Water erosion is a natural process in which raindrops and running water gradually erode the soil surface. Globally, it is one of the most serious soil degradation processes, threatening more than 60% of cultivated land in the Czech Republic.
When the infiltration capacity of the soil is exceeded, extensive erosion occurs first, but more severe forms of water erosion, such as gully, rill, or gorge erosion, are caused by the concentration of surface runoff.
The occurrence and extent of water erosion is mainly due to:
- the length of the slope and its steepness,
- vegetative ground cover,
- the soil's susceptibility to erosion (its erodibility),
- Rain intensity and the temporal distribution of rainfall over the year.
At Amálie, water erosion and the verification of soil conservation technologies are dealt with by the Research Institute of Melioration and Soil Protection, a public research institution. 84 % of the agricultural area is threatened by water erosion. This is mainly due to the nature of the local soils, which are made up of finer fractions of particles that are more easily taken away by flows. The slope (most often in the 3-5° range) and the size of the soil blocks (up to 50 ha) are also unfavourable. It is the uninterrupted length of the land along the floodplain that causes the more serious forms of water erosion. Although Amálie is situated under a rainfall shadow (annual rainfall of 450-550 mm), there is still plenty of erosively effective rainfall (surface runoff).
The extent of water erosion can be significantly influenced by farming practices. Growing erosion-prone crops (maize, potatoes, sunflowers, etc.) on sloping land will significantly increase the likelihood of water erosion during heavy rainfall. In erosion-prone areas, such as Amálie, is therefore necessary to establish broad-row crops in a soil-protective manner and the crop rotation should include legumes and perennial forage crops.
