Variable Rate Technology (VRT)

Variable Rate Technology (VRT) is a system that allows agricultural equipment to automatically vary the rate of inputs — seed, fertilizer, chemicals, or water — across different zones of a field based on a digital prescription map. Instead of applying a flat rate everywhere, VRT matches inputs to each area's specific needs.

How VRT Works

A VRT workflow has three stages:

1. Data collection — Gather spatial data about field variability. This includes yield maps, soil samples, NDVI imagery, and elevation data.
2. Prescription creation — An agronomist or algorithm divides the field into management zones and assigns target rates to each zone. The result is a prescription map — a georeferenced file (typically Shapefile or ISO-XML) that the equipment controller can read.
3. Execution — The equipment reads the prescription and a GPS receiver. As the machine moves through the field, the controller adjusts application hardware (seed meters, spray nozzles, spreader gates) in real time to match the prescribed rate for the current location.

Prescription Formats

Prescriptions are stored as vector or raster spatial data. Through FieldMCP, you can read and write prescriptions as GeoJSON with rate attributes. The planting prescriptions glossary entry covers the specific format for seeding operations.

Why Developers Build VRT Integrations

VRT is where agricultural data becomes actionable. Building software that generates or optimizes prescriptions means your code directly influences what happens in the field. Common integration patterns:

• AI-generated prescriptions — Use LLMs connected via MCP to analyze multi-year yield data and soil samples, then generate optimized rate recommendations
• Prescription validation — Check that rates fall within agronomic bounds before sending to equipment
• As-applied comparison — Compare the prescription (what was planned) against as-applied data (what actually happened) to measure execution accuracy

Getting Started

See the tools reference for prescription-related MCP tools and the quickstart guide for connecting your application.