水氮耦合对藜麦产量、氮素吸收和水氮利用的影响

The Effects of Water-nitrogen Coupling on Yield,Nitrogen and Water Use Efficiency of Quinoa

【目的】探讨不同水氮条件对藜麦产量、氮素吸收和水氮利用规律的影响,为藜麦水氮调控提供理论依据。【方法】采用田间小区试验,设3个灌溉定额(0、30、50 mm)和5个施氮水平(0、37.5、75、112.5、150 kg/hm^2),研究了不同水氮处理对藜麦干物质累积量、氮素吸收累积量、产量、收获指数、土壤氮素表观盈亏量、氮肥农学效率、氮肥利用率和水分利用率等的影响。【结果】与不施氮肥相比,在37.5~150 kg/hm^2范围内提高氮肥施用量可以显著增加藜麦干物质累积量、氮素吸收累积量和产量,增幅分别为59.4%~229%、42.9%~277%、288%~1214%;随着灌溉量的提高,藜麦生育期干物质积累量也相应提高,增幅为9.2%~39.7%,氮素累积量增幅为25.5%~56.7%,产量增幅为20.2%~24.9%;水氮互作对藜麦干物质累积量和藜麦籽粒氮素积累量有显著影响;藜麦收获指数在施氮量37.5 kg/hm^2、灌溉定额为50 mm时达到最高(35.7%);施氮量在75~112.5 kg/hm^2之间较为合理,不会造成较大的氮素盈余;氮肥农学效率在施氮量75 kg/hm^2,灌溉定额为30 mm时达到最高(26.8 kg/kg);氮肥利用率和水分利用率在施氮量150 kg/hm^2,灌溉定额为50 mm时分别达到最高(81.6%和0.73 kg/m3)。【结论】藜麦最佳水氮管理方案:施氮量为112.5 kg/hm^2,灌溉定额为50 mm。

【Background】Quinoa was introduced to China in the 1980s and it has attracted increased attention since then because it is rich in nutrition.In 2013,there was about 667 hm^2 of quinoa in Jingle county of Shanxi province and in 2019,the planning area had increased to 13333 hm^2.Despite the quick expansion,there is limited study on how quinoa responds to water and nitrogen application in China.【Objective】The objective of this study is to investigate the combined effect of different irrigations and nitrogen fertilizations on yield,water and nitrogen use efficiency of quinoa in attempts to provide guidance on managing water and nitrogen application in quinoa production.【Method】The experiment was conducted in a field;it consisted of three irrigation levels(0,30,50 mm)and five nitrogen applications(0,37.5,75,112.5,150 kg/hm^2).In each treatment,we measured the dry matter accumulation,nitrogen uptake,yield,harvest index,apparent nitrogen budget,nitrogen agronomic efficiency,nitrogen utilization rate,water consumption and water use efficiency of the crop.【Result】As nitrogen fertilization increased from 37.5 to150 kg/hm^2,the dry matter accumulation,overall nitrogen uptake and yield increased by 59.4%~229%,42.9%~277%and 288%~1214%respectively,compared to the CK.With the irrigation amount increasing,the dry matter accumulation increased from 9.2%to 39.7%,nitrogen uptake increased from 25.5%to 56.7%,and the yield increased from 20.2%to 24.9%.The interaction between irrigation and nitrogen affected both dry matter accumulation and nitrogen accumulation in the grains at significant level.When nitrogen application was 37.5 kg/hm^2 and irrigation was 50 mm,the harvest index was maximum(35.7%).Applying nitrogen in the region of 75 to 112.5 kg/hm^2 was rational and would not cause substantial nitrogen surplus.When nitrogen application was 75 kg/hm^2 and irrigation was 30 mm,the nitrogen agronomic efficiency was maximum(26.8 kg/kg),while when nitrogen application was 150 kg/hm^2 and irrigation was 50 mm,the nitrogen and water use efficiency was highest,being 81.6%and 0.73 kg/m3 respectively.【Conclusion】The optimal nitrogen application and irrigation was 112.5 kg/hm^2 and 50 mm respectively for quinoa production in the studied area.