Microtomography research of physical properties of urban soil

Physical properties and their dynamics under anthropogenic impact are important for the rational use of urban soil and its fertility management. However, due to the urban soils anthropogenic transformation features some classical methods are not applicable in specific cases. Thus, the cutting ring method for determination a soil bulk density does not give objective results in horizons with a high proportion of anthropogenic inclusions. The microtomographic method allowed us to obtain new information on the parameters of the pore space of the humus-accumulative horizons of urban soils. It is shown that the value of closed porosity is the most informative diagnostic indicator of the soil structural condition. Simultaneously, anthropogenic transformation of the soil is accompanied by a significant change in the volume of closed pores. The diameter of macropores visible in tomographic sections increases in the sequence: Urbic Technosols, Technic Chernozems (Calcic), Haplic Chernozems (Calcic). (paper)