Data/hora: 20/06/2024 06:45:42

Biblioteca(s): | Embrapa Soja.
Data corrente: | 21/08/2008
Data da última atualização: | 22/08/2008
Autoria: | BROWN, G. G.; MARTINS, P. T.; MATSUMURA, C.; SILVA, S. H. da; FERRARI, E.; KORASAKI, V.; PASINI, A.
Título: | Growth of Pontoscolex corethrurus in an oxisol mixed or not with different amounts of sand and/or organic matter.
Ano de publicação: | 2006
Fonte/Imprenta: | In: International Symposium on Earthworm Ecology, 8., 2006, Kraków. Abstracts... Kraków: Jagiellonian University, 2006. p. 61.
Idioma: | Inglês
Conteúdo: | Pontoscolex corethrurus is a pantropical geophagous endogeic earthworm species native to the Guyana Shield area in Northern Brazil. It is found throughout the country, mainly in disturbed ecosystems, although it also may inhabit natural ecosystems far from its original habitat, where it must be considered an exotic invasive species. Its distribution has been associated with a wide-ranging tolerance to different soil types and environments (Lavelle et al., 1987). However, the species is rare in agricultural fields of Northern Paraná State, Brazil. Therefore, the present study was undertaken to evaluate possible soil limitations for the colonization of this species at the Embrapa Soybean experiment station (Londrina, Brazil). P. corethrurus were incubated at 27ºC in the laboratory, using the Rhodic Hapludox from the station and different amounts of added organic matter (OM; composted city organic wastes) and sand. The following treatments were used: 100% soil; soil+2% (weight) OM; soil+4% OM; soil+10% OM; soil+10% sand; soil+30% sand; soil+60% sand. A potting mixture used in the greenhouse (70%soil, 20%sand, 10%OM) was also tested. Mean C content of the mixtures ranged from 1.2 to 4.3% and sand contents from 8 to 76%. Each container (10 cm square plastic box) received about 140g air-dry substrate, and water at 70-80% field capacity. Each box had 1 specimen and each treatment was replicated 14 times. The worms were cultivated for 395 d, and the substrates changed approximately every 20 d. After 1 yr, only 5 worms were alive in the soil+60% sand treatment and>9 individuals in the remaining treatments. A negative relationship was observed between sand content and earthworm biomass (R2 = 0,60). Worm biomass and soil C content showed a polynomial relationship (R2 = 0,89), with maximum values at 2.8% C. Positive linear correlations (R2 = 0,5) with soil P and Mg were also observed. Worms grew best in soil+2% OM, followed by soil+10% sand, soil+4% OM, soil 100%, and soil+30% sand. These results indicate that the soil from Embrapa Soybean is adequate for the development of P. corethrurus, and that some other factor must be limiting colonization by this species. Furthermore, a small increase in soil OM (from 2.3-2,6% C) could greatly benefit the populations of this species.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (28429-1) - UPC - SP - -- - 11489 -  - 11489 - DIS