Basic property analysis of sod-forest soil covered by a forest fire in the territory of Usmansky pinery (RF)

Abstract The paper deals with nine years analyzing of physical, physicochemical and chemical properties of sod-forest gley-eluvial soil in the territory of Usmansky pinery in European Russia exposed to large-scale fire in 2010. We discovered that in a layer of 0-10 cm there is a decrease in the content of the clay fraction by 6.15%, that is 63.4% in relative percentages, also the content of medium dust decreased by 0.16%, that is 3.02% in relative percentages and fine dust by 1.21%, that is 47.5% in relative percentages. It was revealed that in 2011 the year after the forest fire, the soil had higher pHH2O it went up from 4.12 (reference soil) to 5.36 (pyrogenic soils) and lower hydrolytic acidity, which decreased from 6.38 (reference soil) up to 5.98 (post-pyrogenic soils 2018) [mmol (eq) / 100 g of soil] compared to 2010. Due to fire the humus content decreased from 3.93 (reference soil) up to 2.82 % (post-pyrogenic soils 2018), decrease of exchange cations from 8.16 up to 7.65 [mmol (eq) / 100 g of soil]. From 2011 to 2018 there has been a decrease in the content of alkaline-hydrogenated nitrogen from 9.02 (reference soil) up to 6.06 (pyrogenic soils 2011).