What's different in 2014? Late planting?
What might be different this year with nitrogen?
- Cool soils in much of the northern Corn Belt mean slow mineralization, so that means low soil N levels in surface soils without (surface-applied) nitrogen.
- Cool soils will dry slowly, with possible planting delays and/or planting into wet soils that could slow root access to and uptake of soil nitrogen.
- Nitrogen will have a long “dwell time” in the soil, which means slow conversion to nitrate and low nitrogen loss potential as long as soils stay cool and rainfall is low.
- But delayed planting and/or slow growth means that nitrogen uptake won’t start early, so loss potential in May and June will be important.
- Weather patterns could make soil compaction more damaging to roots and nitrogen uptake in 2014 than in 2013.
What if we plant late?
- "If planting is really delayed into the second week of May, yield losses approach 1 bu./day, so plant first and worry about fertility later
- If soils have warmed to average (early May) temperatures by planting, some mineralized N will be available, especially in corn following soybeans.
- If we do this, we should follow planting with broadcast UAN if possible, especially in corn following corn (without starter).
- Nafziger sees no reason to change N rates based on soil conditions or planting date.
- While we don’t at this point expect high N loss conditions, “at present corn and anhydrous ammonia prices, I see so reason to change N rates based on soil conditions or planting date,” Nafziger says.