中国生态农业学报2016，Vol.24Issue(12)：1623-1632,10.DOI:10.13930/j.cnki.cjea.160449
灌溉和施氮对河西走廊紫花苜蓿生物量分配与水分利用效率的影响
Effects of water and nitrogen fertilizer on biomass distribution and water use efficiency of alfalfa (Medicago sativa) in Hexi Corridor
摘要
Abstract
Alfalfa (Medicago sativa) has high nutritional quality and biomass production and is widely used as pasture in animal production and soil erosion control. There are many factors influencing the production of alfalfa, including fertilizer and water use. The applications of both nitrogen and irrigation have been the critical factors for improving water use efficiency without considerable yield reduction in alfalfa. Thus the determination of a reasonable application of nitrogen and irrigation is important for the optimization of biomass distribution characteristics and improvement of water use efficiency in alfalfa fields in Hexi Corridor. To that end, a field study was conducted in 2014 in Jiuquan City (in the Hexi Corridor of Gansu Province, China) to research the effects of different irrigation amounts (W1: 60% of the conventional irrigation amount; W2: 80% of the conventional irrigation amount; W3: the conventional irrigation amount, 1 920 m3·hm-2) and nitrogen application rates [N1: 0 kg(N)·hm-2; N2: 40 kg(N)·hm-2; N3: 80 kg(N)·hm-2; N4: 120 kg(N)·hm-2] on biomass distribution characteristics and water use efficiency of 2-year alfalfa plantations. The study investigated the effects of nitrogen application, irrigation and the related interaction on alfalfa plant height, branch number per plant, leaf-stem ratio, root volume, root biomass, aboveground- belowground biomass ratio and water use efficiency. The results suggested that W2and W3treatments significantly increased plant height, branch number per plant and aboveground biomass. It also increased root biomass, root volume in 20-40 cm, 40-60 cm and 0-60 cm soil layer and water use efficiency. Moreover, plant height, branch number per plant and aboveground biomass were not obviously different between W2 and W3 treatments. This suggested that 80% of the conventional irrigation scheme not only maintained normal biomass production in alfalfa plants, but also improved water use efficiency. Branch number per plant, leaf-stem ratio, root volume, root biomass, aboveground-belowground biomass ratio and water use efficiency initially increased and then decreased with increasing nitrogen application. These parameters peaked under the treatment of 80 kg(N)·hm-2nitrogen, which suggested that nitrogen application significantly influenced root development and water use efficiency of alfalfa plants. Besides this, W2N2 or W2N3 treatments had the potential to optimize plant height, branch number per plant, root volume and belowground biomass in the 0-20 cm, 20-40 cm and 0-60 cm soil layers. The ratio of aboveground to belowground biomass and water use efficiency was also optimized under W2N2 or W2N3 treatments. It was concluded that 80% of the conventional irrigation amount and 80 kg(N)·hm-2of nitrogen application were the optimal treatment for alfalfa pasture in Hexi Corridor.关键词
水氮互作/河西走廊/紫花苜蓿/产量构成/水分利用效率Key words
Water-nitrogen interaction/Hexi Corridor/Alfalfa/Yield components/Water use efficiency分类
农业科技引用本文复制引用
冯萌,于成,林丽果,吴冬强,宋锐,刘慧霞..灌溉和施氮对河西走廊紫花苜蓿生物量分配与水分利用效率的影响[J].中国生态农业学报,2016,24(12):1623-1632,10.基金项目
甘肃省科技重大专项项目(2013GS05907)和兰州大学中央高校基本科研业务费(lzujbky-2014-m01)资助 （2013GS05907）
