Resumo

RUIZ, Magaly  e  PAOLINI, Jorge. El cultivo y el agua de riego sobre el carbono de la biomasa microbiana. Agronomía Trop. [online]. 2004, vol.54, n.2, pp.161-178. ISSN 0002-192X.

In the present study, soil microbial biomass carbon (MBC) was determined in eight soils located in the Valencia Lake basin, cultivated with sugarcane or banana and irrigated with waters of different composition or origin (waste-, ground- and lake-water), and in two soils under natural vegetation (control soils). MBC was estimated by substrate induced respiration method. MBC varied between 206 and 1.553 µg microbial C g^-1 soil. Highest values occurred in control soils and in the lacustrine soil cultivated with sugar cane and irrigated with waste waters. The values of MBC were higher in the alluvial soils cultivated with sugarcane than in the alluvial soils cultivated with banana (P<0.05). The MBC to soil organic carbon ratio ranged from 1.4 to 4.1% and agreed with the data found in the literature for agricultural soils. MBC was correlated strongly with total organic carbon (r = 787; P<0.0001). Results show the influence of cultivation and crop management practices on MBC.

Palavras-chave : Substrate induced respiration; lacustrine soils; alluvial soils; irrigation waters; sugar cane; banana.