%0 Journal Article %T 不同轮作模式下氮肥用量对土壤有机氮组分的影响 %T Effects of Nitrogen Application Rate on Fractionation of Soil Organic Nitrogen Relative to Crop Rotation Mode %A 贾 倩 %A 廖世鹏 %A 卜容燕 %A 张 萌 %A 任 涛 %A 李小坤 %A 丛日环 %A 鲁剑巍 %A JIA,Qian %A LIAO,Shipeng %A BU,Rongyan %A ZHANG,Meng %A REN,Tao %A LI,Xiaokun %A CONG,Rihuan %A LU,Jianwei %J 土壤学报 %J ACTA PEDOLOGICA SINICA %@ 0564-3929 %V 54 %N 6 %D 2017 %P 1547-1558 %K 氮肥;水旱轮作;旱地轮作;全氮;土壤酸解态氮 %K Nitrogen fertilizer; Paddy-upland rotation (RR); Continuous upland rotation (CR); Soil total N; Soil acidolysable nitrogen %X 通过三年六季的田间定位试验,对比研究了水旱轮作(水稻/油菜)和旱地轮作(棉花/油菜)下氮肥用量对土壤有机氮含量及其组分的影响。结果表明,经过三年轮作后,周年轮作氮肥投入超过300 kg hm-2(以纯氮计,下同)的处理0~20 cm土壤全氮含量明显增加。与不施氮处理相比,周年氮肥用量为300 kg hm-2和375 kg hm-2水旱轮作处理0~20 cm土壤全氮含量增加了13.6%~23.5%,而旱地轮作处理则增加了15.0%~23.0%,土壤酸解态氮含量增加是土壤全氮变化的主要原因。两种轮作模式下土壤酸解态氮含量无显著差异,但土壤酸解态氮各组分的变化却不相同。水旱轮作中酸解铵态氮增加的比例(33.8%)低于旱地轮作(53.9%),但其酸解未知态氮含量增加的比例(36.0%)高于旱地轮作(16.6%)。综上所述,周年氮肥合理施用能明显提高土壤有机氮含量,水旱和旱地轮作下土壤酸解态氮库各组分变化差异明显。根据不同轮作模式下土壤有机氮库转化特点,优化氮肥施用对于提高作物产量和氮肥利用率具有重要意义。 %X A 3 a field experiment, consisting of 6 croppings, was conducted to investigate effects of N fertilization on content and fractionation of soil organic N relative to N application rate and crop rotation mode, paddy/upland (rice/rapeseed, RR) rotation and upland (cotton/rapeseed, CR) rotation. Results show that after the 3 years of crop rotations cultivations, soil total N content in the 0~20 cm soil layer increased remarkably in plots more than 300 kg hm-2 in N input. Compared with CK (No N fertilization, N0-0), soil total N content increased by 13.6%~23.5% and 15.0%~23.0%, respectively, in the treatments 300 kg hm-2 and 375 kg hm-2 in N application rate under either RR or CR rotation. The increase in soil total acidolysable N content accounted for most of the increase in soil total N. Although no significant difference in soil total acidolysable N content was observed between plots under RR and CR rotations, fractionation of the soil acidolysable N varied between plots. The proportion of soil acidolysable ammonium N increased by 33.8% in the plots under RR rotation, much lower than that (53.9%) in the plots under CR rotation, but the increment of unidentified soil acidolysable N in proportion was higher in plots under RR rotation (36.0%) than that (16.6%) in the plots under CR rotation. To sum up, reasonable N fertilization may significantly increase soil organic N content. Fractionation of the soil organic N pool varies sharply between plots under RR and CR rotations. It is, therefore, of important significance to optimize N fertilization for high crop yield and high N utilization efficiency in the light of the characteristics of soil organic N transformation under different rotation systems. %R 10.11766/trxb201706230077 %U http://pedologica.issas.ac.cn/trxb/home %1 JIS Version 3.0.0