Space-age farming

Issue Date: February 16, 2011

This image of a 450-acre Napa Valley vineyard was recorded by the Landsat 5 satellite last July 29. The image measures grape canopy density with a vegetation index. Since green leaves absorb red light (for photosynthesis) and reflect near-infrared light, scientists can use images such as these to measure crop canopy density. Blue pixels represent blocks with dense canopies while brown pixels represent blocks with sparse canopies; yellow and green pixels represent blocks with moderate canopy densities. Information from such images can help farmers fine-tune crop irrigation. (See story on Page 14.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.