【摘要】 以新台糖22号(ROC22)为试材,通过网室盆栽试验方法,在总施氮量(15N标记尿素5g/盆,相当于450kg.hm-2)相同条件下,研究了全部基施(T1)、50%基施+50%在分蘖期追施(T2)和30%基肥+30%在分蘖期追施+40%在伸长期追施(T3)3种施氮方式对甘蔗氮肥效率与氮素去向的影响。结果表明:甘蔗吸收的氮素约18%～29%来源于当季施用的尿素氮,71%～82%来自土壤和种茎氮;氮肥利用率为21.0%～34.52%,残留率为37.61%～44.13%,有21.35%～41.39%的氮素损失。3种施氮方式下,氮肥残留在0～20cm土层较多,在20～40cm残留较少。随氮肥施用时间后移,甘蔗吸收的氮素、来源于肥料氮素的比率、氮肥利用率、氮肥残留率、蔗茎产量及产糖量明显增加,而氮肥损失率显著下降,蔗茎的氮素分配率和蔗糖分积累略呈下降趋势,同时氮素在0～20cm土层的残留呈上升趋势,在20～40cm土层呈下降趋势。从经济效益和环境效益考虑,T3施氮方式的效果较为理想。更多还原

【Abstract】 A pot experiment in greenhouse was conducted with 15N-labeled urea 5g/pot(equal to 450kg·hm-2) total nitrogen by three kinds of treatments of disposable bottom application nitrogen before sowing(T1),50% nitrogen before sowing and 50% nitrogrn during tillering stage(T2),and 30% nitrogen before sowing,30% nitrogen during tillering stage and 40% nitrogen applied during elongation stage(T3) to investigate the use efficiency and fate of fertilizer nitrogen using the sugarcane cultivar ROC22.Results showed that almost 18%~29% of total N uptake by sugarcane was supplied by fertilizer,and 71%~82% N derived from soil and seed-stem.Nitrogen use efficiency ranged from 21.0% to 34.52%,with 15N-fertilizer residue of 37.61%~44.13%,and 15N-fertilizer loss of 21.35%~41.39% among three treatments.Under the three levels of nitrogen application,residual was 15N-fertilizer was mainly distributed in 0~20cm top soil.The uptake of nitrogen and the proportion of total N from fertilizer in sugarcane plant,the yield of stalk and sugar after the nitrogen applied,and the use efficiency and residue ratio of 15N-fertilizer increased significantly over time,while loss rate of 15N-fertilizer decreased significantly with a slight decline trend of nitrogen distributtion and sucrose accumulation in stalk.The results also indicated that after the nitrogen applied the amounts 15N-fertilizer residue in 0~20 cm top soil showed a rising trend,but dropped in 20~40cm soil profile.From the viewpoints of economic benefit and ecological benefit,the nitrogen fertilizer applied of T3 could be optimal treatment.更多还原