Using a herbicide to control weeds--especially in the initial growing stages--is vital to the health of a crop, because weeds usurp water, nutrients and space.

FORBES: Commentary

For example, researchers in Arizona are using real-time kinematic global positioning systems, an ultra-precise version of GPS that can measure positions with sub-inch accuracy levels, to control weeds in cotton fields with steel cultivators.

FORBES: American Agriculture's 'Sputnik Moment'