Quantity and Quality of Organic Matter in Soil after Application of Various Organic Materials/Ilość I Jakość Materii Organicznej W Glebie Po Aplikacji Różnych Materiałów Organicznych

Organic carbon concentrations in soil, irrespective of the year of research increased significantly after application of organic materials for the soil fertilization in comparison with the soil from the NPK mineral treatment. The content of low molecular humus compounds extracted from soil using H₂SO₄ solution was small, regardless of the applied fertilization or year of research. However, after the third year of research a significant increase in this humus fraction content was noted in soil of all treatments where fertilization was applied. After the third year of research, carbon content in alkaline extract rose significantly in soil of all treatments where fertilization with organic materials was applied, in comparison with the soil from mineral NPK treatment. The content of humic acid carbon in soil was lower than fulvic acid carbon, which resulted in lower than one values of Cha : Cfa ratio. However, obtained results point to marked increase in both humus fractions in results of residual effect of applied fertilization. Residual effect of applied fertilization apparently increased the value of absorbance coefficient A4/6, which points to a decreased degree of condensation of humic acid molecule and greater aliphatisation.