Amos Wanjala Wawire

Dr. Amos Wanjala Wawire

Agricultural Sciences, Karatina University, Nyeri, Kenya
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2021 in Heliyon
Verified
Journal Article
Open access
AWAmos Wanjala Wawire
Amos Wanjala Wawire
ÁCÁdám Csorba
Ádám Csorba
JTJózsef A. Tóth
József A. Tóth
EMErika Michéli
Erika Michéli
MSMárk Szalai
Márk Szalai
EKEszter Kovács
Eszter Kovács
Declining soil fertility continues to hinder agricultural production especially among resource-constrained smallholder farmers in sub-Saharan Africa, prompting for evaluation of the strategies used by these farming communities. In this study, we assess soil fertility management among smallholder farmers in Mount Kenya East region. The aim is to examine underlying factors conditioning the uptake of integrated soil fertility management (ISFM) practices in this region; determine the adoption relationship between the practices; and to cluster these techniques. Data for this study was collected between January–March 2019 through a household survey based on a farm household questionnaire and complemented with semi-structured interview with farmers and extension officers. Statistical analyses were generated using SPSS. We use hierarchical clustering analysis to visualize ISFM combination patterns, and correlation matrix in factor analysis to determine the inter-relationship between different ISFM practices. Fisher's exact test and Welch's t-test were used to examine the association between explanatory variables and adoption of ISFM practices. Results show that the decision to invest in fertility practices was correlated with a number of farmers' socio-economic, farm-related factors and institutional characteristics. Fertilizer application correlated significantly with manure use, agroforestry and minimum tillage. ISFM techniques were separated into 3 sets following Ward's hierarchical clustering, namely, manure, fertilizer use and agroforestry (cluster 1 or C1), slash-no-burn, residue burn and fallowing (C2); and residue application and minimum tillage (C3). The study recommends creation of an enabling environment including innovative financing opportunities to facilitate farmers' investment capacities in ISFM and cushion them from potential income loss resulting from implementation of some technologies.

5 June 2025 in Land
Verified
Journal Article
Open access
PDF file
Brian Rotich KanyongiBrian Rotich Kanyongi
Brian Rotich Kanyongi
TSTamas Andras Szegi
Tamas Andras Szegi
Yuri Andrei GelsleichterYuri Andrei Gelsleichter
Yuri Andrei Gelsleichter
Márta FuchsMárta Fuchs
Márta Fuchs
COCaleb Melenya Ocansey
Caleb Melenya Ocansey
ACAdam Csorba
Adam Csorba
Understanding how elevation gradients and soil depths influence soil organic carbon stocks (SOCS) and total nitrogen stocks (TNS) is essential for sustainable forest management (SFM) and climate change mitigation. This study investigated the effects of elevation and soil depth on SOCS and TNS in the Mount Kenya East Forest (MKEF). A stratified systematic sampling approach was applied, involving collection of 38 soil samples from two depths (0–20 cm and 20–40 cm) across three elevation zones: Lower Forest (1700–2000 m), Middle Forest (2000–2350 m), and Upper Forest (2350–2650 m). Samples were analysed for bulk density (BD), pH, texture, soil organic carbon (SOC), and total nitrogen (TN), using standard laboratory methods. In topsoil (0–20 cm), SOCS ranged from 109.28 ± 23.41 to 151.27 ± 17.61 Mg C ha−1, while TNS varied from 8.89 ± 1.77 to 12.00 ± 2.46 Mg N ha−1. In subsoil (20–40 cm), SOCS ranged from 72.03 ± 19.90 to 132.23 ± 11.80 Mg C ha−1, with TNS varying between 5.71 ± 1.63 and 10.50 ± 1.90 Mg N ha−1. SOCS and TNS increased significantly with elevation (p < 0.05), exhibiting the following trend: Lower Forest < Middle Forest < Upper Forest. Topsoil consistently stored significantly higher SOCS than subsoil (p < 0.05), emphasizing the critical role of surface soils in carbon sequestration. Regression analysis revealed a significant positive relationship between SOCS and TNS (R2 = 0.84, p < 0.001). Both SOCS and TNS were positively correlated with elevation, SOC, TN, and total annual precipitation (TAP), but negatively correlated with BD and mean annual temperature (MAT). These findings provide baseline data for monitoring SOCS and TNS in the MKEF, offering insights into sustainable forest management strategies to improve soil health and enhance climate change mitigation efforts.

12 April 2023 in Agronomy
Verified
Journal Article
Open access
PDF file
AWAmos Wanjala Wawire
Amos Wanjala Wawire
ACAdam Csorba
Adam Csorba
MMMohammed MohammedZein
Mohammed MohammedZein
Brian Rotich KanyongiBrian Rotich Kanyongi
Brian Rotich Kanyongi
JPJustine Phenson
Justine Phenson
EMErika Michéli
Erika Michéli
The smallholder farming systems in Sub-Saharan Africa (SSA) are highly diverse and heterogeneous in terms of biophysical and socio-economic characteristics. This study was conducted in upper Eastern Kenya (UEK) to categorize farm households and determine the influence of socio-economic characteristics (SeC) and soil fertility management practices (SFMP) on soil fertility across farms. Conditioned Latin hypercube sampling (cLHS) was performed to determine 69 soil sampling sites within Meru and Tharaka Nithi counties. From each household (whose field soil sample was obtained), data relating to resource endowment and soil fertility management were collected through a household questionnaire survey. Standard laboratory procedures were used to analyse soil samples. Data reduction was performed using categorical principal component analysis (CATPCA) (for SeC and SFMP) and standard principal component analysis (PCA) (for soil properties). Two-step cluster analysis identified three distinct farm categories or farm types (FT), namely, low fertility farms (FT1), moderately fertile farms (FT2), and fertile farms (FT3). The correlation of clusters against soil properties was significant across pH, soil organic carbon (SOC), cation exchange capacity (CEC), available P, plant available K, and exchangeable bases. FT1 had low SOC, pH, CEC and available P (soil characteristics), low usage of fertilizer and manure (soil fertility management), and smaller household size, lower income, and smaller farm size (socio-economic). FT2 had lower SOC (compared to FT3) and available P. In terms of soil fertility management, FT2 had higher cases of fallowing and composting with moderate fertilizer usage. Households in this category had moderate income, family size, and land size (socio-economic). FT3 had relatively high SOC, pH, CEC, and mineral nutrients. This farm type was characterized by high fertilizer use (soil fertility management) as well as larger household size, higher income, and larger farm size (socio-economic). The results indicate the importance of nutrient management in enhancing soil quality. Delineation and characterization of farms based on the various parameters including resource endowment reveal imbalanced farm resource flows, suggesting a need for locally tailored interventions suited for location-specific conditions to facilitate improved targeting of soil fertility-enhancing technologies and sustainable crop production regimes. While fertilizer is one of the most critical inputs for enhancing agricultural production, it is a major contributor to nitrous oxide emissions from agriculture and can have negative environmental effects on soil biota and water sources. Farmers’ knowledge on the use of fertilizer is thus necessary in developing strategies (such as integrated approach) to promote its efficient use and minimize its detrimental impacts.

13 February 2017 in Journal of Agricultural Science
Verified
Journal Article
Open access
PDF file
AWAmos Wanjala Wawire
Amos Wanjala Wawire
SWSabina M. Wangia
Sabina M. Wangia
JOJulius Juma Okello
Julius Juma Okello
Access to markets by Smallholder farmers has conventionally been constrained by lack of market information. Efforts to strengthen access of farmers to markets has triggered the mushrooming of several projects that embrace ICT tools in promoting access to competitive market information. Nevertheless, most farmers still lack access to accurate market information, such as existing commodity prices. This study examines the determinants of the use of ICT tools among smallholder farmers for agricultural transactions. The study uses Kenya Agricultural Commodity Exchange (KACE), one of the ICT-based marketing platform, as the case study. The objectives of the research are to determine the factors that influence access to agricultural information, and establishing factors that determine the intensity of use of ICT tools in accessing agricultural information. Survey was conducted among 136 smallholder farmers in Bungoma County. Both purposive, and multi-stage sampling were used to obtain the sample for this research. The study finds that several farmer characteristics, farm and capital endowment factors affect the use of ICT tools, particularly mobile phones. Gender, age, literacy level, affordability, perceived importance, mobile ownership and group membership were found to be significant in influencing the decision to use KACE ICT tools and the intensity of use of these tools for agricultural transaction activities. The study further recommends for policies that support the expansion of ICT projects, training on their applications and sensitization on the use of these platforms. The study suggests for policies to address gender disparities on access and use of ICT tools for agricultural transaction.