Use of biochar to manage soil salts and water: Effects and mechanisms

Xinqing Lee, Fang Yang, Ying Xing, Yimin Huang, Liang Xu, Zhongtang Liu, Ran Holtzman, Iddo Kan, Yunlong Li, Like Zhang, Hui Zhou

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)
183 Downloads (Pure)

Abstract

Soil salinization is a widespread land degredation, especially in water-stressed regions, jeopardizing agriculture sustainability. Current desalinization methodology involves excessive water consumption. Biochar has the potential to mitigate soil salinization while increasing water holding capacity. As a saline and sodic material, however, how it works and whether it can be used to sustain the agriculture at reduced water resource remain to be studied. Here, by monitoring transport of water, salts and nutrients in the profile of irrigation-silt soil during watering and evaporation in both laboratory and field in Kashgar oasis, Xinjiang, China, we find biochar exacerbates salinization upon application. This is changed, however, after several cycles of irrigation-evaporation due to strengthened salt leaching in irrigation and salt removal out of the depth through intensified top accumulation by evaporation, both resulting from increased capillary effect and thereby the enhanced movement of salts despite the competing electrical adsorption to the cations. The resulted salt distribution facilitates desalinization by removing the top 2 cm soil. Biochar also promotes evaporation after irrigation due to inceased water content and capillary suction. This is reversed once the soil cracks, a common phemomenon in irrigated land. Biochar counteracts the cracking through alleviation of soil compaction, saving tillage while lowering water evaporation, e.g., by 43% at 10% biochar. Our findings indicate that application of biochar changes salt distribution, enabling desalinization with little water consumption. Together with the effect of anti-fracturing and enhanced salt leaching, it lowers water demand substantially, providing a novel solution for agricultural sustainability in salt-affected regions.

Original languageEnglish
Article number106018
Number of pages11
JournalCatena
Volume211
Early online date12 Jan 2022
DOIs
Publication statusPublished - Apr 2022

Bibliographical note

© 2022, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders.

This document is the author’s post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version may remain and you are advised to consult the published version if you wish to cite from it.

Funder

Chinese-Israeli Intergovernmental Scientific and Technological Cooperation Project [grant number 2015DFG92450

Keywords

  • Desalinization
  • Land degradation
  • Salinization
  • Salt-affected soil
  • Water conservation

ASJC Scopus subject areas

  • Earth-Surface Processes

Fingerprint

Dive into the research topics of 'Use of biochar to manage soil salts and water: Effects and mechanisms'. Together they form a unique fingerprint.

Cite this