Intensive vegetable cropping systems rely heavily on nitrogen (N) inputs from multiple synthetic and organic fertilizer applications. The majority of applied N is lost to the environment through numerous pathways, including as nitrous oxide (N₂O). A field trial was conducted to examine the opportunities to reduce N input in an intensive vegetable system without compromising yield. Treatments applied were control (no N), manure (M, 408 kg N ha^–1 from chicken manure), grower practice (GP, 408 kg N ha^–1 from chicken manure + 195 kg N ha^–1 from fertilizer), and 2/3 GP (two-thirds of the total N input in GP), all with and without 3,4-dimethylpyrazole phosphate (DMPP). Nitrogen recovery in the GP treatment was determined using ¹⁵N-labeled fertilizer. Using only manure significantly lowered celery (Apium graveolens L.) yield and apparent N use efficiency (ANUE) compared with GP. Reducing N input by one-third did not affect yield or ANUE. Use of DMPP increased ANUE despite no yield improvement. More than 50% of the applied N in the GP treatment was lost to the environment, with almost 10 kg N ha^–1 emitted as N₂O over the season, which was 67 times more than from the control. Reducing the N input by one-third or using manure only reduced N₂O emissions by more than 70% relative to GP. This study shows that there is a clear opportunity to reduce N input and N₂O emissions in high-fertilizer-input vegetable systems without compromising vegetable yield.

中文翻译：

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在不影响产量的情况下提高集约化蔬菜系统中氮利用效率的机会

集约化蔬菜种植系统严重依赖来自多种合成和有机肥料应用的氮 (N) 输入。应用的大部分氮通过多种途径流失到环境中，包括作为一氧化二氮 (N ₂ O)。进行了田间试验以检查在不影响产量的情况下在集约化蔬菜系统中减少氮输入的机会。施用的处理包括对照（无氮）、粪肥（M，408 kg N ha ^–1来自鸡粪）、种植者实践（GP，408 kg N ha ^–1来自鸡粪 + 195 kg N ha ^–1来自肥料），以及2/3 GP（GP 中总 N 输入的三分之二），均含有和不含 3,4-二甲基吡唑磷酸盐 (DMPP)。GP 处理中的氮回收率使用¹⁵ N 标记肥料。与 GP 相比，仅使用粪便显着降低了芹菜 ( Apium Graveolens L.) 的产量和表观氮利用效率 (ANUE)。将 N 输入减少三分之一不会影响产量或 ANUE。尽管没有提高产量，但使用 DMPP 增加了 ANUE。在GP处理中，超过50％施用的N散失到环境中，整个季节中将近10 kg N ha ^–1以N ₂ O的形式排放，这是对照排放量的67倍。与 GP 相比，将 N 输入量减少三分之一或使用粪肥仅将 N ₂ O 排放量减少了 70% 以上。这项研究表明，有明显的机会减少 N 输入和 N ₂在不影响蔬菜产量的情况下，高肥料投入蔬菜系统中的 O 排放。