氮肥用量及基追比例对地黄生长发育和产量的影响

Effect of Nitrogen Fertilization Rate and Ratio Between Basal and Topdressing on Growth and Root Yield of Rehmannia glutinosa Libosch

为了探讨优化氮肥管理对地黄的产量与品质的影响,通过2年的不同氮管理田间小区试验,比较不同管理条件下地黄干物质积累与氮素需求特征,通过不同氮肥用量试验确定氮肥调控总量,通过不同基追比例试验确定氮肥适宜施用时期,最终明确当前生产条件下地黄的氮肥优化用量及基追比例。无论是地黄总生物量还是氮素吸收量,积累高峰均出现在地黄拉线期至块根膨大期,干物质积累量高达0.86g/(d·株),氮素日积累量高达0.014gN/(d·株)。增加氮肥施用量可明显增加地黄产量,最高可增产23%～29%。较氮肥基施相比,分次施氮可以明显增加地黄产量,基追比例3:7处理增产可达25%。当前生产条件,地黄优化氮肥用量为121～132kgN/hm2,基追(拉线期)比例应为3:7。

The aim was to study the effect of optimizing N management on root yield at harvest of Rehmannia glutinosa Libosch and quality. Two on-farm field experiments were conducted to evaluate dry-matter accumulation and N demand characteristics of Rehmannia glutinosa Libosch with different N management, to optimize N fertilizer application rate with different N rate experiments, and to determine optimal ratio between basal and topdressing fertilization with different base： topdressing ratio experiment. Whatever dry-matter and N uptake, the accumulation peaks occurred from root elongate to root enlargement. The highest dry-matter accumulation was 0.86 g/（day, plant） from root elongate to root enlargement, and the highest N uptake is 0.014 g N/（day. plant）. The yield of Rehmannia glutinosa Libosch could increase by 23%-29% by optimal N application rate, compared to no N application. Compared to base N application treatment, the yield of Rehmannia glutinosa Libosch could increase by 25% with base： topdressing of 3：7 treatments. Across two years studies, the optimal N fertilizer rate should be 121-132 kg N/hm2, and 70% of total N fertilizer should be applied the fastest growing stage, such as root elongate phase.