| Texto completo | |
| Autor(es): |
Firmano, Ruan F.
[1]
;
Melo, Vander Freitas
[2]
;
Montes, Celia Regina
[3]
;
de Oliveira Junior, Adilson
[4]
;
de Castro, Cesar
[4]
;
Ferracciu Alleoni, Lus Reynaldo
[1]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Luiz de Queiroz Coll Agr ESALQ, Dept Soil Sci, Ave Padua Dias 11, BR-13418260 Piracicaba, SP - Brazil
[2] Univ Fed Parana, Dept Soils & Agr Engn, UFPR, Rua Funcionarios 1540, BR-80035050 Curitiba, Parana - Brazil
[3] Univ Sao Paulo, Ctr Nucl Energy Agr CENA, Av Centenario 303, BR-13418900 Piracicaba, SP - Brazil
[4] Brazilian Agr Res Corp, Natl Soybean Ctr, Rodovia Carlos Joao Strass Orlando Amaral Access, BR-86001970 Londrina, Parana - Brazil
Número total de Afiliações: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | CLAYS AND CLAY MINERALS; v. 68, n. 3 JUL 2020. |
| Citações Web of Science: | 1 |
| Resumo | |
Highly weathered soils of the humid tropics generally provide a poor mineral reserve of potassium (K), but evidence has been found which indicates that even in such soils non-exchangeable forms of K can be made plant available and this warrants further investigation. The objective of this study was, therefore, to determine the extent to which K can be released from poorly available reserves over a long period of time. The focus was on an Oxisol in southern Brazil cultivated for 32 years with a rotation of soybeans (Glycine maxL.), maize (Zea maysL.), wheat (Triticum aestivumL.), and oats (Avena strigosaL.) with and without K fertilization. Mineral sources of K were identified by X-ray diffraction and by sequential chemical extraction from the clay fraction. The amounts of K-bearing mineral species and the amounts of total and plant-available K were quantified, then the effects of the long-term K-fertilization regime on these values were evaluated. The clay fraction was dominated by hematite, gibbsite, and phyllosilicates such as kaolinite. These minerals were unaffected by the K deprivation in the cropping systems, but in the clay fraction the absence of K fertilization for 32 years reduced the structural order of the 2:1 phyllosilicates associated with K reserves. This effect was most prominent in the root zone of the soil. Deprivation of K for more than three decades decreased the crystallinity of 2:1 phyllosilicates, which could be better evaluated from XRD patterns after the removal of kaolinite and Fe (oxyhydr)oxides. The K-free cultivation reduced the amounts of total soil K by increasing the depletion of K from pools that typically are poorly accessible to plants. (AU) | |
| Processo FAPESP: | 15/18952-3 - Efeito residual da adubação potássica nas formas do nutriente no solo |
| Beneficiário: | Ruan Francisco Firmano |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |
| Processo FAPESP: | 15/19121-8 - EMU concedido no processo 2015/05942-0: sistema de microfluorescência de Raios X |
| Beneficiário: | Hudson Wallace Pereira de Carvalho |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa Equipamentos Multiusuários |