Unraveling the resilience of micro-dams on Austrian potato fields during intense rainfall

Potatoes are especially susceptible to erosion when grown on long and sloped fields due to late seed development and the unique structure of their seedbed. Previous research has shown that micro-dams can effectively reduce surface runoff and sediment yield while also increasing soil water content. One way to further improve micro-dams is to cover them with a greening crop, such as oat or wheat. During intense precipitation events, micro-dams may break and lose their protective effects, whereas micro-dams with cover crops are more sustainable and stay intact. Therefore, this study aims to analyze the resilience of both micro-dams and micro-dams with cover crops on selected fields and all Austrian potato fields in 2022 to intense rainfall events.

Between 2019 and 2022, seven potato fields with both micro-dams and covered micro-dams were surveyed using UAVs (Unmanned Aerial Vehicles) to collect elevation data. This data was used to create digital elevation models (DEM), which were then utilized to evaluate the state of each micro-dam on the field, i.e., whether it was intact, damaged, broken, or undefinable, as well as to calculate topographic parameters, such as slope and LS-Factor, for each micro-dam's position. After a specific precipitation event, the state of each micro-dam was compared with its respective slope and LS-Factor. The obtained data was subsequently applied to all Austrian potato fields of 2022 to assess the potential of micro-dams and micro-dams with cover crops to withstand intense precipitation events and their potential effectiveness.

The first results indicate that there is a distinct difference in slope and LS-Factor between stable and broken micro-dams, regardless of whether they are covered with a greening crop or not. The median slope of all broken micro-dams, whether covered or uncovered, is 8.4%, while stable micro-dams are situated at a median slope of 6%. A similar ratio can be observed in the LS-Factor, with a median of 1.75 for broken micro-dams and 1.15 for stable micro-dams. There are differences between uncovered and covered micro-dams regarding their slope or LS-Factor in all possible states for micro-dams, yet these differences are small and not significant. The application of the data to all potato fields in Austria in 2022 is still ongoing.