Data/hora: 18/06/2024 03:29:44

Biblioteca(s): | Embrapa Meio Norte / UEP-Parnaíba.
Data corrente: | 29/10/1996
Data da última atualização: | 29/10/1996
Autoria: | PARFITT, R. L.; GILTRAP, D. J.; WHITTON, J. S.
Afiliação: | Manaaki Whenua, New Zealand.
Título: | Contribution of organic matter and clay minerals to the cation exchange capacity of soils.
Ano de publicação: | 1995
Fonte/Imprenta: | Communications of Soil Science Plant Analysis, v.26, n.9-10, p.1343-1355, 1995.
Idioma: | Inglês
Conteúdo: | The cation exchange capacity (CEC) at pH 7 was measured for samples of347 A horizons of New Zealand soils. The mean CEC was 22.1 cmolc/kg for the A horizons and 15.2 cmolc/kg for the B horizons. Multiple regressions were carried out for CEC against organic carbon (C), clay content, and the content of seven groups of clay minerals. The results, significant at p<0.001, were consistent with most of the CEC arising from soil organic matter. For the samples of A horizon, the calculated CEC was 221 cmolc/kg per unit C and for the B horizons was 330cmolc/kg C. There was also contribution from sites on clay minerals. Multiple regression indicated that smectite had a higher CEC (70 cmolc/kg) than other minerals but it was not as high as that of type smectites; kaolin minerals had the lowest CEC. There was a significant effect of interaction between organic matter and some clay minerals on the CEC. Samplesfrom B horizons containing allophane had lower CEC than those not containing allophane which is consistent with allophane reacting with carboxyl groups on organic matter. For the samples from the A horizons, however the CEC was higher when allophane was present.
Palavras-Chave: | Capacidade de troca de cations; Minerais de argila; Soils; Solos.
Thesagro: | Matéria Orgânica.
Thesaurus Nal: | cation exchange capacity; clay minerals; organic matter.
Categoria do assunto: | --
Registro original: | Embrapa Meio Norte / UEP-Parnaíba (CPAMN-UEPP)
Exemplares: | CPAMN-UEPP - (7210-1) - ADD - SP - -- -  -  - 1996.00276 - DIS