Peng Ling, Dong Lin Shui, Chen Yin Ping, Song Ai Yun, Zhao Xi Mei, Cui Qian, Feng Lu, Liu Jing Tao
Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta, Binzhou University, Binzhou 256603, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2019 Apr;30(4):1380-1388. doi: 10.13287/j.1001-9332.201904.029.
We explored the effects of multiple times of topdressing nitrogen application under equal level on the characteristics of absorption, utilization, accumulation, and distribution of N and C in four-year-old potted winter jujube during fruit developmental periods using the stable isotope tra-cer technology. The results showed that with the increases of nitrogen application times, the N derived from fertilizer (Ndff) in each organ significantly increased at the fruit maturity. The distribution rates of N in reproductive organ (fruit) and vegetative organs (leaf, deciduous spur, new branch, and fine root) were highest under four-time application, and lowest under one-time application. The opposite pattern was observed in storage organs (trunk, perennial branch, and coarse root). The N utilization rate under four-time application was 27.4% and 15.5% higher than one-time and two-time application, respectively. The more times N being applied, the more total N content and N absorption amount of plant. Soil N abundance and total N content continued to drop under one-time application and increased at the beginning and then declined with the time under two-time application. The relatively stable soil N abundance and total N content appeared in four-time application, which was significantly higher than those in the other treatments in later treatment stages. The chlorophyll content, leaf nitrogen content and photosynthetic rate displayed an order of four-time application > two-time application > one-time application during fruit white-mature period to fruit harvest period. The accumulation and distribution of C varied across different treatments. Increasing nitrogen application times would promote more C being transported to fruit and storage organs but decrease that in annual vegetative organs. Our findings indicated that four-time nitrogen application could enhance and optimize the accumulation and distribution of photosynthetic products by ensuring steady and adequate supply of nitrogen and improving the absorption and utilization of nitrogen during fruit development period, which facilitates the growth, yield and quality of winter jujube.
利用稳定同位素示踪技术，我们研究了等量分次追施氮肥对四年生盆栽冬枣树果实发育期间氮、碳吸收、利用、积累及分配特性的影响。结果表明，随着施氮次数增加，各器官中肥料来源氮（Ndff）在果实成熟时显著增加。生殖器官（果实）和营养器官（叶片、脱落性短枝、新梢和细根）中氮的分配率在四次施氮处理下最高，一次施氮处理下最低。贮藏器官（树干、多年生枝和粗根）则呈现相反的规律。四次施氮处理下的氮利用率分别比一次和二次施氮处理高27.4%和15.5%。施氮次数越多，植株总氮含量和氮吸收量越高。一次施氮处理下土壤氮丰度和全氮含量持续下降，二次施氮处理下先升高后随时间下降。四次施氮处理下土壤氮丰度和全氮含量相对稳定，在后期显著高于其他处理。在果实白熟期至采收期，叶绿素含量、叶片含氮量和光合速率表现为四次施氮处理>二次施氮处理>一次施氮处理。不同处理间碳的积累和分配存在差异。增加施氮次数会促进更多碳向果实和贮藏器官运输，但减少向一年生营养器官的运输。我们的研究结果表明，四次施氮通过确保果实发育期间氮素稳定充足供应、提高氮素吸收利用率，可增强和优化光合产物的积累与分配，有利于冬枣树的生长、产量和品质。
