(NWS graphic)

Some farmers in northwest and north-central Iowa are finding their crops damaged from last week’s cold snap.

Angie Rieck Hinz , a field agronomist with the Iowa State University Extension, says the frost had the greatest effect on soybean fields. “There are some later-planted soybeans that were impacted by that frost because we did get cold enough those mornings that we were below 32 in some places,” Rieck Hinz says, “so usually we think a killing frost is about 28 degrees for soybeans.”

Some pockets of the state did dip into the upper 20s at least two mornings, and a number of fields got nipped. Most farmers will still be able to save the majority of their crops. “It’s just going to take a little bit longer for them to dry down, so harvest is usually delayed a little bit,” she says. “We want them at a certain moisture and it’s going to take a little bit longer after they’ve been frosted to get to that point.”

The color on the soybeans is a key factor after a frost. “We’re always concerned about handling those frost-damaged beans or putting them into the commercial market because if the beans weren’t mature and they were still a little green, it’s pretty easy to get docked at the co-op for those green soybeans,” Rieck Hinz says. “We would advise never to put those green beans or greenish beans directly into the market.”

She says aerating the soybeans may bring about a color change so they’re more of a mature tan. Most of Iowa’s corn crop is mature and ready — or close to ready — for harvest, so frost damage to the corn was minimal. “We, in some cases, were at full maturity or at black layer, but there were some fields that were still in that really late dent stage, so we can anticipate some minor yield loss there.”

High temperatures for the next several days are expected in the 70s with lows in the 50s, ideal harvest weather, with more cold moving in Thursday and Friday.

(By Pat Powers, KQWC, Webster City)