Impacts of soil management and climate on saturated and near-saturated hydraulic conductivity: analyses of the Open Tension-disk Infiltrometer Meta-database (OTIM)

Abstract. Saturated and near-saturated soil hydraulic conductivities Kh (mm h−1) determine the partitioning of precipitation into surface runoff infiltration are fundamental to soils' susceptibility preferential flow. Recent studies found indications that climate factors influence Kh, which is highly relevant in face change. In this study, we investigated relationships between pedoclimatic also evaluated effects land use management. To end, collated Open Tension-disk Infiltrometer Meta-database (OTIM), contains 1297 individual data entries from 172 different publication sources. We analysed a spectrum saturated at matric potentials 0 100 mm. methodological details like direction wetting sequence or choice method for calculating rates had large impact on results. therefore restricted ourselves subset 466 with similar approaches. Correlations Ks higher supply tensions decreased especially close saturation, indicating flow mechanism very saturation than towards dry end tension range. Climate were better correlated topsoil ≥ 30 mm texture, bulk density organic carbon content. find it most likely variables proxies macropore networks created by respective biological activity, pedogenesis climate-specific management choices. Due incomplete documentation source publications OTIM, able investigate only few types agricultural practices. Land use, tillage system compaction significantly influenced effect sizes appearing comparable ones texture carbon. The OTIM show experimental bias present, introduced measurement time relative tillage, design evaluation procedures. establishment best-practice rules tension-disk infiltrometer measurements would be helpful. Future needed how shapes can adapted improve properties. Both tasks require numbers new improved biology history.