Enhanced Efficiency Nitrogen Products Influence Ammonia Volatilization and Nitrous Oxide Emission from Two Contrasting Soils

Core Ideas Ammonia volatilization and N 2 O emissions from N‐sources were assessed in two soils. The N‐(n‐butyl) thiophosphoric triamide reduced NH 3 volatilization losses from both sandy loam and silty clay soils. Nitrapyrin and SuperU reduced N 2 O emissions from sandy loam soil only. Polymer coated urea was effective in reducing both NH 3 and N 2 O emissions from sandy loam soil. Right N‐source could mitigate gaseous N losses from agroecosystems. Potentials of enhanced efficiency nitrogen (EEN) products to control N losses can vary with soil pH, cation exchange capacity, organic matter, water, temperature, and management. A laboratory experiment was conducted to quantify and compare ammonia (NH 3 ) volatilization and nitrous oxide (N 2 O) losses with (i) control, (ii) urea, urea treated with (iii) urease inhibitor, NBPT [N‐(n‐butyl) thiophosphoric triamide], (iv) nitrification inhibitor, nitrapyrin (NP) [2‐chloro‐6‐trichloro methyl pyridine], (v) urea stabilized with NBPT and nitrification inhibitor dicyandiamide (SuperU), and (vi) slow release N fertilizer polymer coated urea (PCU) amendments from Ulen sandy loam and Fargo silty clay soils. Across N amendments, cumulative NH 3 –N losses from sandy loam soil ranged from 0.7 to 4.3% of applied N, and were higher than those from silty clay soil (0.1–0.4% of applied N). In sandy loam, compared to urea, NBPT and PCU reduced NH 3 –N volatilization by 32.3 and 84.2%, respectively, whereas NP and SuperU increased NH 3 –N losses by 98.7 and 20.3%, respectively. However, in silty clay soil, only NBPT exhibited significant reduction in NH 3 –N losses of 71.4%, relative to urea. Cumulative N 2 O emissions did not differ between soil textures and ranged from 3.7 to 7.4% of applied N across N sources. However, soil N 2 O emissions differed among N sources in sandy loam soil. In sandy loam soil, NP, SuperU, and PCU treatments significantly reduced N 2 O‐N emissions by 23.5, 43.8, and 51.1%, respectively, compared to urea. Applicability of using EEN products to mitigate NH 3 and N 2 O emission losses varies with soil texture.