Resumo

RAMOS VASQUEZ, Elena e ZUNIGA DAVILA, Doris. Efecto de la humedad, temperatura y pH del suelo en la actividad microbiana a nivel de laboratorio. Ecol. apl., ene./dez. 2008, vol.7, no.1-2, p.123-130. ISSN 1726-2216.

The aim of this study was to evaluate the influence of three physical-chemical parameters on microbial activity of farm soils under controlled laboratory conditions (18% humidity, 27.5 ºC and pH 7.8). Microbial activities were quantified by carbon dioxide production and dehydrogenase activity. Three different essays for 4 moisture percentages (v/w): 5.0%, 10.0%, 15.0% and 18.0%, 4 temperatures: 8.0 °C, 21.0 ºC, 27.5 ºC and 37.0 ºC, and 4 pH values: 4.0, 6.1, 7.8 and 8.2 were evaluated. A Completely Randomized Design (CRD) was used for each essay consisting of four treatments and four replicates per treatment. The highest values on microbial activity [0.097 mg CO2•g-1•h-1 and 173.09 μg formazαn•g-1•(24h)-1] were obtained at 18% humidity. It was found out that a temperature of 27.5 ºC was optimum for carbon dioxide production [0.140 mg CO2•g- 1•h-1], and 37.0 ºC for dehydrogenase activity [156.78 μg formazαn•g-1•(24h)-1]. A near to neutral pH (7.8) was established as optimum [0.055 mg CO2•g-1•h-1and 171.19 μg formazαn•g-1•(24h)-1].

Palavras-chave: Microbial activity; carbon dioxide production; dehydrogenase activity humidity; temperature; pH value.