Production of crushed stone from carbonate rocks intended for road construction produces а huge amount of screening fractions, which accumulate in landfills. To date, in the Leningrad region 70 million tons of waste from the production of crushed stone has been accumulated. Its use as an ameliorant can significantly reduce the severity of acid soil problems in the region and at the same time solve an important environmental problem – landfill disposal. In a 6-year 10-variant microfield experiment, a comparative study of the reclamation properties of the screening dolomite dropouts without separation into fractions and the particles of 5–7 and 7–10 mm in size used for liming in increasing doses was conducted on a medium-acid sod-podzolic light loamy soil. These dolomite screenings neutralized soil acidity already in the first year, while their positive aftereffect lasted for at least 6 experimental years. The use of a natural mixture of the screenings in high doses was not effective because of high losses of bases from soil. Clustering of individual experimental variables was carried out by their effect on the pH_KCl value over the entire experiment period.

The soil microbiome is composed of various communities that play an important role in the existence of ecosystem services and the sustainable functioning of ecosystems under high anthropogenic loads. The transition of soils to a fallow state and their subsequent transformation lead to a notable alteration in the taxonomic composition of the soil microbiome, impacting the biochemical processes within the soil and its fertility levels. The object of this study comprised different-aged fallow soils of the southern taiga in the vicinity of Ban’kovo village, Leningrad region. The method comprising the high-throughput sequencing of 16S rRNA gene fragments using an Illumina MiSEQ sequencer was used to analyze the microbial community. The general processing of sequences was carried out with the dada2 (v1.14.1) package. It was found that the morphological organization of fallow soils has significant differences from the native podzol. In fallow soils, there are signs of leaching expressed in the accumulation of leached mineral particles, which indicates the degradation of the fallow–arable horizon. At the same time, there is a decrease in the content of P₂O₅ and K₂O and an increase in the content of N-NH₄ and N-NO₃ in fallow soil. The analysis of alpha diversity index values showed that the highest level of alpha diversity in the microbial community is characteristic of 40-year-old soil, the alpha diversity index decreased with the increasing time of the fallow state, and the lowest alpha diversity index was observed in the native podzol. According to the values of the beta diversity index, a high correlation between the soil microbiome and the physicochemical characteristics of the soil was revealed, which indicates the formation of functional specialization in the studied microbial communities. As a result of the study of the taxonomic composition of microbial communities in fallow soils, it was found that the most represented microbial communities in fallow soils belong to Nitrosomonadaceae (Pseudomonadota), Mycobacterium (Actinobacteria), Nitrospira (Nitrospirota), and Luteolibacter (Verrucomicrobiota). The duration of post-agrogenic transformation is the leading factor influencing the changes in microbial communities; so, with an increase in the time that soils were in a fallow state, an increase in the oligotrophic microbial community was observed.

The dumps of dolomite dropouts from road construction occupy huge arable areas in north-western Russia. Although coarse dolomite particles neglected as a liming material due to its slow solubility, we hypothesise that they can serve as a cheap and long-lasting liming material. The weight loss of dolomite particles of various sizes from the dump applied to Albic Retisol and its effect on assimilation of Ca and Mg by barley and wheat were studied. The pot experiment with 300 g soil was conducted for 30 days in a laboratory phytotron. Results showed that coarse particles of dolomite waste had a positive effect on soil acidity already at the initial phases of the experiment. In the process of dissolution of dolomite, all forms of soil acidity decreased. The cultivation of barley had a stronger effect on the dissolution of dolomite particles than the cultivation of wheat. Barley plants accumulated Ca by 1.1-1.4 times higher than wheat, other factors being identical. The relationship between the yield of green biomass and the accumulation of calcium and magnesium in the plants were empirically described using regression analysis. Results of this preliminary study showed that the by-products from dolomite stone processing can be effectively used for reclamation of strongly acidic soil in north-western Russia. This has the dual benefit of reducing the burden on the environment and reclaiming acidic soils. Further studies should include soil microbiological and biological parameters to trace the effect of root activities and dolomite dissolution rate on a field scale.

Environmental pollution from industrial factories via air deposition is an urgent problem worldwide. Phosphate fertilizers, derived from rock phosphate, are characterized by the presence of potentially toxic elements, such as Zn, Co, Pb, Ni, Cr, Mn, Fe, and Cu, which are dispersed in the form of solid dust-like materials from the pipes of the factory. This study aimed to investigate the effects of airborne industrial emissions on the chemical and biochemical compositions of cotton grown in the immediate vicinity of a fertilizer factory in Uzbekistan. The composition of airborne dust deposited on the plants, the chemical composition of the cotton leaves before and after washing, as well as that of above- and below-ground plant organs, and their protein contents were determined. The concentrations of macro- and microelements in the leaves and roots were determined using an atomic absorption spectrophotometer. The fluorine contents in the leaves and in the roots were determined using a fluorine-selective electrode. The radius of dispersion of industrial emissions in the air was best described by measuring the fluorine contents in washed and unwashed cotton leaves. The relationships among P, K, Mg, Ca, S, F, and Mn in plant roots and leaves as a function of distance from the pollutant source were analyzed. Based on the fluorine contents in washed and unwashed cotton leaves, the two following zones of technogenic pollution were distinguished: the zone < 5 km from the factory, with high technogenic pollution, and the zone > 5 km from the factory, with moderate technogenic pollution. It was found that the resistance of cotton to air pollution from industrial emissions is determined by the ability of cotton plants to neutralize toxic compounds by increasing the influx of alkaline earth metals into the affected tissues. This study showed the possibility of growing cotton at a distance of >5 km from the fertilizer factory. It is strongly recommended to analyze the chemical composition of plants located in a highly polluted zone only after the dust particles have been washed off of the plant’s surface. Despite the resilience of cotton to industrial pollution, the monitoring of areas identified as pollution zones is recommended.