title: Carbon mineralizability determines interactive effects on mineralization of pyrogenic organic matter and soil organic carbon.
abstract: Soil organic carbon (SOC) is a critical and active pool in the global C cycle, and the addition of pyrogenic organic matter (PyOM) has been shown to change SOC cycling, increasing or decreasing mineralization rates (often referred to as priming). We adjusted the amount of easily mineralizable C in the soil, through 1-day and 6-month preincubations, and in PyOM made from maple wood at 350 °C, through extraction. We investigated the impact of these adjustments on C mineralization interactions, excluding pH and nutrient effects and minimizing physical effects. We found short-term increases (+20-30%) in SOC mineralization with PyOM additions in the soil preincubated for 6 months. Over the longer term, both the 6-month and 1-day preincubated soils experienced net ∼10% decreases in SOC mineralization with PyOM additions. Additionally, the duration of preincubation affected interactions, indicating that there may be no optimal preincubation time for SOC mineralization studies. We show conclusively that mineralizability of SOC in relation to PyOM-C is an important determinant of the effect of PyOM additions on SOC mineralization.
authors.affiliation: Department of Crop and Soil Science, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Thea
authors.initials: T
authors.lastname: Whitman
authors.forename: Zihua
authors.initials: Z
authors.lastname: Zhu
authors.forename: Johannes
authors.initials: J
authors.lastname: Lehmann
mesh_terms: D002244:Carbon / Q000378:metabolism*; D009518:New York; D009930:Organic Chemicals / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D009930:Organic Chemicals; D012989:Soil Pollutants; D002244:Carbon