the increase in the rate of lime addition. Wheat grain yield increased significantly (p=0.05) due to soil acidity amendment above the control. There was a high positive correlation between wheat yields and soil available P at both sites at harvest. High cost of inorganic inputs, low wheat grain prices and the effects of the erratic rains made the majority of the treatments economically unviable for adaptation by farmers. However, the most profitable treatment was 2 t/ha of lime in Njoro BW 2 at Kipsangui site. There was no viable treatment at Chepkoilel site. Higher wheat yields may probably be achieved from rates of lime above 2 t/ha.
Integrating No-Tillage with Agroforestry Augments Soil Quality Indicators in Kenya’s Dry-Land Agroecosystems
(Elsevier Publishing, 2022-11-14) Kisaka M. Oscar; Shisanya Chris; Cournac Laurent; Manlay J. Raphael; Gitari Harun; Muriuki Jonathan
Conservation agriculture with trees (CAWT) is one of the best-bet strategies for enhanced soil quality under extensive and intensive smallholder farming. CAWT is an agroforestry system that integrates legume trees and shrubs into cropping fields under minimum soil disturbance and tillage. This study identified principal soil quality indicators (SQI) under CAWT system. The study further assessed the effects of CAWT components; i.e. tillage (convention or no-tillage), leguminous trees/shrubs (Calliandra calothyrsus, Gliricidia sepium and Cajanus cajan), and their inter-row spacing (1.5 m, 3.0 m or 4.5 m) on the SQI in the dry-land agroecosystems of eastern Kenya. We finally reported on the suitability of the SQI under CAWT intervention towards maize production. The experimental trials were both researcher (Mother-trials; MTs) and farmer (Baby-trials; BTs) hosted and managed. Principal Component Analyses (PCAs) identified soil fertility and textural components as the main factors explaining soil quality under the CAWT system. In particular, the exchangeable bases (ExBas) such as ExCa, ExK, and ExMg), Cation-Exchange-Capacity (CEC), total soil nitrogen (TSN), soil organic Carbon (SOC), pH, available Phosphorus(P), electrical conductivity (EC), clay and bulk density (BD) were identified as the principal soil quality indicators under the CAWT system. Tree species and varied inter-row spacing, significantly affected available P, BD, pH, ExBas, CEC, SOC, and TSN. The tillage systems significantly (P < 0.05) influenced soil pH, ExBas, CEC, SOC and TSN. A high concentration of TSN was recorded in no-tillage (NT) blocks integrated with C. calothyrsus (41.9 and 41.6 Mg N ha− 1 ) and G. sepium (35.7 and 32.3 Mg N ha− 1 ) both spaced at 1.5 m at the MTs and BTs, respectively. Combining NT with C.calothyrsus spaced at 1.5 m or Pigeon pea at 3.0 m significantly increases available P (from 22.9 to 28.8 mg kg− 1 and 23.4–26.0 mg kg− 1 ) at the MTs, respectively. Significant rise in ExK (1.91–2.25 cmolc kg− 1 ), ExCa (6.86–8.17 cmolc kg− 1 ), and ExMg (2.35–2.78 cmolc kg− 1 ) were observed in NT block’s sub-plots with G. sepium spaced at 3.0 m at the MTs. Conclusively, a shift towards CAWT showed evidence of improving soil quality, nutrient availability and increasing soil nutrient thresholds that can potentially support maize production. By establishing the minimum datasets for soil quality determination through this study, key stakeholders in agroforestry and conservation agriculture (CA) have an efficient costeffective and rapid tool for soil quality assessment, especially in dry-land agro-ecosystems.
Manganese exacerbated chronic khat-induced neurological deficits, inflammation and organ toxicity in a mouse model
(Springer, 2021-12-01) Chepukosi, Kennedy W.; Nyariki, James N.; Jillani, Ngalla E.; Okanya, Patrick W.; Isaac, Alfred Orina
This study sought to determine whether chronic exposure to khat (Catha Edulis, Forsk) increases the vulnerability to the toxic effects of manganese (Mn2+), when co-exposed.Three (3)-week-old forty (40) Swiss albino mice were randomly divided into four groups (n = 10). The various groups received khat and manganese separately or both. The experiment was conducted for 132 days to mimic chronic exposure to khat, with manganese administration in the last twelve days.
Multi-Influencing-Factors' Evaluation for Organic-Based Soil Fertility Technologies Out-Scaling in Upper Tana Catchment in Kenya
(Scientific African, 2020-03) Nganga W. Beatrice; Ng'etich K. Onesmus; Macharia M. Joseph; Kiboi N. Milka; Adamtey Noah; Ngetich K. Felix
Low adoption of soil fertility technologies, partially attributed to low technology out-scaling initiatives, is a critical hindrance to agricultural productivity enhancement of most smallholder farms in sub-Saharan Africa. Application of geospatial tools for spatial suitability evaluation of soil fertility management technologies can be a breakthrough in their promotion and out-scaling existing novel technological initiatives. The study objective was to develop a data-driven multi-influencing-factor (MIF) geospatial approach for out-scaling organic-resource based soil fertility management technologies. Using the developed geospatial approach, we delineated suitable zones for targeted out-scaling of organic resource technologies in the Upper Tana River (UTC) catchment in Kenya. We acquired multiple datasets from different sources and used them to prepare thematic layers. The factors used included rainfall, elevation, cattle density, bulk density, slope, soil pH, soil organic carbon, cation exchange capacity, drainage, and soil texture. The input layers were georeferenced, converted to raster formats, standardized to a range of 1 to 5, after which we generated the suitability map through a weighted overlay technique. The delineated suitability map showed that about 0.002% of UTR was least suitable, 4.7% marginally suitable, 38.5% moderately suitable, 34.7% medium-high suitable while 0.03% was highly suitable for organic resources out-scaling The results obtained indicate the potential of the geospatial approach as a scaling out methodology for organic-based soil fertility technologies. The suitability delineation established that Nyeri, Murang'a and Meru are the most suitable areas for the use of most organic resources in the Upper Tana catchment of the Central Highlands of Kenya. The suitability maps can inform policymakers, planners, and decision-makers in identifying the suitable sites for the use of organic-based soil fertility resources. Based on this study, we recommend the use of the developed a data-driven multi-influencing-factor (MIF) geospatial approach in the scaling out of the organic-based soil fertility technologies, not only in the study area but also other regions in sub-Saharan Africa.
Multi-influencing-factors’ evaluation for organic-based soil fertility technologies out-scaling in Upper Tana Catchment in Kenya
(Scientific African, 2020) Nganga, Beatrice W.; Ng’etich, Onesmus K.; Macharia, Joseph M.; N. Milka Kiboi; Noah Adamtey; K. Felix Ngetich
Low adoption of soil fertility technologies, partially attributed to low technology outscaling initiatives, is a critical hindrance to agricultural productivity enhancement of most smallholder farms in sub-Saharan Africa. Application of geospatial tools for spatial suitability evaluation of soil fertility management technologies can be a breakthrough in their promotion and out-scaling existing novel technological initiatives. The study objective was to develop a data-driven multi-influencing-factor (MIF) geospatial approach for out-scaling organic-resource based soil fertility management technologies. Using the developed geospatial approach, we delineated suitable zones for targeted out-scaling of organic resource technologies in the Upper Tana River (UTC) catchment in Kenya. We acquired multiple datasets from different sources and used them to prepare thematic layers. The factors used included rainfall, elevation, cattle density, bulk density, slope, soil pH, soil organic carbon, cation exchange capacity, drainage, and soil texture. The input layers were georeferenced, converted to raster formats, standardized to a range of 1 to 5, after which we generated the suitability map through a weighted overlay technique. The delineated suitability map showed that about 0.002% of UTR was least suitable, 4.7% marginally suitable, 38.5% moderately suitable, 34.7% medium-high suitable while 0.03% was highly suitable for organic resources out-scaling The results obtained indicate the potential of the geospatial approach as a scaling out methodology for organic-based soil fertility technologies. The suitability delineation established that Nyeri, Murang’a and Meru are the most suitable areas for the use of most organic resources in the Upper Tana catchment of the Central Highlands of Kenya. The suitability maps can inform policymakers, planners, and decision-makers in identifying the suitable sites for the use of organic-based soil fertility resources. Based on this study, we recommend the use of the developed a data-driven multi-influencing-factor (MIF) geospatial approach in the scaling out of the organic-based soil fertility technologies, not only in the study area but also other regions in sub-Saharan Africa
Pharmacological, Chemical, Chromatographic and Spectroscopic Profiles of Extracts and Bioactive Compounds from Selected Kenyan Ruellia Species
(JKUAT, 2021-06-03) Wangia, Christine Ong’ayo
The growing challenge of non-communicable diseases (NCDs) especially in developing world necessitates search for novel drugs that are not only efficacious but also affordable. Plants have traditionally provided a rich source of medicine, and therefore, there is a need to explore the untapped reservoir of medicinal plants for the management of NCDs. Ruellia (Acanthaceae) species are wild perennial creepers which have been reported to possess anti-inflammatory, analgesic, antinociceptive, and antipyretic activities. Therefore, the main objective of this study was to investigate the pharmacological, chemical, chromatographic, and spectroscopic profiles of the bioactive compounds present in three Kenyan Ruellia species. The selected species viz. R. prostrata (RPM), R. bignoniiflora (RBK) and R. lineari-bracteolata (RLB), were studied with special emphasis to antioxidant, analgesic, anti-inflammatory and anti-arthritic activities. Whole plant parts were collected from their natural habitats and both aqueous extracts (hot maceration) and organic extracts (cold maceration) were obtained. The acute toxicity study categorized the aqueous extract of R. prostrata to be in Category 5 (>2000-5000mg/kg) as per Globally Harmonised System. The sub-chronic toxicity studies revealed that the oral aqueous extract of R. prostrata (1000mg/kg per os) had no adverse effects on the internal organs, haematological parameters, and blood biochemistry in Wistar albino rats. The methanolic extract of RLB showed the highest antioxidant activity [1,1-diphenyl-2-picrylhydrazyl radical (DPPH)], scavenging activity, of IC50, 2.9±3.21 μg/mL, comparable to ascorbic acid standard (2.1±0.10 μg/mL). The aqueous extract of RPM showed the highest analgesic activity (Tail flick method) of ED50, 358.90±20.90 mg/kg. The aqueous extract of R. prostrata showed the highest anti- antinociceptive activity (Formalin test) in phase-1 (ED50 22.22±0.52 mg/kg), and phase-2 (ED50 7.07±4.10 mg/kg). The aqueous extract of RPM also showed the highest anti-inflammatory activity (Carrageenan test) of ED50, 168.05±3.25 mg/kg. In vivo anti-arthritic studies (Complete Freund’s Adjuvant-induced arthritis) revealed no differences (p˃0.05) compared to the untreated control in hind paw swelling (mL), hind joint thickness (cm), arthritis score on a scale of 0-16, and inhibition of loss of grip strength (secs) as observed on a rotating rotarod. Aqueous extract of RPM did not suppress the bone marrow unlike methotrexate standard. Chemical profiling revealed the presence of terpenoids, saponins, flavonoids, phenolics, and glycosides. No alkaloids were detected in all the three species. Fourier transform infra-red profiling revealed the presence of -OHstr, C-Hstr, C=Cstr and C-O-C linkages. Some of the compounds in Gas Chromatography-Mass Spectrometry profiling were β-sitosterol, stigmasterol, lupeol, and triterpenes. 13-Docosenamide, (Z)-, l-(+)-Ascorbic acid 2,6-dihexadecanoate, α-D-Glucopyranose, 4-O-. β -D-galactopyranosyl-, squalene, 9-Hexadecenoic acid, methyl ester, (Z), 9-Octadecenamide, (Z)-, 9-Octadecenoic acid (Z)-, methyl ester. These compounds have been documented to possess antioxidant, anti-inflammatory and analgesic activities. The present study concluded that extracts from Ruellia species studied possess antioxidant, analgesic, antinociceptive, anti-inflammatory and anti-arthritic activities, with the aqueous extract of RPM showing the highest activities, followed by the aqueous extract of RBK. This is the first scientific report regarding the efficacy of RPM in a rheumatoid arthritis animal model. The antioxidant, analgesic, antinociceptive and anti-inflammatory activities of R. bignoniiflora and R. linear-bracteolata were reported for the first time. Some compounds identified from the selected Kenyan Ruellia species, such as flavonoids, saponins, phenolics, glycosides, terpenes, β-sitosterol, stigmasterol, and lupeol have been reported in other Ruellia species. The present study recommends that the bioactive compounds present in R. prostrata and R. bignoniiflora should undergo further pre- clinical studies as analgesic and anti-arthritic drugs in a non-human primate before use in man
Physical Characterization of Eri Silk Fibers Produced in Kenya
(Taylor & Francis, 2021-01-02) Oduor, Edison Omollo; Ciera, Lucy; Adolkar, Vijay; Pido, Odoch
Eri silk produced in Kenya was characterized for sericin content, moisture content, surface morphology, thermal properties, functional groups, crystallinity, and single fiber tensile strength. It was found that Kenyan Eri silk possesses comparable physical properties to those of commercial silk producing countries. At a degummed tensile strength of 6.81cN, Kenyan Eri silk had comparable strength despite having low crystallinity (29.2%). This is an indication that on optimizing rearing procedures and practices of Eri silkworms to certain regions of Kenyan environment, better quality silk fibers can be produced that are competitive in the world market.
Survival and Growth of Olive Tree (Olea africana) Seedlings Under Open Field Conditions is Enhanced in Hydrogel Amended Soils Media, Teso Subcounty, Kenya
(East African Journal of Forestry and Agroforestry, 2022-10) Roselyne Awino Orure; Kipkosgei, Sirmah, Peter; Matonyei, Thomas Kibiwot
The rapid decline of timber from natural forests against increasing domestic demand for wood products has caused a steady increase in timber prices in Kenya. Recently, research and development institutions have recognized the ecological and economic value of indigenous tree species and therefore have emphasized the importance of their future production on private smallholder farms rather than in large plantations. This situation has been worsened by climate changes such as the frequent high intensity of prolonged droughts and the nature of soils with poor water retention capacity. As a result, unplanted forest regeneration sites have increased hence a need for re-afforestation of these sites to meet the target for the plantation industry. Therefore, there is a need for mass production of Olea africana seedlings for reforestation programs. One such approach is the application of hydrogels or synthetic polymer organic combinations capable of improving the water and nutrient retention of the soil that can support seedling growth. This study sought to investigate the effects of hydrogel application on selected growth characteristics of O. africana. Seeds were germinated and transferred into two sets of tubes of the same size arranged in a complete randomized block design (CRBD) experiment. The sets were subjected to different levels of hydrogel concentration. Under (0gm as control) and 7gm, 14gm, and 21gm) concentration levels of hydrogel mixed with soil in open field conditions. The height and shoot collar diameter of germinated seedlings were measured every two weeks for two months. The survival of O. africana seedlings decreased with time for all treatments irrespective of the addition of hydrogels with the highest (85%) survival of seedlings on soils mixed with 21gm of hydrogel compared to 0gm hydrogel that recorded (15% survival) eight weeks after

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