Volume 18, Number 67 (Spring 2014)                   JWSS 2014, 18(67): 311-320 | Back to browse issues page

XML Persian Abstract Print

Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

H. Khodaverdiloo, N. Hosseini Arablu. Derivation, Validation and Comparison of Class and Continuous Pedotransfer Functions for Predicting Soil Cation Exchange Capacity in Several Textural Classes. JWSS. 2014; 18 (67) :311-320
URL: http://jstnar.iut.ac.ir/article-1-1923-en.html

Abstract:   (3530 Views)
Cation exchange capacity (CEC) is one of the important indices in soil fertility. Direct measurement of CEC is time consuming and expensive, especially in aridisols containing high amounts of carbonates and gypsum. Alternatively, CEC could be indirectly predicted through pedotransfer functions (PTF). The objective of this study was to predict CEC using class and continuous PTFs.A data set (n = 977) was classified according to the soil textural class and was used to derive the PTFs. Another independent set (n = 173) was used to test the reliability of the PTFs. The root mean of square error (RMSE), mean error (ME) and index of agreement (d) were applied to evaluate the PTFs. Within every textural class, we furthermore evaluated the relative improvement (RI) of the continuous PTFs over the corresponding class PTF. The continuous PTFs were more accurate than class PTFs for finer textural classes while the former showed higher reliability in coarser textural classes. With an increase in relative particle size, prediction bias of class PTFs decreased RMSE was 8.55 and 3.88 in clay and sandy loam textural classes, respectively. Consequently, according to the results obtained in this study, for the prediction of soil CEC, continuous PTFs are suggested to be used for silty loam and finer textural classes while for loam and coarser classes application of class PTFs is preferred.
Full-Text [PDF 179 kb]   (757 Downloads)    
Type of Study: Research | Subject: Ggeneral
Received: 2012/01/23 | Accepted: 2013/04/22 | Published: 2014/06/16

Add your comments about this article : Your username or email:
Write the security code in the box

© 2015 All Rights Reserved | JWSS - Isfahan University of Technology

Designed & Developed by : Yektaweb