Changes in Relationships between Humic Substances and Soil Structure Following Different Mineral Fertilization of Vitis vinifera L. in Slovakia

The quantity and quality of soil organic matter (SOM) depending on many edaphic environmental factors may change in response to agriculture-related practices. SOM humification process can be supported by the application mineral fertilizers, but production vineyards, such information is lacking. NPK fertilizer alters quality, therefore, aim this study was to: (1) assess extent dynamics different (control—no fertilization; 1st NPK; 3rd levels) rates with grass sward cover a productive vineyard changes SOM, humic substances (HS), structure, (2) identify relationships between HS, structure. Results showed that share acids carbon decreased only NPK1 compared control NPK3 treatments. color quotient substance values increased 4 5%, respectively, control. Over period 14 years, content 0.71, 0.69, 0.53 g kg−1 year−1 control, NPK1, NPK3, respectively. HS linearly slight differences due application. vulnerability structure fertilization—more at higher level. rate formed crust decreasing following order: > NPK3. In treatment, relations were most abundant greatest significance, while increasing level NPK, these lost their significance.