From iGrow.org 
In the last seven days, most of the state saw rain events which dumped as much as 10 inches on some crop acres, said Laura Edwards, SDSU Extension Climate Field Specialist.
“How much moisture received and whether it brought damage or relief to agriculture producers really depended on which South Dakota County their land is in,” Edwards said. “Some farmers will need to replant, others have to wait to plant while their field sits several inches under water, and at the same time many ranchers couldn’t be happier because now forage and range conditions are looking better than they have in a long time.”
Most of the heavy precipitation fell on Turner, Lincoln and Minnehaha Counties; totals exceeded 10 inches in the center of the storm. This includes areas west-southwest of Sioux Falls that received over six inches in 24 hours from Saturday to Sunday morning. A stretch from Onida to Miller also received at least 6-8 inches; with several northwestern South Dakota counties receiving several inches from localized, intense thunderstorms. Stream flow on the Big Sioux and Vermillion Rivers came up quickly, but are projected to fall within a few days, barring additional heavy precipitation.
“Our primary concern right now is flooding in fields in the eastern part of the state,” Edwards said.
Depending on the type of rainstorm, Edwards says fields could be impacted by flash flooding, which can erode soil, wash away new seed and leave large cutouts in fields; or fields are under standing water, which can suffocate young plants.
Edwards says that based on discussions with SDSU Extension Agronomists, the impact this flooding will have on the 2013 crop all depends on how fast fields dry up and how mature the crop is – if plants have a few leaves above the waterline, the crop may survive. She adds that some of the long term effects won’t be known until later in the growing season.
“This has been a cold wet spring punctuated by extreme rainfall. If the plants do survive this most recent event, we have yet to know what type of diseases may follow,” she said.
The heavy rain can also induce crusting on the soil surface, which can slow down emerging plants, or cause uneven emergence in corn and soybean fields.
As to whether or not South Dakota is still in a drought, Edwards says it all depends on where in South Dakota you’re located.
“The eastern side of the state has made phenomenal gains this spring which has improved the drought situation dramatically. I still have some concern about the long term deep soil moisture all across the state that could affect us later this summer,” she said. The western counties are holding steady, but drought impacts could emerge quickly as the area enters its dry summer season.
Another severe weather event is expected to sweep across the state May 29 and 30, bringing with it a potential for severe weather that may include strong winds and hail.
Before replanting, Edwards encourages farmers to consult their crop insurance representatives.
More information will be posted to iGrow.org .