脲酶/硝化抑制剂对壤质潮土氮素淋溶影响的模拟研究

 【目的】揭示尿素中添加脲酶/硝化抑制剂后，土壤中硝态氮、铵态氮的迁移转化以及淋溶损失规律。【方法】温室土柱淋溶培养试验，研究尿素中单独添加脲酶抑制剂N-丁基硫代磷酰三胺（NBPT）和硝化抑制剂双氰胺（DCD），以及两者配合施用对氮素在土体中淋溶损失的影响。【结果】在施尿素氮600 kg•hm-2条件下，尿素中添加NBPT、DCD以及DCD与NBPT配合施用，均可在24 d之前显著降低淋溶液硝态氮浓度，并在30 d后达到峰值，DCD、DCD与NBPT配合施用的峰值延缓了7 d。整个试验周期中，DCD处理对氮素淋溶表现为较好的抑制效果，NBPT以及DCD与NBPT配合施用，在培养试验后期抑制效果较好。最终NBPT、DCD、DCD与NBPT配施3种处理可显著降低硝态氮累积淋失量分别达11.6%、13.7%和17.2%。【结论】在一定施肥量条件下，脲酶抑制剂和硝化抑制剂两者单施或配施均可降低硝态氮累积淋失量。

Effects of Urease/Nitrification Inhibitor on Soil Nitrogen Leaching Loss in Loamy Fluvo-Aquic Soil

【Objective】 The objective of this study was to determine the effects of urease/nitrification inhibitors on the transformation and leaching of nitrogen from urea.【Method】A soil column leaching experiment was conducted in a greenhouse to observe nitrogen transformation and leaching loss following the application of urea with a urease inhibitor N-(n-Butyl) thiophosphoric triamide (NBPT), a nitrification inhibitor dicyandiamide (DCD), or both.【Result】When urea-N was applied at 600 kg•hm-2, NBPT and DCD combined or separately application significantly reduced the NO3--N concentration in the leacheate before 24 days, and reached the peak after 30 days. DCD, or DCD and NBPT combined application retarded the peak by 7 days. DCD had a greater effect on reducing nitrogen leaching through the whole monitoring period, the combination of NBPT or DCD and NBPT had a good effect especially in the latter period. For the whole leaching study period, the combination of NBPT, DCD, DCD and NBPT significantly reduced the nitrate accumulation by 11.6%, 13.7% and 17.2%, respectively. 【Conclusion】When fertilizer was applied to a certain extent, nitrate leaching loss can be reduced by applying urea fertilizer with a urease and/or nitrification inhibitor.