Stimulating effect of humic acid, potassium humate, Amino Energy on plant growth and the nature of this phenomenon

Many scientists pointed out the stimulating effect of humic acids: Nefedov, Bottomley, A. V. Blagoveshchensky and A. A. Prozorovskaya, N. A. Krasilnikov, Liske, Olson, Niklevsky and Voitsekhovsky, Kuti and Pechnik, later - M. M. Kononova and N. A. Pankova, Bieber and Mataziner, Otto, Flyg, Guminsky, Guminsky and others, but the conditions under which this action manifests itself, and what is the physiological essence of this phenomenon, have not been studied. Prior to the beginning of our work on this issue, such points of view were expressed.

A. V. Blagoveshchensky, noting the complexity of the molecule of humic acids, came to the conclusion that they cannot have any significance for the direct nutrition of plants, and suggested that humic acids have hormonal properties.

The enhancement of the action of P₂O₅ and K₂O under the influence of humic acid, potassium humate was pointed out by A. A. Prozorovskaya, who conducted a number of experiments in soil crops. She also studied the effects of humic acid on the exoosmosis of sugars on onion scales. The results of this experiment showed that the exoosmosis of sugars increased to 160-180% under the influence of humic acid. In addition, A. A. Prozorovskaya came to the conclusion that, in large doses, humic acids can serve as a source of iron for plants, but basically their positive effect should be attributed to the stimulating effect on the vital activity of plant organisms.

Kissel explained the positive effect of coal preparations, on the one hand, by their effect on the physicochemical properties of the soil, and, on the other hand, by a stimulating effect on the plant cell and, first of all, on the development of chloroplasts.

Bottomley, working with bacteriorized peat, composts and extracts from humus, as well as with humate, found that small doses of extracts from humic acid contributed to a significant increase in the formation of dry matter of plants. Most of the experiments were carried out with duckweed. He considers special organic substances, which he calls "auximons", the action of which Bottomley compares with the action of catalysts, to be the active principle in humate and other plant residues.

Bottomley's experiments were verified by Clarke and Roller, who conducted their studies with different sources of mineral nutrition. The results obtained by them confirmed Bottomley's experiments and showed that plants, duckweed in particular, can develop without organic substances, but develop better in their presence. Under sterile conditions, the effect of these extracts was more noticeable.

N. A. Krasilnikov explains the positive effect of humus substances in the soil on the growth of higher plants by the impact on them of the products of vital activity of microorganisms. Studying the effect of microorganisms (130 species) on wheat seedlings, N. A. Krasilnikov found that different microorganisms have different effects on the growth of wheat seedlings. Some of them are growth inhibitors, others are activators.

When studying the effect of bacteria on the growth of isolated roots of wheat, peas, and corn, N. A. Krasilnikov and N. Gorkina found that the vital products of microbes (humic acid should also be included) are of decisive importance in the development of roots.

N. A. Krasilnikov confirms this conclusion in his later works. He notes that antibiotics, which are produced in the soil by fungi and bacteria, are also an important factor in the life of a higher plant. For example, it was found that gramicidin C has a depressing effect on the development of clover, while penicillin and aspergellin have a positive effect.

P. A. Vlasyuk notes that under the influence of the introduction of humic acids (potassium humate) in the amount of 2-3 l / ha (or 15% concentrate), the development of the root system and the assimilating surface improves, and the accumulation of chlorophyll and sugar content in plants increases, and redox enzymatic activity. He explains this by improving the conditions of mineral nutrition, which are created due to the sorption capacity of humate.

Liske came to the conclusion that the positive effect of humate is due to the presence of humic acids, which increase the permeability of the plant membrane and thereby increase the flow of minerals into the root cell.

The point of view of Niklevsky and Voitsekhovsky, who observed an enhanced development of roots under the influence of humic substances extracted from manure and brown coal, is close to this idea. They believe that the effect they are seeing is due to the increased permeability of the root cells and better utilization of nutrients.

Kuti and Pechnik at the Chemical Institute of the Hungarian Agricultural Academy repeated and expanded the experiments of Niklevsky and Wojciechowski. They found out the mechanism of the stimulating action of humic substances, potassium humate, that is, whether humic acid acts as a hormone or increases the permeability of the cell membrane.

Studying the action of humic acid sol both on a living plant and by observing the phenomena of diffusion and osmosis of colored solutions in gelatin and in the excised core of the sugar beet root, they did not come to definite conclusions, although they were more inclined to assume the hormonal nature of the action of humic acids.

Over the years, we have set different tasks, but the main goal was to study the effect of humic acids on the processes of plant nutrition and to develop the most effective ways to use them for fertilizer purposes.

During the entire period of research, we carried out a wide variety of experiments both in soil, and in sandy and water cultures, which also showed that humic and fulvic acids have a stimulating effect on higher plants.

This property of humate manifests itself differently depending on a number of conditions, such as: the properties of the humic acids themselves, fulvic acids, the biological characteristics of plants, the external environment, etc.

Since the effective use of potassium humate as a microfertilizer is impossible without establishing the conditions under which its stimulating effect will manifest itself most fully, as well as the nature of the phenomenon itself, we conducted a number of studies in this direction, the results of which are published in this article.

 

Method of work

It has already been pointed out that one group of researchers associates the positive effect of humic acids with their effect on the permeability of root cells and, as a consequence, with an increase in nutrients, the other with their effect on the physicochemical properties of the soil and the conditions for the growth of the root system.

In order to isolate the action of humic acids, humate from these factors and avoid reactions of their interaction with soil salts or nutrient mixtures, we set up a series of experiments on distilled water with seedlings up to three weeks old, when the plant can still develop due to endosperm nutrients. . It is at this time that the biological characteristics of individual plant species are most clearly manifested, and they react extremely strongly to external conditions.

Seeds for these experiments were germinated for 5-7 days in tap water on a grid, after which they were planted in half-liter jars with distilled water, where the plant growth stimulator Potassium Gutate + Phosphorus was added . The effect of humic and fulvic acids was judged by the change in the length of the roots, which were measured individually. From all measurements, the arithmetic mean root length u was derived. square deviation from the mean. The experiments were repeated four times.

The sources of humic acids in our experiments were: sapropel, weathered coal and accompanying carbonaceous shales, the so-called "soot", dark chestnut soil.

The extraction of humic acids was carried out with a 2% KOH solution according to the method developed by the research laboratory of our company Agro.Bio for the extraction of humic acid from this raw material. This solution of potassium humate was dialyzed to a neutral reaction of washing water according to the phenolrot indicator, after which it was transferred into a volumetric flask, brought to the line with distilled water, and the carbon titer was established in it (Kubel-Timan method).

To obtain humates of divalent and trivalent metals, proceed as follows: a certain volume of potassium humate was taken, a solution of the chloride salt of the corresponding metal was added to it in excess and left for a day. The resulting precipitate of polyvalent metal humate was collected on a filter, washed with water until the sample for chlorine disappeared, and applied under the plant.

Conditions for the manifestation of a stimulating effect

the rubber potassium

The first task of our work was to identify the optimal doses of humic and fulvic acids in terms of stimulating effect. Experiments were carried out with potassium humate, obtained from the "soot" described above with two crops: spring wheat and beans (Phasolus aureus).

The purpose of the first experiment was to reveal the effect of different concentrations of humic and fulvic acids at the beginning of seed germination. For this purpose, the technique of Blagoveshchensky A.V. and Kolofiva A.A. was applied.

The experience was laid in March in 2 series. 20 grains of beans were placed in porcelain cups and 2 ml of potassium humate of the appropriate concentration were added. In the first series, the cups were covered with glass, and thus a constant concentration of the solution was maintained in them throughout the entire experiment. In the second series, the dishes were left in the open air, the solutions slowly evaporated, and the seedlings were exposed to increasing concentrations. This series was included because in the south of Ukraine, when germinating under natural conditions, plants are exposed to ever-increasing concentrations of soil solution due to the rapid drying of the upper soil horizons.

Bean roots were measured on the 4th day of the experiment (Table No. 1).

Table 1

The increase in the length of the roots under the influence

various concentrations of potassium humate

 

From these data it follows that potassium humate stimulates the growth of bean sprouts in concentrations up to hundredths of a percent.

It is important to note that when dried, humic acid partially coagulates and remains in the sol state only at the highest concentration. Thus, the toxicity of its large doses is related to its physicochemical state, and the process of transition from a sol to a gel should be considered as a mechanism for self-regulation of concentration. The presence of humic and fulvic acids in the properties of self-regulation of concentrations creates special advantages for their use in areas with insufficiently humid climate, such as Kherson, Zaporozhye, Odessa and Nikolaev regions. The toxicity of humic and ulmic acids in relation to microorganisms and the relationship of this phenomenon with their physical and chemical state were first discovered by Academician Williams.

The experiment with spring wheat was aimed at elucidating the effect of different concentrations of potassium humate on root growth in a later phase of plant development, as well as the significance of the physicochemical state of the acid. To minimize the effect of additional factors, tap water was taken for coagulation of humic acid. The experiment was laid in two versions: on distilled and tap water.

On March 8, the seeds were placed on the grid, 16 were transplanted into jars, 19 the first measurements of the roots were made, 23 the second. The results are summarized in table. 2.

table 2

Effect of different concentrations of potassium humate

on the growth of spring wheat roots

 

 

The data of this experiment show that the maximum effect of the humic and fulvic acid sol was observed within thousandths and ten thousandths of a percent, the concentration of the sol above thousandths of a percent reduces its effect.

her action.

When humic acid is introduced in the form of a gel, the picture changes. The effect of potassium humate is observed only when the dose of the gel is increased. This position finds its explanation in the properties of humic acid, which belongs to extremely hydrophilic colloids and, at low concentrations of electrolytes, is easily peptized by water. The positive effect of large doses of this concentrate must be explained by the fact that part of it goes back into solution.

An experiment carried out with durum wheat gave exactly the same results.

It is known that humic acid with monovalent metals gives soluble salts, which form highly dispersed true solutions, and with two and trivalent metals - insoluble, precipitating.

In order to establish even more clearly the significance of the solubility of humic acid, from April 1 to April 15, another experiment was carried out with spring wheat.

Potassium humates, Mind "Agro.Bio", Amino Energy "Agro.Bio", Humate + Fe "Agro.Bio" and Humate + Iron + Sulfur "Agro.Bio" were introduced as a source of humic acid at a concentration of 0.0006% ( Table 3).

Table 3

Influence of various salts of humic acid on the growth of spring wheat roots

 

 

These data show that Mind "Agro.Bio" and Amino Energy "Agro.Bio" humates work best , followed by potassium humate . Humates Humate + Fe "Agro.Bio" and Humate + Iron + Sulfur "Agro.Bio" have a lesser effect. Thus, those humates that give highly dispersed and true solutions have the strongest stimulating effect.

In order to establish how different agricultural crops react to the stimulating effect of humate, an experiment was carried out in June with seedlings of different plants. The methodology of the experiment is the same as the previous ones. Potassium humate concentrate (15%) was taken as a source of humic acid. The dialyzed potassium humate was tested at a concentration of 0.0005%. The results of the experiment with cereals are given in table. four.

From the data presented, it can be concluded that humic acid and fulvic acid had a positive effect on all tested crops, but individual species and even varieties did not react with the same activity. In addition, the effect of humic acid on the development of roots and stems was not the same; more noticeably it affected the development of the roots. Strengthening of stem growth under the influence of potassium humate was observed only in more responsive crops.

The greatest influence on the growth of roots of the first order and the formation of roots of the second order was exerted by potassium humate in experiments with winter wheat. Under the influence of microfertilizer potassium humate + phosphorus, the total length of the root system in winter wheat (grade X) increased by about 15 times , in y (grade Y) - 23 times.

The second place according to the reaction to the preparation of potassium humate + Phosphorus can be put barley variety-9, in which the total length of the root system has increased 11 times. It is interesting to note that the second grade of barley - Variety-32 almost did not react to this preparation at all.

The influence of the studied preparation "potassium humate + phosphorus" on the development of roots in spring wheat was observed in all varieties. Of the wheat varieties, Trizo and Aranka were especially reactive. Weakest of all Reno.

Of the other grain crops, oats-Chernigovskiy 28, millet Kharkivske and rice Ukraine 96 responded well to the microfertilizer.

Table 4

The influence of sodium humate on the formation of roots in cereal crops (According to the experience of 1948)

fertilizer

The effect of these acids on the growth of legumes is illustrated in Table. 5.

Table 5

Effect of sodium humate on root formation in legumes

 

The table shows that legumes react to humic acids weaker than cereals. In the first place in terms of reaction to humic acids, here you need to put alfalfa and beans.

In table. 6 shows the results of the experiment with oilseeds.

Table 6

Effect of potassium humate on root formation in oilseeds

 

 

Comparing all these data, we can conclude that humic and fulvic acid, introduced in the form of potassium humate at a concentration of 0.0005%, has a strong effect on the vital activity of cereals, less legumes and to a lesser extent on most oilseeds. All these groups of agricultural crops differ primarily in the nature of reserve nutrients. In cereals, their main type is starch, in legumes - proteins, in oilseeds - fats. Obviously, the reason for the difference in the ratio of these agricultural crops to humic acid at the beginning of plant development must be sought in the different nature of the transformation of organic substances.

In order to test this situation, tomatoes, table and sugar beets and kok-saghyz were additionally included in the experiment.

The results of the experience are given in table. 7.

Table 7

The effect of potassium humate on root formation in various crops

 

 

The data obtained show that all these crops, in which carbohydrates are the main reserve nutrient, respond positively to potassium humate. Since kok-saghyz develops very slowly in the initial period, experience with it was proposed for up to 45 days. At the same time, it turned out that the control plants almost completely died, while the plants that were the subject of the experiment felt great, the roots and rosette developed further, and by the time the experiment ended, the rosette consisted of 10 leaves, and in the control of 4.

Experimental data allow us to divide all agricultural plants according to the reaction to the microfertilizer potassium humate + phosphorus into four groups:

1.   A group of very strongly reacting plants: tomatoes, potatoes, sugar and table beets.

2.   A group of strongly reacting plants: winter and spring wheat, except for the "Triso" variety, barley, with the exception of the "Nedra" variety, oats, millet, corn, rice, kok-saghyz, alfalfa.

3.    A group of well-reacting: peas, beans, peas, lentils, peanuts, sesame seeds, cotton OD-1.

4.   A group of less well-reacting plants: sunflower, castor bean, cotton (most varieties), gymnosperm pumpkin.

From the literature it is known that a number of substances contribute to the rooting of cuttings. In order to test whether potassium humate would have an effect on root formation in cuttings, an experiment was set up in a greenhouse under solar heating according to the following method: plant cuttings were kept in potassium humate at a concentration of 0.0006% for 24 hours [controls were kept in tap water] and landed in boxes with sand as without mineral

fertilizers, and in sand fertilized with potassium phosphate and ammonium nitrate at the rate of 0.1 g of phosphorus and potassium nitrogen per kilogram of sand.

On April 16, the first inspection of the plants was made and the following was found: the sedum cuttings began to take root in all variants of the experiment and there was no difference in the condition of the roots. On the cuttings of lacfioli, chrysanthemum and ivy in the variants treated with potassium humate, calus formation was observed. During this experiment, the weather was very cold, and the growth processes in the plant were very slow. Therefore, when it became warmer, we watered with potassium humate all those variants of the experiment in which the cuttings treated with humate were planted. Controls were simultaneously poured with water. On May 7 the experiment was over. The results obtained are summarized in Table. eight.

Table 8

The effect of potassium humate on the rooting of cuttings in% of the total number of cuttings

 

 

These data show that the best root growth under the influence of humate was in privet, Babylonian willow, lacfioli, chrysanthemum, and echeveria. Mineral fertilizers did not have a positive effect on the rooting of cuttings.

Simultaneously with this experiment, sedum and tomato cuttings were planted in jars with distilled water according to the scheme: a) without potassium humate and b) with potassium humate at a concentration of 0.0006%. On the 15th day of the experiment, that is, on April 16, roots appeared on the roots of sedum both in humate and in distilled water. On tomatoes, roots appeared only where the microfertilizer Potassium Humate + Phosphorus was applied Agro.Bio

Then it was noticed that the roots in the fertilizer Potassium Humate + Phosphorus grow much better: there are more of them, they are longer and covered with second-order roots. On May 10, the experiment was terminated.

The results are shown in table. 9.

Table 9

The influence of potassium humate on the rooting of sedum and tomato cuttings

From the above data, it can be seen that humate in liquid form had an exceptional effect on the development of roots in cuttings of tomato and sedum. It is interesting to compare the effect of humic acid on cuttings of sedum in sand, where it takes root so well, and in distilled water, where it was in conditions that did not meet its physiological requirements.

It turns out that the effect of microfertilizer on the rooting of this crop was more pronounced precisely when the plant was placed in unusual conditions.

The nature of the influence of plant growth stimulants based on potassium humate

It is known from the literature that there are two fundamental points of view regarding the nature of the effectiveness of humic fertilizers. Some researchers believe that humates improve the physical and chemical properties of the soil and thus create more favorable conditions for the growth and development of plants, while others suggest a direct effect of humic, fulvic and ulmic acids on the plant organism.

In our experiments on the study of the effect of humic, fulvic and ulmic acids on plants, the studied acids were introduced in very small quantities and gave a positive effect in aquatic cultures, where the effect on the physicochemical properties of the medium is excluded. Therefore, the reason for the effectiveness of humic acids must be sought in the direct effect on the plant organism. The idea of ​​the nature of this phenomenon can be reduced mainly to two points of view.

One group of researchers believes that potassium humate as a highly dispersed sol, in contact with root cells, affects their physico-chemical state, increases the permeability of protoplasms and thus contributes to the supply of nutrients to the plant. According to another group of authors, the positive effect of the above acids on the plant is due to the phytohormones contained in them. It is generally accepted that humic acid does not enter the plant and does not take part in the nutrition process.

Let us consider the results of our investigations from the point of view of these provisions .

If humates were introduced by us in the presence of mineral substances, then the results obtained could be most easily explained by the fact that humic and fulvic acids, in contact with root cells, affected their permeability in a purely physical and chemical sense, thereby increasing the supply of nutritious mineral substances. into the plant, which in turn affected the synthesis processes and led to an increase in yield.

But how to explain the sharp increase in the length of the root of the first order, the formation of roots of the second order, increased leaf growth in a number of crops under the influence of our microfertilizer potassium humate + phosphorus Agro.Biowhen they are added directly to distilled water? Here, there could be no influence on the supply of nutrients from the outside either by increasing the permeability or by increasing the solubility of the salts of the nutrient solution as a result of the reaction of interaction with humic, fulvic and ulmic acids, since these salts were not present in the root nutrition medium at all. A simple one could not take place: the transfer of nutrients to the roots from other organs, since in these experiments an increase in the size of the stems is clearly visible. Therefore, it must be concluded that the above acids independently affect the entire body of the plant. The idea that the effect of humates is due only to their external action on root cells and an increase in their permeability in a purely physical and chemical sense is wrong.

According to the second point of view, the effect of humic fertilizers on the plant is determined by the presence of phytohormones in them.

In order to find out whether the observed effect is due to the humates themselves or the presence of phytohormones in extracts that can be extracted from caustobiolites together with humic acid, a special experiment was set up.

We took samples of our raw materials from different depths, assuming that at great depths they do not contain humic acids, while in the surface layers (up to 3.5 m) acids are already formed due to the oxidation of humins and humites. From all these varieties of shale, extracts were made with water, alcohol and 2% KOH. Aqueous and alcoholic were prepared in the cold by extracting samples with the appropriate solvent in a ratio of 1:10 for 10 days, and alkaline - by heating for 30 minutes. The last extract was dialyzed to a neutral reaction of the wash water according to the phenolrot indicator. The alcohol extract was diluted with water, after which the alcohol was distilled off, and all the extracts were brought to the same volume, then they were added in equal amounts to distilled water under the plant.

The experiment was set up with spring wheat. Plants were planted in jars on June 22, measurements were taken on June 28.

The table shows that all extracts that do not contain humic acids did not have a stimulating effect, and those containing increased root growth. Therefore, the observed effect of exposure to these extracts must be explained by the presence of soluble acids in them, and not by the presence of phytohormones in their composition. This position is absolutely indisputable for alkaline extracts containing humic, fulvic and ulmic acids, as for alcohol extracts, in which phytohormones are also dissolved, the following assumptions may arise: phytohormones of the Carboniferous flora in the process of humification did not decompose to final decomposition products, but underwent changes, similar to those that led to the transformation of the Carboniferous flora in the soil.

These transformations are characterized, as is known, by the polymerization of molecules, dehydrogenation, and carburization. Such a transformation of phytohormones, if it took place, should have led, on the one hand, to the loss of hormonal action, and on the other, to a kind of conservation of them in some inactive form. As the reverse metamorphosis proceeds, when the processes of hydration, dispersion* and oxidation take place, these “canned” inactive phytohormones could be regenerated and pass into an active state.

The objection to this may be the following:

1.    established by F. Kegl, the rapid loss of auxin activity during storage, especially auxin B, which occurs upon storage in the dark and even under vacuum after a few months;

2.    lower melting point of growth substances (auxin A - 196°, auxin B - 183°, heteroauxin - 164-165°) than the metamorphosis temperature (according to Erdman, 300°) of coal;

3.                    sensitivity of phytohormones to alkalis.

Experience has shown that, regardless of the method of obtaining, all dialyzed humates had a stimulating effect on the growth of the root system.

Phytohormones, and even more so vitamins, are very labile substances, often unsaturated, and it is absolutely unbelievable that they could retain their physiologically active properties after such treatment.

Comparing the data characterizing the chemical properties of phytohormones, vitamins and similar substances with the properties of humic acids and with the results of an experiment in which extracts were introduced under the plant, containing and not containing humic, fulvic and ulmic acids, we can come to the final conclusion that the effect of direct exposure soluble acids is determined not by the presence of phytohormones in them, but by the presence of humic, fulvic and ulmic acids themselves.

 

But how to explain the effect of humates on the vital activity of plants?

We rejected the opinion that the influence of humates is reduced to a purely external effect on the physicochemical properties of the protoplasm of root cells and an increase in permeability. Based on the special experience described above, we also rejected the opinion that the action of humic, fulvic and ulmic acids is due to the presence of phytohormones in them. The profound effect of true acid solutions on the vital activity of the organism can be explained quite simply if we assume that the studied acids, being in a state of true solution, enter the plant and are included in the general metabolism. An objection to this assumption is the point of view that humate, having a very bulky molecule, cannot enter the plant.

Let us consider this objection in the light of data on the structure of the humate molecule. Back in 1938, Sedletsky wrote that humate, being polymeric compounds, is built like a chain, which can break in different places and under different conditions give products of different molecular weights. S. S. Dragunov considers humic substances as heteropolycondensates of various molecular weights, as a result of which, in his opinion, they can be divided into several fractions according to solubility. In accordance with this, he considers fulvic acids as aqueous solutions of humic acids. Thus, these studies show that humic acids are complex compounds that can be broken down into simpler ones. The question arises whether it is possible at the present stage of development of the science of plant nutrition to assume that

Let's look at the available data. Back in 1911-1913. in his classic studies under sterile conditions, I. S. Shulov showed that amino acids are absorbed by higher plants. Now this idea finds its full confirmation in the experiments of G. M. Shavlovsky, who applied the method of feeding with metathione and lysate of microbial cells containing a radioactive isotope of sulfur, and found it in a plant.

In order to prove that microbial waste products enter the plant, N. A. Krasilnikov, Corresponding Member of the USSR Academy of Sciences, used antibiotics and then indexed them in the plant.

EN Kozlova points to the penetration of organic insecticides into plant tissues.

The idea of ​​the entry of organic substances into the plant is also confirmed in the works of K. I. Semigrey, Ya. M. Gelerman and N. G. Kholodny. The last question raised was the use of volatile organic compounds in the soil by higher plants.

A.P. Shcherbakov, analyzing the formation of the October growth in woody plants, comes to the conclusion that it is formed mainly not due to the transfer of assimilation products from the needles, but due to the direct assimilation of the decay products of soil organic matter according to the type of isolated root nutrition.

It must be recalled here that the use of organic substances by isolated roots is now beyond doubt. Consequently, the enzymatic apparatus of root cells is adapted to the use of organic substances, regardless of whether they come from the leaf or from the external environment. From a biochemical point of view, there is no profound difference between autotrophic and heterotrophic nutrition.

Work over many decades has greatly shaken the old ideas about how higher plants use carbon.

As an example, let us refer to the work of a group of employees headed by A. L. Kirsanov, Corresponding Member of the USSR Academy of Sciences, in which, with the help of radioactive carbon, the intake of carbon dioxide through the roots and its dark fixation was proved.

All this makes it plausible that humic, fulvic, and ulmic acids can enter the plant.

In order to prove this fact, it is necessary to establish its presence in the cell sap by some specific reaction. Unfortunately, the author of this work is not aware of such a reaction, and therefore, in order to prove the intake of humic acid, it was necessary to follow an indirect agrobiological route.

In the period from April 20 to May 10, a special experiment was laid with spring wheat, which was based on the following reasoning: if humates are a series of polymeric compounds and differ in the degree of condensation and the size of the molecules, then the products of their hydrolysis will be unequally absorbed by the plant, therefore, the degree of stimulating effect they have will be different. From this point of view, fulvic acids. should be absorbed better and give a greater effect than hymatomelanic acid (terminology by Sven Oden, 1922), and the latter is better than potassium humate. Dry humic acid should give the least effect. For the experiment, hymatomelanic acid was obtained by the method described above from a “soot” sample of our raw material. A weighed portion of humic acids in 1 g was infused for 10 days with 100 mlalcohol in the cold. Then, the alcohol extract was drained, diluted with water, and alcohol was distilled from it. When the alcohol was completely distilled off, the solution was transferred into a volumetric flask, topped up with water to the mark, and the carbon titer was determined. After that, the solution was added at the desired concentration.

We failed to obtain fulvic acids from the "soot", since the solutions after the precipitation of humic acids were colorless, therefore, did not contain fulvic acids. The experiment was started on April 20, the plants were transplanted into tales on April 27, the first measurement was made on May 3, the second - on May 10. We present the results of the experiment in Table. eleven.

Table 11

Influence of different fractions of humic acids on the growth of
spring wheat roots

 

From the above data, it can be seen that all fractions of humic acids "soot" have the ability to affect the plant. The effect of hymatomelanic acid on the length of first-order roots was the same as that of sodium humate (the difference lies within the experimental error), but it was undoubtedly more active on the number of second-order roots.

Powdered humate had a weaker effect than liquid potassium humate.

The results of this experiment confirm the idea that the effect of humic acids on the plant is due to the plant's assimilation of the products of hydrolysis of humic, fulvic and ulmic acids.

The second experiment confirming the entry of humic acids into the plant is an experiment in isolated crops with spring wheat. Experiment scheme: 1) external solution - Gelrigel mixture

internal - distilled water; 2) external solution - Gelrigel nutrient mixture + potassium humate 0.0002%, internal - distilled water; 3) external solution - Gelrigel mixture, internal - distilled water + potassium humate 0.0002%. The experiment was laid in glasses with a capacity of 200 ml in four repetitions. The seeds were placed on the net on February 28, and measurements were made on March 5 and the experiment was completed.

The results of the experience are given in table. 12.

Table 12

Effect of potassium humate on the growth of spring wheat roots in isolated crops

 

 

The table shows that potassium humate, introduced into an external or internal solution, lengthened the roots in another vessel.

The result of this experiment can only be explained by the fact that humic acid entered the plant and was included in the general metabolism.

Since it is established that the studied acids enter the plant and are included in the general metabolism, it can be expected that if we take several plants of the same species and variety and artificially change the metabolism in some of them, and then plant them all in solution containing potassium humate, we get a different reaction for each plant.

Since the effectiveness of humate is related to metabolism, it can be assumed that under different temperature conditions,

changing the transformation of organic substances in the plant, the effect of acids on root development will be different.

To verify this position, a special experiment was carried out.

The experiment was established with seedlings of winter wheat and barley in aquatic cultures according to the scheme: 1) water, 2) water + potassium humate at a concentration of 0.0003%. In this case, one series of experiments was carried out at a temperature of 14-18°, and the other at a temperature of 8-12°.

The seeds were placed on the grid on February 15, the plants were transplanted into vessels on February 25, measurements were taken on March 25. The results are shown in table. 13.

Table 13

Efficiency of potassium humate depending on the ambient temperature

 

 

It can be seen from the table that the temperature of the experiment had a very strong effect on the effectiveness of potassium humate, and this effect was greater on winter wheat at higher temperatures, and vice versa on barley.

All this leads to the conclusion that humic fulvic and ulmic acid, being in an ion-dispersed state, is absorbed by the plant and performs a certain physiological function.

CONCLUSIONS

1.    True solutions of humic fulvic and ulmic acids have a direct effect on higher plants. In concentrations of thousandths and ten thousandths of a percent, they stimulate the vital activity of the plant organism. During the precipitation of humic acids, this property is inactivated.

2.    Various agricultural plants react differently to potassium humate: best of all - potatoes, tomatoes, sugar beets; good - winter wheat, spring wheat, barley, oats, millet, corn, rice, kok-saghyz, wheatgrass, alfalfa; slightly worse - beans, peas, lentils, peanuts, sesame, cotton; less effective on sunflower, castor bean, cotton (most varieties), kenaf, gymnosperm pumpkin.

3.   The effect of humic fertilizers on the vital activity of a higher plant is determined not by the presence of phytohormones and other substances in them , but by the influence of the acids themselves.

4.   Humic, fulvic and ulmic acid, which is in an ion-dispersed state, enters the plant and is included in the general metabolism of the plant organism.