Effect of the pesticide 2,4-D on microbial activity of the soil monitored by microcalorimetry

Citation
Ags. Prado et C. Airoldi, Effect of the pesticide 2,4-D on microbial activity of the soil monitored by microcalorimetry, THERMOC ACT, 349(1-2), 2000, pp. 17-22
Citations number
28
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
THERMOCHIMICA ACTA
ISSN journal
00406031 → ACNP
Volume
349
Issue
1-2
Year of publication
2000
Pages
17 - 22
Database
ISI
SICI code
0040-6031(20000401)349:1-2<17:EOTP2O>2.0.ZU;2-N
Abstract
Microcalorimetry was applied in a series of experiments to follow the effec t caused by the pesticide 2,4-dichlorophenoxiacetic acid (2,4-D) on microbi al activity of red Latosol soil. The activity of the soil was stimulated by addition of 6.0 mg of glucose and 6.0 mg of ammonium sulfate under a 35% c ontrolled humidity in a soil sample of 1.50 mg. Power-time curves recorded on calorimeter were followed by the increasing amount of the pesticide, fro m 0 to 10.0 mg, which affected directly the total thermal effect evolved by microorganisms. The curves showed a synergism on total thermal effect obta ined by addition of 1.0 mg of pesticide, causing a consumption of 2,4-D by microorganisms, as. new source of nutrients. However, above this mass, the total thermal effect decreased exponentially. The increase of the amount of pesticide is associated to a decrease on the microbial activity of the soi l, probable due to the increase of the toxic products formed from degraded 2,4-D, affecting strongly the life in this ecosystem. (C) 2000 Elsevier Sci ence B.V. All rights reserved.