Influence of forest vegetation on color, reflectivity and humus content in soils of northern variant ravines of the steppe zone of Ukraine

Unique natural forests grow in the conditions of ravines of the steppe zone of Ukraine. Soil scientists have been researching the soils of ravines for more than 60 years. Despite long-term research, aspects of the genesis of specific ravine soils, which are reflected in their optical properties, are still virtually unexplored. Based on this, the aim of our work is to establish the characteristics of the influence of forest vegetation on color and reflectivity, as well as the closely related content of humus in the soils of the northern variant ravines of the steppe zone of Ukraine. Soil samples were taken from each genetic horizon of sections laid in the Glybokyy ravine (near the village of Andriivka, Novomoskovsk district, Dnipropetrovsk region). Soil color indices were determined by scanning soil samples followed by image analysis. The reflectivity of soils was investigated using a monochromator. The humus content in soils was determined by the standard method of wet oxidation of organic matter according to I. V. Tyurin. As a result of the performed researches it is established that the upper horizons of the soils of the Glybokyy ravine differ in the reduced values ​​of the indicators of the HSB, RGB and Lab systems, with depth their values ​​increase. The upper horizons of the ravine soils are characterized by reduced values ​​of brightness coefficients at wavelengths of 480, 650 and 750 nm, as well as the integrated brightness coefficient, with depth there is a gradual increase in their values. The color indicators of the RGB and Lab systems are the most successful for diagnosing and predicting the humus content in the soils of the ravine. Forest chernozems and forest-meadow soil of the ravine, which were formed under natural forest vegetation, are characterized by reduced values ​​of color indicators of HSB, RGB and Lab systems, reduced values ​​of brightness coefficients and increased humus content compared to chernozems, the genesis of which is related.