1st International Conference of Soil and Agriculture:
TOWARDS SOIL SUSTAINABILITY
11–13 June 2024 • Lublin–Nałęczów, Poland

https://doi.org/10.24326/ICSA1.PP.29
Published online: 4 October 2024

Selected indicators of soil health in variously contaminated urban garden soils
Katarzyna Szopka¹*, Dariusz Gruszka¹, Iwona Gruss², Anna Karczewska¹, Dorota Kawałko¹

¹ Institute of Soil Science, Plant Nutrition and Environmental Protection, Wrocław University of Environmental and Life Sciences, Grunwaldzka 53, 50‑357 Wrocław, Poland
² Department of Plant Protection, Wrocław University of Environmental and Life Sciences, Plac Grunwaldzki 24a, 50‑363 Wrocław, Poland
* Corresponding author:

Abstract
Studies carried out in urban areas indicate a large local variation in the contamination of these soils. In cities, there is a problem of uptake of potentially toxic elements from garden soils by vegetables grown for consumption, which poses a health risk to consumers. Contamination of garden soils is also dangerous to soil organisms, reducing their abundance and biodiversity. To measure and asses changes in soil properties and functioning to understand soil health as a tool a range of soil health indicators have been developed. Thus, systemic approaches based on different kinds of indicators (physical, chemical, and biological) in assessing urban soil health should be discussed. This study focusses on the urban gardens soils in Wrocław (Poland), where elevated levels of trace elements were identified. The aim of this study was to evaluate the possibility of using standard chemical tests and ecotoxicological tests to assess the contamination of urban garden soils. Soils were collected from three urban gardens located in Wrocław (Poland), which were selected based on the high risk of local heavy metal contamination related to historical or current industry, high road traffic, and the flood that occurred in 1997. Total forms of selected trace elements (Pb, Zn, Cd, Cu) were determined by soil mineralization with “aqua regia”, which corresponds to the content of trace elements close to total. Potentially soluble forms were extracted in dilute nitric acid according to the ISO standard (17586: 2016) and in 1M ammonium nitrate according to the ISO standard (ISO 19730: 2008). The standardized Ostracode test kit was used for ecotoxicological test. The test involved incubating organisms for 6 days to assess the impact of contaminants on their growth. All of the examined soils had exceeded permissible levels of trace elements, especially Zn, Pb and in some soil samples also Cd. Despite the high total Zn concentrations in soils, the amounts of easily soluble Zn forms (released from soils in the extractions with 1 M NH₄NO₃) remained low. A similar relationship was found for lead. The highest inhibition of the growth rate of Heterocypris incongruens was observed for the sampling point in which the highest contamination with trace elements, in particular lead, were found. This biotest could be an alternative screening tool in the assessment of toxicity caused by soil contamination with heavy metals and metalloids.

Keywords: urban contamination of soils, ecotoxicological tests

How to cite
Szopka K., Gruszka D., Gruss I., Karczewska A., Kawałko D., 2024. Selected indicators of soil health in variously contaminated urban garden soils. 1st International Conference of Soil and Agriculture: Towards Soil Sustainability. https://doi.org/10.24326/ICSA1.PP.29