2026-09-03 ノースカロライナ州立大学（NC State）
＜関連情報＞
- https://news.ncsu.edu/2026/09/study-shows-microbes-dead-or-alive-can-be-early-measures-of-soil-health/
- https://elibrary.asabe.org/azdez.asp?JID=3&AID=56094&CID=jn2026&v=4&i=3&T=1&refer=7&access=
再生型土地管理システムにおける土壌炭素循環の指標 Soil Carbon Cycle Proxies in a Regenerative Land Management System
Murray Sternberg, Biswanath Dari, K. Taylor Cyle, Milon Barmon, Jack Kagan, Gwen Read, Manoj Kumar Reddy Sangireddy, John Kimes, Randall Quillian, Debjani Sihi
Journal of Natural Resources and Agricultural Ecosystems Published:17 July 2026
DOI:10.13031/jnrae.16646
Highlights
- Regenerative practices influenced soil carbon cycle proxies.
- Microbial biomass, respiration, and enzyme activities served as early indicators of soil carbon change.
- Tree species in agroforestry strongly influenced soil carbon dynamics.
- Cover crop species shaped soil biogeochemical responses.
- Conservation tillage maintained soil carbon and nitrogen pools in the short term.
ABSTRACT
.Regenerative land management practices can address climate change and food security challenges. While changes in long-term carbon (C) storage in soil systems occur over extended timescales, biological parameters provide early insights into these processes. To improve our understanding of how regenerative land management practices influence soil organic matter (SOM) dynamics and soil C stabilization, we evaluated soil C (and nutrient) cycle proxies under cover crop (mono and cover crop mix), agroforestry (pecan and loblolly pine), and conservation tillage (no-tillage and minimum tillage) practices in the University Research Farm at North Carolina A&T State University. Total and microbial pools and flux (respiration) of soil C were higher in agroforestry systems with pecan vs. pine trees in the mid-term (~8–10 growing seasons). Total soil C (and flux) and the C-degrading enzyme (beta-glucosidase) were generally higher in cereal- and legume-based cover crop types than brassica, and the opposite was observed for N-degrading enzymes. Soil C benefits were more pronounced in mixed vs. mono cover crop species. While the total soil C and nitrogen (N) pools and respiration were maintained under conservation tillage practice, microbial biomass carbon (MBC) was a reliable indicator of how reducing tillage can spur biological activity in the short term (~2 growing seasons). Microbial necromass C was only sensitive to changes in the practice being applied within the pecan agroforestry system, and bacterial necromass only responded to cover crop types. Our study provides some early-on, informative, and consistent indicators of changes in soil C (and nutrient) cycling relevant for decision-making for land use for climate change mitigation.
