Optimizing Cyanobacterial Biomass for Soil Restoration: Nutrient Enrichment and Microbial Modulation in Degraded Grasslands of Hulun Lake

• Published in: Bulletin of environmental contamination and toxicology Vol. 114; no. 5; p. 75
• Main Authors: Cao, Bingshuai, Zhang, Zhaoyong, Tong, Yi, Wang, Qi, Li, Wenjing, Wei, Cuilan, Zang, Chi, Wang, Wenlin
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2025; Springer Nature B.V
• Subjects: Ammonium; ammonium nitrogen; Aquatic Pollution; bacterial communities; Biomass; bulls; China; Cyanobacteria; Cyanobacteria - physiology; Decomposition; dose response; Earth and Environmental Science; Ecotoxicology; Enrichment; Environment; Environmental Chemistry; Environmental Health; Environmental Restoration and Remediation - methods; Eutrophication; Grassland; grassland soils; Grasslands; Lakes; Lakes - chemistry; Lakes - microbiology; Microorganisms; Modulation; nitrate nitrogen; Nitrogen; Nitrogen - analysis; Nutrient availability; Nutrient content; Nutrient dynamics; Nutrient enrichment; Nutrient release; Organic carbon; Phosphorus; Phosphorus - analysis; Physicochemical properties; Plant growth; Pollution; potassium; Quantitative analysis; remediation; Soil - chemistry; Soil bacteria; Soil improvement; Soil Microbiology; Soil microorganisms; Soil nutrients; Soil quality; soil restoration; Soil Science & Conservation; Soils; species; species diversity; stoichiometry; total nitrogen; Total organic carbon; Waste Water Technology; Water Management; Water Pollution Control; China; Hulun Lake; Degraded grassland; Hulun Lake; Soil properties; Cyanobacterial degradation; Bacterial community
• ISSN: 0007-4861; 1432-0800; 1432-0800
• DOI: 10.1007/s00128-025-04030-z

The organic and active substances released from cyanobacterial decomposition have a positive effect on improving soil quality and promoting plant growth. However, the mechanism of its influence remains unclear, particularly regarding its impact on grassland soil. The study was conducted in the periphery of eutrophic Hulun Lake using a gradient amendment experiment (0%, 3%, 5%, 10% cyanobacterial biomass) on adjacent degraded grassland soils. This design aimed to assess the effects of cyanobacterial inputs on soil physicochemical parameters and microbial community restructuring. Quantitative analyses revealed significant nutrient enrichment, with available phosphorus (AP), available potassium (AK), and nitrogen pools demonstrating differential responses. Nitrogen species exhibited the most pronounced enrichment: total nitrogen (TN) increased by 26.21%, ammonium nitrogen (NH₄⁺-N) by 41.99%, and nitrate nitrogen (NO₃⁻-N) by 54.96% relative to controls. Concurrently, stoichiometric ratios displayed dose-dependent modulation: the total organic carbon to total nitrogen (TOC/TN) ratio decreased by 3.85% under 5% biomass treatment, whereas TOC/AP and TN/AP ratios increased by 13.23% and 18.03%, respectively, indicating altered carbon-phosphorus-nutrient coupling dynamics. Additionally, cyanobacteria enhanced the alpha diversity of the soil bacterial community without altering its overall structure or composition. The decomposition and nutrient release process of cyanobacteria in the soil mainly occurs in the first 30 days, which can improve the soil nutrient content and enhance bacterial community diversity. The application of cyanobacteria for the remediation of degraded grasslands represents a valuable approach that effectively utilizes cyanobacterial resources.