摘要:
抗生素类药物作为添加剂被用于养殖业中,大部分以原形或其代谢产物形式进入土壤环境,对土壤环境造成生态危害。通过盆栽实验,研究了不同浓度罗红霉素(ROX)对小麦各生长期根际土壤微生物生物量氮、脲酶和无机氮的影响。结果表明,添加ROX后土壤微生物生物量氮在小麦苗期、拔节期和抽穗期受到显著抑制,而在灌浆期和收获期,土壤微生物生物量氮却显著增长;与对照相比,低浓度(0.2和0.5 mg·kg-1)和中浓度(1.0和2.0 mg·kg-1)ROX胁迫显著抑制小麦生长苗期、灌浆期和收获期的根际土壤脲酶活性,而在拔节期和抽穗期,却显著诱导脲酶活性;但高浓度(10.0 mg·kg-1)ROX胁迫却显著抑制小麦生长期内脲酶活性。低、中浓度ROX胁迫显著诱导小麦生长期中根际土壤中铵态氮浓度增长,而高浓度组ROX胁迫显著抑制土壤中铵态氮浓度。ROX胁迫抑制硝态氮,显示出ROX会影响土壤氮循环。
Abstract:
Antibiotics were used as additive medicines in aquaculture, and most of their prototypes or metabolites were discharged into the soil and cause environmental hazard. This manuscript shows the impact of different concentrations of roxithromycin (ROX) on soil microbial biomass nitrogen, urease enzyme, and inorganic nitrogen in rhizosphere soil in various growing periods of wheat using pot experiment. Results showed that soil microbial biomass nitrogen was significantly inhibited by ROX in seedling stage, jointing stage and heading stage, while it was significantly increased by ROX in filling period and harvest stage. Compared with control (CK), the soil urease activities were significantly inhibited in seedling stage, filling stage and harvest stage of wheat, and were significantly induced in jointing stage and heading stage of wheat by low concentration (0.2 or 0.5 mg·kg-1) and medium concentration (1.0 or 2.0 mg·kg-1) groups of ROX. However the soil urease activities were significantly inhibited by high concentration (10.0 mg·kg-1) of ROX in all wheat growth periods. Edaphic ammonium nitrogen was significantly induced by low and medium concentration of ROX in all wheat growing periods, while it was significantly inhibited by high stress of ROX. The suppressing of nitrate nitrogen by ROX indicates that the soil nitrogen cycle in the agricultural ecosystem could be influenced by different concentrations of ROX.
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