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An estimated 20% of the world's land surface is underlain by lithologies favorable for karst formation. Karst features (e.g., sinkholes) and soils coevolve, likely influencing local pedogenesis, soil carbon storage, and hydrologic patterns. While karst is widespread, our understanding of the influence of karst geomorphology on pedogenesis remains limited. To better estimate the impact of karst geomorphology on pedogenesis, we characterized nine pedons as a function of landscape position (i.e., toposequence) in two subsidence sinkholes located in the Inner Bluegrass physiographic region of central Kentucky; we characterized a suite of soil physical, chemical, and mineralogical properties. The Inner Bluegrass is underlain by a phosphatic limestone and is susceptible to karst formation. Expectedly, total carbon was greater in lowland positions relative to upland landscape positions. However, inverse relationships between elevation and clay content, selective iron, aluminum, and silicon extracts contradicted previous toposequence trends. Clay mineralogy differences between toeslope and summit positions suggested sediment transport from summit to toeslope positions. Karst geomorphology may limit pedogenesis and facilitate more rapid material export through karst conduits compared to other lithologies. Given the extent of karst terrains and lithologies susceptible to karst formation, future work is needed to understand the magnitude of the impact of karst on pedogenesis and other earth system processes. Core Ideas: Sinkholes are common features in karst topography and have variable morphologies.Soil physical and chemical properties are variable between karst sinkholes.Typical toposequence trends may be reversed in sinkholes due to the impact of karst features. [ABSTRACT FROM AUTHOR]

Indigenous vegetables play an important role in Kenyan food security, but production is limited by poor seed quality. Traditionally, seeds have been traded through informal networks, but a new formal seed sector is emerging. This study assessed the relative potential for formal or informal seed systems to meet the need for high-quality indigenous vegetable seed. By evaluating determinants of farmers' seed purchasing behaviour, we conclude that informal seed systems have greater potential to meet this need and should be strengthened. This study suggests that policy-makers should use context-specific data to guide decisions on seed policy. [ABSTRACT FROM AUTHOR]