How to create management zones based on a productivity map
This guide will show you how to create a Management zones map based on a productivity map. The goal is to group productivity zones into a lower number of management zones e.g.: 3 instead of 7), to facilitate managing the field.
Creating the vector layer
As a first step, we will create a new Management zones layer based on a copy of theproductivity map layer.
This way we will be able to create the Management zones map without modifying the productivity map.
- Pick the Create vector layer tool from the Edition panel:
- A dialog will pop up. Choose Copy layer as shown in the image below, then click on Next to proceed.
- Fill in the creation form; enter the name of your layer, the group which will contain it. Under "Layer to be duplicated", select the productivity map for the field you want to create management zones. Make sure this is properly set; otherwise you will end up with polygons for a different field. Once that's done, click on Finish to complete the process.
- The reference panel will now show the layer you just created:
Join productivity polygons into management zones
In a productivity map, polygons are assigned 7 different classes according to their productivity: VERY HIGH, HIGH, MEDIUM TO HIGH, MEDIUM, MEDIUM TO LOW, LOW AND VERY LOW. These are also shown in the symbology.
You may have a large number of productivity polygons; planning samples for each one of them can be time consuming. So in this stage you will group them in new management zones polygons, which will make for a more manageable sampling process.
- Review your productivity map layer, then use any of the Selection tools to select the polygons you want to add to a new management zones polygons.
You will end up with a number of polygons selected
- Click on the Edit Object button in the Edition panel. The Drawing tools panel will show up. Click on the Join Objects tool.
- A window will pop up, asking you to choose the main object; its data will be kept and assigned to the new object which will absorb all other polygons. In this case, all objects have similar values, so you may pick the first item and click on Accept.
- The split between polygons will disappear. As a consequence, all your productivity polygons have now merged into a single management zone polygon
You may now apply the same process for the rest of your map.
Label your management zones
In order to identify your management zones, you need to label them. You can do this by editing their data.
- Select all your management zones, then click on the Edit selected object data tool from the Edition panel.
- A table will pop up showing rows corresponding to each selected object, and columns corresponding to each atrribute. Clicking on a cell will show a cursor, allowing you to modify existing data or add new; the selected polygon will show up highlighted in the map.
|Note:||You may modify data only from those columns colored yellow. White columns are completed automatically and cannot be modified.|
- Go to the Zone attribute and enter a number for the current management zone; this value will act as a label for this zone. Click on Accept to enter your zone numbers.
- To finish this, click on the Save button.
|Warning:||If you're creating Management Zones as part of the Precision Farming Cycle, make sure your zones are labeled following this format: [Field Name] - [Zone Nr]|
Classify zones based on Zone number
In order to get your zones ready for the next steps, it's recommended to classify them based on the Zone attribute. This will be used:
- To generate a map of the zones, and support your sampling
- To generate a Variable input rate recommendation (or prescription) map, by management zones. This is done with the Prescriptions tool, which requires a classified layer as input.
In order to classify your management zones map based on Zone, follow these steps:
- Make sure the Management zones layer is active.
- Click the Edit cartography and layer properties tool in the Edition panel.
- A dialog will pop pup. Select the Symbology Tab.
- Now choose the Classes wizard:
- The Classes wizard will show up. Make sure you select the Zone field as Identifier. Then complete it with your choice of colors, then click on Accept.
- Back in the Symbology tab, choose your symbology. Choose your fill and borders. In the Label box, make sure the Zone attribute is selected, then click on the Brush icon to apply to all classes.
Click on "Accept" and your polygons will be shown in the symbology you assigned them.