Degradation of flubendiamide as affected by elevated CO2, temperature, and carbon mineralization rate in soil

Mukherjee, Irani; Das, Shaon Kumar; Kumar, Aman

Degradation of flubendiamide as affected by elevated CO2, temperature, and carbon mineralization rate in soil

2016

Mukherjee, Irani | Das, Shaon Kumar | Kumar, Aman

An experiment was conducted under three levels of atmospheric CO₂ [ambient (398 ± 10 μmol mol⁻¹), elevated (570 ± 10 μmol mol⁻¹) and open condition], three levels of temperature (4, 25, and 40 °C) to study the degradation pattern of flubendiamide in soil and also carbon mineralization in soil. Results of this study revealed that flubendiamide was found to persist longer under outdoor condition (T₁/₂, 177.0 and 181.1 days) than ambient (T₁/₂, 168.4 and 172.3 days) and elevated condition (T₁/₂, 159.3 and 155.3 days) at 1 and 10 μg g⁻¹ fortification level, respectively. Results also revealed that flubendiamide dissipated faster at 40 °C (T₁/₂, 189.4 days) than 25 °C (T₁/₂, 225.3 days). Slower dissipation was recorded at 4 °C (T₁/₂, 326.3 days). Thus, increased CO₂ levels and temperature following global warming might adversely affect flubendiamide degradation in soil. Laboratory study on microbial biomass carbon (MBC) and carbon mineralization (Cₘᵢₙ) in soil revealed that in des-iodo flubendiamide-treated soils, MBC significantly increased up to 45 days and then decreased. Flubendiamide-treated soil showed a non-significantly decreasing trend of soil MBC with time up to the 15th day of incubation and after 15 days significantly decreased up to 90 days of incubation. In des-iodo flubendiamide-treated soil, the evolution of CO₂ decreased up to 45 days, which was increased after 45 days up to 90 days. In flubendiamide-treated soil, CO₂ evolution decreased up to 30 days and after 45 days, it increased up to 90 days.

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