Deep Plowing (DP) Combined with Green Manure (GM) Enhances Soil Physicochemical Properties in Salt-Affected Soils of Ukraine

This study evaluated the rehabilitation of salt-affected ordinary chernozem in Ukraine using a combination of deep plowing (75 cm) and green manure application (100 t/ha), a highly effective and sustainable technique for reclaiming salt-affected ordinary chernozem (a process termed self-amelioration). Calcium salts were mobilized from deeper soil layers to the surface using the integrated strategy, a process known as “self-amelioration”. This increased the humus horizon from 50 to 75 cm and significantly improved water-related physical characteristics and soil structure. The carbonate concentration increased to 8.7%, while the soil bulk density (SBD) dropped from 1.2 to 0.98 g/cm3. Higher calcium levels (8.3–8.7%) and the improved calcium saturation of the soil-absorbing complex decreased alkalization, increasing the soil’s buffer capacity. “The percentages of absorbed sodium, potassium, and other exchangeable cations decreased from 6.6–7.0% to 4.3–5.2% of all exchangeable cations”. In addition to increasing soil organic carbon (SOC) and total NPK levels, the addition of green manure significantly reduced the amount of salt in the soil. However, effectiveness depends on local conditions, such as soil salinity, precipitation, and temperature, with the greatest soil organic carbon improvements observed in moderately saline, dry environments. Crop yields increased by 21–38% under this treatment. The results suggest that integrating deep plowing with green manure use is an effective and sustainable approach for restoring salt-affected soils.