Location: Soil Management and Sugarbeet Research
Project Number: 3012-12210-001-029-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2024
End Date: Sep 1, 2027
Objective:
To identify mechanisms and quantify soil carbon (C) storage and loss in semi-arid rangeland ecosystems to further develop and refine grazing management practices that minimize environmental impact and increase resilience to climate variability. Given the extension of rangelands, increasing their soil C stocks through improved grazing management has the potential to be an important climate change mitigation strategy. However, semi-arid rangelands are also relatively unresponsive systems and their potential to increase soil C storage in response to management changes remains an open and debated question. Understanding the mechanisms of C sequestration and loss in this environment will be important in quantifying their potentials to developing management practices that sustain soils during climate change and subsequent evaluation of soil health.
Approach:
We will sample soils to 1m depth in rangelands across Colorado and Wyoming which received contrasting grazing management for a least a decade. Sites will include long-term ARS research sites such as the Cheyenne East Unit site where grazing treatments (ungrazed, light, and heavy) have been in place since 1982. Soils will be preprocessed and analyzed for the C, both organic and inorganic, and N storage along the depth profile and across functionally different soil organic matter fractions. Soils will also be characterized for pH, texture and their chemical fingerprint by FTIR and other advanced chemical techniques. The effect of historical management on soil C storage and other properties will be explored by appropriate statistical analyses. Project results will be presented at professional meetings and published in professional journals. We also anticipate using them to improve modeling of semi-arid rangelands by the MEMS 2 model, since the management history is well documented and fully controlled.
Both parties are actively engaged in independent research projects evaluating the effects of rangeland management on C cycling and sequestration, and climate change mitigation (reduced emissions, C sequestration, and adaptation).
