Impacts of ammonia volatilization from broadcast urea on winter wheat production

Abstract

Ammonia (NH 3) volatilization from broadcast urea may lead to significant N losses in winter wheat. We aimed to: (a) quantify N losses through NH 3 volatilization from fields fertilized with urea and urea amended with a urease inhibitor (NBPT) under cold weather months (February-April), and (b) investigate the impact of N losses through NH 3 volatilization on the winter wheat production. We employed the integrated horizontal flux (IHF) method with passive NH 3 samplers to quantify NH 3 volatilization at five sites in Kansas. Urea and urea + NBPT were broadcast at a rate of 60 kg N ha-1 over circular plots. We assessed the impact of NH 3 losses on wheat at three sites employing different rates of urea and urea + NBPT. NH 3 losses volatilization varied from 0.3 to 29.6% of total N applied. The largest N losses (>23% of applied N) occurred when urea was broadcasted to moist soils followed by a dry period. Amending urea with NBPT reduced NH 3 volatilization losses by more than 20% on the campaigns with the largest N losses (>23%). However, our results showed no significant differences for wheat yield, N-recovery and agronomic efficiency between urea and urea + NBPT treatments likely due to the reduced NH 3 volatilization (<17%) where the impact on winter wheat was measured. Our results suggest that winter wheat farmers should carefully evaluate the soil surface moisture conditions before broadcasting urea to avoid potential NH 3 volatilization losses even under cold conditions (average soil temperature ranging from 2.5 to 7.7 • C).

Genotype‐specific nitrogen uptake dynamics and fertilizer management explain contrasting wheat protein concentration

“…Urea‐ammonium nitrate (28% N) liquid fertilizer was the N source used in all applications at GS20 and GS25 to minimize N losses associated with application of urea (Perin, Santos, Lollato, Ruiz‐Diaz, & Kluitenberg, 2020). The urea‐ammonium nitrate was applied using a backpack sprayer with a CO 2 tank and a 1.5‐m hand boom equipped with TEEJET streamer nozzles (StreamerJet SJ3‐02‐VP).…”

Wheat nitrogen utilization efficiency and yield as affected by nitrogen management and environmental conditions

“…In the present study, there were unfavorable conditions for NH 3 volatilization after the top-dressing fertilization carried out at GS21 in L rainfed and L irrig , because there were 78.3 mm of rainfall in the four days following this fertilization, which incorporated urea into the soil. On the other hand, in PG rainfed the topsoil and the plant residues on the soil surface remained dry in the 11 days following the top-dressing fertilization, and the soil pH (4.7) was very acidic, conditions that inhibit the activity of the enzyme urease (Perin et al, 2020). Therefore, these environmental conditions were unfavorable to NH 3 volatilization, bringing agronomic efficiency closer between the two N fertilizer sources.…”

Effect of using hydrogel polymers on morphometric, forage production, and nutritional characteristics of cactus pear

“…However, conventional fertilization provided lower crude protein values than the other strategies (Table 2); even with the use of the recommended doses of nutrients for the maximum performance of the plant, in soils with sandy texture due to their respective granulometry, there is little retention of K, therefore, high losses by leaching occur, associated with this, in the semi-arid region at high temperatures cause losses by volatilization; occurring when using urea as a N-source (Duarte et al, 2013;Perin et al, 2020).…”