August 13, 2013

Trip Report - Iowa

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

Last Saturday, August 10th, I traveled through Iowa (before the rain which fell in Iowa Saturday night and Sunday morning) with the following observations:

Iowa Corn

  • The soil moisture in the eastern one third of Iowa is OK, but the soil moisture is short in the central one third of the state and it is very short in the western one third of the state. The driest areas I saw were in southwest Iowa especially on the hillsides.
  • The earliest planted corn pollinated fine and is in the milk stage. The majority of the corn is in the blister stage and appears to have had no problem pollinating. The latest planted corn will pollinate over the next week or so while some of the replanted corn in the drowned out potholes probably won't pollinate for at least another two weeks.
  • There is a lot of variability to the corn and the question now is if the ears will be able to retain all the kernels or if there will be tip-back on the end of the ears. There are some very good ears in Iowa, but it is too early to say for sure if the ears will retain all the kernels or not. It is too early to judge the yield potential of the worst fields because the ears are too small to show anything meaningful. The early planted corn in the state will have the highest yields and the latest planted corn will have the lowest yields.
  • The amount of moisture stress increases as you move west in the state. In the driest areas, there are patches in the fields where it is so dry that there will be very little to harvest. In the areas that are not as severely impacted, there will be corn to harvest, but I expect significant tip-back on the ears. In the western part of the state, a lot of the lower leaves have started to fire and turn brown and that will continue as long as there is no additional rainfall.
  • The corn in Iowa is doing better than the soybeans because the deeper root system of the corn allows it to tap into the subsoil moisture. The next two or three weeks will be critical for most of the corn in Iowa. If there is good rainfall, the ears will retain all the kernels and there won't be much tip-back. If there is not good rainfall, there will be significant tip-back especially if the temperatures warm up.
  • The cooler temperatures have definitely helped conserve the moisture and lower the water demand of the corn crop. As dry as it is in much of Iowa, if the temperatures would have been in the upper 90s, it would have been a complete disaster. Going forward, the worst scenario for the corn would be a warm up in temperatures without accompanying rainfall. The best scenario would be above average temperatures accompanied by an inch of rain a week for the next four weeks and then a later than normal frost.
  • The Iowa corn crop is going to be below trend line, it's a question now of how far below. The rainfall over the next several weeks will determine if the corn yields are going to be in the low 160s bu/ac or in the 140s bu/ac.

Iowa Soybeans

  • The soybeans in Iowa are not as good as the corn. In general, the soybeans continue to be slow in their development with the latest planted soybeans the furthest behind. The dry weather has also contributed to their slow development.
  • The best soybeans are generally in the eastern part of the state and they are thigh-high with a good color and have a good yield potential. The soybean condition declines the further west you go in the state. There are so many soybeans that are knee-high or less in height and they will continue to be very slow growing unless they get significant rainfall this week and every week for the next three or four weeks. The worst soybeans are pathetic - six inches tall, stunted, and extremely dry and probably won't be harvested at all.
  • There is a lot of moisture stress appearing on the soybeans, but the cooler temperatures have kept the stress from being even worse.
  • The next 2-3 weeks will determine the fate of the soybeans in Iowa. If they could get an inch of rainfall every week until the end of August, the plants would retain the pods that have been set and the pods will fill out. If it stays dry, a lot of the flowers and pods will be aborted and many of the pods will have less than three seeds per pod.
  • The worst thing for the soybeans would be if the temperatures warmed up to above normal and it stayed dry. That would seal the fate of many of the soybeans.
  • There is tremendous variability in the soybeans. If there is a good end to the growing season, some soybeans in Iowa could yield 50-60 bushels per acres. Conversely, with a poor end to the growing season, there will some soybean fields in Iowa that are so bad that the field will probably not be harvested; the plants will not be big enough to get across the cutter bar and into the combine.
  • The soybean crop in Iowa is going to be below trend line, it's just a matter of how much below trend line.