How the unique properties of soil kaolin affect the fertility of tropical soils
| Autor: | N. Prakongkep, Robert Gilkes |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
biology
Chemistry Potassium Platy Mineralogy chemistry.chemical_element 020101 civil engineering Geology 04 agricultural and veterinary sciences 02 engineering and technology biology.organism_classification 0201 civil engineering Crystal Chemical engineering Geochemistry and Petrology hemic and lymphatic diseases 040103 agronomy & agriculture Tropical soils 0401 agriculture forestry and fisheries Substrate (aquarium) Mica Crystal habit FERRIC IRON |
| Zdroj: | Applied Clay Science. 131:100-106 |
| ISSN: | 0169-1317 |
| DOI: | 10.1016/j.clay.2016.01.007 |
| Popis: | The kaolin (s.l.) in many tropical soils is distinctly different from most specimen and industrial kaolins. Crystal structure is highly disordered and crystal sizes are much smaller than for specimen and industrial kaolins. The crystal habit of soil kaolins is diverse ranging through euhedral hexagonal and anhedral platy, spheroidal and tubular. The specific surface of soil kaolins is higher than for most industrial kaolins. Consequently, cation and anion retention capacities are higher although there is no compelling evidence that the high structural disorder of soil kaolin is associated with a greater specific reactivity of the kaolin surface. A small amount of ferric iron substitutes for octahedral Al but there is generally little or no substitution of other cations. Soil kaolin commonly contains minor amounts of potassium but this is present in mica layers within, attached or associated with kaolin crystals so that potassium is not within the kaolin structure. Due to its considerable chemical reactivity soil kaolin helps provide an effective substrate to support agriculture and other land uses in the tropics. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect