Ammonium Uptake Is the Main Driver of Rhizosphere pH in Southern Highbush Blueberry

Christopher S. Imler,Camila I. Arzola,Gerardo H Nunez

Published 2019 in Hortscience

ABSTRACT

Unlike most horticultural crops, blueberry (Vaccinium spp. section cyanococcus) prefers low-pH (4.2–5.5) soils. Other plants can acidify their rhizosphere to create a hospitable microenvironment. Southern highbush blueberry (SHB; Vaccinium corymbosum interspecific hybrids) plants do not acidify their rhizosphere in response to Fe deficiency, but other factors that affect rhizosphere pH have not been elucidated. We report results from two hydroponic experiments exploring N uptake effects on the rhizosphere pH of ‘Emerald’ SHB. Ammonium (NH4+) uptake led to rhizosphere acidification, whereas nitrate (NO3–) uptake led to rhizosphere alkalization. When grown in a split-root hydroponic system, roots that took up NH4+ acidified the rhizosphere to a greater extent that roots not exposed to NH4+. Rhizosphere acidification was observed even in a nontreated control. These results suggest that NH4+ uptake is the main driver of rhizosphere pH in SHB. N form effects suggest that fertilization with NO3– might lead to undesirable rhizosphere alkalization.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-34 of 34 references · Page 1 of 1

CITED BY

Showing 1-12 of 12 citing papers · Page 1 of 1