Variable Rate Fertilizer Maps

Create a variable-rate fertilizer prescription map in GeoPard from zones, assign fertilizer rates, and export it for machinery.

Create a fertilizer Rx map in GeoPard in three parts:

1. Build management zones.

2. Assign fertilizer rates.

3. Export the map to the machine format you need.

GeoPard workflow for building and using management zones

What you need before you start

• A field boundary in GeoPard.

• At least one data source for zoning.

• A fertilizer plan with target rates, min/max limits, and units.

Good starting data sources:

• Satellite imagery

• Soil sampling or soil scanner data

• Yield maps

• Topography

• As-applied history

For a quick first map, start with satellite imagery. For stronger agronomic logic, combine imagery with soil, yield, or topography.

Step-by-step

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1. Open the field and start a zones map

Open the field. Click Create Zones Map. Choose Single-layer if you want a quick fertilizer map from one source.

Start creating a zones map from the field page

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2. Select the zoning source

Choose the layer that best reflects fertilizer demand.

Common choices:

• Satellite Monitoring for biomass or crop vigor patterns

• Soil data for pH, EC, organic matter, P, K, Mg, Zn, or other lab values

• Topography for slope-driven variability

• Yield for productivity response

If you use satellite imagery, pick the most relevant image and index. Then continue.

Select the source layers for zoning

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3. Configure the zones

Set the map title, number of zones, classification type, and minimum polygon area.

Practical defaults for fertilizer maps:

• 3-5 zones for most fields

• Natural Breaks when you want stronger rate separation

• Larger minimum polygon area when the spreader should avoid tiny polygons

Then click Run Analysis.

Define zone count, classification, and polygon size

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4. Save the zones map

Wait until the analysis finishes. Review the result. Then click Save & Finish.

Save the finished zones map

After saving, open the new zones map.

Open the saved zones map to assign fertilizer rates

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5. Assign fertilizer rates

Use the Rates Distribution Tool to convert zones into a fertilizer prescription.

Typical setup:

• Select the fertilizer product

• Set the unit, such as kg/ha, lb/ac, or l/ha

• Choose Average Value or Total Amount

• Define how much rates should change between low and high zones

• Add min and max limits if needed

• Review totals and savings

• Click Save

GeoPard Rates Distribution Tool

Use higher rates in stronger zones when the crop can respond more. Use reverse logic when low-productivity zones need more correction, like lime or some base nutrients.

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6. Optional: add trial blocks or strips

If you want to test fertilizer rates in the same pass, add trial layouts directly on the Zones Map page.

What you can do:

• draw trial strips or blocks on top of the fertilizer zones map

• assign different fertilizer treatments or rates to each trial area

• set replications, angle, width, buffer, and block structure

• shuffle treatment placement to reduce positional bias

• keep trials as a geospatial layer linked to the exact field position

This is useful when you want to compare rates in real field conditions instead of relying only on field averages.

Example of RCBD trial blocks placed directly on top of a zones map

Match trial width and angle to machine width and travel direction for cleaner execution and better analysis later.

Trials stay linked to the zones map. You can visualize them on the field, reuse trial locations later, and export trials merged with the zones map in one application-ready file.

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7. Export the fertilizer map

From the zones map page, click Export and choose the format required by your terminal or platform.

ISOXML is the common option for machine-ready fertilizer prescriptions.

If you send prescriptions to John Deere, use these tutorials:

• Export Rx Maps to John Deere Operations Center as Files

• Export Rx Maps to John Deere Operations Center as Work Plans

Open the zones map page

Click Export

Download ISOXML

The downloaded ZIP includes ISOXML variants for different monitors

Optional: start from existing as-applied fertilizer data

If you already have an application dataset, upload it first and use it as a zoning source or reference layer.

Upload fertilizer application data as a shapefile

This is useful when you want to:

• rebuild a better fertilizer map from previous operations

• compare target rates with applied rates later

• create follow-up nutrient maps from real machinery data

Best practices for fertilizer VRT maps

• Keep the first version simple. Use 3-5 zones.

• Avoid very small polygons unless the machine can handle them.

• Match units to the terminal before export.

• Set min and max rates to stay within agronomic and machine limits.

• Use field trials or post-season analysis to improve the map next year.

Related pages

• Field Management Zones (Productivity Zones) Creation Process

• Assign Variable Rates in the Zones (Ag inputs Rates Distribution Tool)

• Field Trial Analytics

• Export VRA map In ISOXML Format

• Export Rx Maps to John Deere Operations Center as Files

• Export Rx Maps to John Deere Operations Center as Work Plans

• Evaluate Accuracy of Fertilizer Application