Peat Soil Burning in the Mezzano Lowland (Po Plain, Italy): Triggering Mechanisms and Environmental Consequences

Abstract

 Peat burning in the Mezzano Lowland is a process active since wetland reclamation and variously affects the soil structure and carbon content. The main carbon loss occurs in the depth interval 10-70 cm, where temperature up to 750°C is recorded. The process induces negative effects to surrounding environment, agriculture activities and possibly also human health.

Soil organic carbon data comparison after 85 years and new 13C/12C compositions: The case study of the Ferrara province (Northeastern Italy)

“…According to a one-way ANOVA, there was a highly significantly difference among the districts (p < 0.001), with the δź 3 C values for the LV district being more negative (up to −26.6‰) than the others (Figure 6), indicating the presence of dominance of C3 plant-derived OM in this district. This is supported by the literature, with reports of δź 3 C values for soil OC in Ferrara province ranging from −29‰ to −21‰ (Brombin et al, 2020;Natali et al, 2018Natali et al, , 2021Salani et al, 2021).…”

“…Nitrogen contents were measured by an elemental analyzer Vario Micro Cube (Elementar). Analytical precision and accuracy of the instruments based on repeated soil samples and standards (Bodenstandard and Sulfanilamide) were better than 7% of the absolute measured value (Natali et al, 2018(Natali et al, , 2021. Carbon isotope ratios ( 13 C/ 12 C) were determined using a Vario Micro Cube set to 950˚C and coupled to an isotope ratio mass spectrometer (IRMS) (Isoprime 100; Isoprime).…”

“…The spatial distribution of soil δ 13 C, which reflects the SOC content, is plotted in Figure 7a and shows the presence of two sample groups: one characterized by the lowest OC contents (see Figure 3b) and associated with carbon isotopic ratios near to 0‰ (FM and FL districts) and another characterized by the highest OC concentrations (>20 wt%) and most negative δ 13 C values (down to −26.6‰, representative of the samples collected from the LV district). Samples from the LV region included drained marshes and swamps, with many samples having more than 5 wt% OC and δ 13 C values more negative than −25.5‰, which represent the typical C signature for peatlands derived from C3 plants (e.g., common reed, Phragmites australis; Cavanilles, 1791, Scarton et al, 2002) in Ferrara province (Natali et al, 2018(Natali et al, , 2021; Figure 8). In contrast, the least negative C isotopic values (close to 0‰) indicate soils with low OC content, where IC is the most abundant C fraction.…”

“…In fact, plough tillage accelerates OM decomposition by breaking soil aggregates and increasing soil aeration, which in turn promotes microbial activity and SOM mineralization with consequent release of carbon dioxide (CO 2 ) into the atmosphere (Kibet et al, 2016;Wang et al, 2011). In addition, conventional agriculture is responsible for direct and/or indirect emissions of other GHGs, such as nitrous oxide (N 2 O), derived from nitrogen (N) fertilizers applied to agricultural soils, and methane (CH 4 ) emissions triggered by the anaerobic conditions in cultivated flooded areas like rice paddies and from open biomass burning (Aguilera et al, 2015;Natali et al, 2021Natali et al, , 2023Van Lynden & Lane, 2004). There are many examples in the literature of continuous decrease in SOC that occurs following LULCC and prolonged use of conventional agricultural practices adopted in the 1950s to create new cultivated areas and improve crop yields in response to increasing demands for food from a growing population (Europe: Aguilera et al 2018;Gardi & Sconosciuto, 2007;González de Molina et al, 2020;Smith et al, 2007;China: Qiu et al, 2009;United States: Parton et al, 2015).…”

Fire in the Earth System: Introduction to the Special Collection

“…Natali et al. (2021) evaluated carbon loss and mobility of metals resulting from burning of peat soils in Italy, inferring that 580 kg of CO 2 were released per cubic meter of burned soil, negatively affecting agricultural activities as well as contributing to greenhouse gas in the atmosphere.…”