When you build a management zone, you choose a method that decides where one zone ends and the next begins. The method changes the map more than any other setting, so it's worth knowing what each one does before you pick. This article explains the methods and shows them side by side on the same field. It has no steps. To build a zone, see Create a management zone.
What every method is doing
Your source data, whether an NDVI image or a soil test result, is a set of values spread across the field. A method sorts those values into the number of zones you ask for. The methods differ in how they draw the lines between zones: by equal steps in value, by equal share of the field, by natural gaps in the data, or by breaks you set yourself.
These settings shape the result whichever method you choose:
- Number of zones — how many groups the values are split into.
- Minimum polygon size (ac) — the smallest area a zone patch can be. Anything smaller merges into its neighbor. A minimum of about one acre keeps zones practical for an applicator to follow.
- Aggregation method — which value each zone carries. It appears beside each zone in the zone list and becomes the zone's value on the map. See Choose the value each zone carries.
- Use zero as starting point — sets the first zone's value to 0 instead of the lowest value in your data.
The same field, three ways
Each example below builds five zones with a minimum polygon size of 0.5 acres from the same Dynamic NDVI image (15 Sep 2026) of a 297-acre field. NDVI on this field runs from 0.07 to 0.63, and most of the field sits between 0.18 and 0.30.
Equal Interval
Equal Interval divides the full range of values into equal steps and places each point in the step its value falls into.
On this field, each step is about 0.11 NDVI wide. Because most of the field falls in one step, Zone 2 covers 82% of the acres. Zone 1 holds only the lowest spots along the south edge. Zone 5 ends up with no acres, because its patches are smaller than the 0.5-acre minimum and merge into their neighbors. Equal Interval fits when you're not concerned about small high- or low-yielding spots and want a simple map.
| Zone | Low-end | High-end | Area (ac) | Percent area |
|---|---|---|---|---|
| 1 | 0.07 | 0.18 | 7.97 | 2.7% |
| 2 | 0.18 | 0.30 | 242.29 | 81.6% |
| 3 | 0.30 | 0.41 | 42.55 | 14.3% |
| 4 | 0.41 | 0.52 | 3.97 | 1.3% |
| 5 | 0.52 | 0.63 | 0.00 | 0% |
Quantiles
Quantiles orders the values and splits them so each zone holds the same number of points.
Every zone covers a similar share of the field, between 16% and 27%. To get there, the value ranges collapse in the middle. Zones 2, 3, and 4 each span only 0.03 NDVI, while Zone 5 spans 0.33. Areas with nearly the same NDVI can land in different zones, so the map looks busier than the field is. Quantiles rarely fits NDVI imagery unless high- and low-health areas take up about the same share of the field.
| Zone | Low-end | High-end | Area (ac) | Percent area |
|---|---|---|---|---|
| 1 | 0.07 | 0.21 | 79.61 | 26.8% |
| 2 | 0.21 | 0.24 | 48.74 | 16.4% |
| 3 | 0.24 | 0.27 | 50.17 | 16.9% |
| 4 | 0.27 | 0.30 | 47.84 | 16.1% |
| 5 | 0.30 | 0.63 | 70.43 | 23.7% |
Natural Breaks
Natural Breaks places the lines where the data has natural gaps, so values within a zone are as similar as possible and values across zones are as different as possible.
Zones 1 through 3 split the bulk of the field, where most of the variation is. Zones 4 and 5 pick out the smaller high-NDVI strips, such as the west edge, without giving them more acres than they have. This map follows the patterns in the image most closely.
| Zone | Low-end | High-end | Area (ac) | Percent area |
|---|---|---|---|---|
| 1 | 0.07 | 0.22 | 81.88 | 27.6% |
| 2 | 0.22 | 0.27 | 104.79 | 35.3% |
| 3 | 0.27 | 0.32 | 78.28 | 26.4% |
| 4 | 0.32 | 0.41 | 21.12 | 7.1% |
| 5 | 0.41 | 0.63 | 10.72 | 3.6% |
Custom
Custom lets you set the breaks yourself by entering the highest value allowed in each zone. Values outside every range fall into the outermost zones. You can also start from any other method and adjust its breaks. As soon as you change a break, the method switches to Custom.
Auto
Auto makes one zone for each distinct value in your data, so you don't set the number of zones. It fits data that already comes in a few set values, such as a formula or soil map with stepped rates.
Zone per shape
Zone per shape makes one zone for each shape in your source data. It fits an uploaded file where every polygon should stay its own zone.
Choose the value each zone carries
Once the method sorts values into zones, Aggregation method picks the single number each zone carries. That number appears beside each zone in the zone list, along with its area.
| Aggregation method | The zone's value is |
|---|---|
| Data average | The average of the data in the zone |
| Data median | The median of the data in the zone |
| Data minimum | The lowest data value in the zone |
| Data maximum | The highest data value in the zone |
| Bin minimum | The low end of the zone's range |
| Bin maximum | The high end of the zone's range |
| Bin middle | The middle of the zone's range |
The Data options come from the values actually in each zone. The Bin options come from the range the method drew, whether or not any data falls at that exact value.
When every value is the same
If a formula, soil map, or advanced prescription produces the same value everywhere on a field, the result is a single zone covering the whole field rather than a scatter of identical polygons.