Effect of different nitrogen rates and use of DMPP nitrification inhibitor on N2O emissions from wheat in sub-tropical Ferrosols. Kingaroy, Queensland, 2011 [Theme 1: Inhibitors for reducing emissions]

The objective of this experiment was to investigate the role of different N fertilization rates and the use of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP, commercially sold as Entec) in reducing N2O emissions from subtropical wheat systems over winter. At the same time, particular attention was given to the yield response shown by the different treatments, in order to evaluate the respective economical sustainability and N2O intensity.
The field experiment was set up in Kingaroy ( S-E QLD), on a euchrozems Ferrosol soil, using a randomized complete three-block design (three replicates per treatment). The four treatments encompassed three different fertilization rates and two types of Urea (conventional and DMPP urea): control treatment (L1: 0 kg-N ha-1), sub-optimal N rate (L2: 20 kg-N ha-1 –conv. urea) and optimal N rate (L3: 80 kg-N ha-1 –conv. Urea, L4: 80 kg-N ha-1 –DMPP urea).
The N2O emissions were measured from planting (July 8th) to harvest (November 27th 2011) with a fully automated greenhouse gas measuring system.
In order to gain optimum understanding of the dynamics influencing greenhouse gas production and release in agricultural soils, the air temperature and the soil moisture inside the measuring chambers were constantly monitored. To compare the "environmental" performances of the four treatments with agronomical sustainability grain yields were also determined.

本试验旨在探究不同氮肥施用量，以及硝化抑制剂3,4-二甲基吡唑磷酸盐（3,4-dimethylpyrazole phosphate，商品名为Entec）在降低亚热带冬小麦田氧化亚氮（N₂O）排放方面的作用。同时，重点关注不同处理下的产量响应，以评估各处理的经济可持续性与氧化亚氮排放强度。
本田间试验设于澳大利亚昆士兰州东南部金格罗伊（Kingaroy, S-E QLD）的典型铁铝土（euchrozems Ferrosol）土壤中，采用随机完全区组三重复设计（每个处理设置3次重复）。共设置4种处理，涵盖3种不同施氮水平与2种尿素类型（常规尿素与DMPP尿素）：空白对照（L1：0 kg-N ha⁻¹）、次优施氮量处理（L2：20 kg-N ha⁻¹，常规尿素）、最优施氮量处理（L3：80 kg-N ha⁻¹，常规尿素）与L4：80 kg-N ha⁻¹，DMPP尿素。
2011年7月8日播种至11月27日收获期间，采用全自动温室气体监测系统测定N₂O排放通量。
为深入理解农田土壤温室气体产生与释放的动态调控机制，本试验持续监测了测定箱内的空气温度与土壤含水率。同时，为对比4种处理的"环境表现"并评估其农艺可持续性，还测定了籽粒产量。