Farmers who think their crops survived the recent flooding need to get in their fields and take a look around. Even if seeds and plants survived the heavy rains, they could be damaged, said South Dakota State University Extension Educator Bob Hall. The only way to know for sure is to do some research. “You can't be an armchair agronomist. You've got to get out there and look it over,” Hall said. If crops have been underwater since the rains fell, don't bother. They're dead, Hall said. But if they were under for only a day or two or three, samples need to be uprooted and checked for color. The tissue of most plants should be bright green or bright white or, perhaps, a somewhat duller shade of either of those colors. If the tissue looks tan or black, Hall said, the plant has had too much water and not enough oxygen. Hall said different parts of individual fields should be checked as plant conditions could be dissimilar. Low-lying areas that routinely hold water might not dry out all summer, Hall said. If that's the case, there is no use in planting them. Even if seeds and seedlings have survived so far, there is still the potential of crusting problems, Hall said. Crusting is when the soil dries and gets so hard plants cannot push their way through it. When temperatures are cool, seeds and plants can probably survive under water for three or four days, according to SDSU Extension information. Seventy-seven degrees seems to be a cutoff. Once standing water gets warmer than that, it can kill a submerged plant within 12 to 24 hours. The amount of rain is less important than how long seeds and plants are under water, Hall said. Some researchers think that plants under running water can survive longer than plants under pond water, he said. Either way, though, oxygen to plants is hindered. Grass and alfalfa are more resilient than small grains, Hall said. Farmers who have lost planted crops, but have crop insurance, have more work to do, he said. It might involve planting more seed. Or not. Before a decision about replanting is made, Hall said, ag producers need to check with their insurance agents and “work the pencil to it a little bit.” In other words, some math needs to be done to make sure it's financially smart to plant another crop. There's still plenty of time to plant soybeans and corn, Hall said. But if that means a farmer comes out money behind, there's no need in doing it.