Enhanced Nitrogen Research Initiative

This research will include comparisons of commercially available N fertilizers, namely granular urea and liquid UAN, with and without N fertilizer stabilizers.

IPNI-2014-CAN-AB31

24 Mar 2015

2014 Annual Interpretive Summary


Annual use of N fertilizer in Canada is 1.8 million t; however due to the inefficiency of plant uptake and utilization, crops seldom assimilate >50% of applied N. Nitrogen losses result in lower yields and grain quality, and are a potential environmental concern if N is leached into surface or ground water or lost to the atmosphere as ammonia (NH3) or nitrous oxide (N2O). Nitrogen stabilizers, including nitrification inhibitors (NI), urease inhibitors (UI), or polymer-coated controlled-release urea, may decrease losses and increase N use efficiency (NUE).

In 2014, trials were conducted in spring at Lethbridge, AB and fall and spring at Edmonton and Devon, AB and with three N sources (eNtrenchTM treated urea, ESN(R) polymer-coated urea, SuperU(R) and urea), with five nitrogen application rates (0, 50, 75, 100, and 125% of soil test recommendations). Spring wheat was grown at all 3 sites. Data gathered included N2O emission using a steady state Photoacoustic gas monitor at the Edmonton site only. Soils samples were collected prior to application, two and four weeks after emergence, and post harvest to assess the N balance. NDVI was quantified at stem elongation and mid-anthesis and crop vigor ratings were taken. In addition to wheat yield, wheat stubble and grain N analysis, test weights and grain quality were also measured.

During the 2014 crop year, the weather was slightly cooler and drier compared to 30-year average weather. For example at the Devon site the average temperature was 0.3 C compared to the 1.9 C of the 30-year average, and for precipitation 354 mm of moisture compared to the 30-year average of 405 mm. All enhanced N fertilizer forms, whether fall or spring applied, resulted in greater concentrations of ammonium and lower concentrations of nitrate two and four weeks after crop emergence, compared to regular urea. Relative to urea, eNtrench had a N2O emission reduction of 18% in the fall, but SuperU and ESN emissions were not reduced. In the spring, eNtrench reduced N2O emission by 24%, and SuperU by 30% compared to urea. N2O emissions from ESN were not reduced compared to urea. Another year of field experiments and data measurements will be collected during the 2015 growing season.