Dr. Johannes Lehmann (Professor, School of Integrative Plant Science, Soil and Crop Sciences Section, Cornell University, Ithaca, New York) will present The Leo M. Walsh Distinguished Lecture in Soil Science entitled “Soil Organic Matter Formation: Concepts and Controversies” on Wednesday, April 20 @ 3:30 pm in Room 270 Soils Bldg.
Abstract – Soil organic matter is a defining feature of soils and underpins much of its ecosystem services, influencing soil fertility, water quality and greenhouse gas emissions. Yet its nature and formation are still debated. Interactions of organic matter with soil mineral surfaces and aggregation are seen as key to its persistence, but have not been explicitly included in soil organic matter models. While pyrogenic carbon is increasingly recognized as an important component of organic matter in many soils, its mineralization does not match the time scales of litter decomposition to fit seamlessly into existing soil carbon models. The concept of humification is still propagated in the literature and research on humic substances extracts is in fact increasing in the environmental and water sciences. Consolidating existing concepts of soil organic matter cycles is therefore urgently needed, and this presentation discusses some recent evidence that may also inform carbon sequestration in soil as a way to mitigate and adapt to climate change.
A reception will immediately follow Dr. Lehmann’s presentation. This lecture is made possible by the generosity of Leo M. Walsh and the Leo M. Walsh Distinguished Lecture in Soil Science Fund.