Document Type
Article
Publication Version
Version of Record
Publication Date
5-2026
Abstract
No-till systems improve soil functions and are widely adopted in South Dakota cropping systems. However, these cropping systems have become increasingly simplified due to reduced small grain adoption, potentially reducing carbon inputs and microbial diversity. Therefore, this study aimed to (i) quantify the effects of crop rotations and cover cropping on soil organic carbon (SOC), total nitrogen (TN), and their labile fractions across the 0–80 cm soil profile, and (ii) assess how these management practices affect microbial properties in the topsoil (0–7.5 cm), using a long-term no-till (>30 years) field experiment in South Dakota. Main treatments included a corn (Zea mays L.)–soybean [Glycine max L. (Merr)]–oat (Avena sativa L.)–rye (Secale cereale L.) rotation (CSOR) and a corn–soybean rotation (CS) in a randomized complete block design with four replicates. Each rotation plot was split into cover crops (CC) and no cover crops (NCC). Near-surface SOC concentrations, microbial biomass carbon, and enzyme activities were increased by CC but showed little response to rotations. Both CSOR and CC increased TN, water-extractable carbon and nitrogen, and permanganate-oxidizable carbon in the topsoil. The CSOR promoted bacterial and total microbial phospholipid fatty acid abundance during the corn phase in fall and promoted arbuscular mycorrhiza fungi in spring under CC. In the fall, CC increased all microbial groups in both rotations, with greater benefits under CSOR in spring. Overall, at this long-term no-till site, cover crops and, to a lesser extent diversified rotations, can improve near-surface SOC concentrations, labile carbon, and microbial indicators.
Publication Title
Geoderma
Volume
469
First Page
117808
DOI of Published Version
10.1016/j.geoderma.2026.117808
Publisher
South Dakota State University
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Sainfort Vital, Sutie Xu, Namrata Ghimire, Peter Sexton, Jixiang Wu, Christopher Graham, Lan Xu, Mengistu Geza, Enhanced near-surface soil labile carbon and microbial indicators under cover crops and crop diversification in long-term no-till systems, Geoderma, Volume 469, 2026, 117808, https://doi.org/10.1016/j.geoderma.2026.117808