The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). The modified HS were obtained by adding APTES to LHS solution at different mass ratios of LHS and APTES, followed by the investigation of siloxane structures using 31Si NMR spectroscopy. The Urbic Technosol was used as a model soil. The size and amount of water-stable soil aggregates were estimated using wet sieving and laser diffraction, respectively. Toxicity was evaluated by monitoring microbial substrate-induced respiration (SIR) and seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability of the 3–5 mm soil aggregates after LHS-APTES application. Field tests showed an increase in the average weighted diameter of micro aggregates (from 59 to 73 μm) and water-stable macroaggregates (from 1.6 to 2.9 mm) due to the LHS-APTES amendment. A substantial increase in SIR from 5 to 9 mg CO2 (kg h)−1 was detected. Better survival of seedlings was observed. The obtained beneficial results indicate that APTES-modified HS can be successfully used as a soil conditioner. The formation of extended siloxane networks was suggested as the main mechanism of the observed improvement in the structure of the amended soils.

The use of environmentally safe products of natural origin is a global trend today. A particular point of interest is the use of humic fertilizers. This is due to the growing awareness of the positive impact of humic substances on plant growth and development as well as on the quality of agricultural products and soil fertility. Humates are physiologically active substances. As a result, they regulate and intensify metabolic processes in plants and soil, and contribute to the bioavailability of nutrients to plants. EldORost is a new-generation humic product that contains humic substances with a high humification degree. In addition to humates, this product contains a complex of amino acids, macro-, and microelements in a bioavailable form for plants. The product is eco-friendly and completely soluble in water, which is a substantial advantage for drip irrigation systems. It can be used for all types of agricultural crops on a wide diversity of soils and climatic zones. It displays the properties of plant hormones while its optimum concentration is as low as 0.0001% (wt). The efficiency of this novel humic product was tested in laboratory and field tests conducted on potatoes and vegetable crops (tomatoes, cucumbers, cabbage, carrots, onions, beets). The obtained results showed high efficiency displayed in the significantly improved sowing quality of vegetable seeds, nominally increased the germination degree and seed germination energy, intensively stimulated the side root development in plants, accelerated the growth of biomass, increased the fruiting period, and reduced maturation on the yield of potatoes and vegetable crops. The obtained data allowed us to characterize this novel humic product from the perspective of an eco-friendly fertilizer and growth promoter.

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КазНУ имени аль-Фараби, Алматы, Республика Казахстан, zhilkibaevoral@mail.ru Изучена стереохимия восстановления 1-метил-2е-фенил-транс-декагидро-хинолин-4-она Гидроксильные производные насыщенных циклических систем широко распространены среди различных классов природных соединений (стероиды, алкалоиды, ксантоспермины, терпены и др.). От стерической направленности гидроксильной группы в этих соединениях в значительной мере зависят и физиологическая активность и химические свойства. С целью исследования влияния метильной группы на направленность реакции и на биологическую активность, нами было изучено восстановление 1-метил-3е-фенилдекагидрохинолин-4-она (1) в различных условиях [1][2][3]. Вторичные спирты 2 и 3 были синтезированы восстановлением 1 натрием в спирте, боргидридом натрия, каталитическим гидрированием и изопропилатом натрия -которые протекают, как правило, стереоизбирательно и отличаются высокими выходами (табл. 1). Восстановление натрием в спирте 1 проходит стереонаправленно и приводит к образованию смеси эпимерных вторичных спиртов 2 и 3 с преобладанием изомера 2 (85,7 % от общего количества смеси изомеров) и небольшого количества его эпимера 3 (14,3 % по ГЖХ). При восстановлении боргидридом натрия с выходом 90,8% образуется смесь аминоспиртов 2 и 3 с преобладанием (80,8 % от общего количества смеси изомеров) изомера 2 и небольшого количества его эпимера 3 (16,1 %). При каталитическом гидрировании также образуется смесь эпимеров 2 и 3 с преимущественным образованием изомера 2 (78,6 %) и 21,3 % -изомера 3. При восстановлении изопропилатом алюминия в абсолютном