INFLUENCE OF GROUNDWATER OCCURRENCE DEPTH ON WATER-PHYSICAL PROPERTIES OF PEAT SOILS IN NORTHERN TRANS-URAL REGION

Results are given from long-term lysimetric studies into the influence of groundwater occurrence levels on water-physical properties of peat soil. The object of research was peat soils typical for forest steppe of Northern Trans-Ural region. It has been found that water-physical properties of peat soils are to a considerable degree determined by their water regime. At the groundwater occurrence level of 0.5 m, the soil bulk density in the root layer (0.3 m) increased during the seven years by 12.8%, ash by 6.9%, and particle density by 3.4%; field moisture capacity remained at the initial level. The deep groundwater occurrence (1.5 m) changed water-physical properties throughout the soil profile, but most significantly in the 0.3 m layer, where the soil bulk density increased by 24.4%, ash by 24.1%, and particle density by 4.2%; field moisture capacity decreased by 36.8%. The decrease in the groundwater level from 0.5 to 1.0 m, and that in the autumn-winter period from 1 to 2 m had almost no effect on water-physical properties of peat soils. The lysimetric data on the effect of groundwater occurrence levels on water-physical properties only reflect the changes that take place. The reasons for the changes, trends of these processes with increasing duration of drainage require the further study.

торфяная почва, грунтовые воды, водно-физические свойства, лизиметры, усадка почвы, плотность сложения почвы, твердая фаза, влагоемкость, peat soil, groundwater, water-physical properties, lysimeter, bulk density, shrinkage, soil bulk density, solid phase, moisture capacity

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