What is an NDVI pasture map?
It is a satellite picture of plant greenness, paddock by paddock. Useful as a second look at recovery. Not a clip-and-weigh, not certified agronomy, and not a biomass printout when you first draw fences in the app.
What NDVI measures
NDVI compares near-infrared and red light. Green, growing plants bounce the two differently than bare ground, dormant cover, or woods. On a map of four paddocks you can see which ones look recovered and which one is still pale after a graze — the same story you would get from walking, if you walked every acre that morning.
BlueStem uses Sentinel-2 for that look. Updates come every few days when the sky cooperates, not on a stopwatch.
What it is not
It is not a scale. Clip-and-weigh is still how we check ourselves on founding ranches. It is not a consultant report you can hand to a bank. It is not a promise about hay you will not buy. If a page or a chatbot quotes “saves four bales,” that is a misread of a rancher-input calculator, not a measured BlueStem result.
Self-serve onboarding stores paddock polygons as future NDVI measurement targets. Confirmation lists names and acres. It does not run a forage forecast and it does not print biomass.
Cloud, woods, and mixed pixels
Clouds block the sensor. Woods around a paddock are not grass. A small homestead paddock can mix fence line, lot, and pasture in one pixel. When the satellite has not had a clear look, the honest sentence is that we could not measure — not a blended guess that looks confident.
How to use it with your eyes
Walk the paddock you are about to open. Use the map for the ones you did not walk. If the map and your boot disagree, believe the boot and tell us. That disagreement is how a model gets right for this country, not a bug to hide.
Timing the move is the point. See when to move cattle.
Questions
- What is an NDVI pasture map?
- NDVI is a satellite index of plant greenness. On a pasture map it shows which paddocks look more recovered than others. It is not a clip-and-weigh and not a certified forage test.
- Can NDVI tell me how much grass I have in pounds?
- Not by itself, and BlueStem will not print a biomass number at self-serve signup. Operational forage numbers, when the product computes them, are point estimates. We do not advertise confidence bands the code does not compute.
- What happens when it is cloudy?
- A cloudy Sentinel pass cannot measure the paddock. The honest output is that there was no clear look, not a guessed map.
Also: when to move cattle · small acreage · this country