Northwest Iowa Crop Conditions

Little planting progress has happened since my last update 10 days ago. NW Iowa received more than 3 inches of rain since then, on ground that was already nearly saturated. Most creeks and rivers are now flooded. Temperatures have fallen below average in the past 10 days, which is not helping the corn that was planted.There will be two different groups of corn this season early planted and late planted without much in-between. It’s too early to tell which group will have the advantage.

Wet cool weather can cause a verity of problems beyond delayed planning:

• Corn is slower to emerge and eventually the seed can develop diseases from saturated cool soil. Most of the corn that was planted nearly 2 weeks ago so far it looks okay, and is close to emergence. It seems likely some fields will suffer from poor/uneven emergence.
• Nitrogen loss from denitrification or leaching is increased by prolonged saturation and tile flow. The cool weather
actually helps slow the nitrogen loss, but we are still concerned about it with all this wet weather.
• Pre-emergence herbicides, in many cases has already been applied. The heavy rain can make these less effective.

It will be at least another week before planters will be back in the fields. The extended forecasts look promising for
that. Generally corn will not suffer yield loss from late planting until after mid-May so there is time. Soybeans can
be planted in June without suffering yield.