Crop production in plastic greenhouses is one of the major sources of plastic pollution worldwide. The main hypothesis of this study is that the regular use of mulch film in greenhouses leads to the cumulative accumulation of microplastic particles (MPs) in the soil, which ultimately leads to changes in the soil properties. Therefore, the main objective of this study was to identify the possible changes in the physical, chemical, and biological properties of soil in greenhouses in three regions of Serbia. The following chemical parameters were determined: electrical conductivity, soil acidity, cation exchange capacity (CEC), total carbon (TC) and nitrogen (TN) content, plant-available phosphorus and potassium content, and trace element content. The following physical parameters were determined: particle size distribution, volumetric mass, specific mass, and porosity; the biological parameters that were determined were microbial respiration and labile carbon. The obtained data were processed using network analysis (NA) to identify the complex relationships between MP content and soil parameters. The NA results support the main findings that the presence of microplastics leads to the destruction of soil structure, which reduces bulk density and increases soil porosity. A strong positive correlation of MPs with soil particles < 0.02 mm and a negative correlation with CEC were found. In the Danube Valley, soil respiration was 78% higher in the open ground compared to a plastic greenhouse. The results contribute to a better understanding of the influence of MPs on soil properties and its ecological functions.

The article presents the results of a comparative evaluation of unconventional annual forage crops based on their productivity in the steppe zone of the Northern Kazakhstan. The subjects of the study were varieties and hybrids of Sorghum-sudan grass hybrids, Zea mays, Echinochloa frumentacea and Pennisétum gláucum. The relevance of the topic lies in the selection and introduction of new, more productive and drought-resistant forage crops for the steppe zone of the Northern Kazakhstan. The objectives of the study are to examine the features of growing forage crops in the steppe zone of the Northern Kazakhstan; conduct a comparative assessment of the productivity of forage crops; and identify the most promising forage crops for cultivation in the steppe zone of the Northern Kazakhstan. The scientific significance of the paper lies in obtaining new data on the comparative productivity of various forage crops in the conditions of the steppe zone of the Northern Kazakhstan. The study used the following research methods: the experimental method by B.A. Dospekhov, the vegetation accounting method by D. Braun, and the soil moisture determination method by N.M. Bakayev; laboratory analyses; and mathematical processing of yield data. The study results showed that the sorghum-sudan grass hybrid had the highest yield: 209.1 c/ha of green mass and 32.6 c/ha of dry matter. Corn and the sorghum-sudan grass hybrid showed a balanced content of crude protein and crude fiber in the forage. The yield of Echinochloa frumentacea and Pennisétum gláucum is lower but still sufficiently high compared to corn and the sorghum-sudan grass hybrid.

The dissolution of Ca and Mg in soil and their translocation in plants from different families when using different doses of liming materials of industrial waste origin have not yet been sufficiently studied. In this study, the influence of increasing doses of ameliorants of carbonate (dolomite flour—DF) and silicate (blast furnace slag—BFS) natures on the change in acid–base properties of soddy-podzolic light loamy soil, yield, and chemical composition of plants of the families Gramíneae (spring wheat), Brassicáceae (spring rapeseed), and Leguminósae (vetch and beans) was studied in five-year pot experiments. In the five-year experiments, the ameliorant of a carbonate nature showed greater effect on soil acid–base properties than that of a silicate nature. A return to the initial state of soil pH was not established in any of the treatments. Both ameliorants showed similar effects on wheat straw biomass, but DF had a greater positive effect on wheat grain yield than BFS. Regardless of the dose of DF applied, the accumulation of Ca and Mg by the plants throughout the study period was higher than when BFS was applied. Among the studied plants, those of the family Brassicáceae were the most responsive to liming and, at the same time, showed high ecological adaptability. Differences in the effects of the two ameliorants on the soil chemical properties were more significant than differences in their effects on plant productivity.