Eukaryal composition and diversity in anaerobic soils influenced by the novel chiral insecticide Paichongding

Changes in soil microbial communities after exposure to neonicotinoids: A systematic review

Neonicotinoids are a group of nicotine-related chemicals widely used as insecticides in agriculture. Several studies have shown measurable quantities of neonicotinoids in the environment but little is known regarding their impact on soil microbial populations. The purpose of this systematic review was to clarify the effects of neonicotinoids on soil microbiology and to highlight any knowledge gaps. A formal systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines using keywords in PubMed, SCOPUS and Web of Science. This resulted in 29 peer-reviewed articles, whose findings diverged widely because of variable methodologies. Field-based studies were few (28%). Imidacloprid was the most widely used (66%) and soil microbial communities were most sensitive to it. Spray formulations were used in 83% of the studies and seed treatments in the rest. Diversity indices were the most frequently reported soil microbial parameter (62%). About 45% of the studies found that neonicotinoids had adverse impacts on soil microbial community structure, composition, diversity, functioning, enzymatic activity and nitrogen transformation. Interactions with soil physicochemical properties were poorly addressed in all studies. The need for more research, particularly field-based research on the effects of neonicotinoids on soil microorganisms was highlighted by this review.

Study on soil physical structure after the bioremediation of Pb pollution using microbial-induced carbonate precipitation methodology

Soil structure is an important index to evaluate soil quality; however, previous researchers have only paid attention to the effect and economic benefits of soil heavy metal remediation. In this study, microbial-induced carbonate precipitation (MICP) technology was used to remediate soil Pb pollution, and its effect on soil structure was studied by sieving and X-ray computed tomography techniques. The results showed that the leaching amount of heavy metals in soil decreased by 76.34% after remediation. Interestingly, due to the addition of organic matter and microorganisms, the soil particle size changed from microaggregates to large aggregates, and the large soil particle size (diameter > 2 mm) increased significantly by 71.43%. The soil porosity increased by 73.78%, which enhanced the soil permeability and increased the soil hydraulic conductivity. Therefore, MICP bioremediation not only remediated soil heavy metal pollution but also promoted the soil aggregation structure, which has important significance for soil remediation and improvement.