The effect of growth stimulants based on humic acids from Ukrainian lignite and biochar from agricultural residues on the growth and development of lettuce (Lactuca sativa)

M. Zhylina¹²*, P.P. Karnozhytskyi³, D. Miroshnichenko³⁴, V. Konohrai⁵, V. Sterna² and J. Ozolins¹

¹Riga Technical University, Faculty of Natural Sciences and Technology, Institute of Biomaterials and Bioengineering, Paula Valdena Street 3, K-1, LV-1048 Riga, Latvia
²Institute of Agricultural Resources and Economics, Stende Research Centre, Dizzemes, Dizstende, Libagu parish, Talsu County, LV-3258, Latvia
³Department of Oil, Gas and Solid Fuel Processing Technology, National Technical University Kharkiv Polytechnic Institute, 2, Kyrpychova Str., UA 61002 Kharkiv, Ukraine
⁴Coal Department, State Enterprise Ukrainian State Research Institute for Carbochemistry (UKHIN), UA 61023 Kharkov, Ukraine
⁵Education-Scientific Institute of Natural and Agrarian Sciences, the Bohdan Khmelnytsky National University of Cherkasy, 81 Shevchenko Boulevard, UA 18031 Cherkasy, Ukraine
*Correspondence: maryna.zhylina@gmail.com

Abstract:

Significant amounts of plant-based waste are generated annually in the agricultural and food industries, including straw, corn residues, nutshells, and fruit pits. Disposing of this waste often relies on basic methods that avoid further processing, presenting an urgent environmental challenge. One efficient solution is converting biomass into biochar, which serves as a soil amendment. Developing cost-effective recycling methods has become critical with the increasing scarcity and rising cost of raw materials. The Dnipro Lignite Coal Basin in Ukraine offers extensive lignite reserves, enabling the production of affordable, high-quality humates for soil enhancement. In this study, wheat and barley straw were pelletized with barley bran at a 90:10 ratio. Pyrolysis was conducted at 500 °C with a heating rate of 5 °C·min⁻¹ and a one-hour holding time. The resulting biochar was added to a lettuce cultivation substrate at a 1:10 biochar-to-peat ratio. Humic substances derived from lignite were applied in 3% and 9% aqueous solutions, and environmental conditions, such as humidity and temperature, were monitored throughout the 35-day trial. Results showed that granulated biochar increased lettuce rosette diameter by 7.5% compared to perlite substrates and by 11.6% compared to peat. Additionally, 3% humate solutions enhanced rosette diameter by 11.6% and biomass weight by 25.77%. These findings confirm that biochar from agricultural residues and lignite-derived humates effectively boost lettuce yield and quality.

Key words:

agricultural residues, Agro-ecology, biochar, biomass, carbon cycle, crop, growth stimulants, Lactuca sativa, lignite-derived humates, renewable resources, soil quality

The biological basis for the use of protein growth stimulant made from cattle split for wheat foliar feeding and disease suppression

L.E. Kolesnikov¹*, M.I. Kremenevskaya², I.E. Razumova¹, Yu.R. Kolesnikova³, E.V Tambulatova² and E.O. Yazeva²

¹Saint-Petersburg State Agrarian University, Faculty of Agrotechnology, Soil science and Ecology, Department of Plant Protection and Quarantine, 2 Petersburg Shosse (highway), RU196601 St-Petersburg – Pushkin, Russia
²ITMO University, School of Biotechnology and Cryogenic Systems, Faculty of Food Biotechnologies and Engineering, 49 Kronverksky Pr., RU197101 St- Petersburg, Russia
³Federal Research Center N.I. Vavilov All Russian Institute of Plant Genetic Resources (VIR), Ministry of Science and higher education, Department of Plant Introduction, 42-44 Bolshaya Morskaya street, RU190000 St-Petersburg, Russia
*Correspondence: kleon9@yandex.ru

Abstract:

The new modern preparation – protein growth stimulant – was generated in accordance with technology of employees of Saint-Petersburg ITMO University and Saint-Petersburg State Agrarian University. Biological activity of the preparation was determined by measurements of 20 indicators of the wheat productivity. In addition, 16 indicators of different types of pathogenesis were determined. These can be formed at distribution of Helminthosporium root rot, wheat rust species, powdery mildew and wheat leaf blotch. The use of the protein growth stimulant promoted increase of potential yield in 80% of samples. In comparison with the control, 15 wheat varieties, treated with the preparation, showed an increase in the main productivity indicators: the length of the spike, the number of spikelets per spike, the weight of 1,000 grains, the productive tilling capacity and the general bushiness. The intensity of Helminthosporium root rot development decreased 11.9% (it was found in 53.3% of samples) and the wheat leaf blotch by 15.6% (in 66.7% of samples). The wheat brown rust development intensity decreased insignificantly (3.6% compared to the control). In the same time, values of the pathogen pustule area decreased at average by 79.8%. There was an increase in total nitrogen in wheat leaves at 92% of samples. As was revealed, the effectiveness of the protein growth stimulant largely depends on the wheat variety. To conclude, the prospect of using the new effective protein growth stimulant to increase productivity of wheat and protection from diseases was shown.

Key words: