By Karl Plume
CHICAGO (Reuters) - The most intense drought to hit the U.S. Midwest farm belt since 2012 deepened over the past week, sapping soil moisture and threatening crop yield potential in the heaviest corn and soybean production areas of the United States.
But a series of rain storms forecast over the next two weeks in the southern and central Midwest could help stabilize or improve crop conditions that have been eroding for weeks and recharge soil moisture just ahead of the corn crop's critical pollination period in late July.
The improving weather outlook triggered steep breaks in corn and soybean markets this week after concerns about the dry start to the U.S. summer crop season had rallied prices to multi-month highs last week.
However, drought conditions worsened in the heaviest crop production areas of the Midwest over the past week. Weekly drought Monitor data showed 65% of the region in moderate drought or worse as of June 27, up from 58% a week earlier and the broadest area since 2012.
More than 89% of Iowa, the top corn and No. 2 soybean state, and nearly 93% of Illinois, the largest soy grower and second-largest corn producer, were under moderate drought or worse.
"Right now about 45% of the corn and soy belt is where the main concerns are, and it's right through the heart of the belt." said Joe Woznicki, meteorologist at Commodity Weather Group.
A series of rain systems beginning this weekend will likely benefit crops, particularly in central and southern areas of the Midwest, he said.
"After the next two weeks, the main portions of the belt that are going to remain too dry would be southeast Minnesota, Wisconsin, northeast Iowa, Michigan and Missouri, or about a quarter of the belt," Woznicki said.
Conditions varied over the past week in the High Plains, with the drought worsening in eastern Nebraska and Kansas but improving in western Nebraska and the Dakotas, Drought Monitor data showed.