Physico-morphological causes of apple tree falls in case of closed declines

Stationary field experiments to study the influence of negative landforms were carried out on the territory of Michurin Gardens LLC Michurinsky district of the Tambov region in industrial apple plantations (Ligol variety, rootstock 54-118, planting year 2018, planting scheme 5×2.4 m, black steam soil maintenance system). The novelty of the research lies in the need to study the influence of constantly changing climatic conditions, sometimes with sharply negative consequences. So, in 2020, in the intensive plantations of Michurin Gardens LLC, there was a complete death of apple trees in 2018, planting on an area of about 3 acres. The plantings were located in closed shallow depressions, which are not always the cause of complete death of trees. Moreover, in the presence of drainage in the form of a permeable underlying parent rock and an illuvial horizon, negative landforms may be quite suitable for gardening. Therefore, we conducted a detailed study of the morphological and water-physical properties of the soil to identify the most significant factor affecting the death of trees. The results of the conducted research allow us to recommend a detailed study of the features of the humus and illuvial horizons of negative landforms according to a complex of water-physical and morphological features when assessing the soil’s horticultural suitability. In closed depressions, the main signs of unsuitable soil are a low-power humus horizon, a heavy loamy granulometric composition, and a high density of the illuvial horizon.