Johannes Lehmann

Dr. Lehmann’s group focuses on nano-scale investigations of soil organic matter, the biogeochemistry of pyrogenic carbon and sequestration in soil, sustainable soil management, biochar systems science, climate change mitigation and adaptation through soil management, and the circular bionutrient economy. The group’s interests span both applied and basic research, follow an interdisciplinary approach, and include developing new approaches to creativity. They study fundamental aspects of soil processes, its management, and develops global projections and decision support systems. Using high-resolution microscopy they investigate what natural organic matter looks like; this work started to question the existence of humic substances to propose functional complexity as a more appropriate framework to explain the persistence of soil organic carbon. Through studies of Amazonian Terra Preta soils, Lehmann became interested in the persistence of fire-derived organic matter and its effect on nutrient and gas cycles in soil, which led to the proposal of biochar as a soil management and climate change mitigation tool. The group is evaluating ways to recycle human excreta as fertilizers, recognizing that in many countries, more nutrients are flushed down the toilet than added to agricultural crops. Together with artists, Lehmann develops art-science tools to identify problems, engage stakeholders, and create questions.