The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) has been reported to effectively reduce nitrogen (N) losses by inhibiting urea hydrolysis. However, the effect of NBPT on soil ureolytic and ammonia-oxidizing microbes is not well understood, with inconsistent effects on crop yield and nitrogen use efficiency (NUE). Further, repeated use or overuse of chemical fertilizers can have environmental implications like soil acidification. A field experiment was conducted at Leigh Creek, Victoria at a site with a history of repeated application of urea alone (40U) or with NBPT (as Green Urea NV® (40GU)) at 40 kg N ha⁻¹, and urea applied at 80 kg N ha⁻¹ (80U), to perennial ryegrass (Lolium perenne L.). We aimed to investigate the temporal effects of NBPT applied with urea on ureolytic and ammonia-oxidizing microbes, pasture dry matter (DM) yield, and NUE within a season following treatment applications. The abundance of ureolytic microbes was higher in the control (CK) compared to all N treatments on all sampling days. The ureC gene copy numbers in 40 GU were significantly lower than in 40U on sampling days seven and 45. There was no significant effect of NBPT on the abundance of ammonia oxidizers, but increasing urea application rate to 80 kg N ha⁻¹ (80U) significantly increased the abundance of ammonia-oxidizing bacteria (AOB) on days 7 and 45, and complete ammonia oxidizers (comammox Nitrospira) clade B on day 7 compared to 40U. There was no significant effect of NBPT on pasture DM yield, N-uptake, or NUE. Increasing N application rate significantly increased pasture DM yield and N- uptake but this did not influence the pasture NUE.

据报道，脲酶抑制剂N-（正丁基）硫代磷酸三酰胺（NBPT）可通过抑制尿素水解而有效减少氮（N）的损失。然而，对于土壤尿素分解和氨氧化微生物对NBPT的影响知之甚少，对作物产量和氮利用效率（NUE）的影响不一致。此外，重复使用或过度使用化肥可能会对环境产生影响，例如土壤酸化。在维多利亚州的利克里克（Leigh Creek）的现场进行了一次现场试验，该现场有重复使用尿素（40U）或使用NBPT（如Green UreaNV®（40GU））在40 kg N ha ^-1重复施用的经验， 80千克N ha ^-1（80U），至多年生黑麦草（黑麦草）L.）。我们的目的是研究尿素施用NBPT对尿素分解和氨氧化微生物，牧草干物质（DM）产量和NUE在处理后一个季节内的NUE的时间影响。与所有采样日的所有N处理相比，对照（CK）中的尿素溶解微生物含量更高。在第7天和第45天采样时，40 GU中的ureC基因拷贝数显着低于40U。NBPT对氨氧化剂的丰度没有明显影响，但尿素施用量增加到80 kg N ha ^-1（80U）在第7天和第45天显着增加了氨氧化细菌（AOB）的丰度，并使用了完全的氨氧化剂（Comammox Nitrospira）第7天的进化枝B与40U相比。NBPT对牧草的DM产量，N吸收或NUE没有显着影响。氮肥施用量的增加显着提高了牧草的DM产量和氮吸收量，但这并不影响牧草的NUE。