PROFILE DISTRIBUTION OF HEAVY METALS AND ENZYMATIC ACTIVITY IN FLUVISOLS OF THE VISTULA RIVER VALLEY, POLAND

摘要

The aim of the study was to examine the relationship between the distance from the Vistula river and the distribution and mobility of Zn, Cu and Mn within profiles of Fluvisols from the Vistula River Valley (Unislaw Basin, Poland). The alluvial soils in this area were recurrently flooded by the river once or twice a year what changes their physico-chemical and biological properties. The range of the floods was varied and of local character, only sometimes exceeded 600-900 m from the river. Over the last 10 years such a flood was noted just once. The total contents of Zn ranged from 30.1 to 228.5 mg·kg~(-1), Cu from 4.6 to 26.1 mg·kg~(-1) and Mn from 261.0 to 1560.8 mg·kg~(-1). These contents of analyzed heavy metals did not exceed environmental quality standards for the soils used currently in Poland. However elevated concentrations of Zn and Mn were observed in profiles near the bank of the Vistula (50 m -profiles M1, M2 and 200 m - profiles M3, M4). Such a clear difference in the concentrations of heavy metals at the zone of 600-900 m from the river suggests a predominating effect of flooding waters. In samples with high pH values, mobile forms of Zn and Cu were low. The highest content of DTPA exctractable metal forms were in the surface horizons, and gradually decreased with depth along with a decrease in organic matter.rnEnzymatic activity differentiated significantly in the investigated soil profiles. Soil samples taken from the surface horizon (0-10 cm) had the highest enzymes activity as compared to their activity found in soil samples from deeper layers. Differences in the enzymatic activity were observed as depended on the distance from the Vistula but no clear trends were observed.