Alteration of desert soil microbial community structure in response to agricultural reclamation and abandonment

Authors: HU, YIGANG - Chinese Academy Of Agricultural Sciences; WANG, ZENGRU - Chinese Academy Of Agricultural Sciences; ZHANG, ZHISHAN - Chinese Academy Of Agricultural Sciences; SONG, NAPING - Ningxia University; ZHOU, HUAKUN - Chinese Academy Of Agricultural Sciences; LI, YIKANG - Chinese Academy Of Agricultural Sciences; WANG, YANI - Chinese Academy Of Agricultural Sciences; LI, CANGSHEN - Chinese Academy Of Agricultural Sciences; Hale, Lauren

Submitted to: Catena
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2021
Publication Date: 8/23/2021
Citation: Hu, Y., Wang, Z., Zhang, Z., Song, N., Zhou, H., Li, Y., Wang, Y., Li, C., Hale, L.E. 2021. Alteration of desert soil microbial community structure in response to agricultural reclamation and abandonment. Catena. 207. Article 105678. https://doi.org/10.1016/j.catena.2021.105678.
DOI: https://doi.org/10.1016/j.catena.2021.105678

Interpretive Summary: In recent decades increased desert land area has been reclaimed for agricultural production, but water shortages have forced abandonment of production in many areas. Understanding below-ground impacts of both desert land reclamation and abandonment are essential to estimate the ecological sustainability of these practices. Soil microbial communities were evaluated in reclaimed cropland and along an abandonment chronosequence to evaluate the impacts of farming on microbial communities and their succession post abandonment. Soil moisture and nutrients closely correlated to shifts in bacterial and fungal populations, which were notably impacted by reclamation, and did not return to their undisturbed states even 10-years post abandonment.

Technical Abstract: Agricultural reclamation via the conversion of desert into arable land is one of the most imperative anthropogenic activities to combat land degradation/desertification. However, lack of irrigation water resources has forced the abandonment of reclaimed agricultural lands and their progression towards unmanaged, natural states may dictate erosion potential. Microorganisms mediate many processes that prevent wind erosion of soils and reduction of soil fertility. However, little is known about how soil microbial community structure responds to desert agricultural reclamation and abandonment. Using quantitative PCR (qPCR) and 16S rRNA high-throughput sequencing approaches, we investigated the changes of bacterial, archaeal and fungal community structures in a farmland soil (FS) and along a 10-year farming abandoning chronosequence (2-year, 5-year and 10-year) in comparison with adjacent native desert in the Badain Jaran desert, China. Reclamation significantly increased microbial community gene copies compared with the native desert control, which generally decreased after farming abandonment. Reclamation significantly increased fungal OTUs, Chao1, and Ace species richness, while abandonment significantly affected bacterial OTUs, Chao1, and Ace species richness. Reclamation and abandonment significantly changed soil microbial community structure mainly via altering their abundances differently, which was microbial taxa dependent. Microbial community structures were closely related to soil moisture and chemical properties [total carbon (C), total nitrogen (N), available phosphorus (P) and the stoichiometry of C, N and P], which explained 24.4-89.0% of their variations. Our results indicate desert soil microbial biomass and compositions differentially respond to agricultural reclamation and abandonment with some irreversible changes in compositions after short-term abandonment. These community trends were driven by shifts in irrigation, fertility and the stoichometry of C, N, and P. The insights are meaningful for agriculture sustainable development and ethical land management in arid desert region.