施氮水平对不同基因型优质小麦干物质积累、产量及氮素吸收利用的影响

采用大田试验,研究了不同施氮水平(0、120、180、240 kg/hm~2)对3种基因型优质小麦品种(郑麦0943、郑麦0856和郑麦7698)干物质积累、产量及氮素吸收利用的影响,旨在深入揭示优质小麦氮素吸收利用特征,为发挥其产量潜力和优化施肥管理提供科学依据。结果显示,施氮可不同程度地促进3种优质小麦生长,施氮量在0~240 kg/hm~2时,功能叶片SPAD值、干物质积累量及产量相关指标总体均随施氮量增加而增加(郑麦0856除外)。不同基因型小麦品种比较,郑麦7698所有处理的产量均高于其他2个小麦品种,主要归因于其穗粒数和千粒质量较高,其中施氮240 kg/hm~2处理的产量(11 591.70 kg/hm~2)、小麦干物质转移率(29.45%)及转移干物质对籽粒的贡献率(91.66%)最高,氮素利用效率、氮素吸收效率和氮素农学利用率随施氮量的增加变化幅度较大。郑麦0856在不施氮条件下产量最低,较其施氮180 kg/hm~2处理的最高产量(10 200.00 kg/hm~2)降幅最大,为18.63%,氮素农学利用率明显高于其他2个品种,说明郑麦0856对氮素较为敏感。郑麦0943在不施氮条件下干物质转移率及转移干物质对籽粒的贡献率明显低于其他2个品种,产量较其施氮240 kg/hm~2处理的最高产量(9 933.45 kg/hm~2)降幅最小,为8.89%,氮素收获指数则高于其他2个品种,且氮素利用效率在不施氮和高氮条件下均较高,说明郑麦0943具有氮素高效利用特征,且干物质积累以生育前期为主。综上,郑麦7698不施氮条件下具有较高的产量,最佳施氮量为240 kg/hm~2;郑麦0856产量对氮素缺乏较为敏感,最佳施氮量为180 kg/hm~2;郑麦0943产量对氮素缺乏不太敏感,具有氮素高效利用特征,最佳施氮量为240 kg/hm~2。

Effect of Application Level of Nitrogen on Dry Matter Accumulation,Yield and Nitrogen Uptake and Utilization of Different Genotypes of High-quality Wheat

A field experiment was carried out to study the effect of application levels (0,120,180,240 kg/ha) of nitrogen on dry matter accumulation,yield and nitrogen uptake and utilization of three genotypes of high-quality wheat (Zhengmai 0943,Zhengmai 0856 and Zhengmai 7698),so as to reveal the characteristics of nitrogen utilization of high-quality wheat and provide scientific basis for realization of great yield potential and appropriate fertilization management.The results showed that nitrogen application promoted the growth of three genotypes of high-quality wheat to different extent.At nitrogen level of 0-240 kg/ha,SPAD value of functional leaves,dry matter accumulation and yield factors overall increased with the increase of nitrogen level (except Zhengmai 0856).On the comparison among different genotypes of wheat varieties,yield of all nitrogen treatments of Zhengmai 7698 were higher than those of two other wheat varieties,mainly due to the increase in grain number per panicle and thousand seed weight,the 240 kg/ha nitrogen treatment of Zhengmai 7698 had the maximum values in yield(11 591.70 kg/ha),dry matter transfer rate(29.45％) and its contribution to grain(91.66％);the extents of variation in nitrogen use efficiency,nitrogen absorption efficiency and nitrogen agronomic efficiency of Zhengmai 7698were relatively large with the increase of nitrogen level.The yield of Zhengmai 0856 was the lowest under the no nitrogen treatment,and the decline of yield was the biggest compared to its highest yield (10 200.00kg/ha) of 180 kg/ha nitrogen treatment,with a drop of 18.63％;its nitrogen agronomic efficiency was significantly higher than those of two other wheat varieties,which indicated that Zhengmai 0856 was more sensitive to nitrogen.Under the condition of no nitrogen,Zhengmai 0943 had the minimum values in dry matter transfer rate and its contribution rate to grain,and the decline of yield was the smallest compared to its highest yield (9 933.45 kg/ha) of 240 kg/ha nitrogen treatment,with the drop of 8.89％;its nitrogen harvest index was higher than those of two other wheat varieties;nitrogen use efficiency of Zhengmai 0943 under the treatments of no nitrogen and high nitrogen were relatively large,which indicated that Zhengmai 0943 showed the characteristics of nitrogen high-efficiency use,and dry matter was mainly accumulated in early growth period.In conclusion,the yield of Zhengmai 7698 was higher than those of two other wheat varieties under the condition of no nitrogen,and the optimum nitrogen application level was 240 kg/ha;the yield of Zhengmai 0856 was sensitive to nitrogen deficiency,and the optimum nitrogen application level was 180 kg/ha;the yield of Zhengmai 0943 was not sensitive to nitrogen deficiency,and the optimum nitrogen application level was 240 kg/ha.