Nowadays a lot of attention is paid to studying the processes of leaf litter decomposition, which is one of the most important stages of biogeochemical cycles. Under simulated conditions these processes can be realised as one of the technological tasks of vermicomposting. Leaf litter is a substrate available for vermicultures, and it is rich in calcium. Vermicomposting of leaf litter makes it possible to get vermicompost samples enriched in calcium combination. This research aimed at studying the agrochemical properties of vermicompost made from leaf litter of particular species of woody plants. To form the substrate for the vermiculture Eisenia fetida Savigny (Lumbricidae) we used the mixture of terrestrial peat with horse manure or the mixture of terrestrial peat with one of three kinds of leaf litter: birch (Betulapendula L.), poplar (Populus nigra L.) and willow (Salix alba L.). These species of woody plants grew within the same area, under similar soil and climate conditions. We carried out vermicomposting in plastic 250-millilitre containers up to the end of the phase of biomass growth. In water extracts from the obtained vermicomposts we measured the concentration of K+, Ca 2+ and NO 3 -. The total capacity of Ca 2+ and K+ in the horse manure vermicompost was, on average, 130 milliequivalents/kg in dry weight. The sum of soluble forms of calcium and potassium in the vermicompost from leaf litter was characterised by a statistically significant decrease in the range: poplar litter willow litter birch litter, and was 113, 106 and 93 milliequivalents/kg correspondingly. We registered the nitrate-ion concentration in the vermicompost from horse manure, from poplar, willow and birch litter at the level of 87, 22, 18 and 14 milliequivalents/kg, correspondingly. The ratio Ca 2+/K+ in the vermicompost from poplar litter was 3.5. In the samples of vermicompost made from poplar, willow and birch litter this index was significantly higher; it was 4.1, 4.7 and 5.7 correspondingly. In accordance with their chemical properties, the two most different variants are the horse manure and poplar litter vermicompost. We tested these two variants on plant objects in hydroponic experiments on studying the speed of root-formation in isolated potato sprouts (the variety Nevsky, Russia). Growing isolated potato sprouts of the variety Nevsky on the extract of the vermicompost from poplar litter resulted in a statistically significant increase in the weight of formed roots (20.17% of the total weight of sprouts) in comparison with the sprouts raised on the extract of the vermicompost from horse manure (12.15%). The obtained effect is discussed from the point of view of the stimulating impact of large amount of Ca 2+ on the root-formation processes of plants.

Установлено наличие специфических свойств вермикомпоста, полученного путём переработки листового опада культурой Eisenia fetida. В вермикомпосте, полученном из конского навоза, суммарное содержание катионов Ca 2+ и K+ составило в среднем ''30 мг-экв / кг сухого веса. Сумма растворимых форм кальция и калия в вермикомпостах на основе листового опада характеризовалась статистически значимым снижением содержания в ряду: тополиный опад-ивовый опад-березовый опад и составила ''''3, ''06 и 93 мг-экв/кг соответственно. Содержание нитрат-иона в вермикомпосте на основе конского навоза, на основе тополиного, ивового и березового опада зафиксировано на уровне 87, 22, ''8 и ''4 мг-экв/кг соответственно. Кратность количественного отношения Ca 2+/K+ в вермикомпосте из конского навоза равнялась 3,5. В образцах вермикомпоста, полученного из березового, ивового и тополиного опада, этот показатель значимо возрастал и достигал значений 4,''; 4,7 и 5,7 соответственно. Выращивание изолированных ростков картофеля сорта Невский на вытяжках из вермикомпоста на основе тополиного опада приводило к статистически значимому увеличению веса образовавшихся корней по сравнению с ростками, выращиваемыми на вытяжках вермикомпоста, полученного из конского навоза.