Plant intraspecific competition and growth stage alter carbon and nitrogen mineralization in the rhizosphere

Plant roots interact with rhizosphere microorganisms to accelerate soil organic matter (SOM) mineralization for nutrient acquisition. Root-mediated changes in SOM mineralization largely depend on root-derived carbon (root-C) input and soil nutrient status. Hence, intraspecific competition over plant development and spatiotemporal variability in the root-C input and nutrients uptake may modify SOM mineralization. To investigate the effect of intraspecific competition on SOM mineralization at three growth stages (heading, flowering, and ripening), we grew maize (C4 plant) under three planting densities on a C3 soil and determined in situ soil C- and N-mineralization by 13C-natural abundance and 15N-pool dilution approaches. From heading to ripening, soil C- and N-mineralization rates exhibit similar unimodal trends and were tightly coupled. The C-to-N-mineralization ratio (0.6 to 2.6) increased with N availability, indicating that an increase in N-mineralization with N depletion was driven by microorganisms mining N-rich SOM. With the intraspecific competition, plants increased specific root lengths as an efficient strategy to compete for resources. Root morphologic traits rather than root biomass per se were positively related to C- and N-mineralization. Overall, plant phenology and intraspecific competition controlled the intensity and mechanisms of soil C- and N- mineralization by the adaptation of root traits and nutrient mining. © 2020 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

Authors
Sun Y.1, 2 , Zang H.3 , Splettstößer T.4 , Kumar A.5 , Xu X. 6 , Kuzyakov Y. 2, 4, 7 , Pausch J.1
Publisher
Blackwell Publishing Ltd
Number of issue
4
Language
English
Pages
1231-1242
Status
Published
Volume
44
Year
2021
Organizations
  • 1 Department of Agroecology, BayCEER, University of Bayreuth, Bayreuth, Germany
  • 2 Department of Agricultural Soil Science, University of Göttingen, Göttingen, Germany
  • 3 College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
  • 4 Department of Soil Science of Temperate and Boreal Ecosystems, University of Göttingen, Göttingen, Germany
  • 5 Chair of Ecosystem Functioning and Services, Institute of Ecology, Leuphana University of Lüneburg, Lüneburg, Germany
  • 6 Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, China
  • 7 Peoples Friendship University of Russia (RUDN University), Moscow, Russian Federation
Keywords
13C natural abundance; 15N pool dilution; arable soil; carbon and nitrogen mineralization; intraspecific competition; maize; root traits; soil organic matter decomposition
Date of creation
20.04.2021
Date of change
20.04.2021
Short link
https://repository.rudn.ru/en/records/article/record/71910/
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