林业科学2017，Vol.53Issue(5)：63-73,11.DOI:10.11707/j.1001-7488.20170508
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
Effects of Nitrogen Application Rate and Frequency on Biomass Accumulation and Nitrogen Uptake of Populus tomentosa under Drip Fertigation
摘要
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 (P <0.01,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.关键词
滴灌施肥/三倍体毛白杨/生物量/N吸收量Key words
fertigation/Populus tomentosa/biomass/N uptake分类
农业科技引用本文复制引用
席本野,王烨,贾黎明..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[J].林业科学,2017,53(5):63-73,11.基金项目
"十二五"国家科技支撑计划资助(2015BAD09B02) （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). （BLX2013018）
