Recycling eutrophic lake sediments into grass production: A four-year field experiment on agronomical and environmental implications

Mina Kiani; Jure Zrim; Asko Simojoki; Olga Tammeorg; Petri Penttinen; Tuuli Markkanen; Priit Tammeorg

doi:10.1016/j.scitotenv.2023.161881

Recycling eutrophic lake sediments into grass production: A four-year field experiment on agronomical and environmental implications

Sci Total Environ. 2023 Apr 20:870:161881. doi: 10.1016/j.scitotenv.2023.161881. Epub 2023 Jan 31.

Authors

Mina Kiani¹, Jure Zrim², Asko Simojoki², Olga Tammeorg³, Petri Penttinen⁴, Tuuli Markkanen², Priit Tammeorg²

Affiliations

¹ Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland; Natural Resources Institute Finland, Helsinki, Finland. Electronic address: mina.kiani@helsinki.fi.
² Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
³ Ecosystems and Environment Research Programme, University of Helsinki, Helsinki, Finland; Chair of Hydrobiology and Fishery, Estonian University of Life Sciences, Tartu, Estonia.
⁴ Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China; Department of Microbiology, University of Helsinki, Helsinki, Finland. Electronic address: petri.penttinen@helsinki.fi.

PMID: 36731548
DOI: 10.1016/j.scitotenv.2023.161881

Abstract

Inefficient use of phosphorus (P) fertilizers leads to the transfer of P into water bodies, causing their eutrophication. Sediment removal is a promising lake restoration strategy that removes nutrients including P accumulated in lake sediments, and opens the opportunity to use removed nutrients in agriculture. In the present study, we investigated the effects of using a thick layer of sediment from the eutrophic Lake Mustijärv on plant growth, and estimated the environmental impacts of different sediment application methods by analyzing greenhouse gas emissions, N and P leaching, aggregate stability, and soil biota. The field experiment (2017-2020) was established on the lake shore with the following treatments: the agricultural control soil (Soil) surrounding the lake, pure sediment (Sed), biochar-treated sediment (SB), and biochar and soil mixed with sediment (SSB). The sediment-based treatments resulted in a similar grass growth performance to the Soil. The availability of most macro- and micronutrients including P (75 vs. 21 g m^-3) were far greater in the Sed compared to the Soil. The sediment-based growing media emitted more CO₂ than the Soil (579 vs. 400 mg CO₂ - C m^-2 h^-1) presumably due to the high rate of organic matter decomposition. The bacterial and fungal community structures of the Sed were strongly differentiated from those of Soil. Also, Sed had lower bacterial diversity and a higher abundance of the bacterial phyla associated with solubilizing P including Proteobacteria and Chloroflexi. Sediment-based growing media increased more than seven times the risk of mineral N and P leaching, and the biochar treatment only had a short-lived beneficial effect on reduction of the sediment's leached P concentration. The sediment application rate should be adjusted to match the crop requirements to minimize greenhouse gas emissions and nutrient leaching when upscaling the case study to larger lakes with similar sediment properties.

Keywords: Biochar; Greenhouse gas emission; Microbial community; Nutrient leaching; Nutrient recycling; Sediment removal; Sustainable ecosystem.

MeSH terms

Agriculture
Bacteria
Carbon Dioxide
China
Eutrophication
Geologic Sediments / chemistry
Greenhouse Gases*
Lakes* / chemistry
Phosphorus / analysis
Poaceae
Soil

Substances

biochar
Greenhouse Gases
Carbon Dioxide
Soil
Phosphorus