Exercises: Evaluating Wind Erosion Problems with WEPS

South Dakota

Following are some example problems that we will use to evaluate some wind erosion problems in Haakon County, South Dakota.

Situation 1 -Two-year rotation

The scenario for the problem is:

•	The farm is located in Haakon County, South Dakota

•	The CLIGEN station is Milesville and the WINDGEN station is Pierre Municipal

•	The Soil Map Unit used in the evaluation is: Craft Cv 85 VFSL

•	The original two-year cropping system is Winter Wheat-Fallow

•	The field size is: x axis - 2600 ft.; y axis - 2600 ft.

•	Orientation of field operations and rows is – North (0 or 360 degrees)

•	Operations are performed parallel to x axis

•	The early WEPS evaluations will be run for 5 rotation cycles

•	Barriers - None

Figure 1.26 shows the two-year rotation of Winter Wheat and Fallow, including the dates and field operations.

*Winter Wheat (32 bu. yield) – Fallow (Conventional)

When we expand the two-year rotation to include Sudangrass (Fig. 1.27), we can add the operations, dates of operation, and the Sudangrass crop directly to the two-year rotation or we can build a separate template for Sudangrass. The new template can then be inserted into the rotation. We recommend the option of building the separate template for Sudangrass , and the template will then be available the next time you are building a rotation that includes this crop.

Figure 1.28 shows the three-year rotation of Winter Wheat; Fallow; and Sudangrass, including the field operations and the dates they were performed.

*Winter Wheat (32 bu. yield) – Fallow (Conventional) and Sudangrass (~ 6000 lbs.)