SPATIO-TEMPORAL PATTERNS OF MAIZE YIELD VARIATION WITHIN UKRAINE

The aim of this research was to characterize the spatial and temporal yields variation of maize in the 10 areas (206 administrative districts) in Polissya and Forest-steppe ecoregions within Ukraine. Between the average yield of maize in Ukraine and yield in the investigated area there is a statistically significant correlation (r=0.86, p˂ 0.001). Thus, despite the fact that only part of the territory of Ukraine was selected for research, general results and conclusions can be approximated to its entire area. The dynamics of maize yields classified as "crop yield stagnation" is typical for most administrative regions of Ukraine. This result shows that the production potential of the territory is not fully utilized, as well as the agricultural strategies needed to be reviewed, and in particular, the cultivation of the maize. Analysis of the spatial and temporal dynamics of maize yield showed the complex nature of the processes that determine it. A common feature of time changes of maize yields for all administrative districts is the presence of the trend that can be described by a fourth degree polynomial. The characteristic points of the fourth degree polynomial curve can be meaningfully interpreted and used to describe the yields dynamic. The absolute term of the polynomial indicates the crop yield in the starting period. The starting level of maize yield is spatially dependent and ranges from 19 dt/ha to 47 dt/ha. This indicator reveals areas with the most favorable agro-physical conditions for maize cultivation. The yield dynamics, which may be explained by the regression, indicates that agro-technological and agro-economic conditions for agricultural production are the total factor that determines the presence of a general trend. The determination coefficient of the regression pattern can be interpreted as an indicator of the role of agro-technological and agro-economic factors in yield dynamics. The most sensitive to these factors is the northern and western regions of the region, and the least – southern