The Effects of the Interaction of Pesticides with Humin Fraction as Influencing the Sustainable Development of Agroecosystems

Abstract

Humin (HUM) is the most stable fraction of the soil organic matter, whose properties determine the soil health and sustainable development of agroecosystems. The aim of the paper was to determine changes in the properties of the HUM after interaction with selected pesticides, which can be visualized using photoluminescence methods. The HUM was isolated from the mollic horizon of Phaeozems arable soils derived from different parent materials in Poland. The isolated and purified HUM were saturated in a batch experiment with selected herbicides and insecticides, then analyzed for chemical composition and spectroscopic properties: Electron Paramagnetic Resonance, fluorescence, and delayed luminescence. The research showed that the interaction of the HUM with selected pesticides caused significant changes in the elemental composition of the HUM; however, no changes in their aromaticity/aliphaticity were found. The impact of pesticides was also marked by a reduction in the concentration of radicals, fluorescence and delayed luminescence intensity and properties. Changes in spectroscopic characteristics and their relationship with soil organic matter (SOM) structure properties require further research so that their results can be used in the management of agroecosystems in accordance with the principles of sustainable development.