Ammonia loss from a sub-tropical pasture, Gatton, Queensland, 2013

This trial has been completed in late December 2013 at Gatton. The treatments were:
1. Control (Granular urea, 40 kg N/ha, surface applied)
2. Granular urea (40 kg N/ha, surface applied) + urease inhibitor (NBPT, Green ureaNV)
3. Granular urea (40 kg N/ha, surface applied ) + nitrification inhibitor (DMPP, Urea with ENTEC)
The treatment areas (30 m) were located 50 m from all external boundaries and from adjacent treatments. Treatments were hand spread and applied to the 30 m diameter treatment areas in strips to ensure even application. Emissions of ammonia and nitrous oxide were measured, using passive samplers and closed static chambers, respectively. Soil mineral N, grass biomass and 15N recovery were also measured.

本试验于2013年12月末在加顿（Gatton）完成。试验设置如下处理组：
1. 对照组（颗粒尿素，施氮量40 kg N/ha，表面撒施）
2. 颗粒尿素（施氮量40 kg N/ha，表面撒施）+脲酶抑制剂（urease inhibitor，NBPT，Green ureaNV）
3. 颗粒尿素（施氮量40 kg N/ha，表面撒施）+硝化抑制剂（nitrification inhibitor，DMPP，ENTEC尿素）
各处理区为直径30米的区域，设置于距离所有外部边界及相邻处理区50米的位置。试验采用人工撒施，以条带方式将肥料施加于直径30米的处理区内，以确保施用均匀。分别采用被动采样器和密闭静态箱测定氨气与一氧化二氮的排放。同时还测定了土壤矿质氮、牧草生物量及15N回收率。