中国农业科学 ›› 2022, Vol. 55 ›› Issue (18): 3600-3612.doi: 10.3864/j.issn.0578-1752.2022.18.010

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

酸性土壤硝化作用对柑橘铵毒害的效应

范子晗(),罗雅尹,熊华烨,张育文,康福蓉,王昱桁,王洁,石孝均,张跃强()   

  1. 西南大学资源环境学院,重庆 400715
  • 收稿日期:2021-08-11 接受日期:2021-09-17 出版日期:2022-09-16 发布日期:2022-09-22
  • 通讯作者: 张跃强
  • 作者简介:范子晗,E-mail: fanzihan0466@163.com
  • 基金资助:
    国家重点研发计划(2016YFD0200104);国家自然科学基金(31801932)

Effect of Nitrification on Ammonium Toxicity to Citrus in Acidic Soil

ZiHan FAN(),YaYin LUO,HuaYe XIONG,YuWen ZHANG,FuRong KANG,YuHeng WANG,Jie WANG,XiaoJun SHI,YueQiang ZHANG()   

  1. College of Resources and Environment, Southwest University, Chongqing 400715
  • Received:2021-08-11 Accepted:2021-09-17 Online:2022-09-16 Published:2022-09-22
  • Contact: ZHANG YueQiang

摘要:

【目的】通过监测铵态氮水平对不同pH土壤溶液的影响,结合对香橙砧木幼苗生长及生理指标的影响研究,阐述柑橘对铵态氮的响应过程,为酸性土壤中柑橘氮素优化管理提供理论支撑。【方法】试验为双因素设计,主处理为2种土壤,副处理为5个铵态氮水平。以酸性黄壤和石灰性紫色土为供试土壤,选用香橙砧木幼苗为试验材料,设置0(A0)、50(A50)、100(A100)、200(A200)、400 mg·kg-1(A400)5个铵态氮水平,研究施铵态氮水平对土壤溶液铵态氮、硝态氮浓度变化及对柑橘生长、根系形态及活力、氮素吸收代谢、抗氧化酶系统和丙二醛含量的影响。【结果】与石灰性土壤相比,酸性土壤硝化过程减缓,其土壤溶液中铵态氮浓度和铵硝比在试验30 d时仍维持较高水平。与A0处理相比,A400处理的柑橘根长降低13%,且根系活力与铵态氮水平呈显著负相关。叶片和根系的丙二醛含量与铵态氮水平呈正相关,并激发了氧化应激反应,尤其增加了叶片POD酶活性。与石灰性土壤相比,酸性土壤中柑橘总氮积累降低17.6%,但叶片和根系中铵硝比分别升高了27.2%和61.1%。聚类分析表明,酸性土壤中生长的柑橘在施氮量超过100 mg·kg-1时受到毒害,碱性土壤中生长的柑橘则没有受到明显毒害。【结论】酸性土壤中,铵态氮施用过量引起土壤溶液中铵态氮长时间累积,造成丙二醛含量增加、细胞膜受损和氮代谢失调等铵毒害现象,表明柑橘铵毒害与土壤硝化作用密切相关。

关键词: 氮, 柑橘, 土壤溶液, 铵毒害, 抗氧化系统

Abstract:

【Objective】The response process of citrus to NH4+-N was elaborated by observing the impact of NH4+-N level on different pH soil solutions, combined with a study on the impact of orange rootstock seedling growth and physiological indicators, which provided theoretical support for the best citrus nitrogen management in acid soil. 【Method】 The experiment was designed as a two-factor experiment, with 2 soils as the main treatment and 5 N levels as the secondary treatment. Using acidic yellow soil and alkaline purple soil as the test soil, the seedlings of Xiangcheng (junos Sieb. ex Tanaka) were selected as the test material, and five NH4+-N levels of 0 (A0), 50 (A50), 100 (A100), 200 (A200), and 400 mg·kg-1 (A400) were set. The effects of ammonium application level on the concentration of ammonium nitrogen and nitrate nitrogen in soil solution and on the biomass, root morphology, nitrogen absorption, antioxidant system, nitrogen metabolism, MDA content and root activity of citrus were studied. 【Result】 Compared with calcareous soil, the nitrification process in acid soil was slowed down. The NH4+-N concentration and NH4+/ NO3- ratio in the soil solution of acid soil remained at a higher level at 30 days of the test. The root length of the citrus under A400 treatment was reduced by 13% when compared with the A0 treatment, and the root vitality was significantly negatively correlated with the ammonium application level. The MDA content of leaves and roots was positively correlated with the ammonium level, which stimulated the oxidative stress response of the roots, especially increased the POD enzyme activity of the leaves. Compared with calcareous soil, the total nitrogen accumulation of citrus on acid soil decreased by 17.6%, while the ratio of ammonium to nitrate in leaves and roots increased by 27.2% and 61.1%, respectively. Cluster analysis showed that citrus in acidic soil was toxic when N application rate exceeded 100 mg kg-1, while citrus in alkaline soil was not significantly stressed.【Conclusion】 In acidic soil, the excessive application of ammonium nitrogen caused the accumulation of ammonium nitrogen in soil solution for a long time, resulting in the increase of MDA content, cell membrane damage and nitrogen metabolism disorders as well as other ammonium toxic phenomena, indicating that ammonium toxicity in citrus was closely related to soil nitrification.

Key words: nitrogen, citrus, soil solution, ammonium toxicity, antioxidant system