Publications

2022
Musafiri, C. M., Kiboi, M., Macharia, J., Ng'etich, O. K., Okoti, M., Mulianga, B., Kosgei, D. K., et al. (2022). Does the adoption of minimum tillage improve sorghum yield among smallholders in Kenya? A counterfactual analysis. Soil and Tillage Research, 223, 105473. Website Abstract
Climate change is a major drawback to food security in most developing countries. Promoting minimum tillage and climate-smart crops is essential in mitigating and adapting to climate shocks. However, information on the impacts of minimum tillage on crop productivity under farmers' conditions is limited in Western Kenya. We assessed the effects of minimum tillage adoption on sorghum productivity among smallholder sorghum farmers in Western Kenya. We used household survey data collected from 300 smallholder farmers and performed an endogenous switching regression model to analyze the effects of minimum tillage adoption on sorghum yields. The results revealed that the adoption of minimum tillage increased sorghum yields by 11%, from 1163 to 1146 kg ha−1. The occupation of the household head, acreage, soil fertility perception, and farm credit significantly and positively determined minimum tillage adoption. The remittance, agricultural associations, weather information, and site negatively and significantly determined minimum tillage adoption. Our findings suggest that minimum tillage adoption under drought-tolerant crops such as sorghum could improve community wellbeing through increased crop productivity, notwithstanding the changing climate and associated weather shocks.
Atkinson, E. G., Dalvie, S., Pichkar, Y., Kalungi, A., Majara, L., Stevenson, A., Abebe, T., et al. (2022). Genetic structure correlates with ethnolinguistic diversity in eastern and southern Africa. The American Journal of Human Genetics, 109, 1667-1679. Website Abstract
Summary African populations are the most diverse in the world yet are sorely underrepresented in medical genetics research. Here, we examine the structure of African populations using genetic and comprehensive multi-generational ethnolinguistic data from the Neuropsychiatric Genetics of African Populations-Psychosis study (NeuroGAP-Psychosis) consisting of 900 individuals from Ethiopia, Kenya, South Africa, and Uganda. We find that self-reported language classifications meaningfully tag underlying genetic variation that would be missed with consideration of geography alone, highlighting the importance of culture in shaping genetic diversity. Leveraging our uniquely rich multi-generational ethnolinguistic metadata, we track language transmission through the pedigree, observing the disappearance of several languages in our cohort as well as notable shifts in frequency over three generations. We find suggestive evidence for the rate of language transmission in matrilineal groups having been higher than that for patrilineal ones. We highlight both the diversity of variation within Africa as well as how within-Africa variation can be informative for broader variant interpretation; many variants that are rare elsewhere are common in parts of Africa. The work presented here improves the understanding of the spectrum of genetic variation in African populations and highlights the enormous and complex genetic and ethnolinguistic diversity across Africa.

Pages