The effect of the various modifications of soil surface on the evaporation process | Vplyv rôznych úprav povrchu pôdy na proces vyparovania

The aim of the study was to research how different types of cultivation and modification of soil surface, as well as various additives added directly to the soil surface or soil profile, affect the evaporation process. Monitoring the process of evaporation, the total amount and intensity of evaporation, as well as changes in intensity with time of evaporation and soil moisture was carried out by a laboratory experiment on 13 experiment specimens. The experiment with free water surface, the zero option and the sample for measurement of potential evaporation were established for general comparison. The adjustment of surface to convex and concave shape, adjustment of granularity by adding dust particles, adjustment of evaporation area size by covering the surface with glass balls and the adjustment of surface layer moisture were applied on the other variants. Agro-technical measures were simulated by loosening the soil profile to the depth of 0.5 cm and 2.0 cm and rolling. The evaporation process in a variant with adjusted hydrophysical parameters by detergent application and in a variant with modified capillary properties by placing a net on the soil surface were studied, too. Initial weights of all samples were reported and subsequently, at intervals during the experiment, the samples were weighted by digital scales. The amount of evaporated water in grams was converted to millimetre of water column. Then, the measured and calculated data were processed by mathematical and statistical program Microsoft Excel. Based on the experiment it can be stated that the largest amount of water was evaporated from the free water surface (VZ.1). By adjusting the capillary properties of the surface layer (VZ.13) the process of evaporation was supported. Adjustment of the surface composition granularity (VZ.9) caused that the value of evaporation exceeded the value of zero evaporation variant (VZ.2) in a large extent. Agro-technical measures used for surface adjustment of experimental variants had the expected effect on the evaporation process. Rolling (VZ.8) supported the evaporation rate from the soil surface. Aerating (VZ.6, VZ.7) reduced the evaporation from the soil. After the evaluation of the evaporation process from the surface on which the hydrophysical adjustment of surface layer was performed (VZ.11) it could be stated that the reduced evaporation may be credited to the change of the soil particles wetting angle and the different surface tension of detergents. The reduction of the size of evaporation area (VZ.10) led to the lowest value of evaporated water.