Creating management zones and writing prescriptions

Imagery brought into your fields through FarmQA's integration with Planet can be used to help you write variable rate prescriptions for your fields. Any NDVI Planet image can be used to create custom management zones for your fields. Management zones can then be used to write any variable rate prescription you'd like for your fields, and ultimatley exported to use as you see fit. Check out the article below to learn how to create management zones and write variable rate prescriptions for your fields in FarmQA. 

Understanding the interpolation methods used to create your management zones

Create a management zone from Planet NDVI imagery

Edit your management zones

Creating a management zone from multiple satellite images

Upload a pre-existing zone map

Writing and exporting a prescription from a management zone

Export your prescriptions

Understanding the interpolation methods used to create your management zones

FarmQA has three built-in interpolation methods that can be used to create management zones from your imagery or soil samples: the Equal Interval method, the Quantiles method, and the Natural Breaks method. These likely aren't familiar terms, and it's important to understand the differences between these methods while you're setting up your zones. To give you a better idea of what your zone maps will look like when using one of these methods, we have created management zones based off of the Planet NDVI image below. Each zone map will have 4 zones with a minimum zone size of 0.5 acres. 

Each image below shows you what creating management zones based off of image above will look like if you're using the Equal Interval, Quantile, or Natural Breaks method of interpolation. We provide a definition for each method to give you a better understanding of the process we use to generate your zones. Under each image you'll find a table that breaks down the range of NDVI values in each zone as well as the total acreage each zone takes up. 

Equal Interval

Creates zones that equally divide the range of all values and then places data points into zones according to their value.

Zone maps produced by the Equal Interval interpolation method might be considered conservative by some. Most low-health zones around the edges of the field are captured by Zone 2 with Zone 1 representing few more dramatic low-health zones. The field is largely homogeneous with Zone 3 taking up by far the most space. If you're not as concerned about smaller high- or low-yielding spots in your fields, using the Equal Interval method to produce your zone maps might work best for you. 

Quantiles

Orders the data by value and then places them into zones such that each bin has the same number of items.

Due to each zone being approximately the same size, the zones that represent high and low values (Zones 1 and 4) are much larger than the dark red and green regions in the original image. This interpolation method has also greatly reduced the range in values for Zones 2, 3, and 4, with each having an NDVI range of 0.02 while Zone 1 has a range of 0.23. We would generally not recommend using this method for producing zone maps from NDVI imagery unless if you're using a base image that has high- and low-health areas that take up roughly the same area within a field. 

Natural Breaks

Groups data points into zones such that the difference between the values across zones is maximized while the difference between values within zones is minimized.

The zones generated by the Natural Breaks method most closely represent the breaks seen in the original NDVI image. The high- and low-health zones represented by the dark green and dark red values in the original image are well covered by Zones 1 and 4. Note also that high-health patches are better captured in Zone 4 in the image below compared to other zone maps. 

Create a management zone from Planet NDVI imagery

Available from the: Web App

User Permissions: Enterprise Administrator, Agronomist

• Within the Map tab, locate the field you want to create management zones for and click on it. 
  
• In the slide out map pane, click the Edit layer icon next the map layer that contains the image you want to create a prescription zone from. 
• Locate the image you want to use, then click the Create management zone icon (pictured below). 

• Fill out the following information to setup some parameters for your management zone (pictured below): 
  1. Give your management zone a Name.
  2. Add a Description to your management zone if you want to. 
  3. Toggle on the Show labels  option.
  4. Use the Clustering Algorithm dropdown menu to choose a method used to generate your management zone map. For most users, we recommend the Equal Interval method. 
  5. If desired, set a Minimum polygon size (ac) for your management zones. This will depend on what you want to get out of your management zones as well as the size of your field. 
  6. Set the Number of zones you'd like for your field. 
  7. Use the Colors dropdown menu to choose a color scheme to color your management zones with. If desired, you can toggle on the Invert option to swap the colors used to color your zones. 

• Click the Create zones button to get an initial view of your management zones for this field.
• Your zones can be edited in the following-ways in the Zone designer page (pictured below): 
  1. Use the Colors dropdown to change the color ramp of your zones.
  2. Click the dropdown arrow to the right of any of your zones to update the Name and Legend of that zone, or remove the zone by clicking on the Delete button.
  3. Click the Add button to add another zone.

• Zone breaks can be edited by clicking on the Method dropdown on the left-hand side of the screen, then by clicking on the Custom option. You'll then be able to access the View and edit breaks (pictured below). 

• Users can edit the Zone names and Values for each of these zones. To save your updates, click the Update zones button, or if you're unhappy with your changes, users can click the Revert button (pictured below).

• If you are satisfied with how your zones look, click the Save button to save these to your management zones folder. 
• If you're ready to use this zone to create a prescription, click on the Save and create prescription button. 

Edit your management zones

Available from the: Web App

User Permissions: Enterprise Administrator, Agronomist

• In the Map tab, locate and click on the field you want to edit management zones for. 
• In the slide-out map pane, click on the More button, then click on the Management zones button.
• Select the management zone you want to edit, then click on the Edit button (pictured below). 

• The management zone editing tools are available in the Edit zone bar at the top of the screen. The management zone editing options are as follows:
  •  Change zone
  •  Grid alignment
  •  Split
• Use the Change zone function to change a zone from one to another. Use the Zone dropdown to pick your new zone color, then click on the zone you want to reassign (pictured below). 

• Use the Grid alignment option to break your field up into manageable grids. Use the X and Y boxes to set the width and height of your grids. Units can be set in feet or meters. When you have your grids setup the way you like, click the OK button (pictured below).

• The Split dropdown contains three different tools that users can use to split up their zones. These options are as follows: 
  •  Grid (this is the same as the previously mentioned Grid option)
  •  Image
  •  Shapes
• The Image editing tool lets a user superimpose an image of the user's choosing and use that to split your zones. In the example seen below, a 'Split Field Zone' map that contains two zones that split the field is used to split the zones in the field in half. 

• The Shapes  option lets the user access drawing options to edit their zones. The drawing options users have access to are described below: 
  
  •  Add polygon: draw a shape that corresponds to the area you want your new zone to encompass (pictured below). 

• • Add circle: draw a circle that corresponds to the area you want your new zone to encompass (pictured below).

• • Add line: draw a line to section off an area of your management zone and assign that zones to new values (pictured below). 

• To save any edits that you've made to your zones, click the OK button on the right-hand side of the Edit zone bar. 

Creating a management zone from multiple satellite images

Available from the: Web App

User permissions: Enterprise Administrator, Agronomist, Grower

• Log in to your FarmQA account from the web app if you haven't already. 
• In the Map tab, locate and click on the field you want to create a zone map for. 
• In the slide-out map pane, locate the layer that contains the imagery you want to use to create your zone then click the View layer button (pictured below). 

• Click the Multi-select option in the View layer window to begin selecting images (pictured below). 

• Select the images you want to use to create your zone by clicking on the Add to cart on the right-hand side of your desired images (pictured below). 

• Click the shopping cart in the upper right-hand corner of the View layer window, then click the     Create zones button (pictured below). 

Upload a pre-existing zone map

Available from the: Web App

User permissions: Enterprise Administrator, Agronomist, Grower

• Log in to your FarmQA account from the web app if you haven't already. 
• In the Map tab, locate and click on the field you want to upload a zone map for. 
• In the slide-out map pane, click on the More button, then click on the Management zones button. 
• Click on the Select zone file (or drop here) button and browse your computer to search for the management zone you want to upload. You're also able to drag and drop that file into the slide-out map pane (pictured below). 

Writing and exporting a prescription from a management zone

Available from the: Web App

User Permissions: Enterprise Administrator, Agronomist

• Log in to your FarmQA account from the web app if you aren't already. 
• Within the Map tab, locate the field you want to create a prescription for and click on it. 
• Click on the Zones button in the slide out map pane (pictured below). 

• Find the management zone you want to write a prescription for, then click on the Create prescription  icon (pictured below). 

• In the Specify attributes window, input the name of the attribute you're going to be writing prescriptions for, like nitrogen or seeding rate. Use the dropdown menu to the right of that text box to specify whether it's going to be a Number or Text based prescription. 
• Click the Add button below the attribute name to add another attribute to create a prescription for if want to. 
• Click the Next button to continue writing your prescription (pictured below). 

• In the Specify the values for each zone window, put in the prescription values you'd like to associate with each of your management zones. 
• Fill in more information about your prescriptions in the Description box if you'd like to provide more context to your prescription. 
• When you're done, click the Download button (pictured below). 

• Your prescription will be downloaded as a zipped shapefile. The zipped folder will contain four files: .DBF, .PRJ., .SHP, and .SHX. 

Export your prescriptions

Available from the: Web App

User Permissions: All users

• Click on the Fields icon, then click on the Prescriptions tab.
• Check the box to the left of the prescription you want to export, then click on the Export button (pictured below). 

• In the Export prescriptions page, choose whether you'd like to export your fields to a Shapefile or a PDF. Use the dropdown menus underneath the PDF export options to customize how your PDF export looks in the following ways (pictured below): 
  • Map type
  • Header
  • Orientation
  • Page size

• When you've set your export options, click on the Export button at the bottom of the screen. 
• If you chose the Export to PDF option, a load sheet displaying your prescription and other important information will be downloaded to your account. Here's some of the information you'll find on your load sheet (pictured below): 
  1. The chemicals applied in the prescription, which are called Rx attributes.
  2. Location of the field the prescription was applied to, given in latitude and longitude.
  3. The rate of product applied in each zone.
  4. The total amount of product applied in each zone. 
  5. Product totals across the whole field.