Evaluation on determination of soil CEC for highly calcareous soils. (S02-wang387579-poster)
Authors:
Q. Wang* - Univ. of FL/IFAS Y. Li - Univ. of FL/IFAS W. Klassen - Univ. of FL/IFAS
Abstract:
Four different methods were evaluated for the determination of soil cation exchange capacity (CEC) in calcareous soils with various contents of calcium carbonate, range from less than 100 g kg-1 to over 900 g kg-1 and, also with 100 to 600 g kg-1-1 of CaCO3 added to an acid soil. The results showed that with calcareous soil, a liner correlation between each two methods existed with or without CaCO3 removal, CEC was increased either the carbonate was removed from the calcareous soils or CaCO3 was added into the acid soil. With CaCO3 removal from the soils, CEC was increased by 13.6 to 26.1%, while with CaCO3 addition to the acid soil, 2.8 to 16.9% of CEC was improved. The results indicate that the interference of CaCO3 on CEC was unavoidable by applying the current methods even though the solution pH for all the four methods was 8.2 or 8.0. Modified LiEDTA and Li formate methods produced a low level of CEC, which results from the low affinity of Li to the soil. Double saturating solution method had an advantage in accuracy but failed in simplicity. The advantage of both relative accuracy and simplicity by the method with NaOAc-NaCl in 60% ethanol with pH 8.2 makes this method more acceptable and recommendable to CEC determination in highly calcareous soils.
Speaker Information: Qingren Wang, Univ. of FL/IFAS, Tropical Research and Education Center, Univ.
of, Homestead, Florida, FL 33031-3314; Phone: 305 246 7001 ext.286; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 1:00 PM-4:00 PM Presentation Start: 1:00 PM (Poster Board Number: 1524)
Keywords: soil; CEC; calcareous; determination
