Deep green fields in Iowa are a good indicator the crops going along nicely; however, this year there are a few discolored strips. ISU extension field agronomist Mark Johnson says the reason for that is compaction.
”It’s pretty common this year to see some patterns." He says, "With all the rain we’ve had, it’s been really bad all through the planting season and ever since the planting season, we’ve never really dried these soils out and gotten down to field capacity very much. And so if we did anything to complicate that by putting in say a compaction layer. So, where the planter wheel was, it compacted the soil more than than the rest of the planter."
Johnson says it's easy to tell apart plants that have compaction problems to those that don't when you put them side-by-side. Uprooting a plant without compaction lets more soil fall from the roots. But compacted soil will stick in clumps.
He says, "It’s not draining so it’s staying wetter with the same amount of rain. And a lot of these roots you can see they’re going out the sides trying to get away from that compacted area."
If the soil is compacted, the right weather conditions can put it right, "That’s where the compaction was. So really the best thing that can happen to this kind, is a really nice, gentle, soaking rain that isn’t excess rain. Kind of helps soften this up. Gives it a chance to drain away."