Corn harvest advanced to 24% done and the soybean harvest inched up to 26% complete as of Sunday, with both  behind the five-year averages, USDA said on Monday.

Related: Corn 15% harvested, soybeans 10%

While Iowa was fairly dry this past week allowing for 5.4 days for field work, the muddy fields that remained from previous storms slowed harvest progress.

Iowa corn was 10% cut as of Sunday, compared with 11% a year ago and the 19% average. It was other states that were affected by rain, with Illinois reporting 5.2 days suitable for fieldwork, Indiana 3.9, and Ohio 3.0.

Corn harvest advanced to 24% done, USDA said on Monday. This is behind the five-year average.

“The beginning of the week was mild allowing farmers to get out to the fields, but near continual rain showers towards the end of the week halted most fieldwork,” Indiana said.

The national corn ratings slipped one point to 73% good/excellent, while soybeans improved a point to 74%. The national average corn yield potential calculated by Farm Futures based on the condition ratings slipped to about 173.3 bushels per acre. Calculations show yield potential increased in the past week in four states, decreased in seven including Iowa  and was unchanged in six.

The calculated soybean yield potential increased slightly to a topside forecast of 50.5 bpa. Soybean yield potential improved in 10 states, was unchanged in four and declined in four from a week ago. The improvements included a minor rise in Iowa.

Winter wheat planting advanced to 43%, compared with 44% a year ago and the 45% average. Wheat emergence was 20%, versus 16% a year ago and the 17% average.

In Kansas, winter wheat was 40% planted and 12% emerged, which trailed the five-year averages. Statewide topsoil moisture was rated 9% surplus, 77% adequate, 10% short and 4% very short.

Nationally, sorghum was 41% harvested versus the 36% average. The crop rating was unchanged at 66% good to excellent.