Assessment of profile distribution of carbon of labile and water-soluble form of soil organic matter

Abstract

For a long time, scientists are researching the soil organic matter (SOM) and soil organic Carbon (SOC). But their relevance does not diminish because there are importance for scientists as to form databases for simulation and forecast as use the latest research methods. It is proved that for the verified forecasting and modeling of Carbon cycle processes, data is needed throughout the soil profile, not only just in its upper layer (0-30 cm). An important indicator of environmental change is the labile organic matter of soils. Therefore, the purpose of our work is to evaluate the profile changes of the SOC, its labile and water soluble forms in soils of different types and different uses. We studied the soils of the podzolized series (gray forest and chernozem podzolized) and meadow-chernozem soil, located in the agroecosystems of a single-slope catena. The samples of soils selected from the genetic horizons from top horizons to the parent materials for the analysis of the contents of the SOM, SOC and some soil properties (acidity, soil texture, exchange cations of Calcium and Magnesium, Nitrogen). The results of laboratory analyzes were processed statistically and using multivariate methods. We have found that land use and associated with it the type of vegetation have a major impact on the quantity and distribution of SOC as labile as water soluble forms. Therefore, we discovered that the gray forest eroded soil under the perennial grasses has the highest mean of labile and water soluble forms of SOC. The same indices are the smallest under intensive use arable land for meadow-chernozem. Chernozem podzolized is characterized by average values of content of SOC of labile and water soluble forms. Moreover, these values are significantly lower for arable land, while the ecotope is under grassland, these values are higher. In general, labile and water soluble forms of SOC decreases downwards with a depth; that correlated with the same changes of humus content. The content of exchange cations of Magnesium and clearly decreases with depth profiles for all soils, regardless of their origin. The latter fact requires some more detailed research.