Response of soil enzyme activities to synergistic effects of biosolids and plants in iron ore mine soils

Abstract

Past mining activities in Swaziland have left a legacy of abandoned mine sites (iron ore, asbestos, diamond and coal mine dumps), all of which have not been reclaimed. These sites were recently (2013) considered by the country's wastewater treatment authorities as suitable places where biosolids can be applied, firstly as a biosolids disposal alternative and, secondly, as a strategy to accelerate mine soil remediation through phytostabilization. In order to understand the effects that this might have on mine soil conditions and microbiota, two (2) plant growth trials were conducted in biosolid-treated iron mine soils and one (1) trial on undisturbed soil, under greenhouse conditions, for twelve (12) weeks. According to the results obtained, the combination of biosolids and plants led to significant improvements (p \ 0.05) in parameters related to soil fertility. Significant increases (p \ 0.05) in alkaline phosphatase, b-glucosidase and urease soil enzyme activities were also observed. Copper and zinc were significantly (p \ 0.05) increased (Cu from 17.00-50.13 mg kg ); however, these sludge-derived metals did not affect enzyme activities. Improvements in soil physicochemical conditions, organic matter-metal complexes, effects of plants on metals and the essentiality of Cu and Zn to soil enzymes were thought to have masked the effects of metals. Increases in soil enzyme activities were considered to be indicative of improvements in the quality, fertility health and self-purification capacity of iron mine soils due to synergistic effects of biosolids and plants.

Enzymatic activity as an indicator of regeneration processes in degraded soil reclaimed with various types of waste

“…Literature shows that enzymatic activity has been repeatedly used in investigations of the condition of the soil environment affected by various degrees of anthropopressure (Cele and Maboeta 2016;Joniec et al 2012Joniec et al , 2015Li et al 2008Li et al , 2009Margesin et al 2000;Taylor et al 2002;Zaborowska et al 2016). In their investigations, Li et al (2009) focused on the potential of analysis of FDA hydrolytic activity and the activity of eight hydrolases for assessment of a long-term impact of heavy metals on soil.…”

The Influence of Sewage Sludge Composts on the Enzymatic Activity of Reclaimed Post-Mining Soil

“…Enzyme activity reflects the advancement of soil-forming processes [64], illustrates the trends of pedogenic processes in post-mining soils, and enables the assessment of the effectiveness of reclamation treatments being applied [62]. The literature shows that enzymatic activity has been repeatedly used to study the state of soil environments affected by different degrees of anthropopression [16,[99][100][101][102].…”

Microbial Biomass Carbon and Enzymatic Degradation of Carbohydrates by Application of Vermiculite to Reclaimed Substrates

“…The addition of coarse wood fragments increases the functional diversity of the microbial community, but not enzymatic activities of highland reclamation areas after oil production in Northern Alberta, Canada (Kwak et al, 2015). The activity of β-glucosidase enzyme in soil is considered to be a good indicator for efficiency of recultivation processes (Doni et al, 2012;Cele and Maboeta, 2016). The addition of bio-crust significantly improves soil microbial biomass and enzyme activities (alkaline phosphatase, dehydrogenase and urease) in the upper layer of copper-contaminated tailings ponds (Chen et al, 2009).…”