Contribution of soil constituents to the cation exchange capacity as determined by different extraction methods
01/Jun/2009
The cation exchange capacity (CEC) is a physicochemical property dependent on mineral and organic soil constituents. Despite the use of different procedures and extractors the CEC is normally expressed considering only the pH control or not of the extracted solution. This study aims to discuss the significance of the contribution of organic carbon and clay to the CEC of an Acrisol, using different determination methods. For this purpose, 75 samples of an abruptic Red-Yellow Acrisol from the Universidade Federal de […]
Mineralogy and sources of potassium in soils from Rio Grande do Sul state cultivated with flooded rice
01/Sep/2002
Lowland soils cultivated with flooded rice in the State of Rio Grande do Sul, Brazil, show a lack of response to potassium fertilization in this culture, even in soils with a low level of available potassium. This study was carried out with the objective to verify the contribution of soil mineralogy as a potential potassium source for rice cultivation. Four representative soils from regions of the State of Rio Grande do Sul (Planossolo Hidromórfico, Planossolo Haplico, Gleissolo Haplico and Chernossolo […]