Pedotransfer functions for predicting soil-water retention under Brazilian Cerrado

Abstract

The objective of this work was to determine pedotransfer functions to predict water retention at the -33 and -1500 kPa matric potentials of soils under Cerrado, in the south of the state of Mato Grosso, Brazil. Samples (n=156) were collected for model calibration (n=124) and validation (n=32). A stepwise multiple regression was used to determine pedotransfer functions. Willmott’s index of agreement, root-mean-square error, Pearson’s correlation coefficient, and the confidence index were used to evaluate the performance of the functions and to compare them with those described in the literature. The most efficient variables to estimate water retention were: microporosity, total sand, and clay at -33 kPa; and total sand, silt and clay at -1500 kPa. The regional pedotransfer functions explained more than 94% of water retention variance in the studied soils. The reliability of the functions to predict water retention increased, at -33 kPa, with the use of the structural property microporosity and, at -1500 kPa, with the use of granulometric parameters. The studied regional pedotransfer functions predict water retention at the -33 and -1500 kPa matric potentials of soils under Cerrado, in southern Mato Grosso, better than the functions described in the literature.

The “extra pinch” of pseudosand to enhance tropical biogeochemical processes understanding

“…A texture determination without chemical and mechanical destruction would be sufficient. This proxy could be effective when looking into water movement in soils through pedotransfer functions, which also has been done so far by highly regionalizing models and pedotransfer functions (e.g., Rosseti et al, 2022). Thus, it was mostly assumed that pseudosands would have similar characteristics to sand and that higher sand values would represent the conditions found in the field with regard to hydrology.…”