Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity
- Author(s)
- Richard Brackin, Torgny Nasholm, Nicole Robinson, Stephane Guillou, Kerry Vinall, Prakash Lakshmanan, Susanne Schmidt, Erich Inselsbacher
- Abstract
Globally only ≈50% of applied nitrogen (N) fertilizer is captured by crops, and the remainder can cause pollution via runoff and gaseous emissions. Synchronizing soil N supply and crop demand will address this problem, however current soil analysis methods provide little insight into delivery and acquisition of N forms by roots. We used microdialysis, a novel technique for in situ quantification of soil nutrient fluxes, to measure N fluxes in sugarcane cropping soils receiving different fertilizer regimes, and compare these with N uptake capacities of sugarcane roots. We show that in fertilized sugarcane soils, fluxes of inorganic N exceed the uptake capacities of sugarcane roots by several orders of magnitude. Contrary, fluxes of organic N closely matched roots' uptake capacity. These results indicate root uptake capacity constrains plant acquisition of inorganic N. This mismatch between soil N supply and root N uptake capacity is a likely key driver for low N efficiency in the studied crop system. Our results also suggest that (i) the relative contribution of inorganic N for plant nutrition may be overestimated when relying on soil extracts as indicators for root-available N, and (ii) organic N may contribute more to crop N supply than is currently assumed.
- Organisation(s)
- Department of Geography and Regional Research
- External organisation(s)
- University of Queensland, Swedish University of Agricultural Sciences (SLU), Sugar Research Australia
- Journal
- Scientific Reports
- Volume
- 5
- No. of pages
- 9
- ISSN
- 2045-2322
- DOI
- https://doi.org/10.1038/srep15727
- Publication date
- 10-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 106026 Ecosystem research, 106031 Plant physiology, 401101 Cultivation of land
- Keywords
- Sustainable Development Goals
- SDG 2 - Zero Hunger, SDG 15 - Life on Land
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/nitrogen-fluxes-at-the-rootsoil-interface-show-a-mismatch-of-nitrogen-fertilizer-supply-and-sugarcane-root-uptake-capacity(18e45ff9-6a16-4b7e-b2a9-fd4b1389612d).html