Bożena Smreczak

The aim of the study was to assess the impact of the specialization of agricultural production on selected parameters of soil health, i.e., soil organic carbon content (SOC), soil acidification, soil nutrient status, i.e., total nitrogen content (NT), available forms of phosphorus, potassium, and magnesium, and microelements content, as well as the content of selected potentially toxic metals (PTMs). For the study, 18 farms located in the Masovian Voivodeship in Central Poland were selected. They were grouped into six types, and each type was represented by three farms. The study included organic farms; farms specializing in: crop, vegetable, poultry, dairy cattle, and pigs production. A total of 144 soil samples were analyzed. The results showed that the specialization of agricultural production and fertilizer management had a significant impact on most of the tested soil health parameters, except SOC and NT content. Despite the high organic fertilizer doses introduced into soils in poultry (170 kg N per hectare as poultry manure) and pig farms (150 kg N per hectare as pig manure), there was no significant influence of these amendments on SOC content. This may indicate low organic carbon sequestration potential in some Polish agricultural soils. Organic farms had the lowest levels of plant nutrients in the tested soil samples, which may limit soil productivity. All the tested soils were strongly acidified, which could restrict both production and regulatory soil functions. Based on the synthetic index of soil fertility (SSFI), vegetable and poultry farms were characterized by very high fertility, while crop, dairy cattle, and pig farms fell into the medium fertility class. Organic farms were in the lowest fertility class. However, the study suggests that the SSFI may not be the best indicator for assessing soil fertility and health; therefore, further research is needed.

Questions European steppes are among the most threatened ecosystems in the Palaearctic region, mainly because of conversion to arable land. Abandonment may allow for the passive recovery of steppes. We made use of an exceptional old‐field succession chronosequence of nearly 100 years to answer the following questions: (a) Are the plant species composition, species richness and functional characteristics typical of virgin grass steppes able to self‐restore during ca. 100 years after abandonment? (b) Do the rates of recovery of the above vegetation characteristics differ over the studied chronosequence? (c) Do topsoil carbon and nitrogen content change over the succession chronosequence, leading to concentrations similar to that of virgin steppes? Location Southern Ukraine. Methods We sampled vegetation and soil in a virgin grass steppe and in old fields abandoned for 6, 15, 31, 50 and ca. 97 years. We subjected the composition data to multivariate analysis. To test whether species richness, functional and soil characteristics of the old fields diverge from those of the virgin steppe, we used one‐way analysis of variance with Tukey's honestly significant difference (HSD) statistic to create 90% confidence intervals. Results The vegetation composition of the three most recently abandoned old fields differed significantly from that of the virgin steppe. The species richness of vascular plants was lower in old fields than in the virgin steppe. The share of steppe habitat specialists was similar to the virgin steppe only in the field abandoned for ca. 97 years. Functional characteristics were significantly different from the virgin steppe only in the most recently abandoned old field. Contents of C org and N tot in fields abandoned for ≤50 years were lower compared with the virgin steppe. Conclusions The functional characteristics of steppe vegetation seem to recover much faster than its biodiversity. However, based on our results, 100 years can be enough time for the spontaneous re‐establishment of typical steppe vegetation.