A blanket of bright green alfalfa spreads across western Arizona's McMullen Valley, ringed by rolling mountains and warmed by the hot desert sun.
Matthew Hancock's family has used groundwater to grow forage crops here for more than six decades. They're long accustomed to caprices of Mother Nature that can spoil an entire alfalfa cutting with a downpour or generate an especially big yield with a string of blistering days.
