2013 spring N fertilizer recommendations for wheat
Nitrogen Sources – Urea is the most commonly used nitrogen source on wheat because it is generally the most economical nitrogen source, it can be applied by air, and volatility is less likely to be substantial during the wheat season (because temperatures are cool and rain is frequent), than during the summer. Likewise, the need for urease inhibitors, such as Agrotain, is less now, compared to late-spring or summer applications of urea-based nitrogen sources. Ammonium sulfate should generally be applied in an early application, if sulfur may be needed. Liquid nitrogen solution (UAN) can potentially burn leaf tissue, especially if high rates are broadcast on erect wheat, so granular nitrogen sources are generally preferred, particularly for single, or the latter split applications.
Nitrogen Rates – Our wet southern climate may influence nitrogen use efficiency considerably depending upon seasonal rainfall frequency and amount. Thus, specific nitrogen rate suggestions based solely upon crop yield goal are not very reliable for wheat production in the South. Since soil texture significantly influences soil-water relations and potential nitrogen loss during typical wet springs, our general recommended spring nitrogen rates vary depending on soil texture. We normally suggest from 90 ‑ 130 lbs. N/a. on light-textured soils and 120 – 150 lbs. N/a. on heavy clay soils. However, monitoring crop response to nutrition, culture and environmental conditions offers producers substantial opportunity to fine tune your rate more specifically.