Spatial Differentiation of Soil by Physical Properties in Intensive Apple Orchards by the Time of Their Uprooting

The study was conducted between 2019 and 2025 in intensive non-irrigated apple orchards in the Lipetsk and Tambov regions. The research focused on soil conditions in orchard aisles and trunk strips, analyzing soil structure and water retention before uprooting 16-year-old trees.

Soil properties were examined at various depths (up to 90 cm) in both the row-to-row zones and trunk strips. Key parameters analyzed included aggregate water resistance, soil structure coefficient, solid phase density, bulk density, total porosity, hygroscopicity, maximum hygroscopic moisture and soil moisture retention. The correlation between total humus content and water-physical parameters was also assessed.

The water resistance of aggregates >0.25 mm was significantly lower in the row-to-row zones compared to trunk strips, particularly in the 0-20 cm layer. The soil structure coefficient in row spacings was 1.7-4.4 times lower than in trunk strips, with differences observed up to 60 cm deep. Solid phase density in row spacings was 0.1-0.15 g/cm³ higher than in trunk strips, with bulk density differences of 0.1-0.2 g/cm³ up to 90 cm deep. The total porosity in the 20-50 cm layer of row spacings was 5.8% lower than in trunk strips. Soil hygroscopicity in the 0-90 cm layer was 0.55-0.7% lower in row-to-row zones compared to trunk strips, with the 0-30 cm layer in row zones having 2 times lower hygroscopicity than in its virgin form. Maximum hygroscopic moisture in the 0- 30 cm row-to-row layer was 4 times lower than in the virgin type and in the 30-60 cm layer, 5.6 times lower. The lowest moisture capacity in the 0-60 cm row-to-row layer was 9.0-15.0% lower than in the trunk strip, where it remained at virgin soil levels. Soil moisture at the rupture of capillary bonds in the 0-60 cm range was 2.2-2.3 times lower in the intensive orchard than in row-to-row zones. The correlation coefficient (r) between total humus content and water-physical parameters ranged from 0.55 to 0.7.