CAJ | 학술논문

运用15 N示踪法研究了大田条件下不同氮肥用量与施肥方式对萝卜氮素吸收、分配及肉质根产量的影响。试验设置3个氮水平（0、60和120 kg/hm2）和两种基追肥比例[基肥∶破肚期肥料∶膨大期肥料＝50％∶20％∶30％（A）和30％∶20％∶50％（B）]，共5个处理，依次记作N0、N60A、N60B、N120A、N120B。结果表明，在施N 0120 kg/hm2范围内，随氮施用量的增加，萝卜吸收的肥料氮素、土壤氮素数量及肥料氮在土壤中的残留量显著增加，氮素的吸收利用率和土壤残留率显著下降，氮素损失率显著增加。当氮用量为120 kg/hm2时， N120A和N120B处理萝卜吸收的肥料氮素、土壤氮素及肥料氮在土壤中的残留量分别为30.50、53.64、14.88 kg/hm2和35.56、56.61、17.81 kg/hm2，采收期肉质根产量分别为67.6 t/hm2和72.5 t/hm2，比对应的低氮处理（N60A和N60B）分别增加64.07％和66.67％，且N120B处理萝卜氮素吸收利用率显著提高。因此，适量施氮并增加肉质根膨大期的施氮比例，可有效提高氮肥利用率，显著增加萝卜肉质根产量。在本试验条件下，施氮量为120 kg/hm2，按照基肥∶破肚期肥料∶膨大期肥料比例30％∶20％∶50％进行施肥，是兼顾产量和氮肥利用效率的最佳氮肥运筹方式。
운용15 N시종법연구료대전조건하불동담비용량여시비방식대라복담소흡수、분배급육질근산량적영향。시험설치3개담수평（0、60화120 kg/hm2）화량충기추비비례[기비∶파두기비료∶팽대기비료＝50％∶20％∶30％（A）화30％∶20％∶50％（B）]，공5개처리，의차기작N0、N60A、N60B、N120A、N120B。결과표명，재시N 0120 kg/hm2범위내，수담시용량적증가，라복흡수적비료담소、토양담소수량급비료담재토양중적잔류량현저증가，담소적흡수이용솔화토양잔류솔현저하강，담소손실솔현저증가。당담용량위120 kg/hm2시， N120A화N120B처리라복흡수적비료담소、토양담소급비료담재토양중적잔류량분별위30.50、53.64、14.88 kg/hm2화35.56、56.61、17.81 kg/hm2，채수기육질근산량분별위67.6 t/hm2화72.5 t/hm2，비대응적저담처리（N60A화N60B）분별증가64.07％화66.67％，차N120B처리라복담소흡수이용솔현저제고。인차，괄량시담병증가육질근팽대기적시담비례，가유효제고담비이용솔，현저증가라복육질근산량。재본시험조건하，시담량위120 kg/hm2，안조기비∶파두기비료∶팽대기비료비례30％∶20％∶50％진행시비，시겸고산량화담비이용효솔적최가담비운주방식。
A field experiment was conducted to study the effect of nitrogen application rates and methods on the uptake and distribution of N by radish using 15 N isotope tracing method.Three N rates (0, 60 and 120 kg/ha) and two application proportions of basal∶15 d after seeding∶30 d after seeding[50%∶20%∶30%(A) and 30%∶20%∶30%(B)]were designed with total of five treatments reordered as N 0, N60A, N60B, N120A and N120B, respectively. The result showed that the nitrogen absorbed from fertilizer and soil by radish ,the residual N amount in the soil were increased significantly , the absorption and utilization rate and soil residual rate were decreased as consequence , although the N loss rate still increased with the nitrogen application rate increased from 0 to 120 kg/ha.At the application rate of 120 kg/ha, the nitrogen absorption was 30.50 kg/hm2 from the fertilizer and 53.64 kg/ha from soil, and the residual N amount in soil was 14.88 kg/ha with the treatment of N120A, the N absorption was 35.56 kg/ha from fertilizer and 56.61 kg/ha from soil and the residual N amount in soil was 17.81 kg/ha with the treatment of N120B.The root yield for the treatments of N120A and N120B were 67.6 t/ha and 72.5 t/ha, respectively, 64.07% and 66.67% higher than those for treatment N 60A and N60B.The highest nitrogen use efficiency was obtained in the treatment of N120B.Therefore, appropriate nitrogen application with increasing topdressing nitrogen ratio in later growth stage could increase root yield of radish and the nitrogen use efficiency .The recommended N application rate for radish in the studied area is N 120 kg/ha with application ratio of 30%for basal , 20%for 15 d after seeding and 50%for 30 d after seeding.