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林业科学 ›› 2017, Vol. 53 ›› Issue (5): 63-73.doi: 10.11707/j.1001-7488.20170508

• 论文与研究报告 • 上一篇    下一篇

滴灌施肥下施氮量和施氮频率对毛白杨生物量及氮吸收的影响

席本野, 王烨, 贾黎明   

  1. 北京林业大学省部共建森林培育与保护教育部重点实验室 北京 100083
  • 收稿日期:2016-03-14 修回日期:2016-05-25 出版日期:2017-05-25 发布日期:2017-06-22
  • 通讯作者: 贾黎明
  • 基金资助:
    “十二五”国家科技支撑计划资助(2015BAD09B02);国家自然科学基金项目(31400532;31670625);中央高校基本科研业务费专项资金项目(BLX2013018)。

Effects of Nitrogen Application Rate and Frequency on Biomass Accumulation and Nitrogen Uptake of Populus tomentosa under Drip Fertigation

Xi Benye, Wang Ye, Jia Liming   

  1. Key Laboratory of Silviculture and Conservation of Ministry of Education, Beijing Forestry University Beijing 100083
  • Received:2016-03-14 Revised:2016-05-25 Online:2017-05-25 Published:2017-06-22

摘要: [目的] 为滴灌施肥下的毛白杨提供合理的氮(N)肥管理建议。[方法] 以毛白杨(无性系B301)速生纸浆林(林龄3~5年)为研究对象,于20102012年研究施N量和施N频率对毛白杨生物量积累和N吸收的影响。试验设置为施N量 115(N115),230(N230)和345(N345)kg·hm-2a-1和施N频率所组成的6个滴灌施肥处理和1个只灌溉不施肥的对照处理(CK)。试验期间,对林木生长、生物量积累、N吸收量和土壤养分进行测定。[结果] 自然条件下,3~5年生毛白杨林地土壤的表观矿化N量为23~42 kg·hm-2a-1,CK林分N吸收量约为60 kg·hm-2a-1,土壤供N量难以满足高产林分的N吸收量。滴灌施肥能明显促进毛白杨生长,其中,以施N量为115 kg·hm-2a-1、生长季内分4次施入处理(N115F4)最具生长优势,其2011和2012年林分总生物量分别达到33.9和45.5 t·hm-2,较CK分别显著提高42%和49%(P<0.05)。不同施N量水平对总生物量影响显著,2011年,N115处理总生物量显著大于N230和N345处理(P<0.05);2012年,N115显著大于N345处理(P<0.05),略大于N230处理(P > 0.05)。施N频率对生物量未产生明显影响,但较高的施N频率(F4)能提高林木年均N吸收量(P<0.05)。用二次回归方程拟合林分总生物量与施N量之间的关系,方程拟合效果较好(P<0.01,R2=0.482),由方程计算出最佳施N量为192 kg·hm-2 a-1,其90%置信区间为148~236 kg·hm-2 a-1。[结论] 滴灌施肥下,毛白杨人工林常规施N量(N345)并没有带来产量的增益效应,采用滴灌施肥技术能够比常规施肥技术减少肥料用量。施肥频率虽对产量没有影响,但采用较高的施N频率可提高林分的N吸收量,减少养分在土壤中的残留。3~5年生毛白杨人工林进行滴灌施N肥时,建议施N量为192 kg·hm-2a-1,每年分4次施入土壤。

关键词: 滴灌施肥, 三倍体毛白杨, 生物量, N吸收量

Abstract: [Objective] This study aimed to provide recommendations for N fertilizer management of Populus tomentosa under drip fertigation. [Method] A field experiment was conducted in 2010-2012 (stand age of 3-5 years) to investigate the effects of nitrogen rate (NR) and application frequency (NF) on biomass accumulation and N uptake of P. tomentosa (clone B301) in a fast-growing pulp plantation. The experiment included six N fertigation treatments, which were a factorial combinations of three NR (115(N115), 230(N230) and 345(N345) kg·hm-2a-1) and two NF (two (F2) or four (F4) times per year). A control treatment (0 N with irrigation, CK) was also included in the experiment. Diameter at breast height, height, biomass, N uptake and soil N were measured periodically during the experiment. [Result] Under natural condition (ambient environment), the soil N supply capacity (includes apparent N mineralization (23-42 kg·hm-2a-1 in the P. tomentosa plantation of age 3-5) and soil inorganic N) could not provide P. tomentosa with adequate nutrient for optimal growth. The amount of apparent N mineralization was 23-42 kg·hm-2a-1 in the plantation of age 3-5. The trees in CK incorporated nearly 60 kg·hm-2a-1 from soil N sources, which could not maintain a high level of yield of P. tomentosa plantation. N fertigation showed a positive effect on tree growth, and especially trees under the N115F4 treatment had the highest growth rate. Total biomass (TM) in the N115F4 treatment reached 33.9 and 45.5 t·hm-2 in 2011 and 2012, respectively, which were 42% and 49% significantly higher than that in CK (P < 0.05), respectively. Variance in NR could significantly affect the TM of stand. In 2011, the TM under N115 was significantly higher than that under N230 and N345 (P < 0.05), while in 2012 it was significantly higher than N345 (P<0.05) and not significantly higher than N230(P >0.05). NF showed almost no effect on biomass accumulation, but higher NF (F4) resulted in significantly higher average annual N uptake (P <0.05). The relationship between total biomass and NR could be well fitted (P0.01, R2=0.482) with the quadratic regression equation. The optimal NR calculated from the equation was 192 kg·hm-2a-1, and its 90% confidence interval was 148-236 kg·hm-2a-1. [Conclusion] To sum up, under drip fertigation, the traditional NR (N345) in P. tomentosa plantation did not bring biomass yield benefits, and adopting drip fertigation technique could decrease the fertilizer application rate relative to the traditional fertilization technique. NF had no effect on biomass, but higher NF could be applied to increase N uptake. Thus, when apply N fertigation to 3-5 years old P. tomentosa plantation under drip irrigation, the recommended NR is 192 kg·hm-2a-1, which should be applied in four times within a year.

Key words: fertigation, Populus tomentosa, biomass, N uptake

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