Increased nitrogen supply promoted the growth of non-N-fixing woody legume species but not the growth of N-fixing Robinia pseudoacacia

Sci Rep. 2018 Dec 17;8(1):17896. doi: 10.1038/s41598-018-35972-6.

Abstract

Nitrogen (N) is an essential macronutrient for plant development and growth, and the deposition of N has increased in recent decades. Legumes that fix N can also provide N for nearby species. However, N in soil inhibits N fixation. We tested the effects of N fertilisation on one N-fixing (Robinia pseudoacacia) and two non-N-fixing (Sophora japonica and Senna surattensis) woody legume species, which were subjected to five different N levels (0, 1.5, 2.9, 5.9 and 11.4 mg N per plant day-1) under greenhouse conditions. The growth of the two non-N-fixing species was promoted by N supply, while that of R. pseudoacacia was unaffected. Among the three species, R. pseudoacacia had the largest specific leaf area and chlorophyll concentration, S. japonica had the largest root-to-shoot ratio and main root-to-lateral root ratio, and S. surattensis had the largest leaf N and phosphorus concentrations. The N-fixing species was mostly unaffected by N supply. The growth, leaf chlorophyll concentration, and leaf number in the non-N-fixing species were promoted by N supply. The N-fixing species showed better growth in low-N environments, while under increased N deposition, its growth was similar to that of the non-N-fixing species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ecosystem
  • Environment
  • Fabaceae / drug effects*
  • Fabaceae / growth & development*
  • Nitrogen / pharmacology*
  • Nitrogen Fixation / drug effects*
  • Plant Leaves / drug effects
  • Plant Leaves / growth & development
  • Plant Roots / drug effects
  • Plant Roots / growth & development
  • Plant Shoots / drug effects
  • Plant Shoots / growth & development
  • Robinia / drug effects*
  • Robinia / growth & development*
  • Soil / chemistry
  • Wood / drug effects*
  • Wood / growth & development*

Substances

  • Soil
  • Nitrogen