N2-fixing black locust intercropping improves ecosystem nutrition at the vulnerable semi-arid Loess Plateau region, China

Baoguo Du; Junzhu Pang; Bin Hu; Diane E Allen; Tina L Bell; Sebastian Pfautsch; Florian Netzer; Michael Dannenmann; Shuoxin Zhang; Heinz Rennenberg

doi:10.1016/j.scitotenv.2019.06.245

N₂-fixing black locust intercropping improves ecosystem nutrition at the vulnerable semi-arid Loess Plateau region, China

Sci Total Environ. 2019 Oct 20:688:333-345. doi: 10.1016/j.scitotenv.2019.06.245. Epub 2019 Jun 17.

Authors

Affiliations

¹ College of Life Science and Biotechnology, Mianyang Normal University, 166 Mianxing Road West, Mianyang, 621000, China; Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, Freiburg, 79110, Germany.
² College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi, 712100, China.
³ College of Forestry, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi, 712100, China; Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, Freiburg, 79110, Germany. Electronic address: hubjoe@126.com.
⁴ School of Agriculture and Food Sciences, University of Queensland, St Lucia, Queensland, 4072, Australia.
⁵ School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia.
⁶ School of Social Science and Psychology, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.
⁷ Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, Freiburg, 79110, Germany.
⁸ Institute for Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstrasse 19, Garmisch-Partenkirchen, 82467, Germany.
⁹ Institute of Forest Sciences, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, Freiburg, 79110, Germany; College of Sciences, King Saud University, Riyadh, Saudi Arabia.

PMID: 31233915
DOI: 10.1016/j.scitotenv.2019.06.245

Abstract

The Loess Plateau in northwestern China constitutes one of the most vulnerable semi-arid regions in the world due to long-term decline in forest cover, soil nutrient depletion by agricultural use, and attendant soil erosion. Here, we characterize the significance of N₂-fixing Robinia pseudoacacia L. and non-N₂-fixing Juglans regia L. for improving nutrient availability and water retention in soil by comparing a range of biological and physicochemical features in monoculture and mixed plantations of both species. We found that N₂-fixing Robinia facilitates the nitrogen and phosphorus composition of non-N₂-fixing Juglans in the mixed stand as a consequence of improved soil nutrient availability, evident as higher levels of nitrogen and labile carbon compared to mono-specific stands. This demonstrates that intercropping N₂-fixing Robinia with non-N₂-fixing woody plants can greatly improve soil carbon and nitrogen bioavailability as well as whole-plant nutrition and can potentially mediate water retention with additional sequestration of soil organic carbon in the range of 1 t C ha^-1 year^-1. Thus, intercropping N₂-fixing woody species (e.g. Robinia pseudoacacia or Hippophae rhamnoides L.) with locally important non-N₂-fixing tree and shrub species should be considered in afforestation strategies for landscape restoration.

Keywords: Degraded soil; Intercropping; Juglans regia; Robinia pseudoacacia; Soil carbon sequestration; Soil nutrient availability; Whole-plant nutrition.

MeSH terms

Agriculture / methods*
China
Desert Climate
Ecosystem
Nitrogen
Nitrogen Fixation / physiology*
Robinia / physiology*

Substances

Nitrogen