N.N. Gapeeva, PhD in Biological sciences
Modern intensive agricultural production assumes, on the one hand, the maximum harvest from crops with minimum costs, and on the other hand - the preservation and increase of soil fertility. One of the techniques that allow to successfully solve these problems is the use of humic drugs in the cultivation of crops.
Humates are a group of natural high-molecular substances that, due to their structural features and physico-chemical properties, are characterized by high physiological activity. Their origin is associated with the processes of bio-chemical decomposition and transformation of plant litter, animal remains, protein bodies of microorganisms.
The mechanism of action of humic substances is to stimulate all biochemical processes in the organism of plants. This effect is especially noticeable in the early stages of plant development (seed germination and root system formation), but it also manifests itself throughout the ontogeny, including the harvest of plant products. Humic substances change the permeability of cell membranes, increase the activity of enzymes, the content of chlorophyll and the productivity of photosynthesis. Along with this, humates are not toxic, not carcinogenic, and do not have a mutagenic effect, which allows them to receive to be received as environmentally friendly products.
When humates are introduced into the soil, the soil microflora becomes more active and the rate of biochemical reactions "biota-soil-plant" is increased, respiration and gas exchange, decomposition and synthesis of organic matter are accelerated, the stock of organic matter is increased, and the humification of plant residues.
The biological activity of these or other humic preparations largely depends on the raw materials from which they are isolated. The raw material for the production of humic preparations can be compost, organic waste, sapropel, peat and brown coal.
Specificity of raw materials for the production of humates is that in the row of caustobioliths peat and sapropel which are the youngest fossils, partially retaining fragments of the structure of plant tissue.
Probably, due to the presence of protein residues, humic preparations from peat and sapropel contain 1.5-2 times more nitrogen than preparations from coals, and due to the residues of saccharides, approximately equal amounts of humic acids and substances of acid-soluble fractions, including number of fulvic acids.
In addition, peat humates are more uniform in composition and contain less ballast inclusions. Brown coals in the process of diagenesis pass deeper stages of humification, leading to the loss of proteins and carbohydrates. Therefore, in comparison with humic preparations from peat, preparations from coals contain more carbon and less - hydrogen and nitrogen, and humic acids dominate in the composition of organic matter. The low content of salts of fulvic acids is explained by the fact that they, unlike humic ones, are soluble in water. During the formation of brown coals, fulvic acid are washed out of them and used by a natural circular collar for their own needs. This is a significant minus disadvantage of humates derived from brown coals, because salts of fulvic acids, due to their mobility and physiological activity, have a high bioavailability.
Thus, along with a certain generality of the structure, humic preparations obtained from various raw materials have individual properties. Therefore, the specific features of their impact on living organisms will be determined by the composition of humic drugs, which in turn depends largely on the source of humic raw materials, the characteristics of the deposit and the technology for producing humic products.
The purpose of this research was to study the biological activity of humic preparations obtained from various raw materials and to identify various aspects of their effect on the growth and development of plants.
The determination of the biological activity of humates was carried out in accordance with GOST R 54221-2010 (testing on cucumber seeds). The essence of the method is to determine the increase in germination, the length of stems and roots, and also the mass of plants under the action of humic preparations (0.01% aqueous solution) compared to the control experiment (aqueous solution). The increase in these indicators and reflects the biological activity of humic drugs.
Measurements of growth parameters (root and stem length) were performed using a metal ruler with a pitch of 0.05 cm. The mass of seedlings was determined on laboratory scales in accordance with GOST 24104 with an error tolerance of ± 0.1 mg. The normal germination of seeds was counted twice: after 3 days of thermostating and on the 9th day after germination in the light.
A double layer of filter paper, moistened with an aqueous solution of humic preparations (0.01%), was placed in a Petri dish. In the control experiment, the paper was wetted with distilled water. Seeds of cucumbers were sown in the cups and placed in the dark in a thermostat for 3 days, and then for another 6 days in the light at room temperature. After 9 days from the beginning of the experiment, we determined the germination of seeds, as well as the measurement of the length of the stems, roots and mass of the plants. Calculations of the change in the indices were carried out as a percentage of the control shoots, the repetition of the experiment was fivefold. The results of the experiment are presented in the table.
After 3 days of thermostating, the amount of normally germinated seeds in the control group was 34, which was 96.4% of the total number. In the group of seeds treated with a humate made from low peat, the germination rate was 100% (35 pieces), and in the group using humate from brown coal - 93% (33 pieces). After 9 days of germination the germination of seeds of cucumbers was: in the control group - 100%, in the variant using peat humate - 100% and when processing seeds with humate from brown coal - 96.4%.
Average length of stems, cm
Average length of roots, cm
Average weight of sprouts, g
The results of the experiment showed that the treatment of cucumber seeds with 0.01% solutions of humic preparations increases the germination energy and stimulates the growth and development of seedlings (Fig.).
Fig. The influence of humic drugs on biological activity of cucumber seeds
So, when treating seeds with peaty humate, the average length of stems in comparison with the control increased by 45.6%, and when using humate from brown coal - by 34.0%. The average length of the primary root in the variant with the use of humate from coal exceeded the same indicator in the control by 20.7%, while the use of humate from peat showed an increase to 59, 0%. The biological activity for increasing the mass of propellants was also higher in the group of seeds treated with peat humate and amounted to 45.0% versus 25.0% in the group of humates from brown coal.
Thus, the conducted studies confirm the high biological activity of humic preparations. They increase the energy of seeds, accelerate the growth of shoots and roots and increase the biomass of seedlings. The maximum increase in biological activity in all the indicators studied was observed with the germination of seeds with a humate obtained from low-lying peat. The results of the experiment allow us to conclude that humic preparations obtained from low-lying peat are, in their biological activity, superior to humates isolated from brown coal.