Ammonia Volatilization from Urea and Mitigation by NBPT following Surface Application to Cold Soils
Ammonia Volatilization from Urea and Mitigation by NBPT following Surface Application to Cold Soils
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DOI：
10.2136/sssaj2011.0229
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发表时间：
2011-11-01
影响因子：
2.9
通讯作者：
Wallander, R.
中科院分区：
文献类型：
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作者：
Engel, R.;Jones, C.;Wallander, R.
尿素是冬小麦（Triticum aestivum L.）在寒冷的天气月份（十月至四月），在半干旱的北方大平原。本研究旨在量化在此期间，从表面施用的尿素（100 kg N ha（-1））和N-（正丁基）硫代磷酰三胺（NBPT）的尿素的NH3挥发损失。氨的排放量进行了量化的微气象综合水平通量的方法与采样器放置在桅杆上的中心的圆形地块（20米半径）。12个试验中，尿素的累积NH3损失各不相同，但平均为施氮量的20.5%。最大的损失（30-44%的施入氮）发生在高含水量的土壤表面，然后是一个缓慢干燥的时期，很少或没有降水。排放发生的时间较长，通常持续> 42 d。当平均日土壤温度（1 cm深度）为-2至5 ℃时，经常出现高NH3通量（> 30 g Nha（-1）h（-1））的时期（1-2周）。在一个试验中，24.3%的施氮损失后，尿素施加到一个140毫米的积雪。通过在干燥的土壤表面施用尿素来缓和氨的损失。如果随后的降水量较小（< 8 mm），则损失量减少到施氮量的10 - 20%。如果事件严重（> 18 mm），则损失<10%。用NBPT（1 g kg（-1））包衣尿素可使累积NH3损失减少66%。挥发保护作用在酸性土壤上持续2 - 3周，在碱性土壤上持续> 7周。这项研究表明，显着的NH（3）的损失，从表面施加尿素可能会发生在寒冷的天气月份。
Urea is frequently surface applied to winter wheat (Triticum aestivum L.) during cold weather months (October-April) in the semiarid northern Great Plains. This study was conducted to quantify NH(3) volatilization loss from surface-applied urea (100 kg N ha(-1)) and urea amended with N-(n-butyl) thiophosphoric triamide (NBPT) during this period. Ammonia emissions were quantified by a micrometeorological integrated horizontal flux method with samplers placed on a mast in the center of circular plots (20-m radius). Cumulative NH(3) losses from urea varied but averaged 20.5% of applied N across 12 trials. The largest losses (30-44% of applied N) occurred aft er urea was applied to high-water-content soil surfaces, followed by a period of slow drying with little or no precipitation. Emissions occurred for a prolonged period oft en lasting > 42 d. Periods (1-2 wk) of high NH(3) flux (> 30 g N ha(-1) h(-1)) frequently occurred when mean daily soil temperatures (1-cm depth) were -2 to 5 degrees C. In one trial, 24.3% of applied N was lost aft er urea was applied to a 140-mm snowpack. Ammonia losses were moderated by applying urea to dry soil surfaces. If precipitation events that followed were light (< 8 mm), losses were reduced to 10 to 20% of applied N. If the events were heavy (> 18 mm), then losses were < 10%. Coating urea with NBPT (1 g kg(-1)) reduced cumulative NH(3) losses by 66%. Volatilization protection lasted 2 to 3 wk on acidic soils, and > 7 wk on an alkaline soil. This study demonstrated that significant NH(3) losses from surface-applied urea could occur during cold weather months.