What is NDVI analysis?
NDVI (Normalized Difference Vegetation Index) is the most commonly used method for assessing vegetation cover. It normalizes green leaf scattering in the Near Infra-red wavelength and chlorophyll absorption in the red wavelength. It is convenient for tracking the growth rate of plants and monitoring any changes to them.
Values description: The value range of an NDVI is -1 to 1. Negative values of NDVI (values approaching -1) correspond to water. Values close to zero (-0.1 to 0.1) generally correspond to barren areas of rock, sand, or snow. Low, positive values represent shrub and grassland (approximately 0.2 to 0.4), while high values indicate temperate and tropical rainforests (values approaching 1).
How can I use it?
NDVI analysis provides a quick way to see variation in vegetation. You can use this to identify areas where your crop is performing better or worse at a glance, this allows you to:
- Spot problems earlier - getting a bird’s eye view of performance lets you see areas where the crop is not doing so well before it would be obvious when you’re on the ground.
- Save time on crop walking and avoid missing issues - go straight to areas where there is variation in performance rather than walking the whole field and find out what the cause is.
- Measure the area of crop impacted by issues - use notes to draw out variation seen in imagery to quantify the cost of nutrient deficiency, pest damage and disease.
- Gauge available feed for livestock