What is NDVI? A farmer's guide to satellite crop health monitoring
What is NDVI?
NDVI stands for Normalized Difference Vegetation Index. It is a measurement derived from satellite imagery that tells you how healthy your crops are — without ever visiting the field.
Satellites like Sentinel-2 capture images of the Earth in multiple wavelengths of light, including wavelengths that human eyes cannot see. Healthy plants reflect a lot of near-infrared light and absorb red light for photosynthesis. NDVI uses this difference to calculate a score between -1 and +1.
How to read NDVI scores
0.6 to 0.9 — Healthy, dense vegetation. Your crops are thriving.
0.3 to 0.6 — Moderate vegetation. Crops may be in early growth stages or experiencing mild stress.
0.1 to 0.3 — Sparse vegetation. Possible stress, disease, or drought impact.
Below 0.1 — Bare soil, water, or dead vegetation.
Why NDVI matters for farmers
Traditional crop monitoring requires walking the fields, hiring agronomists, or flying drones. NDVI from satellite imagery gives you the same information — remotely, at no hardware cost, updated regularly.
With FarmHawk, NDVI scores are automatically calculated for every farm analysis. You receive a color-coded health map showing exactly which parts of your farm are thriving and which need attention. This helps you:
Detect pest infestations or disease before visible symptoms appear
Identify irrigation problems or water stress zones
Track crop growth stage across your entire farm
Make data-driven decisions about fertilisation and harvesting
How FarmHawk uses NDVI
FarmHawk's AI doesn't just show you a raw NDVI map. It interprets the data in context — considering your specific crop type, growth stage, regional climate, and historical patterns. The result is an actionable advisory in your language, not just a number.
For example, an NDVI score of 0.45 on a rice paddy in Andhra Pradesh during the tillering stage means something different than the same score on a cocoa plantation in Lagos during the harvesting season. FarmHawk's crop-specific engines understand these differences.
Frequently asked questions
Can NDVI detect specific crop diseases?
NDVI detects vegetation stress, which is often the first sign of disease. While it cannot identify the specific pathogen, a sudden NDVI drop in a section of your farm is an early warning that something is wrong — often 1-2 weeks before visible symptoms appear.
Does NDVI work on all crops?
Yes. NDVI measures vegetation health, so it works on any green crop — rice, wheat, sugarcane, cocoa, cotton, maize, and all 84 crops that FarmHawk supports.
Do I need special equipment to get NDVI data?
No. FarmHawk uses satellite imagery that is already orbiting above your farm. You only need a phone or computer to access your NDVI reports. No drones, no sensors, no hardware.