The Middle Eastern kingdom needs hay for its 170,000 cows. So, it's buying up farmland for the water-chugging crop in the drought-stricken American Southwest.Saudi Arabia's largest dairy company will soon be unable to farm alfalfa in its own parched country to feed its 170,000 cows. So it's turning to an unlikely place to grow the water-chugging crop — the drought-stricken American Southwest. Almarai Co. bought land in January that roughly doubled its holdings in California's Palo Verde Valley, an area that enjoys first dibs on water from the Colorado River. The company also acquired a large tract near Vicksburg, Arizona,...