PREFERENTIAL WATER FLOWS IN TECHNOGENIC SOILS

Abstract

A technogenic soil (technozem) was created on the surface of the former sludge pond of the iron-ore quarry in the course of land rehabilitation. The upper chernozemic layer in the technozem was underlain by the sandy or loamy layers. The water regime of this soils differed from the water regime of background automorphic natural soils and was characterized by the periods of water stagnation at the boundary between the two layers. In 20 years this type of water regime resulted in the development of a columnar structure in the lower part of the chernozemic layer. The coatings on the ped faces in this part of the profile had an increased content of Fe and Ca ions. There was no differentiation of the carbon of organic substances and carbonates in the soil profile. Field studies of water flows in this soil with the use of starch label and laboratory experiments on infiltration of salt solutions though the soil columns with determination of breakthrough curves demonstrated the existence of preferential water flows in technozem. Rapid infiltration of water through preferential water paths in chernozemic layer after abundant rainfalls and during the snowmelt season leads to the development of perched water above the textural boundary.