EVALUATION OF AGROECOLOGICAL DIVERSITY AND SOIL PRODUCTIVITY OF SMALLHOLDER FARMS IN BUSIA COUNTY, KENYA

Abstract

Agroecological biodiversity signifies the above ground variety and variability of different biological elements in agricultural systems; crops, livestock, tree species, and farm activities. Soil productivity relates to how capable a soil is concerning supporting plant growth and maintaining agricultural production over an area and time. The term, therefore, is synonymous with physical features of the soil in question as well as chemical, which include fertility, organic matter, and microbial activity. This research initiated in 2024, was fundamentally designed to critically assess the influence of agroecological biodiversity on soil productivity within the context of smallholder farming systems in Busia County, Kenya. The overarching goal was to empirically determine if diversification practices, specifically those aligned with established agroecological principles, yield a measurable, positive effect on soil productivity indicators. To quantify the degree of agroecological biodiversity practiced by farmers, the study employed the FAO’s Tool for Agroecology Performance Evaluation (TAPE) framework. This structured approach integrated four key, interlinked indicators; crop, livestock, tree, and diversified farm activities, to derive a composite agroecological biodiversity score for each participating farmer and the study area as a whole. The requisite sample size (n=210) was purposively acquired from the Ministry of Agriculture, livestock and Fisheries of Busia County's smallholder farmer population using Fisher's formula to ensure statistical representativeness. The specific criterion for inclusion was documented exposure to, and current implementation of, agroecological biodiversification practices since 2020, facilitated either by government agencies or private development entities. A random sampling technique was then strategically applied to select farmers. Six distinct administrative wards were initially identified for the study. In wards where the number of eligible farmers exceeded 35 (n>35), a simple random sampling procedure was executed using Microsoft Excel to select the final participants. For wards containing fewer than 35 farmers, or where selected farmers were unavailable or declined consent to participate, a snowball sampling method was utilized. This ensured that the target sample size of n=210 was achieved across the study area. Primary data collection was executed via a structured questionnaire survey administered using the mobile data collection platform, KoboCollect. The survey instrument was comprehensive, capturing essential information on farmer demographics, detailed inventories of crops cultivated, livestock held, and trees planted, the range of farm activities undertaken, and critically, actual maize yield data from the most recent harvesting season. The data was analysed through mixed methods evaluation using both Microsoft Excel and R software. Most of the households were male headed, with most (67.0%) in the age category of 18–35 years and 42.7% having attained tertiary education. Agriculture (87.9%) accounted as a major source of income. The observed agroecological diversity pattern showed unsustainable extents of practice: crops scored 40.5%, livestock 31.25%, trees 45.5%, and farm activities 41.75%. Despite observed diversification such as predominance of kienyeji poultry, maize cultivation, and single-species tree systems; soil productivity remained predominantly low, with most farms falling under SPI Class V (0–19%). Correlation analysis of agroecological biodiversity with soil productivity results in an R value of -0.0383, implying no significant relationship between agroecological biodiversity and soil productivity. These findings imply that although to a minimal extent

v

agroecological diversification exists, soil productivity is not directly influenced by it. However, the diversification might promote the resilience of soil over time, as influenced by climate change or from some other secondary intervention on soil vitality. Farm-specific interventions such as soil testing are recommended to address productivity challenges, while future research should explore the resilience benefits of agroecological biodiversity.