Productivity of agricultural crops under climate change in the Central Forest Steppe of Ukraine

Abstract

Aim. The aim of the study is to analyze climatic parameters, moisture reserves and dynamics of productivity of grain crops (winter wheat and corn) depending on the system of adaptation measures (fertilization, tillage) for the period 1913-2022, to determine their classification features according to fractal properties, to identify trends in further changes in agrocenoses of the Central Left-Bank Forest-Steppe of Ukraine. Methods. To achieve the goals and objectives, the following methods were used: analysis of scientific and methodological literature on the research topic, collection of information, comparison, generalization, systematization, as well as the use of modern methods of descriptive statistics. Results. On the territory of the central part of the Forest-Steppe (1913-2022), there were no periods of deviations of hydrothermal climate conditions towards aridization to the point where they acquired a steppe character. The lower boundary of hydrothermal conditions varied around T=+150C, and the upper boundary around T=+300C. A direct correlation (R=+0.81-0.85±0.02) was found between the amount of annual precipitation and the lower and upper limits of hydrothermal climate conditions, and the trend of annual precipitation growth was more rapid than the increase in temperature. Precipitation was a compensating factor, which can be regarded as self-regulation of the Forest-Steppe zone’s resistance to steppeification. In the age cycle, the climate humidity index reached its highest values in the periods 1981-1990 and 1998-2004, and subsequently, by 2020-2022, the humidity index was decreasing in a downward trend to values close to 100%. The humidity of the climate of the warm season and the period of active vegetation reached its maximum value in the period from 1931 to 1950, and from 1980 to 1990 the humidity index decreased rapidly, reaching values less than 90% in 2020-2022, indicating a deterioration in the conditions of crops’ vegetation to excessively harsh compared to previous periods of the age cycle. Conclusions. Climate change that has already occurred and continues to occur in the Central Forest-Steppe affects grain yields: increased winter temperatures and precipitation, prolonged frost-free periods, and increased CO2 concentrations lead to an increase in the area of land suitable for agriculture. In order to ensure sustainable grain production, agricultural producers in the Forest-Steppe of Ukraine should use modern grain varieties adapted to new climatic conditions and agroecological tillage technologies (shallow moldboardless loosening with flat-cutters or flat-cutting, mulching, use of organic mass of post-harvest residues as fertilizer in the fields, etc.