Effects of deltamethrin and profenofos on soil respiration in the presence of organiques amendments in vegetables gardens

Soil management, such as organic amendments application, may play an important role in the effects of pesticide residues on soil microbial activity. In order to evaluate these effects, a field experiment was set up. Deltamethrin and profenofos were used for treatment and applied at the recommended dose. Manure, urban waste compost and green waste compost were provided at a rate of 20 t / ha. Respiratory activity was measured every hour. After 7 days of incubation, glucose, nitrogen and phosphorus were added. The interaction between organic amendments and pesticides have showed that only treatment with deltamethrin-manure have significantly decreased the basal respiration (RB) with 0.038 mg C-CO2 g-1 soil compared to the pesticide control (0.058 mg C-CO2 g-1 soil). Profenofos- cattle manure and profenofos-compost treatments have significantly inhibited SIR (Substrate Induction Respiration) compared to profenofos-control (0.097). Both deltamethrin and profenofos have significantly increased the lag time and maximal respiration compared to the control (P˂0.05). The organic amendments and pesticides interaction have significantly reduced the lag time (11h), compared to the pesticide control (26h). Cattle manure has reduced microbial catabolism in the presence of deltamethrin, but urban waste compost and green waste compost have stimulated microbial catabolism (BR) and anabolism (SIR).