National Geographic : 1977 Oct
Salad days in the lettuce fields can bring young workers as much as $55 a day. Unionized harvest ers (right) take a break from the laborious piecework of cutting heads from stalks in a field near Picacho Peak, site of the only Civil War skirmish in Arizona. With their fertile soils and long growing seasons, desert farms yield prodigious crops. On the beam, as seen in a time exposure, a laser-guided land scraper operated by Floyd Spar levels a field billiard-table flat. This technique helps prevent run off of irrigation water, typically reducing consumption by a third. With the water table falling and wells increasingly expensive to run, laser planing has been de ployed in the technological battle to conserve water.