Abstract
Manganese (Mn) is an essential micronutrient that influences carbon (C) cycling by binding or oxidizing soil organic matter. Mn fractions in soil and their plant availability depend largely on soil pH, which is commonly altered by agricultural practices. Fractions of Mn in soils range from readily available (e.g., bioavailable Mn, exchangeable Mn) to stabilized (e.g., Mn-oxide minerals, Mn contained in silicates). The distribution of soil Mn with depth was assessed in contrasting land use systems (organic agriculture, conventional agriculture, and unmanaged forest) using a sequential extraction method that targets Mn fractions ranging in bioavailability. Both agricultural sites had similar amounts of total Mn but had available Mn (1-7% of total Mn) lower than that of the unmanaged forested site (15% of total Mn). Manganese and organic C were generally positively correlated, but this relationship depended on soil depth, Mn fractions, and concentrations, while land management change had little influence.
| Original language | English |
|---|---|
| Pages (from-to) | 316-320 |
| Number of pages | 5 |
| Journal | ACS Agricultural Science and Technology |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 17 2025 |
Funding
This research was funded by the Laboratory Directed Research and Development program of Oak Ridge National Laboratory managed by UT-Battelle, LCC for the U.S. Department of Energy under contract DE-AC05- 00OR22725, and by the Critical Interfaces Science Focus Area project supported by the Office of Biological and Environmental Research in the DOE Office of Science. We thank Patricia Lazicki for assistance with soil sample collection.
Keywords
- agriculture
- Manganese
- mineral-organic associations
- nutrient availability
- soil organic carbon