With dry conditions last summer and early precipitation growers may be having a harder time assessing nitrogen needs this year.
This past summer N stayed in the soil profile longer due to little precipitation. For those with below trend line yields that applied N for trend line or higher yields in the spring of 2012, much of the N was still in the soil last fall.
According to DuPont Pioneer agronomists, the soil N "carried over" could be a great benefit for the corn crop in June. However, as growers continue to receive precipitation, the likelihood of that happening is getting smaller. Spring storms will likely leech the N out of the soil before the plants use it.
While N fertilizers such as anhydrous ammonia, urea and urea-ammonium nitrate (UAN) exist in various forms, the basics of nitrogen availability still apply. Stable ammonium (NH4+) forms are gradually broken down into highly soil mobile nitrate (NO3-) that readily leeches out of the soil profile. This break down process is known as nitrification. Nitrification generally occurs at soil temperatures above 50 degrees, and increases as temperatures rise above this level.
Nitrification inhibitors such as nitrapyrin and DCD (dicyandiamide) are compounds that slow the conversion of ammonium to nitrate and have proven effective for this purpose.
For more information related to soil nitrogen, including tips for managing nitrogen>, contact your Pioneer sales professional or visit www.pioneer.com.