GRAINS-Wheat firms, edges up from one-month low as U.S. crops suffer further damage

SYDNEY, March 21 (Reuters) - U.S. wheat futures edged higher on Wednesday, rebounding from a one-month low touched in the previous session, after damage to crops in a key producing region from dry weather. FUNDAMENTALS * The most active wheat futures on the Chicago Board Of Trade were up 0.1 percent to $4.53-1/2 a bushel by 0109 GMT. Prices closed up 0.5 percent on Tuesday, recovering from a low of $4.50 a bushel - the lowest since Feb 22. * The most active soybean f