Effects of leonardite on the coastal saline soil improvement

ABSTRACT

This study investigated the influence of leonardite on coastal saline soil YX1 (very slightly saline), YX2 (slightly saline) and YX3(strongly saline) with 0/10/30/50 g/kg addition dosage during the 81-day incubation. Changes of pH, electrical conductivity, soil texture, micromorphology, functional groups and mineral constituents of soil were discussed. Results showed that the application of leonardite enhanced the urea hydrolysis, increased the activities of urease and phosphatase in the coastal saline soil. The urease and phosphatase activity reached the maximum on the 8th incubation day. Leonardite raised C and N content in the soil colloid as well as the C/N value. However, leonardite had limited effects on the soil texture and mineral components during the incubation period. The application of leonardite would promote the activity of soil micro-organisms and relative enzyme to improve the soil ecosystem. It could benefit the amelioration of coastal saline soil, and provide the theoretical direction for agricultural production.

KEYWORDS:

• Coastal saline soil
• leonardite
• amelioration
• incubation
• Yellow River Delta

Acknowledgements

This work was supported by National Natural Science Foundation of China (41671319), the Chinese National Key Research and Development Program (2016YFD0200303), Taishan Scholar Program of Shandong Province (No. tsqn201812116), One Hundred Talents Program of Chinese Academy of Sciences (Y629041021), Science and Technology Service Network Initiative of the Chinese Academy of Sciences (KFJ-STS-QYZX-114), Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province, and Two-Hundred Talents Plan of Yantai (Y739011021). The authors would like to thank the reviewers for their valuable suggestions and comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

Jie Wang is a Ph.D candidate with major of environmental engineering.

Jun Wu is a professor in the field of environmental engineering.

Jian Lu is a professor in the field of environmental engineering.

Guodong Yuan is a professor in the field of saline soil remediation.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 41671319]; the Chinese National Key Research and Development Program [grant number 2016YFD0200303]; Science and Technology Service Network Initiative of the Chinese Academy of Sciences [grant number KFJ-STS-QYZX-114]; One Hundred Talents Program of Chinese Academy of Sciences [grant number Y629041021]; Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province; Taishan Scholar Program of Shandong Province [grant number No. tsqn201812116]; Two-Hundred Talents Plan of Yantai [grant number Y739011021].