Variability of saturated hydraulic conductivities in the agriculturallycultivated soils

摘要

The knowledge of the moisture conditions in a variably saturated zone of soil and their management is one of the main possibilities that allow the agronomists to raise significantly the fertility of soils. A progressive scientific method for describing the moisture conditions in a variably saturated zone uses a numerical simulation on a mathematical model. The accuracy of the outputs from the model (i.e. moisture profiles) depends mainly, besides the physical and mathematical structures of the model, on the accuracy of the input data. The upper boundary condition comprises the climate and phenological parameters. The initial condition is represented by the moisture profile at the beginning of the simulation and by the main hydrophysical properties of the soil. One of the main hydrophysical properties of soil is the value of the saturated hydraulic conductivity (K). This study is aimed at the determination of its temporal variability, keeping in mind also its areal one (with respect to the sampling data from various verticals). Several methods exist for the determination of the K values. In this study, a laboratory method with the falling head method (K_labor) was used. The areal-temporal variability of the K_labor values was evaluated for the vegetation period of the year 2003 on the locality Most pri Bratislave.