Effects of liming on the microbial biomass and its activities in soils long-term contaminated by toxic elements

Abstract

The effects of liming by CaO and CaCO 3 on soil microbial characteristics were studied during laboratory incubation of long-term contaminated arable and grassland soils from the vicinity of lead smelter near Příbram (Czech Republic). The CaO treatment showed significant negative effects on soil microbial biomass C and its respiratory activity in both studied soils, despite the fact that microbial biomass C in the grassland soil increased sharply during the first day of incubation. The metabolic quotient (qCO 2 ) in soils amended by CaO showed greater values than the control from the second day of incubation, indicating a possible stress of soil microbial pool. The vulnerability of organic matter to CaO could be indicated by the availability of K 2 SO 4 -extractable carbon that increased sharply, particularly at the beginning of the experiment. The amendment of soils by CaCO 3 moderately increased the soil microbial biomass. The respiratory activity and qCO 2 increased sharply during the first day of incubation, however it is not possible to ascribe them only to microbial activities, but also to CaCO 3 decomposition in hydrogen carbonates, water and CO 2 . The pH values increased more sharply under CaO treatment in comparison to CaCO 3 treatment. The improvement of soil pH by CaCO 3 could be therefore more convenient for soil microbial communities.

Microbial Response to Soil Liming of Damaged Ecosystems Revealed by Pyrosequencing and Phospholipid Fatty Acid Analyses

“…This has led to improvement of soil fertility in limed sites compared to unlimed areas [14–16]. Relationship between soil pH and its effect on the activity and composition of microbial populations have been discussed in various reports [4,6,8–10,17–19]. Low pH inhibits the growth of soil bacteria in favor of more resistant fungi [18,20].…”

Soybean root rot caused by Fusarium oxysporum and Fusarium graminearum: interactions with biotic and abiotic factors

“…Previous reports suggest that increasing soil pH by liming reduces soil fungal populations and at the same time improves bacterial growth (Alabouvette 1999; Muhlbachova and Tlustos 2006;Scher and Baker 1980). According to our observations, liming with CaCO3 had a significant reduction effect on root rot of soybean caused by Fg during a four-week period.…”

N Mineralisation from Bioresources Incubated at 12.5°C

“…This difference may be due to the different adsorption rates of Ca 2+ from the two different liming materials onto the colloidal complex, increasing base saturation and ultimately increasing soil pH. Lyngstad [23] found an increase in N mineralisation over a 3-year period as a result of adding CaCO 3 lime, whilst Mühlbachová and Tlustoš [24] found that although soil microbial activity initially decreased after application of CaO compared to CaCO 3 in the first days of incubation, CaO ultimately caused rapid mineralisation of the organic matter compared to CaCO 3 . Alternatively, the difference in the mineralisation of N between these two products may be due to water soluble Ca 2+ from LAB stimulating microbial aggregation within the soil matrix soon after incorporation, subsequently accelerating decomposition and mineralisation of N. Mahoney et al [25] found evidence of microbial aggregation when lime was added to an anaerobic sludge digester.…”