A proper use of tillage, fertilizer and their combination (interaction) play an important role in crop yields increasing. Indeed, under global warming and rainfall reduce traditional systems of  primary tillage are not always justified. Therefore, the development and research of new primary tillage systems and their combination with the fertilization systems are topical.

Scientific and technological progress in modern agriculture has reached an unprecedented development. Potential opportunities to increase the agricultural land productivity is extremely large. In Ukraine, using only 2 % of photosynthetic active radiation (PAR) during the growing season can annually receive more than 125 kg of dry mass of organic matter per hectare. Agriculture systems in addressing this extremely important task is crucial. Favorable physical properties and soil modes regimes is one of the prerequisites display of soil fertility, obtaining high and sustainable yields of agricultural crops which necessitates constant maintenance of optimum soil conditions for plants. This is especially true for the black soil with the highest level of agriculture intensification. The issue of tillage and fertilization in cereals have not been studied properly by now. Indeed, in some cases crops weediness increases, in others – agrophysical soil fertility indicators get worse and productivity reduces. This depends on many factors that must be considered, i.e weather conditions, pre-crops in crop rotation, biological features of crops, soils, fertilization, soil pollution with weed seeds and others.

The aim of the research was to study and experimentally find out the most efficient interaction of mechanical tillage and fertilization and their influence on crop yields change under variable rotation.

The study of these issues was conducted on the experimental field of BNAU.

We have found that pea reacts negatively to subsurface tillage. The average yields reduce, as compared with the control, was 0.35 t of grain grain per hectare, which is primarily due to higher weediness, and therefore less efficient was using the nutrients and moisture from the soil per hectare, which is primarily due to higher weediness, and therefore due to less efficient use of the nutrients and moisture from the soil by legume plants. Replacement of subsurface tillage for differentiated and durable shallow ones reduces the grain yield, but this difference does not achieve statistically significant variables.

Winter wheat yields under durable plowing, differentiated and durable shallow cultivation was almost the same and amounted on experiment variants, respectively, to  4.61 ; 4.58 and 4.55 t/ha, and under loosened cultivation it was 4.02 t/ha, which is almost 13 % less than the control. Agrotechnical efficiency of fertilizers did not differ significantly under durable subsurface cultivation, under differentiated and durable shallow cultivation in crop rotation and it reduced under loosening subsurface cultivation.

The average spring barley grain yield in 2012-2014 on all variants of the experiment was: under durable plowing in crop rotation – 3.52 t/ha,  under flat hoe loosening – 2.47 t/ha, under differentiated cultivation – 3.63 t/ha, durable disking – 3.77 t/ha.
Thus, if there is an increase in grain yield under differential and durable shallow cultivation by 0.11 and 0.25 t/ha respectively (3.1 and 7.1 %) as compared with the control, this indicator decreases by 1.05 t/ha or nearly 30 % under subsurface cultivation. Agrotechnical efficiency of fertilizers under differentiated soil cultivation is on the control level, it is higher under durable disking, and lower under flat hoe cultivation. Thus, spring barley grain yield increase under putting N₁₅P₁₅K₁₅, N₃₀P₃₀K₃₀ and N₄₅P₄₅K₄₅ was, respectively: under durable plowing in the crop rotation – 0.67; 1.42 and 1.96 t / ha, under falt hoe loosening – 0.63; 1.37 and 1.86 t/ha, under differentiated cultivation – 0.68; 1.43 and 1.98 t/ha, under durable disking – 0.71; 1.49 and
2.06 t/ha, compared with non-fertilized areas.

It has been found out that the highest yield of grain crops in the crop rotation was under combined tillage system.
A significant decrease in the productivity was found under subsurface cultivation system. Increase in the fertilization levels resulted in significant increase in of winter wheat productivity under all cultivation systems.

Key words: productivity, crop rotation, crops, yield, cultivation, fertilization.