Rapid development of cyanobacterial crust in the field for combating desertification

PLoS One. 2017 Jun 23;12(6):e0179903. doi: 10.1371/journal.pone.0179903. eCollection 2017.

Abstract

Desertification is currently a major concern, and vast regions have already been devastated in the arid zones of many countries. Combined application of cyanobacteria with soil fixing chemicals is a novel method of restoring desertified areas. Three cyanobacteria, Nostoc sp. Vaucher ex Bornet & Flahault, Phormidium sp. Kützing ex Gomont and Scytonema arcangeli Bornet ex Flahault were isolated and tested in this study. Tacki-SprayTM (TKS7), which consists of bio-polysaccharides and tackifiers, was used as a soil fixing agent. In addition, superabsorbent polymer (SAP) was applied to the soil as a water-holding material and nutrient supplement. Application of cyanobacteria with superabsorbent polymer and TKS7 (CST) remarkably improved macro-aggregate stability against water and erodibility against wind after 12 months of inoculation when compared to the control soil. The mean weight diameter and threshold friction velocity of the CST treated soil were found to be 75% and 88% of those of the approximately 20-year-old natural cyanobacterial crust (N-BSC), respectively, while these values were 68% and 73% of those of the N-BSC soil after a single treatment of cyanobacteria alone (CY). Interestingly, biological activities of CST were similar to those of CY. Total carbohydrate contents, cyanobacterial biomass, microbial biomass, soil respiration, carbon fixation and effective quantum yield of CST treated soil were enhanced by 50-100% of the N-BSC, while those of control soil were negligible. Our results suggest that combined application of cyanobacteria with soil fixing chemicals can rapidly develop cyanobacterial crust formation in the field within 12 months. The physical properties and biological activities of the inoculated cyanobacterial crust were stable during the study period. The novel method presented herein serves as another approach for combating desertification in arid regions.

MeSH terms

  • Biomass
  • Carbohydrates / analysis
  • Carbon / chemistry
  • Conservation of Natural Resources*
  • Cyanobacteria* / isolation & purification
  • Electron Transport
  • Friction
  • Polymers / chemistry
  • Polysaccharides / chemistry
  • Soil / chemistry*
  • Soil Microbiology
  • Water / chemistry
  • Wind

Substances

  • Carbohydrates
  • Polymers
  • Polysaccharides
  • Soil
  • Water
  • Carbon

Grants and funding

This work was supported by a grant from the Forest Science & Technology Projects (Project No. S111212L030100) provided by the Korea Forest Service and the Chinese Academy of Sciences visiting professorship for senior international scientists (Grant No. 2013T2Z0007). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.