Abstract
This paper studies the impact of expanded vermiculite, humic substances and organomineral ameliorant fertilizers obtained by immobilizing humic substances on expanded vermiculite on the growth of corn plants. Immobilization of humic substances on natural aluminosilicates, such as expanded vermiculite allows achieving a synergistic effect combining the ameliorative properties of expanded vermiculite, which improves soil structure and water-holding capacity with the fertilizing properties of humic substances, stimulating plant growth and increasing their resistance to stress. In addition, the use of this organomineral ameliorant-fertilizer of prolonged action helps maintain soil fertility for a long time due to the gradual release of nutrients and improvement of the agrochemical characteristics of the soil. Indicators of total biomass, root and aboveground part mass, number and mass of green leaves, as well as morphometric parameters such as plant height and stem thickness were considered in laboratory experiments. The obtained results demonstrate a significant improvement in plant growth when using the developed ameliorant fertilizers under conditions of moisture deficiency and highly depleted soils. According to the results of the experiment, the total biomass with roots increased by 57.3 % when using expanded vermiculite and by 80.7% when adding humic substances. The use of the ameliorant fertilizer "GumiVer" (soil : GumiVer/9 : 1) increased the biomass by 127.6 % compared to the control, which confirms the synergistic effect between the components of the ameliorant fertilizer. The increase in the mass of the aboveground part and the mass of roots when using the ameliorant fertilizer "GumiVer" was 135.8 and 107.3 %, respectively.