Nitrous oxide emissions from ryegrass pasture fertilised with a range of enhanced efficiency fertilisers. Murroon, Victoria, 2010 [Theme 1: Inhibitors for reducing emissions]

This package describes a field trial conducted in 2010 (April to December) to investigate the impact of applying different types of fertilisers to ryegrass pasture on emissions of nitrous oxide (N2O). The project was designed to investigate all potential loss pathways from applied fertilisers by measuring gaseous emissions, soil mineral N levels and plant biomass and N uptake. The trial was run adjacent to a trial that measured ammonia (NH3) loss from surface applied urea-based fertilisers, which is described elsewhere. The N2O trial also complemented a more extensive small plot trial that considered rate effects of applying the different fertilisers on pasture biomass production.

The trial was a block design small plot trial with 5 replications per treatment. Treatments were applied generally on a monthly basis, with a single rate of N (40 kg N/ha). Gas samples were collected from manual chambers every few days to weekly and analysed for N2O, CO2 and CH4, soil samples were collected to 10 cm depth every fortnight and analysed for urea, Ammonium and nitrate, and pasture biomass quantity(dry matter) and quality( N content) samples were collected every month prior to fertiliser application.

本数据集涵盖一项2010年4月至12月开展的田间试验，旨在探究向黑麦草牧场施用不同类型肥料对一氧化二氮（nitrous oxide, N₂O）排放的影响。本试验通过测定气体排放、土壤矿质氮含量、植物生物量及氮素吸收量，探明施用肥料后所有潜在的氮素流失途径。本试验与另一项针对地表施用尿素基肥料的氨（ammonia, NH₃）流失量测定的试验相邻开展，该试验的相关内容另有报道。本次一氧化二氮试验还补充完善了一项规模更大的小区试验，该试验探究了不同肥料施用量对牧场生物量生产的影响。

本试验采用区组设计的小区试验方案，每个处理设置5次重复。肥料处理通常每月施用一次，单次施氮量为40 kg N/ha。研究人员每隔数天至一周使用手动采气箱采集气体样品，分析其中一氧化二氮、二氧化碳（carbon dioxide, CO₂）及甲烷（methane, CH₄）的浓度；每两周采集0~10 cm深度的土壤样品，测定其中尿素、铵态氮与硝态氮含量；并于每月施肥前采集牧场生物量样品，测定其干物质重量与氮含量。