Estimating Crop Residue Removal Effects On Wind Erosion Using Single-Event Wind Erosion Evaluation Program (SWEEP).

Accurate prediction of wind erosion is needed to establish the permissible levels of crop residue removal level for different regions. We applied the Single-event Wind Erosion Evaluation Program (SWEEP), the erosion sub-model from Wind Erosion Prediction Systems (WEPS), to simulate wind erosion effects of different crop residue removal levels (0, 25, 50, 75, and 100%). Experiments of crop residue removal were established in six farmer’s no-till fields in western Kansas in summer 2011. Experimental data including dry soil aggregate size distribution, geometric mean diameter (GMD), geometric standard deviation (GSD), dry aggregate stability, and soil surface roughness were collected in the fall 2011 and spring 2012 for the SWEEP simulation. A rotary sieve, soil aggregate crushing energy meter (SACEM), and pin meter were used to measure dry soil aggregate size distribution, dry aggregate stability, and soil surface roughness, respectively.  The GMD and GSD were calculated based on the result of aggregate size distribution. In SWEEP, a quarter section sized no-till field () was used as the simulation region. Events of varying duration (e.g., 3, 5, and 7 hours) and wind speeds (e.g., 15, 20, and 30 m/s) were applied. Basic information including climate, soil conditions, and residue and crop management were used for wind erosion prediction.  Simulated results showed that soil loss increased with an increase in the residue removal as well as increased soil loss in the spring compared with that in the fall. Winter weathering enlarged the risk of soil wind erodibility, especially plots with low residue cover.