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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Publications at this Location » Publication #390652
Research Project: Management Practices for Long Term Productivity of Great Plains Agriculture

Location: Soil Management and Sugarbeet Research

Title: The role of plant litter traits, and microbial and soil chemical diversity on the formation of particulate and mineral-associated organic matter

Author
item COTRUFO, M - Colorado State University
item HADDIX, MICHELLE - Colorado State University
item KROEGER, MARIE - Los Alamos National Research Laboratory
item Stewart, Catherine

Submitted to: Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2022
Publication Date: 3/23/2022
Publication URL: https://handle.nal.usda.gov/10113/7717469
Citation: Cotrufo, M.F., Haddix, M.L., Kroeger, M.E., Stewart, C.E. 2022. The role of plant litter traits, and microbial and soil chemical diversity on the formation of particulate and mineral-associated organic matter. Soil Biology and Biochemistry. Article e108648. https://doi.org/10.1016/j.soilbio.2022.108648.
DOI: https://doi.org/10.1016/j.soilbio.2022.108648

Interpretive Summary: Soil organic matter is a fundamental resource to humanity for the many ecosystem services it provides. Increasing soil organic matter stocks can significantly contribute to climate change mitigation and the sustainability of agricultural production. USDA and Colorado State University researchers in Fort Collins, CO investigated the fate of organic matter derived from plant materials in soils. Using innovative techniques to label carbon and nitrogen to determine where soil organic matter can build up in soils, their research points to the highest potential for soil organic accrual is in subsoils.

Technical Abstract: Soil organic matter (SOM) is a fundamental resource to humanity for the many ecosystem services it provides. Increasing its stocks can significantly contribute to climate change mitigation and the sustainability of agricultural production is largely controlled by the amount, and chemical composition (structural vs soluble) of C inputs. Elucidating the mechanisms and drivers of the formation of the main components of SOM from residue?, particulate (POM) and mineral associated (MAOM) organic matter, is therefore critical to inform management and policy designed to promote SOM regeneration. We designed a two-tiered laboratory incubation experiment using 13C and 15N labeled plant material to investigate the effects of the physical nature (i.e., structural versus soluble) of plant inputs as well as their chemical composition on (1) the pathways of SOM formation, (2) the soil microbial community and chemical diversity, and (3) their interaction on the efficiency of POM and MAOM formation, in a topsoil and a subsoil. We found that: i) the physical nature of the plant input drove both the pathways and efficiencies of SOM formation; ii) POM formation from the decomposition of structural residues increased in efficiency the more decomposed were the residues, and linearly with soil microbial and chemical diversity, the latter only for subsoil; ii) more input-derived C and N were retained in subsoil because of both higher stabilization in MAOM and POM, and slower residue decay. Our results also confirm the importance of direct sorption of soluble inputs to silt and clay sized minerals for the formation of MAOM in bulk soils. Taken together these finding suggest that the highest potential for SOM accrual is in subsoils from the separate addition of decomposed residues and soluble plant inputs.