Soil acidification in agroecosystems is a natural process that could be accelerated, mainly by the inappropriate application of mineral fertilizers, or prevented, by sustainable management practices. On the basis of a three-year field study in a grassland agroecosystem, the impact of different rates of fertilization with nitrogen (N), phosphorus (P), and potassium (K) on soil chemical parameters related to soil acidity was evaluated. It was found that high-rate fertilization with ammonium nitrate accelerated the soil acidification process, which was additionally intensified by the application of superphosphate and potassium salt. The sum of exchangeable base cations, the values of base saturation and hydrolytic acidity in the soil reflected the interactions between the applied NPK-fertilizer levels. Considering chemical parameters related to soil acidity studied in this experiment, it seems that the best strategies for mitigating soil acidification in grasslands are reducing nitrate leaching, changing fertilizer types and increasing the input of base cations.

There is a lack of studies on the impact of COVID-19-related population mobility and freight transport restrictions on the soil environment. The purpose of this study was to evaluate the impact of automotive pollution on selected parameters describing the quality and healthiness of crop soils based on results obtained before the pandemic (2017–2019) in relation to data from the pandemic period (2020–2021). The study included soils from six cultivated fields located in eastern Poland along national roads (DK No. 74 and 82) and provincial roads (DW No. 761 and 835). Soil samples were taken from distances of 5, 20, 50, and 100 m from the edge of the roadway. The following soil characteristics were determined: pH_KCl, content of total organic carbon (TOC), total nitrogen (TN), and activity of the three enzymes dehydrogenases (ADh), neutral phosphatase (APh), and urease (AU). The degree of traffic-generated soil pollution was assessed by determining the samples’ total cadmium and lead levels (Cd and Pb) and total content of 14 polycyclic aromatic hydrocarbons (Σ14PAHs). The monitoring of cultivated soils showed that the parameters of cultivated soils varied primarily according to the distance from the edge of the roadway. There was an increase in soil acidity and TOC and TN content and a decrease in Cd, Pb, and Σ14PAHs as one moved away from the edge of the roadway. The highest ADh and APh values were found in soils located 100 m from the edge of the road. AU at 5 m and 20 m from the edge of the pavement was significantly higher than at 100 m away. The reduction in vehicular traffic associated with the pandemic did not affect the changes in the reaction of the studied soils and their TOC, TN, and Pb contents. The lowest content of Σ14PAHs was found in 2020. In the case of the amount of Cd in soils, a downward effect was also observed in 2020. However, no significant differences were noted, except for the soils in Skorzeszyce and Łuszczów Kolonia. The reduced influx of xenobiotics into the soil environment stimulated ADh and APh. In the following year (2021), the amounts of tested xenobiotics and enzyme activities in the soils were at a similar level to those in 2019. The results indicate a positive but short-term effect of the pandemic on reducing the contamination of soils located along transportation routes.

The aim of the study was to assess the quality of agricultural soils, which accumulate additional amounts of heavy metals from fertilization and modify their bioavailability, with the use of interdependencies between their biological and chemical properties conditioned by the distance from communication routes. Our results indicated that heavy metals had an impact on enzyme activity in soils and their accumulation was significantly related to the distance from the edge of the road, location of sampling sites, date of soil sampling, and years of research. It was found that the greatest amounts of zinc, cadmium, lead, and copper were accumulated at a distance of 5–20 m from the edge of the road. The highest enrichment factor and geoaccumulation index values were recorded for Pb, followed by Zn, Cu, and Cd. Principal component analysis and regression models showed that the activities of phosphatase and dehydrogenases seem to be the best bioindicators of contamination of roadside soils used for agricultural purposes. Since their activity is related to soil’s organic carbon content, inputs of organic fertilizers and crop residues should be ensured in the agroecosystems along roadsides.