Physiological activity of Mind Extra humate

Studies by a number of scientists have established that organic fertilizers contain substances that can participate in the physiological and biochemical processes of plants. We include vitamins, auxins, antibiotics, various growth activators, etc., in this group of substances. Guided by the works of domestic and foreign researchers, the beneficial effects of humic and fulvic acids found in soil, shale, and leonardite on the vitality of plants and microorganisms have been established. The question of the participation of humic and fulvic acids in plant nutrition has been most fully developed by our scientists previously. In this regard, it was hypothesized that soluble humic substances play some role in the mechanism of action of this type of fertilizer. Experiments in water and sand cultures, the results of which were published by us earlier, showed that humates from leonardite are approximately equal in terms of biological activity.

To study the effect of humic substances on plant vitality under natural growing conditions, a series of experiments was conducted in soil cultures and under field conditions. Field experiments were carried out in the Kherson region. The soil at the experimental site was chestnut. The experiments were replicated four to six times, with accounting plot sizes of 10-100 m². Vegetative experiments were set up in vessels with a capacity of 6-12 kg of chestnut soil, with sixfold replication. In addition, soil composts were established, and a series of studies were conducted using a radioactive phosphorus isotope and the vacuum infiltration method.

The program of physiological and biochemical studies included determinations of total and protein nitrogen (Kjeldahl method), total and protein phosphorus (Lorentz gravimetric method and Malyugin-Khrenova colorimetric method), potassium (Tananaev method), sugars (Hagedorn-Jensen method), ascorbic acid (Murri method), chlorophyll (Getri method), catalase and peroxidase activity (Pochinok method), respiration intensity (Warburg method), photosynthesis intensity (CO₂ absorption), and transpiration intensity and productivity.

EFFECT OF MIND EXTRA PREPARATION ON PLANT GROWTH AND PRODUCTIVITY

Table 1 presents the results of experiments in soil cultures, where the Mind Extra preparation was applied by watering with a 0.001% solution at a rate of 250-300 ml per vessel once a week. Control vessels were simultaneously watered with the same amount of water.

Experiment accuracy: wheat – 2%; maize – 1.1–3.2%; oats – 2.6%; sugar beet – 1.8%; tomatoes – 4.4–4.6%.

From the data in this table, it is evident that watering with the Mind Extra preparation leads to enhanced plant growth and increased productivity. This positive effect could be due to both the direct impact of the preparation on plant vitality and its influence on soil microflora. The latter assumption is particularly plausible, as soil analyses from the vessels and special laboratory experiments have established the stimulating effect of soluble humic substances on the activity of soil microorganisms and on the content of assimilable forms of nitrogen and phosphorus in the soil.

Therefore, to clarify the question of the direct effect of the Mind Extra preparation on plant growth and productivity, additional studies were conducted in 2012–2019.

Observations on roots showed that watering with the Mind Extra preparation and pre-sowing seed soaking in its solution lead to enhanced growth of both the aboveground parts and the root system of young plants.

Experiment accuracy: wheat – 2.9%; maize – 2.7–3.9%; sugar beet – 2.8–2.5%; pea – 4.2%; tomatoes – 3.8–5.7%.

In 2018–2019, vegetative experiments were conducted in which plants were sprayed with Mind Extra once a week at a rate of 25 ml of 0.01% solution per vessel (control vessels were simultaneously sprayed with water).

Experiment accuracy: maize – 3.7–4.4%; tomatoes – 4.5%.

To practically verify the conclusion about the positive effect of the preparation on the vitality and yield of agricultural crops, field experiments were conducted in 2018–2019. Mind Extra was applied before watering with water at a rate of 20 liters of 0.01% solution per 10 m², 2-3 times during the vegetation period with a monthly interval. Before sowing, seeds were sprayed with a 0.2% Mind Extra solution at a rate of 5 liters per 100 kg of seed material. Foliar feeding of crops was carried out once a month at a rate of 1 liter of 0.01% solution per 10 m².

The data from these tables fully agree with the results of the vegetative experiments discussed above. Thus, it can be considered established that soluble humic substances extracted from the substrate with alkalis are physiologically active substances. In small doses, they have a direct stimulating effect on plant growth and productivity.

EFFECT OF MIND EXTRA SOLUBLE HUMIC PREPARATION ON PHYSIOLOGICAL AND BIOCHEMICAL PROCESSES IN PLANTS

To study the nature of the physiological activity of soluble humic and fulvic substances, biochemical analyses of plants from vegetative experiments in soil cultures were conducted, as well as special laboratory studies.

Under the influence of soluble humic and fulvic substances, the content of both total and protein nitrogen in leaves increases (Table 7). At the same time, Mind Extra did not affect the process of using absorbed nitrogen for protein synthesis. The ratio of protein nitrogen to total nitrogen in the leaves of control and experimental plants is approximately the same.

A special experiment established that humic substances have a noticeable stimulating effect on plant growth at reduced phosphorus doses in the root nutrition medium, whereas no such effect was observed when the level of nitrogen nutrition was reduced. Thus, an analogy is suggested between the action of small doses of soluble humic and fulvic substances and recognized growth stimulants, which in our experiments improved the use of phosphorus by plants.

The effect of humic and fulvic acids on the assimilation of mineral nutrition elements by plants can be caused by both an increase in protoplasm permeability and the activation of the rhythm of biochemical processes, especially oxidation-reduction ones. The latter position is most fully reflected in our previous experiments.

Our studies also indicate that under the influence of soluble humic and fulvic substances, oxidation-reduction processes in plants are activated. Thus, analyses of plant leaves from the experiments described above showed that humic and fulvic substances increase the activity of peroxidase and catalase (Table 9). Special experiments in water cultures revealed that soluble humic and fulvic substances increase the intensity of respiration in leaf and root cells of plants (Table 10), which allows plants to assimilate more mineral substances from the soil.

From the data presented, it is evident that Mind Extra activated the respiration of plant tissues independently of phosphorus absorption. Therefore, it can be acknowledged that soluble humic and fulvic substances have a direct effect on the rhythm of oxidation-reduction processes in plants, allowing them to absorb mineral substances more intensely. The latter, especially phosphorus, undoubtedly influence the further course of biochemical processes.

To establish the effect of humic and fulvic substances on plant water exchange, special vegetative experiments were conducted with maize and tomatoes. In one of the experiments, the dependence of the effect of Mind Extra on plant productivity on the degree of soil moisture was studied. Plants were grown at soil moisture levels of 40–45%, 60%, and 75–80% of full moisture capacity. One part of the vessels was watered daily with a 0.001% Mind Extra solution by weight, the other with water.

The positive effect of Mind Extra was most pronounced when soil moisture deviated from the optimal level (the average yield per vessel of dry aboveground mass increased by 30% compared to the control at 45% soil moisture). This suggests that soluble humic and fulvic substances also affect such an important physiological function of plants as water exchange.

It was also established that the Mind Extra preparation does not have a noticeable effect on transpiration intensity, while simultaneously increasing its productivity by 8–14%.

CONCLUSIONS

• Humic and fulvic substances are physiologically active substances. In small doses, they have a stimulating effect on the growth of the aboveground mass and root system of young plants.
• Under the influence of humic and fulvic substances, the most important physiological and biochemical processes in plants are activated: the absorption of mineral substances from the soil, the use of absorbed phosphorus by plants for protein synthesis. Humic substances stimulate the activity of enzymes involved in oxidation-reduction processes, the respiration process in plant tissues, the intensity of synthetic processes, including photosynthesis, and increase transpiration productivity.
• The stimulating effect of small doses of humic and fulvic substances is observed not only when added to the root nutrition medium but also when seeds are soaked in them, leaves are sprayed, and they are introduced (by vacuum infiltration) into plant tissues.
• The results of field experiments allow us to consider that the Mind Extra preparation from leonardite can be used as a plant growth stimulant to increase their productivity on chestnut soils in the southern steppe zone of Ukraine.