Composition and properties of humic acids from light gray forest soil with different fertilizing systems

摘要

The long-term regular fertilization of light gray forest soil resulted in an increased content of carbon and a decreased content of hydrogen in humic acid molecules. A decrease in the nitrogen content in humic acid molecules was observed at the application of lime material. Fertilization resulted in an increase in the portion of aromatic units and decrease in the share of aliphatic fragments in the molecules of humic acids. Humic acids from the soils under treatment with mineral and organomineral fertilizing systems were the most humified.