SMS Map Skills: Creating Prescription Map by Equation Plus Test Strips

Intro:

There are many different methods for creating a Prescription (Rx) map and of inserting test blocks or test strips. This method is available only in SMS Advanced where. Similar steps are performed regardless of whether your Rx is for Fertilizer Application, Planting or Seeding.

Any Rates used in this example do not imply the correct agronomic recommendation but are used for illustration only.  Consult with a qualified agronomist for appropriate information.

Instructions:

1. Create a prescription from your preferred equation. All equation-based recommendations result in a grid style fertilizing prescription map output. Tips: remember to put a “round to increment in the rX so that app rates are grouped without decimal increments.

2. Example Soil Test Map

Example Soil Test Zone Map
Example Soil Test Zone Map

3. Example Rec Map

Example Prescription Map from Equation
Example Prescription Map from Equation

4. For Ease of handling, merge the similar rates from grids into polygons: In Edit mode use select via filter to select the rates by group.

Select cells of a Rate Group
Select cells of a Rate Group

Select then Merge

Select via filter select
Select via filter select

Repeat for all Values until you have a simplified map.

Example of Resultant Simplified Map
Example of Resultant Simplified Map

5. Use the New Sampling Layer to construct a layer that represents your test plots or test strips. Line up your strips according to the path of travel expected by the applicator or use previous guidance lines to achieve positioning.

a) In the manual sampling editor create samples, use the boundary as the backdrop, select size and shape of your plots or strips. If field length strips chooe a length dimension large that field length and a width that equals your applicator swath.

Create Strips in New Soil Sample Tool
Create Strips in New Soil Sample Tool

b) In the Data Grid: Remove un-needed attributes and use the Sample ID to label your treatments in a descriptive manner.

Use Sample ID Column to Enter a Plot Description
Use Sample ID Column to Enter a Plot Description

c) Save as Generic layer, describe and close.

6. Have your new strip layer and Variable rate prescription map in the same map window.

7. To merge these two together: Create New Generic Layer (the tools needed are only found in the generic editor).

8. In the editor window choose Vector overlay as the first step and select the two layers. Also check on Copy Attributes.                                                                               

Vector Overlay Settings
Vector Overlay Settings

9. The result is a new layer. View the data grid to see the result thus far. Save as Fertilizer Prescription, Close then open this new fert layer in a new wondow (it is simpler if only map in the window).

Resultant Combined layer with Zones and Strips
Resultant Combined layer with Zones and Strips

10. Open the map in an editing window and select and merge any strips to be applied as a single rate. Once merged, Select and go to the data grid to enter or confirm new single rate.

Select Zones in a Strip to Merge
Select Zones in a Strip to Merge

11. Once complete Save>Print and Export to the controller of choice.

Final map to export to controller
Final map to export to controller

Karon Tracey Cowan, AgTech GIS

@AgTechGIS

May 2022

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