Volume: 3, 2024
3rd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: E024
DOI: https://doi.org/10.24326/ICDSUPL3.E024
Published online: 24 April 2024
ICDSUPL, 3, E024 (2024)
Potential of brownfield soils for organic matter accumulation and stabilisation
Messias de Carvalho1*, Krystyna Ciarkowska1
1 Soil Science and Agrophysics Department, University of Agriculture in Cracow, Mickiewicz 21, 31-120 Cracow, Poland
* Corresponding author: messias.monteiro.carvalho@student.urk.edu.pl
Abstract
Open-cast mining and metal processing usually last for many years leading to removal of the vegetation cover and the production of spoil material accumulated in heaps. However, with time, soils develop on degraded areas and soil-forming processes begin. The starting point for soil to develop on such areas is the accumulation of soil organic matter (SOM) and a restoration of soil biological activity. The aim of the work was to determine drivers of SOM accumulation and stabilisation in the upper layers of brownfield soils situated on heaps formed after Zn and Pb ore or coal extraction, or located near a Fe ores smelter. The soils were 50 to 400 years old. Three groups of factors were examined to check which most affected the accumulation of organic C: (1) degree of contamination of the soils and grasses with the heavy metals (HMs) Zn, Pb and Cd; (2) amounts of Ca, K, P, Na, biomass and lignin in the upper parts and roots of the grasses; and (3) inherent soil properties (C, N, pH, texture, P, K, CaCO3, enzyme activity). Soil properties: texture, pH, CaCO3, N, Zn, Pb, Cd contents, C stocks and enzyme activities were determined as well as grass chemical composition: (Na, K, Ca, Zn, Pb, Cd) and lignin contents. Stabilisation of SOM was determined by evaluating the structure and composition of humic acids (HAs). In most of the mining soils, HMs intervention values were exceeded eight to 15 times. However, the strong, long-lasting HM contamination did not impact the high C accumulation, although the HAs had a more aliphatic structure and lower maturity than those in the reference soils. The brownfield soil grass roots contained high amounts of HMs and lignin, the latter acting as a barrier against contamination. PCA indicated soil age as the first factor and type of activity (mining or industrial) as the second in forming the soil properties. Multiple regression equations, using an adjusted R2 and the Akaike information criterion, indicated that inherent properties (N, invertase activity, C/N and pH) determined the C accumulation in the brownfield soils, while contamination and grass composition was less important.
Keywords: mining/industrial soils, SOM, plant lignin
How to cite
M. de Carvalho, K. Ciarkowska, 2024. Potential of brownfield soils for organic matter accumulation and stabilisation. In: 3rd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL3.E024