Study of the influence of soil cover and relief on crop productivity
The purpose of the research was to study the influence of soil conditions and the relief of the agricultural landscape on the yield of crops in crop rotation. The work was performed in 1997-2000 at a test site in the Tver region located within the terminal moraine hill. Agroecological transects -fields crossing the main microlandscape positions (relief elements) and elementary soil combinations of the agrolandscape - were used as options of the experiment. The results of the research on crop yields were processed by various methods of multifactor variance analysis. The relief and soil features of the agricultural landscape had almost the same effect on crop productivity. Each of these factors, on average, determined 27-28% of the spatial variability of productivity. The yield of potatoes and winter rye was somewhat more strongly influenced by the relief while the harvest of flax, oats, barley, and herbs depended more on soil conditions. The influence of the factors studied in the experiment on the yield of crops depended on the value of the hydrothermal coefficient. The relationship between the relief and the value of the hydrothermal coefficient was directly proportional (r=+0.87); the relationship between the soil the value of the hydrothermal coefficient was inversely proportional (r=-0.75). Under conditions of a specific soil combination, significant differences in yield were noted much more often than within one relief element. It was assumed that for the development of the theoretical foundations of landscape agriculture, it would be more rational to directly study the phytogenic fields with cultivated vegetation within the agrolandscape to identify the main characteristics of the “sowing topography”, the features of which can be explained on the basis of an analysis of the orographic and soil conditions of the area, as well as other environmental factors.