The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants.

Journal Article (Journal Article)

The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that the carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower - up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production.

Full Text

Duke Authors

Cited Authors

  • Franklin, O; Cambui, CA; Gruffman, L; Palmroth, S; Oren, R; Näsholm, T

Published Date

  • January 2017

Published In

Volume / Issue

  • 40 / 1

Start / End Page

  • 25 - 35

PubMed ID

  • 27241731

Pubmed Central ID

  • PMC5217072

Electronic International Standard Serial Number (EISSN)

  • 1365-3040

International Standard Serial Number (ISSN)

  • 0140-7791

Digital Object Identifier (DOI)

  • 10.1111/pce.12772


  • eng