Nitrogen Type and Availability Drive Mycorrhizal Effects on Wheat Performance, Nitrogen Uptake and Recovery, and Production Sustainability

Rosolino Ingraffia; Gaetano Amato; Moisés A Sosa-Hernández; Alfonso S Frenda; Matthias C Rillig; Dario Giambalvo

doi:10.3389/fpls.2020.00760

Nitrogen Type and Availability Drive Mycorrhizal Effects on Wheat Performance, Nitrogen Uptake and Recovery, and Production Sustainability

Front Plant Sci. 2020 Jun 19:11:760. doi: 10.3389/fpls.2020.00760. eCollection 2020.

Authors

Rosolino Ingraffia¹, Gaetano Amato¹, Moisés A Sosa-Hernández^{2

3}, Alfonso S Frenda¹, Matthias C Rillig^{2

3}, Dario Giambalvo¹

Affiliations

¹ Department of Agricultural, Food and Forest Sciences, Università degli Studi di Palermo, Palermo, Italy.
² Plant Ecology, Institute of Biology, Freie Universität Berlin, Berlin, Germany.
³ Berlin-Brandenburg Institute of Advanced Biodiversity Research, Berlin, Germany.

Abstract

Plant performance is strongly dependent on nitrogen (N), and thus increasing N nutrition is of great relevance for the productivity of agroecosystems. The effects of arbuscular mycorrhizal (AM) fungi on plant N acquisition are debated because contradictory results have been reported. Using ¹⁵N-labeled fertilizers as a tracer, we evaluated the effects of AM fungi on N uptake and recovery from mineral or organic sources in durum wheat. Under sufficient N availability, AM fungi had no effects on plant biomass but increased N concentrations in plant tissue, plant N uptake, and total N recovered from the fertilizer. In N-deficient soil, AM fungi led to decreased aboveground biomass, which suggests that plants and AM fungi may have competed for N. When the organic source had a low C:N ratio, AM fungi favored both plant N uptake and N recovery. In contrast, when the organic source had a high C:N ratio, a clear reduction in N recovery from the fertilizer was observed. Overall, the results indicate an active role of arbuscular mycorrhizae in favoring plant N-related traits when N is not a limiting factor and show that these fungi help in N recovery from the fertilizer. These results hold great potential for increasing the sustainability of durum wheat production.

Keywords: 15N fertilizer recovery; arbuscular mycorrhizal (AM) symbiosis; arbuscular mycorrhizal fungi; mineral nitrogen; nitrogen uptake; organic nitrogen; soil nitrogen (N) availability; soil nitrogen (N) source.