Effect of Urea, ESN, Ammonium Sulphate and Their Blends On Yield, Grain N Removal and Protein Content of Winter Wheat.

Effect of urea, ESN, ammonium sulphate and their blends on yield, grain N removal and protein content of winter wheat 

T. S. Sahota¹

¹Thunder Bay Agriculture Research Station, Thunder Bay, ON, Canada (tarloksahota@tbaytel.net) 

Abstract

Winter wheat makes a significant contribution to the North American economy. Because of relatively longer duration of winter wheat, readily available N fertilizers such as urea may not be able to sustain N supply throughout the crop growth unless applied in split doses. A field experiment in completely randomized block design, replicated four times, was conducted (2008-2011) to evaluate urea, ESN (polymer coated urea), ammonium sulphate (AS) and their blends (1/3^rd, ½ and 2/3^rd N from urea and the rest from ESN and AS alone/and 50 % from each of the two fertilizers) along with a check (No N) for winter wheat (CDC Falcon) production for a total of 13 treatments. Nitrogen at 120 kg ha^-1 was applied in all fertilizer treatments. Entire ESN in the ESN treatments was applied at seeding, whereas in urea and AS treatments, 30 kg N ha^-1 was applied at seeding and the rest in early springs.  Averaged over three years, grain yield increased with N in the order of ESN (1,088 kg ha^-1) > AS (732 kg ha^-1) > urea in single (501 kg ha^-1) or double (30:90) splits (450 kg ha^-1). Fertilizer blends that produced almost equal grain yield response (860 to 1,150 kg ha^-1) to ESN alone were urea + AS (90:30) and all blends of urea, ESN and AS (30, 60 or 90 kg N ha^-1 from urea and the rest contributed equally by ESN and AS). Grain N removal was highest with ESN (116 kg N ha^-1) and urea + ESN + AS in 30:45:45 N proportions (114 kg N ha^-1). Grain protein content with urea in single or double (30:90) splits (> 14 %) was higher than that with ESN (13 %) or AS (13.2 %) or blends of urea with AS/or both AS and ESN (12.6-13.6 %). ESN and AS, but not urea, increased the straw yield by 645 and ~1,000 kg ha^-1, respectively. Straw yield from blends of urea with AS/or both AS and ESN was 540 to 920 kg ha^-1 higher than that with ESN alone. Based on these results, especially the gain in grain yield, winter wheat producers could be advised to apply the N requirement for winter wheat as ESN at seeding.