Injected and Banded Nitrogen Fertilization for No-Tillage Winter Wheat in the Mid-Atlantic.

Wheat acreage produced using no-tillage has increased across Virginia over the last 10 years resulting in a need for refinement of fertilization practices. Recently, an increase in N fertilizer price has prompted producers to look for additional ways to increase efficiencies in fertilizer management. The use of N injection equipment is currently being evaluated in no-tillage corn production in Virginia and may be useful in no-tillage wheat production systems. We initiated a study on loam and sandy loam soils to test the utility of various N treatment application methods and to find the corresponding N rate for each practice. Nitrogen application methods included surface-broadcast, surface-banded (38 and 76 cm bands), and subsurface-banded applications (38 and 76 cm bands) of urea-ammonium nitrate (300 g N kg^-1) at four different N rates (45, 90, 135, and 180 kg N ha^-1). Three no-fertilizer controls were included. Two of the no-fertilizer controls had the subsurface applicator ran across the plots at 38 and 76 cm spacing to test for plant damage from the no-tillage coulters. Nitrogen treatments were made in the spring with 50% of the N applied at Zadok’s growth stage 25 and the remaining N applied at Zadok’s growth stage 30. Wheat grain yield and above ground biomass were used to compare N treatments. Wheat yield was highest when 135 kg N ha^-1 was used (4368 kg grain ha^-1); averaged over application method. Wheat aerial biomass peaked at 9333 kg biomass ha^-1 when 90 kg N ha^-1 was applied; averaged over application method. For application method, 38 cm surface banded applications had superior yields compared to other treatments and averaged 4704 kg grain ha^-1; averaged over N rate. Broadcast, surface banded and 76 cm subsurface banded had similar aerial biomass production and averaged 13% higher than subsurface 38 cm bands. Overall, alternative N production practices may increase yield, biomass production, or decrease necessary N application rates to maintain current production yields.