Theses & Desertations

SOIL BIOASSAY AS A DIAGNOSTIC TOOL IN THE DETECTION OF SOIL- BORNE PATHOGENS OF COMMON BEAN (Phaseolus vulgaris) IN WESTERN KENYA

2026-06-08T09:23:45Z

SOIL BIOASSAY AS A DIAGNOSTIC TOOL IN THE DETECTION OF SOIL- BORNE PATHOGENS OF COMMON BEAN (Phaseolus vulgaris) IN WESTERN KENYA NDUATI, GABRIEL Lack of accurate and precise diagnostic tools and methods for detecting soil pathogens and their impacts on crop yields hinders the productivity of various crops, including beans. This highlights the need to link field disease severities to bioassay results to ease not only the accuracy in detection but also ensure the reliability of the predictions of crop performance. The study was set to evaluate the effectiveness of existing soil bioassays for screening, detecting, and quantifying soil-borne pathogens (Fusarium spp., Pythium spp., and root- knot nematode) and predicting impacts on grain yields and severity levels in smallholder fields. The study was conducted in 50 farmer fields in five counties across Western Kenya. Field demonstration trials consisting of four bean varieties planted on the 4 by 4 m treatment plots were established in each of the five sites. At planting, soil samples were collected for physical and biochemical analysis. A subset of the soil samples was bulked at the field level and assessed for bioassays targeting Fusarium, Pythium, and plant parasitic nematodes. The bean varieties were assessed for disease severities, and agronomic indicators recorded. The study employed descriptive statistics, correlation analysis, and stepwise linear regression using R software. Pearson’s correlation coefficient (r) indicated a significant but weak negative relationship between the Fusarium stem assay and vascular browning (r= -0.27, p = 0.0091). In addition, Pythium seed assay had no association with field root rot severity, while the root knot nematode assay showed a marginally significant but weak positive relationship with field galling infestation (r = 0.14, p = 0.05). Also, a strong negative correlation between vascular browning and bean yield (r = -0.28, p< 0.001), and between disease pressure and yield (r = -0.22, p < 0.001) was observed. A stepwise linear regression model revealed that the interaction between Fusarium stem assay infestation and pH influenced vascular browning (p< 0.001) and stand count (p< 0.01). Similarly, the interaction of Pythium seed assay infestation with POXC significantly affected stand count (p< 0.001), and the association between Root knot nematode assay infestation and stand count was influenced by soil clay content (p< 0.001). Apart from the Root knot nematode assay, the soil pathogen bioassays tested here were not effective in predicting the field incidence. However, our findings revealed the ability of the fusarium stem assay to predict other symptoms associated with disease pressure, suggesting that the bioassays result together with soil fertility assessment can led to a more effective prediction of early disease pressure and yield.

EVALUATION OF IMPACTS OF INTEGRATED LIME AND FERTILIZER APPLICATION ON SELECTED SOIL CHEMICAL PROPERTIES AND SORGHUM PRODUCTIVITY IN ACID SOILS OF WESTERN KENYA

2026-06-08T09:16:02Z

EVALUATION OF IMPACTS OF INTEGRATED LIME AND FERTILIZER APPLICATION ON SELECTED SOIL CHEMICAL PROPERTIES AND SORGHUM PRODUCTIVITY IN ACID SOILS OF WESTERN KENYA ROTICH, EDWIN This research assessed sustainable strategies aimed at enhancing soil fertility and sorghum production in the acidic soils of western Kenya. Microdosing trials were carried out in Kakamega and Siaya. These were executed under two conditions: lime- treated (4 t ha−1) and untreated (0 t ha−1), and were factorially combined with varying application rates of nitrogen (18.8, 37.5, and 75 kg ha−1) and phosphorus (6.5, 13, and 26 kg ha−1). The study employed a randomized complete block design (RCBD) with treatments analyzed using ANOVA, followed by Tukey’s HSD for mean separation. Results revealed liming significantly increased soil pH (from 4.50 to 6.19), reduced exchangeable Al, and improved grain N and P uptake. SOC rose across sites, with lime– fertilizer treatments showing strong positive trends. The application of lime significantly (p < 0.001) enhanced both sorghum biomass and grain yield by increasing soil pH, which in turn mitigated Al toxicity, improved root access to P, and promoted N assimilation. Micro-doses of N and P fertilizers were superior to recommended doses in grain and biomass yield, agronomic efficiency (AE), and harvest index (HI). Nutrient uptake efficiency ranged from 21.91–34.54%, with the maximum at N18.8P6.5. Increasing doses of fertilizer reduced NUE and AE. Combining 4 t ha−1 lime with N75P26 fertilizer maintained the highest gross margins and benefit–cost ratios (BCR > 2.0; p < 0.001) at sites and seasons. Seasonal differences affected profitability, with 2018- LR performing better than other years. The combined application of lime and fertilizer yielded the highest economic efficiency among the treatment options, with lime + N37.5P13 treatment proving to be the most economically viable option among the smallholder farmers. The integration of site-specific fertility management with the conventional application of lime (4 t ha−1), along with microdoses of N and P fertilizers, has the potential to rehabilitate acid-degraded soils in western Kenya, thereby significantly improving sorghum productivity and increasing farmers' incomes.

INTEGRATION OF TIED RIDGES AND FERTILIZER USE TO ENHANCE WATER AND NITROGEN USE EFFICIENCIES FOR MAIZE PRODUCTION IN SEMI-ARID LANDS

2026-06-08T08:41:32Z

INTEGRATION OF TIED RIDGES AND FERTILIZER USE TO ENHANCE WATER AND NITROGEN USE EFFICIENCIES FOR MAIZE PRODUCTION IN SEMI-ARID LANDS ALWANG’A, SUSAN Low maize (Zea mays L.) production in arid and semi-arid lands (ASALs) has been attributed to inadequate soil moisture and declining soil fertility. This could be improved through enhanced water use efficiency (WUE) and nutrient use efficiency (NUE). During the short rain (SR) seasons of 2013 and 2014, a study was conducted at Kenya Agricultural and Livestock Research Organization (KALRO) – Katumani Research Station to monitor WUE, NUE and grain yield in maize production. A 2*2*4 factorial trial of cropping seasons, soil moisture conservation (tied versus untied ridging) and fertilizer types (control, CAN, FYM, CAN + FYM were set up in a Randomized Complete Block Design (RCBD). Rainfall data was put together for the entire study period. Soil and manure analysis were also done. Soil moisture content was monitored using a neutron probe moisture meter, CPN 503-DR. Analysis of variance was executed on soil moisture, maize grain yield and water and Agronomic Nitrogen Use Efficiencies using GENSTAT statistical software 14th edition. Treatments with significant differences were separated using Tukey’s at 95% confidence intervals. In both seasons, treatment combinations under untied ridges had higher soil moisture than those in tied ridging. Plots with tied ridges had higher WUE (1.87kg mm-1 ha-1 ) compared to those with untied ridges (1.00kg mm-1 ha-1 ). Tied ridge plus FYM plots recorded the largest WUE in both SR 2013 (2.9 kg mm-1 ha-1 ), SR 2014 (3.6 kg mm-1 ha-1 ) and in overall (3.23kg mm-1 ha-1 ). On average, maize yields were 53% higher in 2013 than in 2014 SR. FYM in tied ridges resulted in larger yields (294kg ha-1 ) compared to untied ridges (152kg ha-1 ). Tied ridges (3.75kg grain-1 kg N-1 ) had higher NUE than untied (-0.75kg grain-1 kg N-1 ). In both SR 2013 (6.6 kg Nha1 ) and SR 2014 (3.6 kg Nha1 ) seasons, plus the overall mean highest NUE was observed in FYM under tied ridge plots. Application of FYM in combination with CAN and tied ridges seemed to be the best bet for increased maize yields through enhancing both NUE and WUE.

THE EFFECTS OF FARMERS GROUP PERFORMANCE ON HOUSEHOLD FOOD SECURITY IN WESTERN KENYA

2026-06-08T07:07:20Z

THE EFFECTS OF FARMERS GROUP PERFORMANCE ON HOUSEHOLD FOOD SECURITY IN WESTERN KENYA NASAMBU, JOYCE Many developing countries have reintroduced farmer groups into their policy agenda due to their role in accelerating technical and economic change in rural areas. In Kenya, however, farmer groups remain inadequately structured and their performance in promoting food security is not well established. Farmers in western Kenya, particularly in Bungoma and Siaya counties, depend heavily on agriculture as their primary source of livelihood, yet food insecurity persists despite the presence of numerous farmer groups. Previous studies have largely focused on the typologies, structures, and developmental stages of farmer organizations but have paid limited attention to how their performance—under different organizational regimes such as farmer groups and associations—affects household food security. This study therefore investigated the influence of farmer group performance on household food security in western Kenya. The specific objectives of the study were to: examine the effect of farmer group dynamics on food security; establish the effect of farmer group output on food security; and determine the influence of gender relations on farmer group performance. A multistage sampling technique was used to select 587 farmers from 33 farmer groups across Bungoma and Siaya counties, while simple random sampling was employed to identify 371 respondent households. Quantitative data were collected through household surveys, while qualitative data were gathered through document reviews, Key Informant Interviews (KIIs), and Focus Group Discussions (FGDs). Quantitative data were analyzed using descriptive and inferential statistics with the aid of SPSS (IBM), while qualitative data were analyzed thematically. The results revealed a statistically significant relationship between farmer group performance and household food security (F = 10.081, p < 0.001). The R value of 0.228 indicated a positive influence of farmer group dynamics and output on food security. Farmer group output (β2 = 0.152, p = 0.004) had a relatively higher effect than group dynamics (β1 = 0.13, p = 0.015). The study also found that gender disparities persist, with women contributing the majority of farm labour yet being marginalized in decision-making processes. The study concludes that strengthening farmer group performance and promoting gender equality in agricultural decision-making are essential for enhancing household food security and improving rural livelihoods in western Kenya.

EFFECT OF WONDERGRO- A SOIL CONDITIONER FOR ENHANCING DI- AMMONIUM PHOSPHATE (DAP) USE EFFICIENCY IN MAIZE PRODUCTION

2026-06-08T06:52:35Z

EFFECT OF WONDERGRO- A SOIL CONDITIONER FOR ENHANCING DI- AMMONIUM PHOSPHATE (DAP) USE EFFICIENCY IN MAIZE PRODUCTION OGUTU, DISHON Despite maize being considered a staple food crop in Kenya, its productivity is low mainly due to inappropriate soil fertility management, especially in smallholder systems. The continuous decline in soil fertility is a consequence of acidic conditions, nutrient imbalances, and sub-optimal fertilizer use, causing depressed maize yield. Use of balanced and adequate fertilizers while improving other soil conditions is a prerequisite for increasing fertilizer use efficiency and maize production. On-farm trials were conducted during the long and short rains seasons of 2023 & 2024 to asses’ performance of two formulations of WonderGro (WG3 & WG21)- a soil conditioner- in combination with the commonly applied Di-Ammonium Phosphate (DAP) fertilizer on maize yield and the economic return, under a range of soil pH (sub- optimal (pH<5.5) and optimal (≥5.5)) for maize production. Sixteen (16) study sites located in two agroecological zones (AEZ), of medium potential (western Kenya) and high potential (Rift Valley), with expected maize grain yields of 4.5-5t ha- 1 and 6-8t ha-1 , respectively, were selected for the on-farm trials. Each AEZ had eight (8) sites equally distributed in two (2) counties. The trials involved five treatments: 0 kg DAP ha-1 (absolute control), 133 kg DAP ha1 (full rate of recommended DAP application per ha-1 ), 67 kg DAP ha-1 (half rate of recommended DAP application per ha-1 ), 67 kg DAP+WG3 ha-1 and 67 kg DAP+WG21 ha-1, each replicated four (4) times. Maize production in the medium potential AEZ, in the sub-optimal pH category, use of half rate of DAP in combination with WG3, slightly increased yield by 3.5% from the use of the full rate of DAP (133kg DAP ha-1 ), with 2.8tha-1 of maize grain yield in the long rains of 2024. While in high-potential AEZ, suboptimal pH for maize production (<5.5), applying 67 kg DAP + WG21 ha-1 slightly increases yield to 5.1t ha-1 from 5.0t h-1 with application of the full rate of DAP. In high AEZ, there was no variation in maize grain yield in optimal pH, regardless of fertilizer applied, with an average of 7.3 t ha-1 and 6.1t ha-1 for 2023 and 2024 long rains, respectively. Economically, application of 67kg DAP ha-1 +WG21 had the largest Value Cost Ratio (VCR) of 7.54 and 8.24 for long rains 2023 and 2024, respectively, in sub-optimal pH in the high-potential zone. The formulations, therefore, have the potential to boost yield and for better economic returns to the farmers.

FATE OF NITROGEN FERTILIZER IN RAINFED MAIZE SYSTEMS OF TROPICAL HIGHLANDS OF KENYA

2026-06-05T11:27:26Z

FATE OF NITROGEN FERTILIZER IN RAINFED MAIZE SYSTEMS OF TROPICAL HIGHLANDS OF KENYA OLUOCH, KEVIN CHURCHIL Crop production in sub-Sahara Africa (SSA) is often constrained by declining soil fertility associated with negative nutrient balances as a result of continuous cropping with little or no replenishment of nutrients. To offset the negative nutrient balance, especially nitrogen (N), in SSA agroecosystems and meet the ever-increasing food demand, it is paramount to intensify N fertilizer use. However, this could prove deleterious to ecosystem functioning since increased N fertilizer is associated with elevated reactive nitrogen (Nr) loading in the environment. Therefore, a study comprising increasing N fertilizer rates, 0, 25, 50, 75, 100 and 125 kg N ha-1 was conducted in the highland tropics of the Rift Valley, Kenya. The objective was to evaluate fertilizer-induced soil mineral N (Nmin) changes within the soil profile and nitrous oxide (N2O) emissions in maize monoculture systems. On average, the N application of 125 kg N ha-1 exhibited the largest NO3 - (14.8 mg kg-1 ) and NH4 + (11.85 mg kg-1 ) concentration across depth and different N rates. The annual N2O fluxes ranged from 0.33 to 0.77 kg N2O-N ha-1 across the different N rates. Additionally, yield- scaled emissions ranged from 0.07 to 0.14 g N2O-N kg-1 grain yield across different N rates. Increasing N fertiliser rates increased grain yield by 7, 14, 24, 37 and 46 % while applying 25, 50, 75, 100 and 125 kg N ha-1 , respectively. Application of 25 kg N ha-1 gave indications of soil N mining, with a nitrogen use efficiency (NUEgrain) value of > 1, whereas the rest of the N rates had an NUEgrain value of < 1. The optimum physiological efficiency and partial-factor productivity were realised when N was supplied at 75 kg N ha-1 . Overall, the results suggest that increasing N application to 75 kg N ha-1 would not only improve grain yield but also increase soil N intensity, N2O emissions and optimise NUE. Therefore, matching crop demands through judicious N use will be critical to ensure efficient use of fertiliser N and reduce losses to the ecosystem.

GREENHOUSE GAS EMISSIONS, SOIL PHYSICOCHEMICAL PROPERTIES, AND NUTRIENT USE EFFICIENCY UNDER INORGANIC-ORGANIC FERTILIZER SUBSTITUTIONS IN MAIZE AND DESMODIUM CROPPING SYSTEMS

2026-06-03T13:05:47Z

GREENHOUSE GAS EMISSIONS, SOIL PHYSICOCHEMICAL PROPERTIES, AND NUTRIENT USE EFFICIENCY UNDER INORGANIC-ORGANIC FERTILIZER SUBSTITUTIONS IN MAIZE AND DESMODIUM CROPPING SYSTEMS ODERA, IRINE Climate change continues to threaten ecosystem functions, and agriculture remains one of the major sources of greenhouse gas (GHGs) emissions responsible for global warming. However, little is known about the quantities and intensities of GHGs from major cropping systems in Kenya and, by extension, in Sub-Saharan Africa. This study was aimed to quantify GHG emissions - carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes from soil. It also assessed the optimal organic-inorganic fertilizer substitution in maize (Zea mays) and desmodium (Desmodium uncinatum) cropping systems that enhance crop yields and lead to reductions in GHG emissions. The static chamber method was used from April to November 2024. The experiment consisted of six fertilizer substitution ratios (0 0, 25 75, 50 50, 75 25, 100 0, and 0 100% FYM-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 desmodium yield responded positively to increasing Farmyard manure substitution levels (p < 0.0001), with biomass rising under higher organic inputs. Despite these, N2O emission factors and yield-scaled emissions remained consistently low across fertilizer treatments, indicating efficient nitrogen utilization and minimal gaseous losses. The net global warming potential did not vary significantly among treatments. Greenhouse gas intensity declined sharply from the control to the 75,25 fertilizer treatment, representing approximately a 70% reduction. Maize grain yield was highest under the 50,50 (50% FYM, 50% inorganic fertilizer), indicating a strong synergistic effect between organic and mineral nutrient sources. Emission factors increased by nearly 20% relative to the control. Net global warming potential also increased progressively with higher Farmyard manure substitution, showing an approximately 40.7% increase. Despite these increases, the 50,50 treatment achieved the most favorable balance between productivity and emissions, producing the highest maize yield with comparatively lower EF and greenhouse gas intensity (GHGI). Combined FYM–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. FYM- 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.

SPATIOTEMPORAL DYNAMICS OF RIPARIAN GREENHOUSE GAS FLUXES AND SOIL CARBON STOCKS IN THE BURA AND WUNDANYI CATCHMENTS, KENYA

2026-06-03T12:13:54Z

SPATIOTEMPORAL DYNAMICS OF RIPARIAN GREENHOUSE GAS FLUXES AND SOIL CARBON STOCKS IN THE BURA AND WUNDANYI CATCHMENTS, KENYA OWUOR, GODFREY Agropastoral riparian zones are globally linked to increased greenhouse gas (GHG) emissions and soil organic carbon (SOC) depletion, but the Kenyan cases are underrepresented in global datasets. The study investigated variations in GHG fluxes and SOC stocks across three livestock production density levels in the Bura and Wundanyi sub- catchments. Eighteen (18) riparian sites (high livestock density (HLD n=7), low livestock density (LLD n=4), and zero density (ZLD n=7) were sampled between 2021 and 2022 in 2 dry seasons and 2 wet seasons in three topographies [(Upland at >1000 masl), (Midland 700 - <1000 masl), and (Lowland <700 masl)]. Results from Wundanyi showed higher CH4 fluxes under HLD, particularly in the midland zones, where emissions reached 302.5 μg CH4 m−2 d−1. In contrast, ZLD sites acted as net CH4 sinks. The mean CH4 flux for Wundanyi was 30.21 mg CH4-C m−2 d−1. Consistently high CO2 fluxes were recorded in Wundanyi with a mean of 900.17 mg CO2-C m−2 d−1. The highest mean was observed at the ZLD sites, Upland (1146.75 mg CO2-C m−2 d−1) and Midland (1003.25 mg CO2-C m−2 d−1). SOC stocks in Wundanyi averaged 6.91 Mg C ha−1, with higher concentrations recorded in Upland areas (8.01 Mg C ha−1). These stocks were greater during wet seasons (8.47 Mg C ha−1) and showed an increasing trend with livestock density: 6.67, 7.03, and 7.40 Mg C ha−1 in ZLD, LLD, and HLD, respectively. In Bura, CH4 fluxes were predominantly negative with mean absorptions in Midland LLD and Upland HLD areas (- 169.27 and -256.63 mg CH4-C m−2 d−1), respectively. CO2 emissions were moderate, with a mean of 527.07 mg CO2-C m−2 d−1, remaining <700 mg CO2-C m−2 d−1 across sites and livestock systems. N2O fluxes in Bura were moderate, peaking at 155.93 μg N2O-N m−2 d−1 in Midland zones under HLD. SOC stocks were highest in the Midlands at 8.29 Mg C ha−1, with values increasing alongside livestock density (7.13, 7.78, and 9.16 Mg C ha−1 for ZLD, LLD, and HLD, respectively. Bura was a strong methane sink, while Wundanyi recorded CH4 emissions in grazed areas and net uptake in ZLD. The upland and ZLD areas were significant CO2 sources. This study confirms that increasing livestock densities depleted SOC stocks with appreciable human disturbance contributions. Livestock production densities are dictated by topography, and GHG emissions are often part of natural exchange processes. To realise sustainability in livestock systems, sustainable stocking densities, protecting riparian strips, and enhancing vegetative cover should be practised. Long-term catchment-level research to document seasonal nutrient input-output dynamics would improve GHG inventories for sub-Saharan Africa.

EFFECT OF PHOSPHORUS FERTILIZER AND CROPPING SYSTEMS ON RICE BEAN (Vigna umbellata, L.) PRODUCTION IN WESTERN KENYA

2026-06-03T11:53:06Z

EFFECT OF PHOSPHORUS FERTILIZER AND CROPPING SYSTEMS ON RICE BEAN (Vigna umbellata, L.) PRODUCTION IN WESTERN KENYA MIGAYA, ERICK Low soil phosphorus (P) remains a critical constraint to sustainable legume production in Western Kenya. Rice bean (Vigna umbellata L.), a resilient and nutrient-rich yet underutilized legume, offers opportunities for food security enhancement and soil fertility restoration. The crop productivity has been hindered by nutrient deficiencies and suboptimal cropping systems. This study evaluated the effect of phosphorus fertilizer and cropping systems on rice bean soil fertility dynamics, phenology and yields across three agroecological sites; Siaya, Rongo and Kaimosi over two consecutive seasons (September– December 2020 and March–August 2021). A split-plot design was used, with cropping system (monocrop, conventional intercrop and MBILI) as the main factor and P amendments (control at 0 kg P ha−1, FYM at 5 kg P ha−1, combined FYM + inorganic at 15.5 kg P ha−1, and sole inorganic at 26 kg P ha−1) as the subplot factor, replicated three times per site. Data on soil available P, phenological stages, pods per plant, grain yields, phosphorus agronomic efficiency (PAE) and harvest index (HI) were collected and analyzed using Analysis of Variance (ANOVA). Results showed that soil available P was highly responsive to P amendments, with 26 kg P ha−1application producing the highest levels (up to 8.88 mg kg−1 at Rongo monocrop), while 15.5 kg P ha−1 application maintained moderately high levels that balanced immediate nutrient supply with long-term fertility. Cropping system effects on soil P were less pronounced, but monocropping and MBILI showed slightly greater retention than conventional intercropping. Phenological responses were notable: 0 kg P ha−1 plots matured 12–17 days later than 15.5 kg P ha−1 or 26 kg P ha−1 treatments, with delayed flowering and extended vegetative growth under P deficiency. Across sites and seasons, grain yields ranged from 0.24 t ha−1 in conventional controls at Siaya to 1.72 t ha−1 under monocrop with 15.5 kg P ha−1 P in Rongo, highlighting the clear yield advantage of combined nutrient management in low-P soils. PAE varied widely, peaking at 63.42 kg kg−1 under monocrop with fertilizer treatment of 15.5 kg P ha−1 at Rongo. The PAE was higher under the fertilizer treatments of 5 kg P ha−1 and 15.5 kg P ha−1 treatments than under 26 kg P ha−1, indicating superior nutrient use efficiency with organic amendments. Harvest index values reflected biomass partitioning, highest in conventional and MBILI systems (up to 11.10%) compared to 3–4% in monocrops. The study concludes that combining organic and inorganic phosphorus sources within site-specific cropping systems accelerates phenological development, improves nutrient use efficiency and maximizes yield in rice bean production. Extension programs should prioritize farmer training on integrated soil fertility management to promote organic–inorganic nutrient combinations. These findings provide a framework for sustainable intensification of underutilized legumes in phosphorus-deficient soils.

EFFICIENCY OF ARBUSCULAR MYCORRHIZAL FUNGI IN ENHANCING PHOSPHORUS AND COPPER UTILIZATION IN WHEAT GROWN IN FERRALSOLS OF UASIN GISHU COUNTY, KENYA

2026-05-09T12:15:39Z

EFFICIENCY OF ARBUSCULAR MYCORRHIZAL FUNGI IN ENHANCING PHOSPHORUS AND COPPER UTILIZATION IN WHEAT GROWN IN FERRALSOLS OF UASIN GISHU COUNTY, KENYA Njoki, Anne Declining soil fertility characterized by deficiency of both macro and micronutrients is a major challenge to sustainable wheat production. Integrating bio-stimulants such as Arbuscular Mycorrhizal Fungi (AMF) with inorganic fertilizers has been shown to have the potential to enhance wheat production by optimizing their mutual benefits. However, a combination of AMF and micronutrients has not been given the necessary attention, especially in low-input systems such as those dominant in sub-Saharan Africa. Thus, the current study was conducted in Uasin Gishu County, Kenya, for two seasons to evaluate the effect of integrating AMF with phosphorus (P) and copper (Cu) fertilizers on wheat grain yield, nutrient uptake, and use efficiency. Two levels of AMF (0 and 60 kg ha -1 ) were applied with three levels of P: 0 kg, 8.8 kg, and 17.6 kg ha -1 , and three levels of Cu at 0 kg, 5 kg, and 10 kg ha -1 . The experiment was conducted in an RCBD, and fertilizer treatments were applied in a factorial arrangement in the 2018 and 2019 long rains seasons. Results showed that while AMF did not have a significant impact on soil available P, available Cu increased by 32% - 40% compared to the control. AMF also enhanced P and Cu uptake by 27 - 30% and 24 - 38%, respectively. Furthermore, AMF boosted P and Cu uptake efficiency by 30 - 35% and 25 - 40%, respectively, whereas P and Cu use efficiency increased by about 15 - 31% and 18 - 35% above the plots without AMF, respectively. Co-application of P at 8.8 kg ha -1 and 60 kg AMF ha -1 recorded the highest wheat grain yield of 2.84 and 4.72 Mg ha -1 during the 2018 and 2019 long rain seasons, respectively. The study shows that the use of AMF could play a significant role in reducing the amount of inorganic fertilizers, which cuts down the cost of production to most smallholder farmers, but at the same time enhancing nutrient uptake and use efficiencies, and thus grain yield. This study recommends co-application of 60 kg ha -1 of AMF and 8.8 kg P ha -1 for optimal wheat yield and P nutrition in wheat.