Northwest Iowa Crop Conditions

Consistent warm weather this month was great for speeding up crop growth and development, but on the downside soil conditions are drying out. The last big rain was on May 12 and 13th when it poured 3 or more inches over most of the area. The crops have soil moisture to use now, but more rain will be needed soon as roots develop and water use increases. The two-week weather outlook stays warmer than average with about average chances of rain.

Most corn fields have very good stands. The warm weather helped with fast emergence. The first planted corn is up to 8 inches tall or more. Many farms will be sprayed with post-emerge herbicides this week. Corn is in the growth stage where uneven patterns often appear. For example, you may see yellowish streaks through the field in straight lines. It happens at this stage more often because the roots are transitioning from the seed roots to the main nodal roots. Any variations in the soil like uneven residue, planting depth, angled tillage / fertilizer passes, inconsistent nutrient availability, and compaction zones will affect early root development which will show up as patterns in the field through color and size. These patterns typically don’t last long as the corn should grow out of it (unless the issues are more severe). It is something to watch closely so changes can be made, even if it’s for next year.

Soybeans planted between May 9th and 11th (right before the heavy rain) struggled to emerge. Some of those fields were replanted recently, which is still not a big concern. Beans have very good yield potential if they are planted by June 1st or before. The beans benefit from warm soil to speed up emergence and growth. The early May planted beans are 4 to 5 inches tall, and the more recently planted beans are just emerging.