AUTHOR=Yi Yan , Sugiura Daisuke , Yano Katsuya 

TITLE=Quantifying Phosphorus and Water Demand to Attain Maximum Growth of Solanum tuberosum in a CO2-Enriched Environment

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.01417

DOI=10.3389/fpls.2019.01417

ISSN=1664-462X

ABSTRACT=<p>Growth promotion by ambient CO<sub>2</sub> enrichment may be advantageous for crop growth but this may be influenced by soil nutrient availability. Therefore, we quantified potato (<italic>Solanum tuberosum</italic> L.) growth responses to phosphorus (P) supply under ambient (a[CO<sub>2</sub>]) and elevated (doubled) CO<sub>2</sub> concentration (e[CO<sub>2</sub>]). A pot experiment was conducted in controlled-environment chambers with a[CO<sub>2</sub>] and e[CO<sub>2</sub>] combined with six P supply rates. We obtained response curves of biomass against P supply rates under a[CO<sub>2</sub>] and e[CO<sub>2</sub>] (R<sup>2</sup> = 0.996 and R<sup>2</sup> = 0.992, respectively). A strong interaction between [CO<sub>2</sub>] and P was found. Overall, e[CO<sub>2</sub>] enhanced maximum biomass accumulation (1.5-fold) and water-use efficiency (WUE) (1.5-fold), but not total water use. To reach these maxima, minimum P supply rate at both [CO<sub>2</sub>] conditions was similar. Foliar critical P concentration (i.e., minimum [P] to reach 90% of maximum growth) was also similar at nearly 110 mg P m<sup>−2</sup>. Doubling [CO<sub>2</sub>] did not increase P and water demand of potato plants, thus enabling the promotion of maximum growth without additional P or water supply, but <italic>via</italic> a significant increase in WUE (9.6 g biomass kg<sup>−1</sup> water transpired), presumably owing to the interaction between CO<sub>2</sub> and P.</p>