The addition of nitrification inhibitor (NI) with a urease inhibitor, N‐(n‐butyl) thiophosphoric triamide (NBPT), has been reported to offset the reduction of ammonia volatilization by NBPT. An incubation study was conducted to investigate the interaction between NBPT and NI (3,4‐dimethyl pyrazole phosphate) on hydrolysis of urea in five soils with a range of physico‐chemical properties. Untreated urea (UR), NBPT treated urea (UR_NBPT), or NBPT+NI treated urea (UR_DI) were surface‐applied (250 kg N ha⁻¹) to each soil. The soils were incubated (21 °C) and destructively sampled nine times during a 22‐day period. Urea hydrolysis rate (k; d⁻¹) was measured by the disappearance of urea with time and modeled with a first‐order kinetic. The value of k was in the order of UR (0.321) > UR_DI (0.183) > UR_NBPT (0.151) across the five soils. While the urease inhibitor, NBPT, significantly reduced k in each soil, the addition of a NI with NBPT significantly decreased the ability of NBPT to inhibit urea hydrolysis by an average of 21% across the soils. We found that NI significantly reduced the half‐life of urea by about 1 d when compared with NBPT alone. Principal component analysis showed that k did not depend on any of the soil properties, rather, it depended on the type of treatment. Net nitrification rate constant was significantly greater in UR than UR_NBPT in loam and clay soils but not different in sandy loam soils. We conclude that the often‐reported increase in ammonia volatilization with the double inhibitor relative to NBPT alone may not only be due to the persistence of ammonium but may also be due to an increased rate of urea hydrolysis in the presence of a NI.

中文翻译：

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硝化抑制剂可降低N-（正丁基）硫代磷酸三酰胺（NBPT）对尿素水解的抑制作用

据报道，硝化抑制剂（NI）与脲酶抑制剂N-（正丁基）硫代磷酸三酰胺（NBPT）的添加可以抵消NBPT减少的氨挥发。进行了一项孵化研究，以研究NBPT和NI（3,4-二甲基吡唑磷酸酯）在五种具有多种理化性质的土壤中对尿素水解的相互作用。将未经处理的尿素（UR），经NBPT处理的尿素（UR _NBPT）或经NBPT + NI处理的尿素（UR _DI）表面施涂（250 kg N ha ^-1）。将土壤孵育（21°C），并在22天中进行9次破坏性采样。尿素水解率（k ; d ^-1）是通过尿素随时间消失而测得的，并以一阶动力学建模。在五个土壤中，k的值的顺序为UR（0.321）> UR _DI（0.183）> UR _NBPT（0.151）。尽管脲酶抑制剂NBPT显着降低了每种土壤中的k，但添加带有NBPT的NI显着降低了NBPT在整个土壤中抑制尿素水解的能力，平均降低了21％。我们发现，与单独使用NBPT相比，NI显着降低了尿素半衰期约1 d。主成分分析表明，k不取决于任何土壤特性，而是取决于处理类型。在壤土和粘土中，UR的净硝化速率常数显着大于UR _NBPT，但在砂壤土中没有变化。我们得出的结论是，相对于单独的NBPT，经常报道使用双重抑制剂的氨气挥发增加，不仅可能是由于铵的持续存在，还可能是由于在NI存在下尿素水解速率增加。