Soil water retention (SWR) at -0.1, -33, -1500 and -150000 kPa matric potentials and available water content (AWC) were estimated from information available from 729 horizons of salt-affected soils in the Hungarian Detailed Soil Hydrophysical Database. Soil characteristics of the 1:10,000 scale Hungarian soil maps were used as input parameters. Ordinal and nominal (categorical) variables: texture, organic matter content, calcium carbonate content, soluble salt content, pH and soil subtype classes of the soil map were used to develop a new prediction method based on the CHAID classification tree. Results of the model development were compared with results using conventional prediction methods (CRT – classification tree and multiple linear regression). Four types of pedotransfer rules were established by classification tree methods. The first rule uses contiuous-type input parameters, the second uses soil taxonomical information in addition, the third and fourth one uses categorical-type input parameters. In addition, continuous pedotransfer functions (point estimations) were established as well. Results show that the root mean square error (RMSE) of the pedotransfer rules based on categorical-type soil information is between 1.25 vol% (at -150000 kPa) and 6.40 vol% (-33 kPa). Model performance of pedotransfer rules and pedotransfer functions was not significantly different, meaning that with the mentioned available input parameters, for salt-affected soils the prediction accuracy is similar with categorical and continuous-type information. The established methods can be readily used to prepare available water content maps for the topsoil of salt affected soils based on solely soil survey information.

TÓTH Brigitta;  MAKÓ András;  GUADAGNINI Alberto;  TOTH Gergely; 

2012-04-10

TAYLOR & FRANCIS INC

JRC69527

1532-4982,   

http://www.tandfonline.com/doi/abs/10.1080/15324982.2012.657025,    https://publications.jrc.ec.europa.eu/repository/handle/JRC69527,   

10.1080/15324982.2012.657025,