Nitrogen Use Efficiency Field Experimental Data. Hamilton, Victoria, 2012-2013 [Theme 5: Reducing emissions through improved NUE]

This experiment investigates the role that nitrogen use efficiency might play in delivering greater farm profitability and a simultaneous reduction of unnecessary nitrous oxide from high rainfall cropping systems. To achieve this objective a completely randomised block design with ten treatments replicated five times was established on raised beds at Hamilton in south west Victoria. The treatments included a 0N experimental control (0N), four additional rates of N fertiliser (TD10N@Z31, TD35N@Z31, TD85N@Z31 and TD185N@Z31) top-dressed at the first node (Z31) growth stage of wheat growth; a further three treatments involving different timings of N application, all of the N deep banded at sowing (DB100N@Z00), half the N deep banded at sowing and the other half top-dressed at the first node stage (DB50N@Z00_TD50N@Z31), and all of the N top-dressed at first node (TD100N@Z31); a further treatment involving DMPP (3,4-Dimethylpyrazole phosphate, Entec®) coated urea (DMPP85N@Z31) also top-dressed at first node; and finally one deep banded urea (DB85N@Z00) treatment imposed at sowing. Crop biomass, grain yield, grain quality, soil mineral N, soil temperature and soil water and N2O flux have been measured. Static chamber methodology was used to identify relative differences in N2O loss between N fertiliser management.本试验旨在探究氮肥利用效率（nitrogen use efficiency）在提升高降雨区种植系统农场收益的同时，减少不必要的一氧化二氮（N₂O）排放方面所发挥的作用。为达成该研究目标，试验于维多利亚州西南部汉密尔顿（Hamilton）的高垄栽培平台设置完全随机区组设计，共包含10种处理，每种处理重复5次。试验处理包括1个0N空白对照组（0N），4个不同施氮量的氮肥处理：均于小麦生长至第一分蘖节（Z31）生育期追施，分别为TD10N@Z31、TD35N@Z31、TD85N@Z31及TD185N@Z31；另有3种不同施氮时期的处理：分别为播种时一次性条施深施全部氮肥的DB100N@Z00、播种时条施深施50%氮肥且于第一分蘖节生育期追施剩余50%氮肥的DB50N@Z00_TD50N@Z31，以及于第一分蘖节生育期追施全部氮肥的TD100N@Z31；还有1个处理为于第一分蘖节生育期追施添加了3,4-二甲基吡唑磷酸盐（DMPP，3,4-Dimethylpyrazole phosphate，商品名Entec®）的包膜尿素的DMPP85N@Z31；最后1个处理为播种时条施深施尿素的DB85N@Z00。本试验测定了作物生物量、籽粒产量、籽粒品质、土壤矿质氮、土壤温度、土壤含水量以及一氧化二氮通量等指标，并采用静态箱法来识别不同氮肥管理模式下一氧化二氮排放的相对差异。