Which electromagnetic (EM) bands are used in precision agriculture applications?

Which electromagnetic (EM) bands are used in precision agriculture applications?

• A. Ultraviolet and X-ray
• B. Infrared and microwave
• C. Visible and near infrared
• D. Radio and microwave

Answer: (C)

Measuring plant health with remote sensing relies on how leaves interact with specific parts of the spectrum. Healthy vegetation has a distinct reflectance pattern: it absorbs most red light for photosynthesis but reflects a lot of near-infrared light due to leaf structure. This strong contrast between red and near-infrared forms the basis of vegetation indices used in precision agriculture, like NDVI, which quantify crop vigor and help managers spot stress, nutrient gaps, or irrigation needs. Because this diagnostic signal comes from combining visible (red) and near-infrared bands, those two regions are exactly what most precision-agriculture sensors target—whether on drones, satellites, or ground devices. Other options don’t align as well with this approach: ultraviolet and X-ray aren’t practical for wide-field crop monitoring; using infrared without specifying near-infrared misses the key leaf-structure signal used in common health assessments; and microwave or radio approaches focus more on moisture or canopy structure rather than the standard health mapping derived from visible and near-infrared reflectance.

Measuring plant health with remote sensing relies on how leaves interact with specific parts of the spectrum. Healthy vegetation has a distinct reflectance pattern: it absorbs most red light for photosynthesis but reflects a lot of near-infrared light due to leaf structure. This strong contrast between red and near-infrared forms the basis of vegetation indices used in precision agriculture, like NDVI, which quantify crop vigor and help managers spot stress, nutrient gaps, or irrigation needs. Because this diagnostic signal comes from combining visible (red) and near-infrared bands, those two regions are exactly what most precision-agriculture sensors target—whether on drones, satellites, or ground devices. Other options don’t align as well with this approach: ultraviolet and X-ray aren’t practical for wide-field crop monitoring; using infrared without specifying near-infrared misses the key leaf-structure signal used in common health assessments; and microwave or radio approaches focus more on moisture or canopy structure rather than the standard health mapping derived from visible and near-infrared reflectance.