The US Department of Agriculture estimates the value of field crops, fruits and nuts, and commercial vegetables produced on the 2 million farms across the US at more than $87 billion a year. Although that may seem like a staggering sum, profit margins for individual farmers are typically very slim. As a result, farmers are likely to take seriously any technological advance that will help increase those margins. Much of the farming community is adopting "precision farming": tailored methods of seeding, irrigating and treating specific fields in the most efficient manner. Global Positioning System locating, site-specific soil sampling and harvest yield monitoring are becoming accepted tools in the field. Now optical remote sensing systems are poised to join these tools to improve farming efficiency in the next century.