Beyond the bottle: factors affecting adoption of liquid urine fertilizer among smallholder farmers in Southern Malawi

Introduction The growing demand for affordable and sustainable soil fertility solutions in sub-Saharan Africa has renewed interest in human-derived organic inputs such as urine fertilizer. Despite its agronomic potential, uptake among smallholder farmers remains limited. This study examines the factors shaping awareness, adoption, and intensity of urine fertilizer use among smallholder farmers in Southern Malawi. Methods Data were collected from 251 smallholder farmers, all of whom were members of at least one organized farmer group, reflecting the strong institutional embeddedness of rural agriculture. A Triple-Hurdle Model was employed to sequentially analyze the determinants of awareness, adoption conditional on awareness, and intensity of use conditional on adoption. Descriptive statistics complemented the econometric analysis. Results Descriptive findings showed that 46 percent of farmers were aware of urine fertilizer, while 32 percent had applied it. In the first hurdle, education level and extension contact significantly increased awareness, whereas odour concerns significantly reduced it. Conditional on awareness, adoption was positively influenced by extension contact and farm size, while perceived costs and odour concerns emerged as key deterrents. The Inverse Mills Ratio was negative and statistically significant, confirming the presence of selection bias between awareness and adoption. In the third hurdle, intensity of use increased with extension contact, farm size, and poultry ownership, but declined significantly with odour-related concerns. Discussion The results indicate that while farmer organization enhances information access, actual uptake and sustained use of urine fertilizer depend on effective extension engagement, household resource endowments, and perception management. Addressing sensory concerns and cost perceptions is critical for scaling adoption. Policy interventions should prioritize demonstration-based learning, odor-mitigation strategies, and the integration of urine fertilizer into circular bioeconomy frameworks that link sanitation and agriculture.