Mechanism of stabilized sludge-driven remediation in saline-alkali soil: New insights from salt-discharge capacity and microbially mediated carbon/nitrogen cycles.

Sci Total Environ

State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.

Published: December 2024

Stabilized sludge products (SSP) are promising conditioners for saline-alkali soils, capable of enhancing soil physicochemical properties and stimulating microbial communities. However, there is limited knowledge regarding the effects of SSP on soil salt-discharge capacity and carbon/nitrogen cycles. Here, a six-month incubation experiment was conducted to evaluate SSP (0 % ~ 60 %) on saline-alkali soil properties, salt leaching, and microbial functions. It was found that after SSP (≥30 %) treatment, saline-alkali soils were significantly remediated (p < 0.01), with organic matter increasing by 5.3-9.8 times, nutrient levels rising to first-grade, porosity improving by 34.3 % ~ 93.3 %, and meso/macro-aggregates content increasing by 39.0 % ~ 201.3 %. The Na leaching rate increased from 1.1 % to 53.3 % ~ 79.3 %, indicating a substantial improvement in salt-discharge capacity. Correlation analysis revealed that SSP organics loosened pore spaces by promoting soil particle agglomeration, which in turn improved salt-discharge capacity. Further, the 30 % SSP significantly increased the microbial functions involved in nutrient cycling, such as carbon fixation (photosynthetic pathway), nitrogen fixation, dissimilatory nitrate reduction, and nitrification (p < 0.01). Contribution analysis implied that the up-regulation of gene abundance assigned to carbon/nitrogen cycle was attributed to balancing effect of SSP on dominant genera. Finally, the excellent growth of alfalfa seedlings verified the soil productivity restoration of degraded saline-alkali soils. These findings provide new insights into salt stress alleviation and nutrient cycling in degraded saline-alkali soils.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2024.177588DOI Listing

Publication Analysis

Top Keywords

saline-alkali soil
8
salt-discharge capacity
8
carbon/nitrogen cycles
8
saline-alkali soils
8
mechanism stabilized
4
stabilized sludge-driven
4
sludge-driven remediation
4
saline-alkali
4
remediation saline-alkali
4
soil
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!