Fertility Status and Soil Quality Assessment of Chernozem and Stagnosol Soils Under Organic Farming Practices

Modern agricultural practices increasingly threaten soil quality, prompting growing interest in organic farming as a sustainable alternative. This study evaluated the effects of organic management on soil fertility and quality in comparison to conventional and undisturbed systems, focusing on fertile Chernozem and less favorable Stagnosol soils. A minimum data set of indicators was used, including bulk density (BD), soil organic carbon (SOC) content and stock, hot water extractable organic carbon (HWOC), and enzymatic activities (dehydrogenase and urease). An integrative statistical framework (blocked ANOVA and PCA) was applied to examine interactions between soil properties and different management practices, while Pearson’s correlations were employed to explore relationships within the organic system. Organic management improved soil quality in two soils, with pronounced benefits in Stagnosol, even after 5–10 years. Conventional production systems exhibited lower biological activity, poorer chemical properties, and higher BD. Long-term organic management (>10 years) in Chernozem enhanced soil quality levels approaching those of undisturbed pasture, while medium-term organic systems showed transitional characteristics. Sensitive indicators such as BD, SOC and HWOC detected early changes in Chernozem, with enzyme activities providing additional insight in Stagnosol. However, SOC stock did not differ significantly between organic and conventional systems due to BD influence. Overall, these findings emphasize the importance of organic farming practices, especially for less fertile soils, and support the use of integrated indicators for soil quality assessment.