1Federal State Budgetary Educational Institution of Higher Education «Bunin Yelets State University (Bunin Yelets State University), Russian Federation, Lipetsk region, Yelets, Kommunarov str., 28.1.Russia.
2FSSI”I.V. Michurin FSC”30. Michurin St., Michurinsk, Tambov Region, Russia.
*Corresponding Author: V.L. Zakharov, Federal State Budgetary Educational Institution of Higher Education «Bunin Yelets State University (Bunin Yelets State University), Russian Federation, Lipetsk region, Yelets, Kommunarov str., 28.1.Russia. Email: zaxarov7979@mail.ru
The research was carried out in 2024–2025 in intensive apple orchards on chernozem soils of the Tambov and Lipetsk regions of the Russian Federation. Soil compaction is a critical limiting factor in apple orchard productivity. As intensive orchards age, machinery traffic and root activity progressively alter soil physical properties. This study investigated the temporal and spatial dynamics of soil hardness (penetration resistance) across orchards of different ages and on three contrasting soil types in Central Russia.
Soil hardness was measured using a Wile Soil cone penetrometer at 10-cm depth intervals from 0 to 70 cm in row spacing aisles and trunk strips across orchards aged 1, 5, 12 and 50 years, established on podzolized chernozem, leached chernozem and meadow-chernozem soils. Three rootstocks M-9, 62–396 and 54–118 and corresponding planting densities were compared. Pearson correlation coefficients were used to quantify relationships between soil hardness and depth, orchard age and planting density.
Soil hardness increased with depth on all soil types and at all orchard ages. The most rapid hardening was observed in the row spacing of 5-year-old orchards on podzolized chernozem. A plough sole with critical hardness 25.0-30,0 kg/cm2 was recorded only in row spacing on podzolized chernozem at age 5. In trunk strips, soil hardness at age 12 was strongly influenced by rootstock and planting density: The M-9 rootstock at 4 × 0.75 m resulted in the lowest hardness up to 21.0 kg/cm2 in the 0–60 cm layer, while rootstocks 62–396 and 54–118 at wider spacings showed critical hardness from 20–30 cm depth. By age 50, soil hardness decreased across all layers on all soil types. Inverse correlations between soil hardness and orchard age were significant in the 10–20 cm, r = -0.74; 40–50 cm, r = -0.94 and 50–60 cm, r = -0.91 layers.
Apple orchard, Chernozem, Orchard age, Penetration resistance, Plow sole, Rootstock, Soil compaction
