Beyond the Binary: A Multinomial Logit and Mixed-Methods Analysis of the Determinants of Integrated ConservationAgriculture–Agroforestry Adoption among Smallholder Farmers in East Wollega Zone, Ethiopia

<title>Abstract</title> <p>Conservation agriculture (CA) and agroforestry (AF) are widely promoted as complementary pathways to sustainable land management in smallholder Africa, yet most adoption studies treat uptake as a binary choice, obscuring the progressive way farmers actually combine practices. This study examined the determinants of integrated CA-AF adoption among 410 smallholder households in East Wollega Zone, Oromia Region, Ethiopia, using an explanatory sequential mixed-methods design. Households were classified into conventional non-adopters (n = 118), partial adopters (n = 173), and integrated CA-AF adopters (n = 119). A multinomial logistic regression model, complemented by average marginal effects (AMEs) and a Two-Stage Residual Inclusion (2SRI) robustness check, was estimated alongside thematic analysis of 16 focus group discussions and 64 key informant interviews (n = 144). Institutional factors exerted the strongest influence on integrated adoption: land tenure security (AME = 0.112, p &lt; 0.01), training participation (AME = 0.098, p &lt; 0.01), and extension contact (AME = 0.030, p &lt; 0.01). Human capital (education, household size), resource endowments (landholding, livestock), and biophysical stressors (severe erosion, steep slopes) were also significant. Female-headed households showed higher unconditional integrated-adoption propensity but derived significantly smaller returns from extension contact (Gender × Extension β = −0.184, p &lt; 0.05), pointing to service-delivery rather than motivational barriers. Qualitative narratives corroborated and enriched these findings, revealing labour, residue-livestock, and tenure-related trade-offs underlying the statistical patterns. The study contributes a three-stage adoption-pathway framework, evidence for institutional complementarity over isolated interventions, and gender-responsive extension design implications for accelerating sustainable land management in smallholder farming systems.</p>