Bound Residue And Its Bioavailability Of Different Aromatic Ring ¹⁴C-Labelled Herbicide ZJ0273 In Aerobic Soils

In this study,mineralization,bound residue and its bioavailability of multi-position ¹⁴C labeled herbicide ZJ0273,[B ring-4,6-¹⁴C]ZJ0273(B-ZJ0273)and[C ring-U-¹⁴C]ZJ0273 (C-ZJ0273)in aerobic soils were investigated under laboratory condition by isotope tracer techniques and modern instruments.The main results were appended as follows:The results showed that during the course of incubation,the content of ¹⁴C-ER in Red clayey soil(S₁)was significantly higher than that in Fluvio-marine yellow loamy soil(S₂)and Coastal saline soil(S₃).In addition,the ¹⁴C-ER of C-ZJ0273 was coincided with B-ZJ0273.No apparent difference in ¹⁴C-ER content between B-ZJ0273 and C-ZJ0273 was found in the same soil.Both B-ZJ0273 and C-ZJ0273 in the aerobic soils were mineralized to ¹⁴CO₂ via ring cleavage.After 100 days of incubation,the ¹⁴CO₂ from B-ZJ0273 were 0.48%,6.62%and 5.04%of applied amount in three soils,respectively,and significant difference in the ¹⁴CO₂ was observed between C-ZJ0273 and B-ZJ0273 in the same soils.During the whole incubation,the content of ¹⁴C-BR from B-ZJ0273 and C-ZJ0273 increased with time,and the formation of BR was easier in soils with high pH and/or OM content.After 100 days,the contents of ¹⁴C-BR from B-ZJ0273 were 17.52%,28.09%and 35.32%of applied amount in three soils,respectively.Dynamics of BR from C-ZJ0273 was accord with that from B-ZJ0273.In addition,the ¹⁴C-BR of B-ZJ0273 and C-ZJ0273 in soils was mainly distributed in fulvic acid and humin during the whole period of incubation,which implied that humic acid played a negligible role in bound ZJ0273 residue.The effects of bound ZJ0273 residue with different concentrations on the growth of rice and corn were investigated to elucidate its bioavailability.The results showed Soil-bound residue at the level of 0.6,1.2 and 1.8 nmol/g resulted in serious phytotoxic effects to rice seedlings,which were inhibited the growth in different degree after 14-day growth.However,no phytotoxicity of the BR to corn was found in our study,which implied that the BR showed different inhibition effects on different species.This paper aids for acknowledgement of environmental risk assessments and reasonable application and industrialization of the novel herbicide.Multi-position labeled methods in this study provide reference for corresponding research of other pesticides.