Research on the Effects of Rare Earth Combined Contamination on Soil Microbial Diversity and Enzyme Activity

Abstract

Soil microorganisms and soil enzyme activities are important indexes to evaluate soil status. The soil pollution status was evaluated by measuring the physical and chemical properties and heavy metal content of rare earth combined contaminated soil around the Maoniuping old mining area and tailings ponds in different seasons, and measuring the number and diversity of microorganisms and the soil enzyme activities of the arable soil microecology. This research shows that the physical and chemical properties of farmland soil in old mining areas and tailings ponds in different seasons are significantly different, the concentration of rare earth combined contamination in old mines is greater than that in the tailings area, and the changes in the concentration of rare earth combined contamination cause significant changes in soil microecology. Rare earth combined contamination inhibits fungal and bacterial vital activities and promotes the growth of actinomycetes; reduces the sensitivity of sucrase to heavy metal contamination, promotes the activity of phosphatase, and the effect on urease is that of “promotion at low concentration and inhibition at high concentration”; and reduces the community’s ability to use carbon sources and, as a result, the community species are rare and distributed unevenly and the community structure is simple. These results indicate that rare earth combined contamination is potentially harmful to soil microorganisms, which can provide a theoretical basis for the ecological restoration of farmland soil in mining areas.

Effects of Water-Fertilizer-Air-Coupling Drip Irrigation on Soil Health Status: Soil Aeration, Enzyme Activities and Microbial Biomass

“…By improving soil aeration, the soil aeration rate of the crop root zone can be significantly increased, soil microenvironment and soil enzyme activities can be improved, and soil microbial activities can be guaranteed [18]. As one of the most active organic components in the soil, soil enzymes serve as important biological indices to evaluate soil fertility since they can serve as biocatalysts and contain protein [19], and thus, can reflect the transformative ability of soil N, P, and other nutrients [20]. The variety and quantity of soil microorganisms have a substantial influence on the absorption and transformation of soil-crop nutrients.…”