作 者 ：丁宁,彭玲,安欣,陈倩,姜翰,姜远茂

期 刊 ：植物营养与肥料学报 2016年 22卷 2期 页码：572-578

关键词：苹果；不同时期；15N-尿素；吸收；分配；利用；

Keywords:apple, differentstages, 15N-urea, absorption, distribution, utilization,

摘 要 ：【目的】研究不同时期施氮对矮化苹果氮素吸收、 分配及利用的影响,以期为矮化果园合理施肥、 提高氮肥利用率提供科学依据。【方法】以5年生烟富3/M26/平邑甜茶苹果为试材,采用¹⁵N同位素示踪技术,研究3个时期施氮对¹⁵N-尿素的吸收、 分配及利用特性。试验设3个处理,每个处理为1株,重复3次,分别在萌芽期(3月20日)、 春梢缓长期(6月5日)和秋梢生长期(7月10日)3个时期进行施肥, 每次每株施¹⁵N-尿素(丰度10.14%)10 g,普通尿素150 g。果实成熟期(10月15日)取全株样品进行氮的分析测定。【结果】不同时期施肥,植株不同器官从肥料中吸收分配到的¹⁵N量对该器官全氮量的贡献率(Ndff)差异显著。萌芽期施肥,植株在盛花期根的Ndff值最高,多年生枝次之; 从春梢缓长期到果实膨大期,根部吸收的¹⁵N优先向新生营养器官转运,果实成熟前期各器官Ndff均达到较高水平; 到果实成熟期,果实的Ndff值最高。春梢缓长期施肥,秋梢生长期根的Ndff值最高; 果实成熟期新生器官的Ndff均达到较高水平,其中果实的Ndff值最高。秋梢生长期施肥,根和多年生枝等贮藏器官的Ndff值在各测定时期都处于较高水平,随着物候期推移,一年生枝、 叶片和果实等地上部新生器官的Ndff值逐渐增大,到果实成熟期,一年生枝、 叶片和果实等新生器官的Ndff均达到最高水平,但此期果实对¹⁵N吸收征调能力相对减弱。在果实成熟期,不同施肥处理植株各器官的¹⁵N分配率存在显著差异。萌芽期施肥,营养器官的¹⁵N分配率最大; 春梢缓长期施肥,生殖器官的¹⁵N分配率最大; 秋梢生长期施肥,贮藏器官的¹⁵N分配率最大。在果实成熟期,3个施肥时期处理间植株的总氮量、 吸收¹⁵N的量及¹⁵N肥料利用率存在显著差异,均以春梢缓长期施肥处理最大,分别为86.34 g、 1.38 g和30.07%; 秋梢生长期次之,分别为75.64 g、 1.25 g和27.22%; 萌芽期施肥处理最小,分别为72.82 g、 1.09 g和23.63%。【结论】在土壤比较贫瘠的果园中进行矮化栽培,生产上应制定合理的施肥次数,做到少量多次,在春季少施氮肥,初夏(果实膨大期)追施氮肥,同时加强当年贮藏营养,施肥时期适当后移,既能够满足树体不同生长发育阶段的需求,而且还能够尽量减少因灌溉和降水等造成的地表径流和地下淋溶损失等,提高氮肥利用效率。

Abstract:【Objectives】The effects of nitrogen application in different growth stages on nitrogen absorption, distribution and utilization by dwarfed apple trees were studied to provide scientific basis for appropriate fertilization and improve nitrogen efficiency of dwarfed apple orchards.【Methods】Seedlings of five-year-old ‘Fuji’ 3/M26/M hupehensis Rehd. were used as materials, and ¹⁵N-urea(abundance 10.14%)was used as N resource, a field experiment was conducted with three urea application dates: the bud stage(March 20th), spring shoot growing slowly stage(June 5th)and autumn shoot growing stage(July 10th). 10 g of ¹⁵N-urea and 150 g of urea were applied in each sapling. The whole saplings were destructively sampled at the fruit maturity stage(October 15th). Total nitrogen was determined by kjeldahl method and the ¹⁵N abundance was determined by ZHT-03 mass spectrometer.【Results】The contribution of N derived from fertilizer(Ndff)to the total N contents in different organs is significantly affected by the application date. The highest Ndff is in roots at the full-bloom stage when the urea is applied at the bud stage, followed by the perennial branches. From the spring shoot slowly growing stage to fruit rapidly swelling stage, the Ndff values of new organs are higher than those of the storage organs. At the fruit premature stage, the Ndff values of different organs are in high level, and at fruit maturity stage the Ndff value of fruits is the highest. When the fertilization is applied at the spring shoot slowly growing stage, the Ndff in roots of the autumn shoot growing stage is the highest, the Ndff values of new organs are at a high level at the fruit maturity stage, and the Ndff of fruits is the highest. The Ndff values of the storage organs(roots and perennial branches)are at a high level in each period under the autumn shoot growing stage fertilization treatment. Therefore, along with the changing of the phenological period,the Ndff values of new organs(annual branches, leaves and fruits)aboveground increase gradually, and reach the peak at the fruit maturity stage, but the ¹⁵N absorption ability of fruits is weakened in comparison. The ¹⁵N distribution ratios of each organ at the fruit maturity stage are significantly different among different treatments. The ¹⁵N distribution ratio in the vegetative organs is the highest when urea is applied at the bud stage, and that is in reproductive organs when the urea is applied at the spring shoot growing slowly stage, and that is in the storage organs when applied at the autumn shoot growing stage. There are significant differences in the total N uptake of plant, the Ndff and their utilization rates with the three application stages at fruit maturity stage. The highest values(86.34 g, 1.38 g and 30.07%)were measured in the saplings applied fertilizer at the spring shoot growing slowly stage, then were at the autumn shoot growing stage(75.64 g, 1.25 g and 27.22%)and the lowest(72.82 g, 1.09 g and 23.63%)were at bud stage fertilization.【Conclusions】Fertilization should be carrid out at the spring shoot growing slowly stage under the tested soil condition. In practice, less nitrogen should be applied in spring, and more top-dressed in early summer when the fruit is rapid swelling, appropriately postponing fertilization will increase the nutrient storage of the current year.