Leaching of salt-affected soil amended by leonardite

ABSTRACT

Salt-affected soils are widely distributed in arable croplands worldwide with potential productivity so that it is important to develop and utilize these soils. This study investigated the effects of leonardite at the application dosage of 0 (CK), 1% (T1), 3% (T2), and 5% (T3) on amending salt-affected soils under intermittent leaching. Results showed that leaching effectively reduced the electrical conductivity (EC) in soil at CK/T1/T2/T3 with 67.4%/70.9%/75.7%/75.6% of salt discharged. As the dominant cation in leachates, Na⁺ removed accounted for 75.1% (CK), 79.7% (T1), 72.6% (T2), and 71.5% (T3) of the total cation in soil. Sodium adsorption ratio of soil column for CK/T1/T2/T3 treatment decreased by 61.1%/68.1%/50.0%/44.9%. Organic matters in the soil reached 9.74/17.20/31.41/42.88 g/kg for CK/T1/T2/T3 treatment at the end of the experiment, indicating a fertile prospect for reclamation of the salt-affected soils. Soil pH increased with leonardite dosage after leaching in a similar pattern as the decline of EC. The results would provide practical assistance for amending salt-affected soil in the Yellow River Delta.

KEYWORDS:

• Salt-affected soil
• leonardite
• amelioration
• leaching
• Yellow River Delta

Acknowledgments

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 authors.

Additional information

Funding

This work was supported by the Chinese National Key Research and Development Program [2016YFD0200303]; National Natural Science Foundation of China [41671319]; Taishan Scholars Program of Shandong Province [No. tsqn201812116]; One Hundred Talents Program of Chinese Academy of Sciences [Y629041021]; Two-Hundred Talents Plan of Yantai [Y739011021], and Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province.