Surface mulching and a sandy soil interlayer suppress upward enrichment of salt ions in salt-contaminated field

• Published in: Journal of soils and sediments 2019-01, Vol.19 (1), p.116-127
• Main Authors: Wang, Jianyong, Liu, Huiming, Wang, Shaoming, Liu, Yingxia, Cheng, Zhengguo, Fu, Guangqiang, Mo, Fei, Xiong, Youcai
• Format: Article
• Language: English
• Subjects: Contaminated land; Corn straw; Dynamics; Earth and Environmental Science; Enrichment; Environ Risk Assess; Environment; Environmental Physics; Evaporation; Interlayers; Ions; Land pollution; Moisture content; Mulching; Plastics; Profiles; Salt; Salts; Sandy soils; SAR (radar); Sec 2 • Global Change; Sodium; Soil; Soil contamination; Soil dynamics; Soil investigations; Soil layers; Soil profiles; Soil properties; Soil Science & Conservation; Soil water; Soil water movement; Soils; Straw; Sustainable Land Use • Research Article; Topsoil; Vertical advection
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-018-2023-2

Purpose The suppression effect of a sandy soil interlayer on topsoil enrichment of salt ions was investigated. However, whether this suppression effect was enhanced by surface mulching was little documented. The objectives of this study were to compare the suppression effects under different materials mulching, and to investigate an innovative method to suppress the soil salt ions down-to-top enrichment. Materials and methods In this study, the sandy soil layer was pre-positioned at 60–100 cm depth in a salt-contaminated site in advance, achieving the suppression effect on surface enrichment of salt components as expected. Three treatments were herein designed as bare field (CK), plastic film mulching (PM), and maize straw mulching (SM) to examine the dynamics of water and salt movement across soil profiles during the summer with strong evaporation. Results and discussions Results showed that total salt content was increased by 21.3 and 8.0% in CK and SM respectively, while decreased by 24.9% in PM at the end of strong evaporation period, comparing with the beginning. Thus, surface mulching further strengthened this suppression effect, but PM displayed better performance than SM did. The data also demonstrated that vertical transport of soil water was much restrained in PM and SM, accordingly inhibiting upward transfer of salt ions. Particularly, sodium adsorption ratio (SAR) ranged from 14.3–265.7, 17.9–147.1, 38.4–147.2 mmol 1/2  kg −1/2 at a shallow soil layer (0–60 cm) in CK, PM, and SM, respectively. Conclusions The results suggested that sandy soil interlayer settings with plastic mulching are a critical technical strategy for salt-contaminated land reutilization and management.