| dc.creator | Alvarado Ochoa, Soraya Patricia | |
| dc.date | 2015-06-25T14:19:35Z | |
| dc.date | 2015-06-25T14:19:35Z | |
| dc.date | 2004 | |
| dc.date.accessioned | 2023-08-11T22:39:52Z | |
| dc.date.available | 2023-08-11T22:39:52Z | |
| dc.identifier | *EC-INIAP-BEESC-MGC. Quito (T/A472b) | |
| dc.identifier | http://repositorio.iniap.gob.ec/handle/41000/1419 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8269698 | |
| dc.description | Andisols are noted as soils with constant surface-potential colloids dominated by
amorphous aluminosilicates. A combination of routinely performed analyses was used to
evaluate nutrient status, clay mineralogy, and the charge and cation sorption properties of
two acidic Ecuadorian Andisols from experimental fields under crop production.
Additionally, a highly weathered soil of south-central Kentucky was studied to contrast
the constant surface-potential behavior coming from a mineralogical source lacking in
amorphous aluminosilicates. Mineralogical analyses indicated that the clay fraction in
those Andisols was dominated by amorphous material but enough crystalline minerals
were present to be quantified. Surface charge characterization confirmed that those soils
were dominated by constant surface-potential colloids and required an unbuffered
approach to assess cation exchange properties. Also, the magnitude of the effects of pH
on the negative charge was different among the three studied soils, which confirms the
presence of different kinds of major ion-exchange materials, and the predominant role of
soil organic matter as a constant surface-potential colloid. Additionally, the marked
increase in cation exchange capacity and consequent enhancement in the retention of
exchangeable “bases” with increasing pH observed for the Haplustand, Melanudand, and
surface Typic Paleudalf was more marked for Ca than for K. In contrast, K was more
preferred than Ca in the subsurface Typic Paleudalf, whose clay fraction was dominated
by kaolinite. Finally, K/Ca+Mg quantity-intensity relationships for both Andisols showed
that the release of K to the soil solution was influenced by the presence of competing
cations such as Ca and Mg, and their close relationship with changes in soil pH that were
directly affected by soil fertilizer and/or amendment applications. | |
| dc.format | 208 p. | |
| dc.format | application/pdf | |
| dc.language | esp | |
| dc.publisher | Lexigton, Kentucky: College of Agriculture at the University of Kentucky, 2004 | |
| dc.subject | QUÍMICA | |
| dc.subject | ANDISOLES | |
| dc.subject | MINERALES DE CARGAS VARIABLES | |
| dc.subject | RELACIONES DE INTENSIDAD CANTIDAD | |
| dc.subject | Mag.Sc. Thesis | |
| dc.title | Basic nutrient cation chemistry of two Ecuadorian andisols | |
| dc.type | Tesis | |
| dc.coverage | E. E. Santa Catalina | |
