Water-Extractable Organic Matter And Biological Activity Of Agrodernovo-Podzolic Soils Under Main Crops In The Non-Chernozem Region With Different Mineral Nutrition Background

Presently the problem of restoring the potential of cultivated lands in the Non-Chernozem Region of Russia is quite relevant. Thus, it is pointful to study the main factors influencing the fertility and stability of the soils in this zone. One of the leading factors altering the fertility, equilibrium, and stability of soils is organic matter. Its most active and labile in time and space component is dissolved organic matter. Dissolved organic matter actively interacts with living matter in soils and is interconnected with manifestations of biological activity. The aim of the work was to evaluate the optical properties of water-extractable organic matter (WEOM) and to reveal the relationship with the biological activity of sod-podzolic soils under different crops with different backgrounds of mineral nutrition elements. Absorption and fluorescence spectra were used to characterize the optical properties. Biological activity was evaluated by basal and substrate-induced respiration. As a result, it was shown that WEOM optical properties largely depend on the structure of the microbial community. At the same time, WEOM carbon content depended on the level of microbial activity, which, in turn, was largely determined by the presence of mineral nutrition elements. Fertilizer application stimulated microorganisms to process organic matter. At the same time, WEOM became more diverse and more humified.