Barley shoot biomass responds strongly to N:P stoichiometry and intraspecific competition, whereas roots only alter their foraging

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Authors

Aims
Root system responses to the limitation of either nitrogen (N) or phosphorus (P) are well documented, but how the early root system responds to (co-) limitation of one (N or P) or both in a stoichiometric framework is not well-known. In addition, how intraspecific competition alters plant responses to N:P stoichiometry is understudied. Therefore, we aimed to investigate the effects of N:P stoichiometry and competition on root system responses and overall plant performance.
Methods
Plants (Hordeum vulgare L.) were grown in rhizoboxes for 24 days in the presence or absence of competition (three vs. one plant per rhizobox), and
fertilized with different combinations of N:P (low N + low P, low N + high P, high N + low P, and high N + high P).
Results
Shoot biomass was highest when both N and P were provided in high amounts. In competition, shoot biomass decreased on average by 22%. Total root biomass
(per plant) was not affected by N:P stoichiometry and competition but differences were observed in specific root length and root biomass allocation across soil depths. Specific root length depended on the identity of limiting nutrient (N or P) and competition. Plants had higher proportion of root biomass in deeper soil layers under N limitation, while a greater proportion of root
biomass was found at the top soil layers under P limitation.
Conclusions
With low N and P availability during early growth, higher investments in root system development can significantly trade off with aboveground productivity,
and strong intraspecific competition can further strengthen such effects.
OriginalspracheEnglisch
ZeitschriftPlant and Soil
Band453
Ausgabennummer1-2
Seiten (von - bis)515-528
Anzahl der Seiten14
ISSN0032-079x
DOIs
PublikationsstatusErschienen - 11.07.2020

    Fachgebiete

  • Ökosystemforschung - Root system responses, vertical root distribution, specific root length, nutrient stoichiometry, instraspecific competition

DOI

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