+370 (622) 76992 firstname.lastname@example.org
Įmonės kodas 304358859
Tel. +370 (622) 76 992
Įmonės kodas 304358859
PVM mokėtojo kodas LT100010577512
Draugystės g. 17-1, LT-51229 Kaunas
Ričardas Monkevičius +37062276992
MICROBIAL PREPARATIONS FOR AGRICULTURE
Unfortunately, in the existing systems of agriculture, the biological features of soil-forming processes are not taken into account, since in the center of ideas about the formation of crop yields is the well-known theory of mineral nutrition of plants. Ideas of J. Liebig were taken too literally by his supporters and followers, despite the criticism of a number of outstanding researchers. As a result, the agrochemical part of agriculture developed actively. As a consequence of global chemicalization, we have degraded soils that are not able to ensure the realization of the crop yield potential.
It should be noted that, according to modern concepts, soil degradation should be considered not only as the result of a number of factors leading to a decrease in humus content and deterioration in physicochemical parameters, but also as a consequence of processes that minimize (or even eliminate) the microorganisms that are necessary for the harmonious development of plants.
The roots of plants are known to be surrounded by microorganisms that create a peculiar "cover" (the rhizosphere) and are trophic intermediaries between soil and plant. It is the microorganisms that transform compounds that are difficult for the plant to digest into mobile compounds, which are optimal for absorption and metabolism. In 1897 the founder of the soil science, V. Dokuchaev, in his essay "On the issue of the opening of the soil science and microorganism theory departments at Russian universities" wrote: "Undoubtedly, along with manure, bacteria are also introduced into the soil, and their role is apparently not less than the role of the introduced fertilizers". According to the figurative expression of the famous microbiologist N. Krasilnikov, the role of microorganisms inhabiting the rhizosphere of plants resembles the role of digestive organs of animals.
Today, the doctrine of the conjugation of the vital activity of plants and individual groups of microorganisms has been transformed into an understanding of deep integration at the genetic level.
Thus, in the soil-microorganism-plant system, the soil microbiota is an indispensable and integral component. That is why the plant that is provided with a full-fledged complex of microorganisms receives optimal nutrition and, as a consequence, realizes its genetic potential of yield. Today, unfortunately, in some soils certain species of microorganisms are on the verge of extinction. Their place is occupied by microorganisms that are not typical for soil-forming processes and cannot provide effective interaction with plants. At the same time plant roots are inhabited by nonspecific microorganisms, which, accordingly, perform atypical functions - they do not "feed" crops with nutrients, but parasitize on the plant organism. The consequences are known - even with sufficient provision of mineral nutrition, plants cannot form a full yield. If the current points of view on the root nutrition of plants are preserved in agrochemistry and agriculture, the prospect of transforming the soil from a "living body" (according to V. Dokuchaev's expression) into "substratum" is inevitable.
In this connection, there is a need to apply agro-practices aimed at increasing agronomically valuable microorganisms in agrocenoses. The list of these methods is quite large, but first of all it is the presowing bacterization of agricultural crops, the use of composts and organic fertilizers, rational soil cultivation, keeping the scientifically justified crop rotations. The use of microbial preparations in crop cultivation technologies, in our opinion, should become a mandatory technique in agriculture.
The benefits of bacterization are undoubted even under conditions of a normal soil-forming process, since the influence of beneficial forms of microorganisms on the development of plants and the formation of crops is multifaceted. That is why economically developed countries, despite the great opportunities for the production and use of mineral fertilizers (especially nitrogen fertilizers), demonstrate a great interest in microbiological means of intensifying agricultural production.
Today, new highly effective strains of microorganisms have been obtained by methods of analytical selection, based on which biopreparations for soya, lupine, pea, chickpeas, winter and spring wheat, barley, maize, flax, a number of vegetable crops, potatoes, sugar beet, sunflower and rape have been created. On their basis, convenient preparation forms were created. These are Diazobakteryn, Polimiksobakteryn, Albobakteryn and preparations of complex action (Mikrohumin, Ryzohumin, Biohran) (Table 1).
The effectiveness of the new preparations has been tested in all soil and climatic zones of Europe.
The use of biopreparations in technologies for growing crops provides a significant increase in the yields of agricultural crops and the improvement of the product quality. Bacterization of vegetable crops, as well as soy, showed to be especially effective. Gains from the use of biological preparations for soybeans (Ryzohumin) reach 15-20% in the regions of traditional seeding and 30-45% when cultivating crops in new places for them. The use of the biopreparations for soybeans ensures the production of up to 27-30 beans on a single plant with a population of 15-20 on non-bacterized plants. According to data, obtained in field experiments, among the studied factors of influence on crop yields (fertilizers, biopreparations, plant variety, soil treatment system, etc.), pre-sowing bacterization ensured the formation of 25% of peas and 16% of soybeans.
Table 1. Microbial preparations for agricultural crops
Biopreparations based on nitrogen-fixing bacteria
Winter rye, buckwheat, grasses
Biopreparations based on phosphate-mobilizing bacteria
Sugar beet, winter wheat, flax, corn
Biopreparations of complex action
Potatoes, cabbage, tomatoes, cucumbers
Significant yield increases are noted in the case of bacterization of other crops, in particular, winter wheat. For example, the use of biopreparations for presowing treatment of wheat seeds contributed to an increase in yield by 8 centners per hectare with a control yield of 57 centners per hectare. On average, the gains from the bacterization of winter wheat and other cereal crops are about 5 centners per hectare.
What is the reason for the effectiveness?
First of all, it should be specially emphasized that the introduced microorganisms, becoming attached in the rhizosphere of inoculated plants, are capable of actively fixing the air nitrogen and providing a host plant with it. In the case of legumes with a well-formed symbiosis, nutrition with this element can be carried out almost by 100% due to the vital activity of nitrogen-fixing bacteria. In the root zone of cereal crops, the productivity of the nitrogen fixation process is much lower. However, if one considers that nitrogen, that was fixed by the bacteria, is fully used for plant nutrition, then the effectiveness of even 10-15 kg of biological nitrogen will be much higher than the corresponding dose of mineral nitrogen.
In addition, bacterization promotes the transition of sparingly soluble phosphorus compounds into soluble and thus improves the phosphorous nutrition of plants.
Bacterial preparations are the complex influencing factor of the development of plants, and phytohormones and other physiologically active substances of bacterial origin, which are found in significant quantities in biofertilizers, are not of the last importance. Physiologically active substances have a huge impact on the increase in nutrient utilization rates, including fertilizer absorption by plants. It is known that the assimilation of mineral nitrogen from fertilizers does not exceed 50%; phosphorus (even from the best fertilizer - superphosphate) - 20%; potassium - 25-60% depending on the type of soil. The rest is washed out by rain, denitrified, pollutes products, is fixed in the soil (in the case of phosphorus fertilizers), etc. Even if we ignore the ecological inexpediency of such application of mineral fertilizers, we cannot fail to see the economic losses. Application of bacterization significantly increases the degree of fertilizer use by plants.
For example, let us cite the results of a vegetation experiment with barley, carried out with the use of fertilizers labeled with a heavy nitrogen isotope 15N.
As we can see (Table 2), the use of the Mikrohumin for presowing treatment of barley seeds promotes an increase in the content of not only the biological nitrogen (assimilated by bacteria from the air), but also the mineral one (from fertilizers) in plants. In the field, the use of the mineral fertilizers by bacterized plants increases by 20-30%. Sometimes the effect of bacterization is much higher.
Table 2. Influence of barley bacterization on nitrogen nutrition of plants
The mechanism of this phenomenon is quite simple. Physiologically active substances in biopreparations contribute to the growth of the root system, an increase in the area of the root surface and its absorbent capacity (both general and specific), as a result of which the processes of assimilation of nutrients are initiated. Also, individual plant enzyme systems are activated, which affects the intensity of assimilation of mineral compounds and their further metabolic transformation into organic ones. For example, due to the activation of the nitrogen assimilating enzyme system, nitrates from the reserve fund (and nitrates, as it is known, are not poisonous for the plant and can accumulate in significant amounts) are involved in constructive metabolism and with their direct participation such valuable organic compounds as amino acids and proteins are synthesized. That is why the content of nitrates in bacterized plants is always low, and the content of free amino acids and proteins is high. It is unprofitable in the only case - when growing barley for brewing purposes (but in this case there are technological methods that limit the synthesis of proteins).
Another positive side of the use of the microbial preparations is the resistance to individual plant diseases. Useful microorganisms, colonizing the root system (capturing an ecological niche), for a certain time limit the impact of pathogenic microorganisms on the plant. Studies have shown that even seeds obtained from bacterized sites are less infected with pathogens of various diseases, especially fungal ones.
Due to the physiologically active substances contained in the biopreparations, the seed quality of the seed material is significantly improved - the germination energy and seed germination increase.
Bacterization stimulates the processes of chloroplastogenesis and photosynthesis, and this also positively affects the production process of crops.
As already noted above, the root system of plants becomes bigger after inoculation, and this significantly affects the resistance of winter crops to low temperatures, as well as their survival in drought conditions. A more developed root system is capable of providing early development of crops, the accumulation of sugars, and plants become better prepared for winter. Resistance to drought is due to the fact that the developed root system is able to penetrate into the lower horizons of the soil profile and provide itself with moisture in conditions of its deficiency.
The technology of using microbial preparations is not complicated. Bacterization is carried out either mechanically (using existing seed dressing machines, mechanisms that have a screw feed of material), or manually on the day of sowing.
It should be noted that highly toxic pesticides are incompatible with the biopreparations. The treatment of seeds with medium-toxic fungicides should be carried out 2-4 weeks before the bacterization. Joint processing of seeds by the biological preparations and low-toxic fungicides is allowed. Under the condition of bacterization of treated with medium- and highly toxic fungicides, the dose of microbial preparations should be increased.
Working on the issues of combining biopreparations with pesticides, the specialists created the Polimiksobakteryn preparation, which can be used in one tank mixture with a wide range of pesticides. Polimiksobakteryn is effective in growing sugar beet, sunflower, flax, corn, winter wheat. Thus, in the field experiment, the productivity of winter wheat from the use of the preparation increased by 14-19%, depending on the soil fertility (Table 3).
Table 3. Efficiency of Polimiksobakteryn in the cultivation of winter wheat
Biological preparations have a low cost, are technological, harmless to human and the environment.
There is every reason to assert that the need for microbial fertilizers will grow from year to year, taking into account the environmental and economic effects from their application.