Microbial response on changing C:P stoichiometry in steppe soils of Northern Kazakhstan

authored by

Yuhuai Liu, Olga Shibistova, Guan Cai, Leopold Sauheitl, Mouliang Xiao, Tida Ge, Georg Guggenberger

Abstract

Background and aims: The stoichiometric ratio of carbon (C): phosphorus (P) acquisition is strongly correlated with soil available C:P ratio. However how the stoichiometric relationship between acquiring C and P through microbial metabolism affects bioavailable P is poorly understood in semi-arid agricultural ecosystems. Methods: Our objective was to investigate the underlying mechanisms of the P availability in typical P-limited steppe soil from Kazakhstan in response to mineral nutrient (Na₂HPO₄) with and without Dactylis glomerata L. leaves addition in a 38-day incubation experiment. Results: Four bioavailable P fractions content (CaCl₂-P, Citrate-P, Enzyme-P, and HCl-P) were improved. Sole application of P fertilizer decreased the maximal velocity (V_max) of P acquisition enzyme (phosphomonoesterase) but increased microbial C limitation, resulting in increasing the ratio of C to P acquisition but decreasing the ratio of available dissolved organic C: Olsen-P. In contrast, plant residues returning (the application of sole D. glomerata leaves and the combined application of D.glomerata and mineral P) increased V_max of C (β-1, 4-glucosidase, β-D-cellobiosidase, β-1, 4-xylosidase) and P acquisition enzymes, however decreasing microbial C and P limitation through improving microbial metabolism. Furthermore, the spearman correlation and piecewiseSEM analysis suggested that microbial C limitation and EEA_C:P had a negative effect on P availability, illustrating that the decreasing of microbial C limitation can improve soil bioavailable P. Conclusion: The decomposition of organic residues eliminated microbial P limitation and increased P availability by allocating C and P acquisition enzymes to balance the stoichiometric ratio of microbial C and P demand. Graphical Abstract: [Figure not available: see fulltext.].

Organisation(s)

Institute of Soil Science

External Organisation(s)

Ningbo University
The Second Surveying and Mapping Institute of Hunan Province
Zhejiang A&F University (ZAFU)

Type

Article

Journal

Plant and soil

Volume

493

Pages

375-389

No. of pages

15

ISSN

0032-079X

Publication date

12.2023

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Soil Science, Plant Science

Sustainable Development Goals

SDG 2 - Zero Hunger

Electronic version(s)

https://doi.org/10.1007/s11104-023-06235-9 (Access: Closed)