In all industrially developed countries a problem of biological nitrogen – one of the most important in biological researches. High efficiency of use of biological nitrogen defines big practical value of the researches directed on increase of its role in nitric balance of agriculture. Being one of the main links of an ekologizatsiya of agricultural production, biological nitrogen allows to receive big stable crops, providing reproduction of soil fertility.
Modern agrotechnologies in the conditions of intensive agriculture – a determinant defining activity and an orientation of biological processes
Modern agrotechnologies in the conditions of intensive agriculture – a determinant defining activity and an orientation of biological processes. Application of the raised doses of mineral fertilizers, intensive ways of machining of the soil, land improvement and other agrotechnologies considerably intensify microbiological processes of a mineralization of fresh organic substance and a humus, being accompanied reduction of its stocks in soils. Owing to degradation of a humus of the soil gradually lose agronomical valuable properties: absorbing and water-retaining abilities decrease, the structure collapses, the density increases, technological qualities etc. worsen. These processes develop slowly, obviously aren’t shown and often the progressive tense isn’t caused by alarms about fertility of the soil. Actually serious danger of wear process of the soil inevitably approaches.
Modern technologies of cultivation of crops reached "saturation" limits on several aspects: ecological (pollution of environment and suppression of mechanisms of its self-control), power (increase in expenses of irreplaceable energy at each additional unit of production), produktsionny (further increase of doses of fertilizers and chemical preparations leads to oppression of growth and development of plants and soil microorganisms and doesn’t provide effective increase in productivity).
Development is necessary for prevention of the intense ecological situation created in the conditions of intensive agriculture essentially for its new strategy. Interest to nonconventional methods of agriculture and the plant growing, assuming wide use of biological ways of protection and a food of the plants in recent years raised, allowing essentially to limit use yadoximikatov and to reduce doses of nitric fertilizers. The future of a biological and agronomical science, its reserve – studying and application of biological methods of impact on growth, development and efficiency of plants. Transition in the future from modern chemical agriculture to designing of large-scale agrobiogeocenoses on a biological basis is possible when using essentially new methods of management by the genotipichesky and modification variability developed taking into account the last achievements of biology.
The most important feature of ecological agriculture consists in activization of natural azotfiksiruyushchy systems thanks to which a food of cultivated cultures mainly at the expense of biological nitrogen is provided. For receiving the maximum quantity of production with 1 hectare of the earth it is necessary not only to increase supply of nitric fertilizers, but also in every possible way to intensify a biological azotonakopleniye.
Elimination of the nitric deficiency which is creating as a result of its carrying out from the soil by plants, washing away, a denitrification only at the expense of mineral fertilizers is interfaced to difficulties of the power, economic and agrophysical plan. Production of nitric fertilizers very expensively. 30-50 % of power consumption of agricultural industry are the share of a share of chemically connected nitrogen and about 1 % of all energy spent by developed countries of the world. An exit from this situation – the maximum increase in efficiency of biological fixing of nitrogen.
The general scales of a total annual production of a biological azotfiksatsiya in land ecosystems are made by 175-200 million tons from which 99-110 million tons provide the farmland. Taking into account efficiency of nitrogen of fertilizers (for mineral and about 15-30 % for organic) agricultural plants receive no more than 50 % of these sources of 30-35 million tons of nitrogen in year, and annual carrying out it from the soil with production of agricultural industry are made by about 110 million tons. Therefore, the bulk (70-75 %) nitrogen in a crop has other origin: it is nitrogen biological and nitrogen of being mineralized organic substance of the soil, also mainly a microbiological origin. Therefore the azotfiksatsiya is allocated along with photosynthesis in a row the main physiological processes, and biological nitrogen needs to be considered as a factor of formation of fertility of the soil and conservation, a reserve of partial replacement technical in system of fertilizers of crops. Microbiological fixing of the atmospheric – the unique non-polluting way of supply of plants the connected nitrogen: thus pollution of soils, reservoirs and the atmosphere is impossible.
Advantage of biological nitrogen not only in harmlessness. For its accumulation it is required rather small costs of energy of activation of azotofiksiruyushchy microorganisms. At biological fixing by a power source the sun, as a rule, is, the fixed nitrogen is acquired by plants almost completely. As way of providing plants nitrogen it is possible to consider as a lack of a biological azotfiksatsiya only that the mankind yet didn’t learn to operate it rather effectively.
In enrichment of soils by nitrogen at the expense of assimilation from the atmosphere the greatest practical value such groups of soil microorganisms have it: the klubenkovy bacteria fixing molecular nitrogen in symbiosis with bean plants; widespread in soils numerous and various svobodnozhivushchy azotfiksiruyushchy bacteria; the microorganisms, capable to acquire molecular nitrogen in associations with root system not bean plants.
Bean cultures play important role in mobilization of the biological nitrogen, which value in its general balance in agriculture, and consequently, in increase of the contents in it vegetable protein, very essentially. It is known that the positive role of bean cultures in agricultural industry is closely connected with activity of klubenkovy bacteria with which bean plants are in the close symbiotic relations. Efficiency of bean cultures, their crop, accumulation of biological nitrogen by them and vegetable protein substantially depend on nature of relationship macro – and mikrosimbiontov in each separate case.
The most significant reception of increase of efficiency of a symbiotic azotfiksatsiya is entering into the soil of a preparation of klubenkovy bacteria – rizobofita. In areas of traditional cultivation of bean cultures the crop increase from an inokulyatsiya of seeds the rizobofity makes: for soya seeds – 2-4 c/hectares, for peas and lupine grain – 2-3, for green material of bean cultures – 80-100, for clover and lucerne seeds – 6-10 c/hectares. Efficiency of an inokulyatsiya is various and depends on a type of bean plants and a complex of ecological conditions.
It is known that the main supplier of biological nitrogen – bean herbs and leguminous cultures. However ignorance of real scales of a symbiotic azotfiksatsiya, underestimation of a role of this extremely important source of preservation of energy resources and health of the person lead to that bean at us in structure of cultivated areas very modest place – about 10 % is taken away, and in the USA – 26 % and more. According to FAO, in world production of protein about 20 % are the share of a share of leguminous cultures, in Ukraine – only 5 %.
Ability of bean plants in symbiosis with klubenkovy bacteria to acquire atmospheric nitrogen provides with it ecological advantages at its deficiency. Use of this property in agricultural practice allows to reduce considerably or completely to exclude application of mineral fertilizers without essential decrease in productivity of bean cultures, keeping fertility of the soil.
Continuous carrying out of nutrients from the soil at cultivation of crops demands systematic application of fertilizers. Due to the economic, power and environmental problems of increase in production and consumption of mineral fertilizers the urgency of development of new ways of improvement of a mineral food of plants increased. One of them consists in creation of effective bacterial preparations (bacterial fertilizers), promoting strengthening of biological fixing of atmospheric nitrogen, mobilization of cindery elements from soil reserves. Use rizobofita under bean cultures practically excludes need of introduction of mineral nitrogen, increases productivity, improves quality of production.
In the late eighties the XX century on the basis of associative azotfiksiruyushchy bacteria experimental batches of preparations for the main not bean crops which occupy incomparably big cultivated areas, than bean are made. Since 1992 some of preparations make already in industrial volumes: diazofit under wheat, rizoenterin under barley, agrofil under vegetable cultures. Application of these preparations gives the chance is directed to regulate number and activity of useful microflora in a rizosfer of cultivated cultures, to improve security of plants with available nitrogen and thanks to it to increase their efficiency and to improve quality of production. When developing ecologically balanced and effective technologies of cultivation of crops it is necessary to pay special attention to functioning of associative microorganisms. Azotfiksator can connect Svobodnozhivushchiye in soils of 30-50 kg/hectares of nitrogen, and sometimes and it is more.
Annual entering into the soil to 2,2 million t of nitrogen can provide 50-60 kg of this element on 1 hectare of arable lands. In recent years the volume of used nitric fertilizers makes about 15-20 % of requirement, i.e. 10-15 kg/hectares. In agriculture it is partially possible to compensate such acute shortage of nitrogen more intensive use of biological nitrogen. In modern agriculture specific weight of biological nitrogen in the general balance of this element doesn’t exceed 10 % and makes only 6-8 kg/hectares of arable lands. Optimizing agrotechnical and microbiological factors, it is possible to increase a share of biological nitrogen, in its general balance to 35 kg/hectares. In aggregate with nitrogen of organic fertilizers it will make about a half of that amount of nitrogen which is necessary for maintenance of high efficiency of agroecosystems and renewal of fertility of soils.
That is why researchers pay such attention to a problem of a biological azotfiksatsiya. High efficiency of use of biological nitrogen defines big practical value of the researches directed on increase of its role in nitric balance of agriculture. In all industrially developed countries a problem of biological nitrogen – one of the most important in biological researches. Ekologizatsiya of agricultural production gains in the modern world the increasing value in connection with global violations of processes of circulation of the basic biogene elements in artificial agrocenozax. Therefore wide use of biological nitrogen is more and more actual. Being one of the main links of an ekologizatsiya of agricultural production, biological nitrogen allows to receive big stable crops, providing reproduction of soil fertility.
E.Turin, younger research associate of laboratory of plant growing and kormoproizvodstvo of the Crimean institute of agroindustrial production of UAAN.