不同施氮水平对苦荞不同品种生长发育、干物质转运和产量的影响

Effects of different nitrogen levels on growth, dry mattertransport and yield of different Tartary buckwheats

关键词:  苦荞, 施氮量, 生长发育, 干物质转运, 籽粒灌浆, 产量

Key words:  Tartary buckwheat, nitrogen application rate, growth, dry matter transport, grain filling, yield

摘要:

该研究以西农9940和黔苦3号为材料,设置(N1)90、(N2)180、(N3)270 kg·hm^-2三个氮肥处理水平,分析不同施氮量处理对两个苦荞品种的生长、营养器官干物质积累转运和施氮量对籽粒灌浆特性和产量的影响。结果表明:(1)施氮肥显著促进苦养生长发育。随着施氮量的增加,苦荞株高、叶片SPAD值和干物质积累量呈增长趋势,于N3处理达到最大值,显著高于N1和N2处理。且在同一施氮处理条件下,黔苦3号的株高、SPAD值和干物质积累量均优于西农9940。就转运率而言,苦荞的两个品种表现不一致,施氮显著提高西农9940茎叶干物质转运率,黔苦3号则相反; 叶片贡献率随施氮量增加显著增加,茎贡献率则没有显著变化。(2)随着施氮量的增加,苦荞籽粒灌浆持续期增加,最大灌浆速率到达时间延长,平均灌浆速率却降低,百粒重呈下降趋势; 在同一施氮处理条件下,西农9940较黔苦3号灌浆速率更快,百粒重更大。(3)随着施氮量的增加,产量及其构成因素呈先增加后减少的趋势。西农9940的产量在N2处理达到最高,为1 650 kg·hm^-2,较N1、N3处理增产了45.6%和28.2%; 黔苦3号的产量在N1处理达到最高,为616.7 kg·hm^-2,较N2和N3处理增产了12.8%和51.6%。在黄土高原旱作区苦荞种植因品种不同而选择不同的施氮量,建议西农9940最佳施氮量为180～270 kg·hm^-2,黔苦3号最佳施氮量为90～180 kg·hm^-2。

Abstract:

We used Xinong 9940 and Qianku 3 as materials to set three nitrogen fertilizer treatments levels(N1)90,(N2)180,( N3)270 kg·hm^-2, to discuss the effects of different nitrogen application rates on the growth, dry matter accumulation and transport of vegetative organs and nitrogen application rate on grain filling characteristics and yield of two Tartary buckwheat. The results were as follows.(1)Nitrogen fertilizer significantly promoted the growth and development of Tartary buckwheat. With the increase of nitrogen application, the plant height, SPAD value and dry matter accumulation of Tartary buckwheat showed a gradual increase trend, reached the maximum value under N3 treatment, significantly higher than N1 and N2 treatment. Under the same nitrogen application conditions, Qianku 3 was better than Xinong 9940. As far as the translocation rate is concerned, the two varieties of Tartary buckwheat perform inconsistently. Nitrogen application significantly increased the stem and leaf dry matter transport rate of Xinong 9940, while Qianku 3 did the opposite.(2)With the increase of nitrogen application, the day of filling duration of Tartary buckwheat increased, the maximum grain filling date was prolonged, the mean grain flling rate decreased, and the 100-grain weight showed a downward trend. Under the same nitrogen applicaton conditions, compared with Qianku 3, Xinong 9940 had a fasted flling rate and greater grain weight.(3)With the increase of nitrogen application, yield and its constituent factors increased first and then decreased, but the varieties were different. The yield of Xinong 9940 reached the highest in N2 treatment, which was 1 650.0 kg·hm^-2,which was 45.6% and 28.2% higher than that of N1 and N3 treatments. The yield of Qianku 3 reached the highest in N1 treatment, which was 616.7 kg·kg^-2, which increased yield by 12.8% and 51.6% compared with N2 and N3. It was suggested that in the dry farming area of the Loess Plateau, buckwheat breeding and planting depend on the variety of buckwheat, and the optimum amount of nitrogen application should be selected, and the best nitrogen rate of Xinong 9940 was 180～270 kg·hm^-2, and the optimum nitrogen rate of Qianku 3 was 90～180 kg·hm^-2.