Weathering of soils originated from diabase in the Parana Basin, Sao Paulo State, Brazil

Autor(es)

Barbosa Guimaraes, Clecia Cristina ^[1] ; Melo Dematte, Jose Alexandre ^[1] ; de Azevedo, Antonio Carlos ^[1] ; da Silva, Rafael Cipriano ^[1] ; Urbina Salazar, Diego Fernando ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz ESALQ, Dept Solos, Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: REVISTA CIENCIA AGRONOMICA; v. 52, n. 3 2021.
• Citações Web of Science: 0

Resumo

Weathering of the parent material is the initial process that plays an essential role in soil fertility. The study of this process has become crucial to better understand soil dynamics. Most studies on weathering are based on indexes that calculate the feldspar dissolution rate (for example, CIA, CIW, and PIA) which not always reflect the complexity in the soil profile. Other methodologies have been designed to improve these approaches, such as geochemical balance, difference of elemental contents (DE), and the W index. This work aim to assess the efficiency of these methods to identify variations in recent soil profiles developed from diabase as compared to the CIA, CIW, and PIA indexes. Data on the main oxides were used to calculate the geochemical balance, DE, CIA, CIW, PIA, and W indexes to analyze weathering intensity in two profiles originated from diabase in the Sao Paulo State, Brazil. The Ki and Kr indexes and Fe-o/Fe-d ratio were also factored and we analyzed the mineralogy of soil horizons and the source rock. The W index and DE presented greater weathering variation than the CIA, CIW, and PIA in both profiles. The geochemical balance, mineralogy, and the Ki, Kr and Fe-o/Fe-d ratios explained the variations between the horizons. The DE and geochemical balance together generated new information for the analysis of the weathering process than the isolated indexes. (AU)

• Processo FAPESP: 14/22262-0 - Geotecnologias no mapeamento digital pedológico detalhado e biblioteca espectral de solos do Brasil: desenvolvimento e aplicações
• Beneficiário: José Alexandre Melo Demattê
• Modalidade de apoio: Auxílio à Pesquisa - Temático