In the long residential field experiments revealed the dynamics of total long-humus black soil, depending on the recruitment and placement of crop rotation, tillage, fertilizer type and its dosage. Given the forecast changes to humus content in typical black soil humus under different farming systems main components by 2050. Done age excursion into the past and look to the future in the age cycle. The level of humus accumulation during the execution of various processing systems is most significantly changed in the first years after the beginning of the experiment, then the humus content is stabilized and changes very slowly with time as a result of the transition of humus formation to a quasi-equilibrium state with degradation phenomena. The use of various methods for treating chernozem of typical low-humus for 42 years only led to a delay in the processes of dehumification and to some extent stabilized the mineralization of humus, but did not contribute to its preservation and extended reproduction to the initial level at the time of the experiment. The increase in humus content occurs with respect to plowing and a control option without fertilizers. The increase in the content of total humus for simple and extended reproduction of humus in the secular cycle is equivalent to 20-25 tons per 1 ha and 30-33 tons per 1ha, respectively. To ensure established increases in humus, it is necessary to annually introduce manure 10-12 tons per 1 ha for simple and 14-15 tons per 1 ha of extended reproduction of the total humus content annually.

Aim. To determine the specifi ed parameters of the complex model of nitrogen-carbon circulation while using different types of crop rotation, kinds of organic fertilizers and ways of soil cultivation in agroecosystems of the forest-steppe zone of Ukraine. Methods. Field, laboratory, computational, mathematical and statistical. Results. Specifi c types of organic fertilizers affect the emission of СО 2 into the lowest atmospheric layer: in case of humus the typical emission interval is 25–85 t/ha, while in case of secondary products it is 70–160 t/ ha. The impact of the way of chernozem preparation on nitrogen-carbon circulation is manifested in the fact that in case of subsurface tillage the carbon balance in soil was positively increasing compared to ploughing. The interval of СО 2 emission into the lowest atmospheric layer due to the mineralization of humus and organic fertilizers with ploughing changes in a wider range compared against subsurface tillage. Conclusions. The nitrogen-carbon interactions are impaired due to the introduction of humus and removal of secondary products beyond the boundaries of the agroecosystem in the course of ploughing. The application of ground secon- dary products of crop production as organic fertilizers, wrapped up into the surface layer of chernozem during the subsurface tillage of soil, simulates the natural course of nitrogen-carbon circulation in agroecosystems of different types. Natural soil formation process is simulated due to the activation of photosynthetic activity of cultivated crops with СО 2 saturation in the lowest atmospheric layer, which provides for extensive restoration of chernozem fertility in the forest-steppe zone of Ukraine.

To define the factors of managing the potential of moisture resources, the regularities of accumulation and use of moisture from soil by agricultural crops while cultivating them in the system of different crop rotations in the Forest-Steppe of Ukraine. The comparative assessment of the productivity of cereal-hoed 10-field rotation demonstrated that in 2010-2015 the yield of dry substance of the main product increased 1.35 times, the yield of fodder units-1.28 times, and that of cereals-1.23 times. The fraction of the yield of dry substance was 12 % from the total yield which was 2.3 times higher as compared to 1965-1969. The introduction of mineral fertilizers in 5field cereal-hoed rotation promoted the increase in the yield of fodder units by 35.7 %, cereal unitsby 29.1 %. The highest yield from the fertilizers introduced was obtained for tillage, where the yield of fodder and cereal units increased by 56.6 and 60.7 % respectively. Short crop rotations had higher productivity: strong direct correlation (R>0.70) was found between the accumulation of energy in dry substance and the yield of dry substance, fodder and cereal units and the accumulation of energy per 10 t of the moisture used. Regression coefficients for the variables: dry substance, fodder and cereal units, dry substance per 10 t of moisture in the dependence equations were 3.06, 1.25, 7.25 and 2.89 times higher as compared to long crop rotations. It demonstrated the 2.59-fold higher efficiency of forming productivity in short crop rotations and using the total moisture circulation as compared to long crop rotations.

Aim. To present theoretical justifi cation of the increase in potential fertility of typical chernozem with system- atic application of zero tillage via the creation of soil conditions, optimal for photosynthesis, and provision of maximal physiological activity of root systems of cultivated crops to restore natural processes of soil formation in the agroecosystems of the Left-Bank Forest-Steppe of Ukraine. Methods. Field, laboratory, computational, mathematical and statistical. Results. The analysis of scientifi c literature and our own studies (for over 30 years) have demonstrated that the conditions of minimal tillage ensure the connection between the physiologi- cal rhythms of activity of agricultural crops, the rhythms of humus decomposition and synthesis, the fi xation of carbonic acid by the heterotrophic saprophyte microfl ora and carbonation, restoring soil formation in agroeco- systems. Agricultural crops in the agroecosystems are self-developing, auto-regulated, open systems, capable of overcoming the forces, causing the increase in entropy and forming highly regulated and dynamically stable complexes of different hierarchy. High information capacity and codifi cation of cultivated crops defi nes the direction of the development of soil medium in agroecosystems. When the genetic information capacity of the development of cultivated crops resonates with the information capacity of the soil medium development, there is either the soil formation process or the process of extensive fertility restoration in agroecosystems. Conclusions. The maintenance and application of aboveground by-products of crop production, suffi ciently compensated in terms of nitrogen using mineral fertilizers, as organic fertilizers, and wrapped up into the sur- face layer of chernozem during the zero tillage, simulates the natural course of nitrogen-carbon circulation in agroecosystems of different types. The restoration of the natural soil formation model in the agroecosystems is ensured by the stimulation of physiological activity of cultivated crops in the agroecosystems due to the launch of drain mechanisms of carbon with the increase in СО 2 content in the lowest atmospheric layers dur- ing the vegetation period of crops, which should be the basic model of extensive fertility restoration of typical chernozem.

The purpose - to determine the most productive crop rotation with a corresponding set, ratio and placement of field crops for different ways of basic soil tillage, fertilizer levels and weather conditions. Identify the main parts of the interplay of farming on soil fertility, productive and sustainable land use. Methods. Field, laboratory, comparative and analytical. Conclusions. U article summarizes experimentally developed and theoretically grounded and economically approved agri-environmental and biological basis of efficiency scientifically based crop rotation of different rotation group left bank steppe of Ukraine with optimal saturation ratio and placement agrophytocenoses depending on fertilization, tillage methods that enhances fertility and stabilization soil, increase quality agricultural products obtained by reducing the cost of its production. Objective scientific information that could serve as a basis for the development of modern agriculture can only be obtained by an integrated approach to the formulation of research in the field of long multifactor stationary experiment, conducted in the NSC "Institute of Agriculture NAAS." Establishing quantitative patterns of action the main factors in its comprehensive and manifestation of the separation opens up opportunities to create sustainable crop production technologies and development of soil fertility management. Besides great theoretical interest, they immediately practical. Long-term studies (1975-2015 gg.) Typical black soil unstable wetting left-bank forest-steppe Drabiv Experimental Station (now the experimental field) Cherkassy DSHDS NSC "Institute of Agriculture NAAS" set action and mutual influence of crop rotation, fertilizers, basic soil, weather agrophytocenoses on productivity and soil fertility. In view of climate change and market relations, ecological factor rotation is stabilizing soil-plant system for current and future agriculture. It selectively acts on mutual share of productivity crops grown on various soil cultivation technologies, reveals the features of formation of indicators of soil fertility, especially the humus balance and quality. The leading factor in the performance of field crop rotation is: after placing the best predecessors in the application of optimal doses of fertilizers and differentiated cultivation provides a stable grain yield at 5.5-6.5 t / ha. Collecting fodder units 1 hectare of crop rotation area was 10.8 and digestible protein 0,68-0,70 t / ha. Preference is for crop rotation with cereals 80%: 20% peas, 20 - winter wheat, 40% corn. In terms Panfyly research station on the same soil in average for 2004-2013 years. Short rotation driving and the effects of crop rotation and use of fertilizers on the characteristics of water and nutritious regime of soil, humus balance and nutrients, microbial activity processes, weed-infested state of agricultural crops. The meaning of income and quality of plant residues. The dependence of productivity, economic and energy efficiency different rotation types of field rotation. The technique for conducting reconstruction programs researching and the portion of the main factors of interference farming system and weather conditions on land use management.