Northwest Iowa — Last fall was a very difficult application season for manure, because of wet conditions and early freeze up. If the manure did not get applied last fall, there may be a window this spring to get the job done, according to Iowa State University Ag Engineering Specialist Kris Kohl.Kohl says research on continuous corn at the Northeast Research Farm compared swine manure applied at 200 pounds nitrogen per acre in November and April. The yields in the last 3-years averaged 38 bushels per acre higher in the spring versus the fall. The spring plots also had less nitrate loss from the tile lines.
There will still be issues with trying to apply manure in the spring. Wet winters can cause greater loss of nitrogen than the normal dry falls we use to get, according to Kohl.
Kohl has some recommendations for applying spring manure are all about soil compaction. To reduce the problems that compaction will bring:
1. Lower the tire pressure to the lower end of tire manufacturers recommended range.
2. Wait for soil conditions to support loads.
3. Till end rows where traffic has caused the most compaction.
Remember these simple rules for applying manure. If you can’t smell it, you’re not losing it to the air and if the tires don’t leave tracks, there is little compaction, according to Kohl.
Photo at top of page: Iowa State University Ag Engineering Specialist Kris Kohl
