Postagrogenic Change of Enzyme Activity and Organic Carbon in Chernozem during the First 3 Years of Layland Regime
Comprehensive studies of the biological status of ordinary chernozem (Haplic Chernozem (Loamic)) were carried out in the early years of the layland regime in comparison with its arable analogue, old layland and the reference virgin steppe soil. They included a field experiment on transferring the old arable plot with the ordinary chernozems in Botanical Garden of the Southern Federal University to layland. In this experiment, organic carbon and the activity of two classes of enzymes, oxidoreductases (catalases and dehydrogenases) and hydrolases (β-fructofuranosidase) were compared for land-use variants. The organic carbon content in the soil of the young layland increased already in the first year; it did not change significantly in subsequent years of plant cover restoration, and varied depending on the observation period during the growing season. The activity of the enzymes also increases in the first year of the layland regime and continued to recover throughout the time after the cessation of agricultural use. The catalase activity in the young layland soil was by 9% higher (p < 0.05) than in the first year of research, the activity of dehydrogenases increased by 20% (p < 0.05), and β-fructofuranosidase by 10% (p < 0.05). However, the enzymatic activity was significantly lower than in the case of old layland and, especially, of the reference soil in the virgin steppe.