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Experimental evidence that phosphorus fertilization and arbuscular mycorrhizal symbiosis can reduce the carbon cost of phosphorus uptake
Author(s) -
Ven Arne,
Verlinden Melanie S.,
Verbruggen Erik,
Vicca Sara
Publication year - 2019
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1111/1365-2435.13452
Subject(s) - biology , rhizosphere , nutrient , phosphorus , agronomy , human fertilization , symbiosis , mycorrhiza , botany , ecology , chemistry , bacteria , genetics , organic chemistry
Plants allocate substantial amounts of carbon (C) below‐ground to obtain nutrients and other resources. Increasing nutrient availability typically reduces the C investment in root growth and mycorrhizal fungi, hence reducing the C cost of nutrient acquisition. This C cost of nutrient acquisition, however, remains poorly quantified. In a P fertilization experiment with Zea mays, we examined below‐ground C allocation and the C cost of phosphorus (P) uptake. In addition, we compared plants inoculated with arbuscular mycorrhizal fungi (AMF) to those growing in pasteurized soil to examine the same measures in the absence of AMF. P fertilization tended to increase above‐ground plant growth more than it increased the total below‐ground C flux (TBCF; root growth plus rhizosphere respiration), suggesting a reduced investment in nutrient acquisition. This was confirmed by a negative fertilization effect on the TBCF‐to‐total plant P ratio (~25% reduction for high vs. low P fertilization). Soil pasteurization increased this proxy for the C cost of P uptake (~50% increase). This novel quantification of the influence of P availability and mycorrhizal fungi on plant–soil C partitioning can guide the incorporation of these processes in vegetation models. A free Plain Language Summary can be found within the Supporting Information of this article.