By Sam Nelson
CHICAGO (Reuters) - Top U.S. corn and soybean producing state Iowa has received the most spring rainfall since records began 141 years ago, slowing crop plantings and threatening to reduce yields, an Iowa climatologist said on Friday.
"From March through May, which is our spring record keeping period, Iowa had received 17.48 inches of rain as of Thursday," Iowa State Climatologist, Harry Hillaker said. "There may be another 0.15 inch added to that today."
Hillaker said the old record of 15.36 inches was set in 1892 but rainfall seen from March through to May is the most since records began.
Hillaker said typical March-May rainfall in the state was 10.22 inches. "That would be normal and is based on rainfall received for the past 30 years," he said.
Excessive wet weather in the U.S. Midwest has slowed seedings of corn and soybeans, pushing corn plantings up to the end-of-May deadline that farmers can plant without suffering cutbacks in crop insurance coverage.
Farmers who plant corn after the end of May in Iowa and Illinois are hit with reductions in insurance benefits for each day that plantings are delayed.
Hillaker said Iowa runs the risk of flooding since soil moisture reserves have been replenished following the worst drought in over 50 years last year.
"The only time period I can find where it was so hot and dry one year followed by cold and wet the next would be the 1901 and 1902 years," he said.
Additional rainfall late this week into the weekend will further slow corn and soybean plantings in the U.S. Midwest, threatening to reduce yield potential for the 2013 crop season, an agricultural meteorologist said on Friday.
"It's not the best of conditions, there will be more rain for the next two days with the heaviest southeast of a line from Kansas City to Green Bay," said John Dee, meteorologist for Global Weather Monitoring.
Dee said it would turn drier from Sunday through Tuesday but more rain is expected in the Midwest beginning next Wednesday and "we could see more showers next Friday into the weekend." The showers will be widespread and "continue to cause some issues," Dee said.
The slow seeding of both crops this spring has raised concerns about reduced yields at autumn harvest as key phases of crop development will likely be delayed until the heat of the summer. A late planting also increases the possibility of an early frost inflicting further damage on the crops.
The USDA said that corn planting was 86 percent complete as of May 26, up 15 percentage points from a week earlier.
The corn progress was down from 99 percent a year ago and behind the five-year average of 90 percent. But prospects were much improved from just two weeks ago, when muddy fields led to the slowest start on record for corn planting.
Farmers had finished 44 percent of soybean planting as of May 26, compared with 87 percent a year ago and the five-year average of 61 percent. It was the slowest pace for soybeans since 1996, when farmers had seeded just 35 percent of their crop by the end of May.
(Reporting by Sam Nelson; editing by Sofina Mirza-Reid)