Authorities say someone’s deliberately setting field fires across eastern Iowa, keeping fire crews busy day and night.More than 20 field fires were reported in Cedar and Muscatine counties on Tuesday night, while several more broke out in Cedar County on Wednesday. Two other fires were reported in Linn and Jones counties last night, which investigators say may be linked to the other blazes. Most of the fires caused only minor damage but one this week near West Branch came within a few yards of homes.