Caragana korshinskii Kom. plantation reduced soil aggregate stability and aggregate-associated organic carbon on desert steppe

Qi Lu; Hongbin Ma; Yao Zhou; Roberto Calvelo-Pereira; Yan Shen

doi:10.7717/peerj.12507

Caragana korshinskii Kom. plantation reduced soil aggregate stability and aggregate-associated organic carbon on desert steppe

PeerJ. 2022 Feb 16:10:e12507. doi: 10.7717/peerj.12507. eCollection 2022.

Authors

Qi Lu^#¹, Hongbin Ma^#^{1

2}, Yao Zhou¹, Roberto Calvelo-Pereira³, Yan Shen^{1

2}

Affiliations

¹ Ningxia University, School of Agricultural, Yinchuan, Ningxia, China.
² Ningxia University, Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of Northwest China, Yinchuan, Ningxia, China.
³ Massey University, School of Agriculture and Environment, Palmerston North, New Zealand.

^# Contributed equally.

Abstract

Background: After implementing of the "Grain-for-Green" project, Caragana korshinskii Kom. has been widely planted in China's arid regions. Although natural restoration grassland and artificial Caragana plantations measures have long been focuses in carbon research, the combined influence of natural restoration grassland and artificial Caragana plantation measures on aggregate stability and the aggregate-associated organic carbon (OC) remains unclear.

Method: We selected natural grassland (NG) and three different densities of Caragana plantations (high planting density, HG; middle planting density, MD; low planting density, LD) on desert steppe. The soil aggregate distribution and stability index such as fractal dimension (D), mean weight diameter (MWD), geometric mean diameter (GMD), percentage of aggregation destruction (PAD), as well as aggregate-associated OC concentration and stock were measured.

Results: Results shows that the soil aggregates were primarily macroaggregates (>2 mm) and mesoaggregates (0.25-2 mm) under dry sieving while microaggregates (<0.25 mm) were preponderant under wet sieving (more than 57%). Overall, compared with Caragana plantations, the MWD (4.43 and 4.51 mm) and GMD (1.72 and 1.83 mm) were both highest in two soil layers under the NG and the D (2.77 and 2.71) was lowest. Compared with the NG, the aggregate-associated OC stocks in the 0-40 cm depths in the LD, MD, and HD decreased by 41.54%, 46.93%, and 42.03%, respectively. SOC stock was mainly concentrated in the soil aggregate with sizes of >2 mm and <0.25 mm. These results suggested that natural grassland restoration measures could improve the soil aggregate stability and aggregate-associated OC concentration better than Caragana plantation restoration measures, which NG may be optimal for increasing carbon sequestration and stabilizing soil aggregates on desert steppe.

Keywords: Aggregate-associated organic carbon; Caragana shrubs; Desert steppe grassland; Soil aggregate stability.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Caragana*
Carbon
Desert Climate
Fractals
Soil*

Substances

Soil
Carbon

Grants and funding

This work was supported by the Ningxia Science and Technology Innovation Leader Training Program (No. KJT2018003), the Key Research and Development Program of Ningxia province (No. 2018BFH03009), the Key Research and Development Program of Ningxia province (No. 2020BBF02003), and the First-class Discipline Construction Project (Grassland Science Discipline) for the high school in Ningxia (No. NXYLXK2017A01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.